ORCID Profile
0000-0001-7308-3546
Current Organisation
Australian National University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Control Systems, Robotics and Automation | Electrical and Electronic Engineering | Calculus of Variations, Systems Theory and Control Theory | Signal Processing | Applied Mathematics | Automation and Control Engineering | Aircraft Performance and Flight Control Systems | Mechanical Engineering | Control engineering mechatronics and robotics | Control engineering |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Engineering | Expanding Knowledge in Technology | Emerging Defence Technologies | Command, Control and Communications | Expanding Knowledge in the Mathematical Sciences | Water Services and Utilities
Related Links
Publications
Link operations for slowing the spread of disease in complex networks
Publisher: IOP Publishing
Date: 21-06-2011
Security analysis of cyber‐physical systems using norm
Publisher: Institution of Engineering and Technology (IET)
Date: 07-2017
Determination of the parton distribution functions of the proton using diverse ATLAS data from pp collisions at $$\sqrt{s} = 7$$, 8 and 13 TeV
Publisher: Springer Science and Business Media LLC
Date: 05-2022
DOI: 10.1140/EPJC/S10052-022-10217-Z
Abstract: This paper presents an analysis at next-to-next-to-leading order in the theory of quantum chromodynamics for the determination of a new set of proton parton distribution functions using erse measurements in pp collisions at $$\\sqrt{s} = 7$$ s = 7 , 8 and 13 TeV, performed by the ATLAS experiment at the Large Hadron Collider, together with deep inelastic scattering data from ep collisions at the HERA collider. The ATLAS data sets considered are differential cross-section measurements of inclusive $$W^{\\pm }$$ W ± and $$Z/\\gamma ^*$$ Z / γ ∗ boson production, $$W^{\\pm }$$ W ± and Z boson production in association with jets, $$t\\bar{t}$$ t t ¯ production, inclusive jet production and direct photon production. In the analysis, particular attention is paid to the correlation of systematic uncertainties within and between the various ATLAS data sets and to the impact of model, theoretical and parameterisation uncertainties. The resulting set of parton distribution functions is called ATLASpdf21.
Correlations between flow and transverse momentum in
Xe + Xe
Publisher: American Physical Society (APS)
Date: 15-05-2023
Measurement of the top-quark mass using a leptonic invariant mass in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 05-06-2023
Abstract: A measurement of the top-quark mass ( m t ) in the $$ t\\overline{t} $$ t t ¯ → lepton + jets channel is presented, with an experimental technique which exploits semileptonic decays of b -hadrons produced in the top-quark decay chain. The distribution of the invariant mass m ℓμ of the lepton, ℓ (with ℓ = e, μ ), from the W -boson decay and the muon, μ , originating from the b -hadron decay is reconstructed, and a binned-template profile likelihood fit is performed to extract m t . The measurement is based on data corresponding to an integrated luminosity of 36.1 fb − 1 of $$ \\sqrt{s} $$ s = 13 TeV pp collisions provided by the Large Hadron Collider and recorded by the ATLAS detector. The measured value of the top-quark mass is m t = 174 . 41 ± 0 . 39 (stat.) ± 0 . 66 (syst.) ± 0 . 25 (recoil) GeV, where the third uncertainty arises from changing the P ythia 8 parton shower gluon-recoil scheme, used in top-quark decays, to a recently developed setup.
Active actuator fault detection and diagnostics in HVAC systems
Publisher: ACM
Date: 06-11-2012
Measurement of the $$ t\overline{t} $$ production cross-section in pp collisions at $$ \sqrt{s} $$ = 5.02 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 23-06-2023
Abstract: The inclusive top-quark pair ( $$ t\\overline{t} $$ t t ¯ ) production cross-section $$ {\\sigma}_{t\\overline{t}} $$ σ t t ¯ is measured in proton–proton collisions at a centre-of-mass energy $$ \\sqrt{s} $$ s = 5 . 02 TeV, using 257 pb − 1 of data collected in 2017 by the ATLAS experiment at the LHC. The $$ t\\overline{t} $$ t t ¯ cross-section is measured in both the dilepton and single-lepton final states of the $$ t\\overline{t} $$ t t ¯ system and then combined. The combination of the two measurements yields $$ {\\sigma}_{t\\overline{t}}=67.5\\pm 0.9\\left(\\textrm{stat}.\\right)\\pm 2.3\\left(\\textrm{syst}.\\right)\\pm 1.1\\left(\\textrm{lumi}.\\right)\\pm 0.2\\left(\\textrm{beam}\\right)\\textrm{pb}, $$ σ t t ¯ = 67.5 ± 0.9 stat . ± 2.3 syst . ± 1.1 lumi . ± 0.2 beam pb , where the four uncertainties reflect the limited size of the data s le, experimental and theoretical systematic effects, and imperfect knowledge of both the integrated luminosity and the LHC beam energy, giving a total uncertainty of 3.9%. The result is in agreement with theoretical quantum chromodynamic calculations at next-to-next-to-leading order in the strong coupling constant, including the resummation of next-to-next-to-leading logarithmic soft-gluon terms, and constrains the parton distribution functions of the proton at large Bjorken- x .
Search for supersymmetry in final states with missing transverse momentum and three or more b-jets in 139 fb$$^{-1}$$ of proton–proton collisions at $$\sqrt{s} = 13$$ TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 04-07-2023
DOI: 10.1140/EPJC/S10052-023-11543-6
Abstract: A search for supersymmetry involving the pair production of gluinos decaying via off-shell third-generation squarks into the lightest neutralino $$(\\tilde{\\chi }^0_1)$$ ( χ ~ 1 0 ) is reported. It exploits LHC proton–proton collision data at a centre-of-mass energy $$\\sqrt{s} = 13$$ s = 13 TeV with an integrated luminosity of 139 fb $$^{-1}$$ - 1 collected with the ATLAS detector from 2015 to 2018. The search uses events containing large missing transverse momentum, up to one electron or muon, and several energetic jets, at least three of which must be identified as containing b -hadrons. Both a simple kinematic event selection and an event selection based upon a deep neural-network are used. No significant excess above the predicted background is found. In simplified models involving the pair production of gluinos that decay via off-shell top (bottom) squarks, gluino masses less than 2.44 TeV (2.35 TeV) are excluded at 95% CL for a massless $$\\tilde{\\chi }^0_1.$$ χ ~ 1 0 . Limits are also set on the gluino mass in models with variable branching ratios for gluino decays to $$b\\bar{b}\\tilde{\\chi }^0_1,$$ b b ¯ χ ~ 1 0 , $$t\\bar{t}\\tilde{\\chi }^0_1$$ t t ¯ χ ~ 1 0 and $$t\\bar{b}\\tilde{\\chi }^-_1/\\bar{t}b\\tilde{\\chi }^+_1.$$ t b ¯ χ ~ 1 - / t ¯ b χ ~ 1 + .
Search for heavy resonances decaying into a Z or W boson and a Higgs boson in final states with leptons and b-jets in 139 fb−1 of pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 05-06-2023
Abstract: This article presents a search for new resonances decaying into a Z or W boson and a 125 GeV Higgs boson h , and it targets the $$ \\nu \\overline{\\nu}b\\overline{b} $$ ν ν ¯ b b ¯ , $$ {\\ell}^{+}{\\ell}^{-}b\\overline{b} $$ ℓ + ℓ − b b ¯ , or $$ {\\ell}^{\\pm}\\nu b\\overline{b} $$ ℓ ± νb b ¯ final states, where ℓ = e or μ , in proton-proton collisions at $$ \\sqrt{s} $$ s = 13 TeV. The data used correspond to a total integrated luminosity of 139 fb − 1 collected by the ATLAS detector during Run 2 of the LHC at CERN. The search is conducted by examining the reconstructed invariant or transverse mass distributions of Zh or Wh candidates for evidence of a localised excess in the mass range from 220 GeV to 5 TeV. No significant excess is observed and 95% confidence-level upper limits between 1.3 pb and 0.3 fb are placed on the production cross section times branching fraction of neutral and charged spin-1 resonances and CP-odd scalar bosons. These limits are converted into constraints on the parameter space of the Heavy Vector Triplet model and the two-Higgs-doublet model.
Measurement of muon pairs produced via
γ γ
Publisher: American Physical Society (APS)
Date: 05-05-2023
Measurements of the suppression and correlations of dijets in Pb+Pb collisions at
s <
Publisher: American Physical Society (APS)
Date: 11-05-2023
Searches for new phenomena in events with two leptons, jets, and missing transverse momentum in 139 fb$$^{-1}$$ of $$\varvec{\sqrt{s}}=13$$ TeV $$\varvec{pp}$$ collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 19-06-2023
DOI: 10.1140/EPJC/S10052-023-11434-W
Abstract: Searches for new phenomena inspired by supersymmetry in final states containing an $$e^+e^-$$ e + e - or $$\\mu ^+\\mu ^-$$ μ + μ - pair, jets, and missing transverse momentum are presented. These searches make use of proton–proton collision data with an integrated luminosity of $$139~\\text {fb}^{-1}$$ 139 fb - 1 , collected during 2015–2018 at a centre-of-mass energy $$\\sqrt{s}=13~$$ s = 13 TeV by the ATLAS detector at the Large Hadron Collider. Two searches target the pair production of charginos and neutralinos. One uses the recursive-jigsaw reconstruction technique to follow up on excesses observed in $$36.1~\\text {fb}^{-1}$$ 36.1 fb - 1 of data, and the other uses conventional event variables. The third search targets pair production of coloured supersymmetric particles (squarks or gluinos) decaying through the next-to-lightest neutralino $$(\\tilde{\\chi }_2^0)$$ ( χ ~ 2 0 ) via a slepton $$(\\tilde{\\ell })$$ ( ℓ ~ ) or Z boson into $$\\ell ^+\\ell ^-\\tilde{\\chi }_1^0$$ ℓ + ℓ - χ ~ 1 0 , resulting in a kinematic endpoint or peak in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectations. Results are interpreted using simplified models and exclude masses up to 900 GeV for electroweakinos, 1550 GeV for squarks, and 2250 GeV for gluinos.
Interior Point Differential Dynamic Programming
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2021
On Modularity in Reactive Control Architectures, with an Application to Formal Verification
Publisher: Association for Computing Machinery (ACM)
Date: 11-04-2022
DOI: 10.1145/3511606
Abstract: Modularity is a central principle throughout the design process for cyber-physical systems. Modularity reduces complexity and increases reuse of behavior. In this article we pose and answer the following question: how can we identify independent “modules” within the structure of reactive control architectures? To this end, we propose a graph-structured control architecture we call a decision structure and show how it generalizes some reactive control architectures that are popular in Artificial Intelligence (AI) and robotics, specifically Teleo-Reactive programs (TRs), Decision Trees (DTs), Behavior Trees (BTs), and Generalised Behavior Trees ( k -BTs). Inspired by the definition of a module in graph theory [ 16 ] we define modules in decision structures and show how each decision structure possesses a canonical decomposition into its modules, which can be found in polynomial time. We establish intuitive connections between our proposed modularity and modularity in structured programming. In BTs, k -BTs, and DTs the modules we propose are in a one-to-one correspondence with their subtrees. We show we can naturally characterize each of the BTs, k -BTs, DTs, and TRs by properties of their module decomposition. This allows us to recognize which decision structures are equivalent to each of these architectures in quadratic time. Following McCabe [ 26 ], we define a complexity measure called essential complexity on decision structures, which measures the degree to which they can be decomposed into simpler modules. We characterize the k -BTs as the decision structures of unit-essential complexity. Our proposed concept of modules extends to formal verification, under any verification scheme capable of verifying a decision structure. Namely, we prove that a modification to a module within a decision structure has no greater flow-on effects than a modification to an in idual action within that structure. This enables verification on modules to be done locally and hierarchically, where structures can be verified and then repeatedly locally modified, with modules replaced by modules while preserving correctness. To illustrate the findings, we present an ex le of a solar-powered drone completing a reconnaissance-based mission using a decision structure. We use a Linear Temporal Logic-based verification scheme to verify the correctness of this structure and then show how one can repeatedly modify modules while preserving its correctness, and this can be verified by considering only those modules that have been modified.
Close target reconnaissance using autonomous UAV formations
Publisher: IEEE
Date: 2008
Optimal Parameter Selection for the Alternating Direction Method of Multipliers (ADMM): Quadratic Problems
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2015
Optimal contract design for effort-averse sensors
Publisher: Informa UK Limited
Date: 28-06-2020
Search for dark matter in events with missing transverse momentum and a Higgs boson decaying into two photons in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 10-2021
Abstract: A search for dark-matter particles in events with large missing transverse momentum and a Higgs boson candidate decaying into two photons is reported. The search uses 139 fb − 1 of proton-proton collision data collected at $$ \\sqrt{s} $$ s = 13 TeV with the ATLAS detector at the CERN LHC between 2015 and 2018. No significant excess of events over the Standard Model predictions is observed. The results are interpreted by extracting limits on three simplified models that include either vector or pseudoscalar mediators and predict a final state with a pair of dark-matter candidates and a Higgs boson decaying into two photons.
Screening Vitis Genotypes for Responses to Botrytis cinerea and Evaluation of Antioxidant Enzymes, Reactive Oxygen Species and Jasmonic Acid in Resistant and Susceptible Hosts
Publisher: MDPI AG
Date: 20-12-2018
DOI: 10.3390/MOLECULES24010005
Abstract: Botrytis cinerea is a necrotrophic fungal phytopathogen with devastating effects on many Vitis genotypes. Here, a screening of 81 Vitis genotypes for leaf resistance to B. cinerea revealed two highly resistant (HR), twelve resistant (R), twenty-five susceptible (S) and forty-two highly susceptible (HS) genotypes. We focused on the HR genotype, ‘Zi Qiu’ (Vitis davidii), and the HS genotype ‘Riesling’ (V. vinifera), to elucidate mechanisms of host resistance and susceptibility against B. cinerea, using detached leaf assays. These involved a comparison of fungal growth, reactive oxygen species (ROS) responses, jasmonic acid (JA) levels, and changes in the anti-oxidative system between the two genotypes after inoculation with B. cinerea. Our results indicated that the high-level resistance of ‘Zi Qiu’ can be attributed to insignificant fungal development, low ROS production, timely elevation of anti-oxidative functions, and high JA levels. Moreover, severe fungal infection of ‘Riesling’ and sustained ROS production coincided with relatively unchanged anti-oxidative activity, as well as low JA levels. This study provides insights into B. cinerea infection in grape, which can be valuable for breeders by providing information for selecting suitable germplasm with enhanced disease resistance.
Towards Encrypted MPC for Linear Constrained Systems
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2018
Multi-Step Gradient Methods for Networked Optimization
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2013
The ADMM Algorithm for Distributed Quadratic Problems: Parameter Selection and Constraint Preconditioning
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2016
On Privacy of Dynamical Systems: An Optimal Probabilistic Mapping Approach
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2021
Search for doubly charged Higgs boson production in multi-lepton final states using 139 fb$$^{-1}$$ of proton–proton collisions at $$\sqrt{s}$$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 12-07-2023
DOI: 10.1140/EPJC/S10052-023-11578-9
Abstract: A search for pair production of doubly charged Higgs bosons ( $$H^{\\pm \\pm }$$ H ± ± ), each decaying into a pair of prompt, isolated, and highly energetic leptons with the same electric charge, is presented. The search uses a proton–proton collision data s le at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 139 fb $$^{-1}$$ - 1 recorded by the ATLAS detector during Run 2 of the Large Hadron Collider (LHC). This analysis focuses on same-charge leptonic decays, $$H^{\\pm \\pm } \\!\\rightarrow \\ell ^{\\pm } \\ell ^{\\prime \\pm }$$ H ± ± → ℓ ± ℓ ′ ± where $$\\ell , \\ell ^\\prime \\!=\\!e, \\mu , \\tau $$ ℓ , ℓ ′ = e , μ , τ , in two-, three-, and four-lepton channels, but only considers final states which include electrons or muons. No evidence of a signal is observed. Corresponding upper limits on the production cross-section of a doubly charged Higgs boson are derived, as a function of its mass $$m(H^{\\pm \\pm })$$ m ( H ± ± ) , at 95% confidence level. Assuming that the branching ratios to each of the possible leptonic final states are equal, $$\\mathcal {B}(H^{\\pm \\pm } \\rightarrow e^\\pm e^\\pm ) = \\mathcal {B}(H^{\\pm \\pm } \\rightarrow e^\\pm \\mu ^\\pm ) = \\mathcal {B}(H^{\\pm \\pm } \\rightarrow \\mu ^\\pm \\mu ^\\pm ) = \\mathcal {B}(H^{\\pm \\pm } \\rightarrow e^\\pm \\tau ^\\pm ) = \\mathcal {B}(H^{\\pm \\pm } \\rightarrow \\mu ^\\pm \\tau ^\\pm ) = \\mathcal {B}(H^{\\pm \\pm } \\rightarrow \\tau ^\\pm \\tau ^\\pm ) = 1/6$$ B ( H ± ± → e ± e ± ) = B ( H ± ± → e ± μ ± ) = B ( H ± ± → μ ± μ ± ) = B ( H ± ± → e ± τ ± ) = B ( H ± ± → μ ± τ ± ) = B ( H ± ± → τ ± τ ± ) = 1 / 6 , the observed (expected) lower limit on the mass of a doubly charged Higgs boson is 1080 GeV (1065 GeV) within the left-right symmetric type-II seesaw model, which is the strongest limit to date produced by the ATLAS Collaboration. Additionally, this paper provides the first direct test of the Zee–Babu neutrino mass model at the LHC, yielding an observed (expected) lower limit of $$m(H^{\\pm \\pm })$$ m ( H ± ± ) = 900 GeV (880 GeV).
Topology design for optimal network coherence
Publisher: IEEE
Date: 07-2015
Distributed MPC Via Dual Decomposition and Alternative Direction Method of Multipliers
Publisher: Springer Netherlands
Date: 11-11-2014
On frame and orientation localization for relative sensing networks
Publisher: IEEE
Date: 2008
Evidence for Higgs boson decays to a low-mass dilepton system and a photon in pp collisions at s<
Publisher: Elsevier BV
Date: 08-2021
Constraints on the Higgs boson self-coupling from single- and double-Higgs production with the ATLAS detector using pp collisions at
Publisher:
Elsevier BV
Date:
08-2023
Publisher: Elsevier BV
Date: 08-2023
Search for dark matter produced in association with a Standard Model Higgs boson decaying into b-quarks using the full Run 2 dataset from the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 11-2021
Abstract: The production of dark matter in association with Higgs bosons is predicted in several extensions of the Standard Model. An exploration of such scenarios is presented, considering final states with missing transverse momentum and b -tagged jets consistent with a Higgs boson. The analysis uses proton-proton collision data at a centre-of-mass energy of 13 TeV recorded by the ATLAS experiment at the LHC during Run 2, amounting to an integrated luminosity of 139 fb − 1 . The analysis, when compared with previous searches, benefits from a larger dataset, but also has further improvements providing sensitivity to a wider spectrum of signal scenarios. These improvements include both an optimised event selection and advances in the object identification, such as the use of the likelihood-based significance of the missing transverse momentum and variable-radius track-jets. No significant deviation from Standard Model expectations is observed. Limits are set, at 95% confidence level, in two benchmark models with two Higgs doublets extended by either a heavy vector boson Z ′ or a pseudoscalar singlet a and which both provide a dark matter candidate χ . In the case of the two-Higgs-doublet model with an additional vector boson Z ′, the observed limits extend up to a Z ′ mass of 3 TeV for a mass of 100 GeV for the dark matter candidate. The two-Higgs-doublet model with a dark matter particle mass of 10 GeV and an additional pseudoscalar a is excluded for masses of the a up to 520 GeV and 240 GeV for tan β = 1 and tan β = 10 respectively. Limits on the visible cross-sections are set and range from to 0.05 fb to 3.26 fb, depending on the missing transverse momentum and b -quark jet multiplicity requirements.
Search for resonances decaying into photon pairs in 139 fb−1 of pp collisions at s
Publisher:
Elsevier BV
Date:
11-2021
Publisher: Elsevier BV
Date: 11-2021
Production of
Υ ( n S )
Publisher:
American Physical Society (APS)
Date:
22-05-2023
Publisher: American Physical Society (APS)
Date: 22-05-2023
Error-Bounded Reference Tracking MPC for Machines With Structural Flexibility
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2020
An Information-Based Learning Approach to Dual Control
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2015
Search for flavour-changing neutral current interactions of the top quark and the Higgs boson in events with a pair of τ-leptons in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 23-06-2023
Abstract: A search for flavour-changing neutral current (FCNC) tqH interactions involving a top quark, another up-type quark ( q = u, c ), and a Standard Model (SM) Higgs boson decaying into a τ -lepton pair ( H → τ + τ − ) is presented. The search is based on a dataset of pp collisions at $$ \\sqrt{s} $$ s = 13 TeV that corresponds to an integrated luminosity of 139 fb − 1 recorded with the ATLAS detector at the Large Hadron Collider. Two processes are considered: single top quark FCNC production in association with a Higgs boson ( pp → tH ), and top quark pair production in which one of top quarks decays into Wb and the other decays into qH through the FCNC interactions. The search selects events with two hadronically decaying τ -lepton candidates ( τ had ) or at least one τ had with an additional lepton ( e , μ ), as well as multiple jets. Event kinematics is used to separate signal from the background through a multivariate discriminant. A slight excess of data is observed with a significance of 2.3 σ above the expected SM background, and 95% CL upper limits on the t → qH branching ratios are derived. The observed (expected) 95% CL upper limits set on the t → cH and t → uH branching ratios are $$ 9.4\\times {10}^{-4}\\left({4.8}_{-1.4}^{+2.2}\\times {10}^{-4}\\right) $$ 9.4 × 10 − 4 4.8 − 1.4 + 2.2 × 10 − 4 and $$ 6.9\\times {10}^{-4}\\left({3.5}_{-1.0}^{+1.5}\\times {10}^{-4}\\right) $$ 6.9 × 10 − 4 3.5 − 1.0 + 1.5 × 10 − 4 , respectively. The corresponding combined observed (expected) upper limits on the dimension-6 operator Wilson coefficients in the effective tqH couplings are C cϕ 1 . 35 (0 . 97) and C uϕ 1 . 16 (0 . 82).
Search for light long-lived neutral particles that decay to collimated pairs of leptons or light hadrons in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 23-06-2023
Abstract: A search for light long-lived neutral particles with masses in the O (MeV–GeV) range is presented. The analysis targets the production of long-lived dark photons in the decay of a Higgs boson produced via gluon–gluon fusion or in association with a W boson. Events that contain displaced collimated Standard Model fermions reconstructed in the calorimeter or muon spectrometer are selected in 139 fb − 1 of $$ \\sqrt{s} $$ s = 13 TeV pp collision data collected by the ATLAS detector at the LHC. Background estimates for contributions from Standard Model processes and instrumental effects are extracted from data. The observed event yields are consistent with the expected background. Exclusion limits are reported on the production cross-section times branching fraction as a function of the mean proper decay length cτ of the dark photon, or as a function of the dark-photon mass and kinetic mixing parameter that quantifies the coupling between the Standard Model and potential hidden (dark) sectors. A Higgs boson branching fraction above 1% is excluded at 95% CL for a Higgs boson decaying into two dark photons for dark-photon mean proper decay lengths between 10 mm and 250 mm and dark photons with masses between 0.4 GeV and 2 GeV.
Search for direct pair production of sleptons and charginos decaying to two leptons and neutralinos with mass splittings near the W-boson mass in $$ \sqrt{s} $$ = 13 TeV pp collisions with the ATLAS d
Publisher: Springer Science and Business Media LLC
Date: 06-06-2023
Abstract: A search for the electroweak production of pairs of charged sleptons or charginos decaying into two-lepton final states with missing transverse momentum is presented. Two simplified models of R -parity-conserving supersymmetry are considered: direct pair-production of sleptons $$ \\left(\\overset{\\sim }{\\ell}\\overset{\\sim }{\\ell}\\right) $$ ℓ ~ ℓ ~ , with each decaying into a charged lepton and a $$ {\\overset{\\sim }{\\chi}}_1^0 $$ χ ~ 1 0 neutralino, and direct pair-production of the lightest charginos $$ \\left({\\overset{\\sim }{\\chi}}_1^{\\pm }{\\overset{\\sim }{\\chi}}_1^{\\mp}\\right) $$ χ ~ 1 ± χ ~ 1 ∓ , with each decaying into a W -boson and a $$ {\\overset{\\sim }{\\chi}}_1^0 $$ χ ~ 1 0 . The lightest neutralino $$ \\left({\\overset{\\sim }{\\chi}}_1^0\\right) $$ χ ~ 1 0 is assumed to be the lightest supersymmetric particle (LSP). The analyses target the experimentally challenging mass regions where $$ m\\left(\\overset{\\sim }{\\ell}\\right)-m\\left({\\overset{\\sim }{\\chi}}_1^0\\right) $$ m ℓ ~ − m χ ~ 1 0 and $$ m\\left({\\overset{\\sim }{\\chi}}_1^{\\pm}\\right)-m\\left({\\overset{\\sim }{\\chi}}_1^0\\right) $$ m χ ~ 1 ± − m χ ~ 1 0 are close to the W -boson mass (‘moderately compressed’ regions). The search uses 139 fb − 1 of $$ \\sqrt{s} $$ s = 13 TeV proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider. No significant excesses over the expected background are observed. Exclusion limits on the simplified models under study are reported in the $$ \\left(\\overset{\\sim }{\\ell },{\\overset{\\sim }{\\chi}}_1^0\\right) $$ ℓ ~ χ ~ 1 0 and $$ \\left({\\overset{\\sim }{\\chi}}_1^{\\pm }{\\overset{\\sim }{\\chi}}_1^0\\right) $$ χ ~ 1 ± χ ~ 1 0 mass planes at 95% confidence level (CL). Sleptons with masses up to 150 GeV are excluded at 95% CL for the case of a mass-splitting between sleptons and the LSP of 50 GeV. Chargino masses up to 140 GeV are excluded at 95% CL for the case of a mass-splitting between the chargino and the LSP down to about 100 GeV.
Search for a new Z′ gauge boson in 4μ events with the ATLAS experiment
Publisher: Springer Science and Business Media LLC
Date: 12-07-2023
Abstract: This paper presents a search for a new Z ′ vector gauge boson with the ATLAS experiment at the Large Hadron Collider using pp collision data collected at $$ \\sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 139 fb − 1 . The new gauge boson Z ′ is predicted by L μ − L τ models to address observed phenomena that can not be explained by the Standard Model. The search examines the four-muon (4 μ ) final state, using a deep learning neural network classifier to separate the Z ′ signal from the Standard Model background events. The di-muon invariant masses in the 4 μ events are used to extract the Z ′ resonance signature. No significant excess of events is observed over the predicted background. Upper limits at a 95% confidence level on the Z ′ production cross-section times the decay branching fraction of pp → Z ′ μμ → 4 μ are set from 0.31 to 4.3 fb for the Z ′ mass ranging from 5 to 81 GeV. The corresponding common coupling strengths, g Z ′ , of the Z ′ boson to the second and third generation leptons above 0.003 – 0.2 have been excluded.
Measurement of exclusive pion pair production in proton–proton collisions at $$\sqrt{s}={7}\,\text {TeV}$$ with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 17-07-2023
DOI: 10.1140/EPJC/S10052-023-11700-X
Abstract: The exclusive production of pion pairs in the process $$pp\\rightarrow pp\\pi ^+\\pi ^-$$ p p → p p π + π - has been measured at $$\\sqrt{s}={7}\\,\\text {TeV}$$ s = 7 TeV with the ATLAS detector at the LHC, using $${80}\\,{\\upmu \\textrm{b}}^{-1}$$ 80 μ b - 1 of low-luminosity data. The pion pairs were detected in the ATLAS central detector while outgoing protons were measured in the forward ATLAS ALFA detector system. This represents the first use of proton tagging to measure an exclusive hadronic final state at the LHC. A cross-section measurement is performed in two kinematic regions defined by the proton momenta, the pion rapidities and transverse momenta, and the pion–pion invariant mass. Cross-section values of $$4.8 \\pm 1.0 \\mathrm {\\ (stat)} {~}^{+0.3}_{-0.2} \\mathrm {\\ (syst)}\\ {\\upmu \\textrm{b}}$$ 4.8 ± 1.0 ( stat ) - 0.2 + 0.3 ( syst ) μ b and $$9 \\pm 6 \\mathrm {\\ (stat)} {~}^{+2}_{-2} \\mathrm {\\ (syst)}\\ {\\upmu \\textrm{b}} $$ 9 ± 6 ( stat ) - 2 + 2 ( syst ) μ b are obtained in the two regions they are compared with theoretical models and provide a demonstration of the feasibility of measurements of this type.
Search for heavy, long-lived, charged particles with large ionisation energy loss in pp collisions at $$ \sqrt{s} $$ = 13 TeV using the ATLAS experiment and the full Run 2 dataset
Publisher: Springer Science and Business Media LLC
Date: 26-06-2023
Abstract: This paper presents a search for hypothetical massive, charged, long-lived particles with the ATLAS detector at the LHC using an integrated luminosity of 139 fb − 1 of proton–proton collisions at $$ \\sqrt{s} $$ s = 13 TeV. These particles are expected to move significantly slower than the speed of light and should be identifiable by their high transverse momenta and anomalously large specific ionisation losses, d E/ d x . Trajectories reconstructed solely by the inner tracking system and a d E/ d x measurement in the pixel detector layers provide sensitivity to particles with lifetimes down to $$ \\mathcal{O} $$ O (1) ns with a mass, measured using the Bethe–Bloch relation, ranging from 100 GeV to 3 TeV. Interpretations for pair-production of R -hadrons, charginos and staus in scenarios of supersymmetry compatible with these particles being long-lived are presented, with mass limits extending considerably beyond those from previous searches in broad ranges of lifetime.
Measurement of the charge asymmetry in top-quark pair production in association with a photon with the ATLAS experiment
Publisher: Elsevier BV
Date: 08-2023
A search for new resonances in multiple final states with a high transverse momentum Z boson in $$ \sqrt{s} $$ = 13 TeV pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 07-06-2023
Abstract: A generic search for resonances is performed with events containing a Z boson with transverse momentum greater than 100 GeV, decaying into e + e − or μ + μ − . The analysed data collected with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider correspond to an integrated luminosity of 139 fb − 1 . Two invariant mass distributions are examined for a localised excess relative to the expected Standard Model background in six independent event categories (and their inclusive sum) to increase the sensitivity. No significant excess is observed. Exclusion limits at 95% confidence level are derived for two cases: a model-independent interpretation of Gaussian-shaped resonances with the mass width between 3% and 10% of the resonance mass, and a specific heavy vector triplet model with the decay mode W ′ → ZW → ℓℓqq .
Determination of the strong coupling constant from transverse energy-energy correlations in multijet events at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 11-07-2023
Abstract: Measurements of transverse energy-energy correlations and their associated azimuthal asymmetries in multijet events are presented. The analysis is performed using a data s le corresponding to 139 fb − 1 of proton-proton collisions at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV, collected with the ATLAS detector at the Large Hadron Collider. The measurements are presented in bins of the scalar sum of the transverse momenta of the two leading jets and unfolded to particle level. They are then compared to next-to-next-to-leading-order perturbative QCD calculations for the first time, which feature a significant reduction in the theoretical uncertainties estimated using variations of the renormalisation and factorisation scales. The agreement between data and theory is good, thus providing a precision test of QCD at large momentum transfers Q . The strong coupling constant α s is extracted as a function of Q , showing a good agreement with the renormalisation group equation and with previous analyses. A simultaneous fit to all transverse energy-energy correlation distributions across different kinematic regions yields a value of $$ {\\alpha}_{\\textrm{s}}\\left({m}_Z\\right)=0.1175\\pm 0.0006{\\left(\\exp .\\right)}_{-0.0017}^{+0.0034}\\left(\\textrm{theo}.\\right) $$ α s m Z = 0.1175 ± 0.0006 exp . − 0.0017 + 0.0034 theo . , while the global fit to the asymmetry distributions yields $$ {\\alpha}_{\\textrm{s}}\\left({m}_Z\\right)=0.1185\\pm 0.0009{\\left(\\exp .\\right)}_{-0.0012}^{+0.0025}\\left(\\textrm{theo}.\\right) $$ α s m Z = 0.1185 ± 0.0009 exp . − 0.0012 + 0.0025 theo . .
Inclusive-photon production and its dependence on photon isolation in pp collisions at $$ \sqrt{s} $$ = 13 TeV using 139 fb−1 of ATLAS data
Publisher: Springer Science and Business Media LLC
Date: 11-07-2023
Abstract: Measurements of differential cross sections are presented for inclusive isolated-photon production in pp collisions at a centre-of-mass energy of 13 TeV provided by the LHC and using 139 fb − 1 of data recorded by the ATLAS experiment. The cross sections are measured as functions of the photon transverse energy in different regions of photon pseudorapidity. The photons are required to be isolated by means of a fixed-cone method with two different cone radii. The dependence of the inclusive-photon production on the photon isolation is investigated by measuring the fiducial cross sections as functions of the isolation-cone radius and the ratios of the differential cross sections with different radii in different regions of photon pseudorapidity. The results presented in this paper constitute an improvement with respect to those published by ATLAS earlier: the measurements are provided for different isolation radii and with a more granular segmentation in photon pseudorapidity that can be exploited in improving the determination of the proton parton distribution functions. These improvements provide a more in-depth test of the theoretical predictions. Next-to-leading-order QCD predictions from JETPHOX and SHERPA and next-to-next-to-leading-order QCD predictions from NNLOJET are compared to the measurements, using several parameterisations of the proton parton distribution functions. The measured cross sections are well described by the fixed-order QCD predictions within the experimental and theoretical uncertainties in most of the investigated phase-space region.
Measurement of the properties of Higgs boson production at $$ \sqrt{s} $$ = 13 TeV in the H → γγ channel using 139 fb−1 of pp collision data with the ATLAS experiment
Publisher: Springer Science and Business Media LLC
Date: 11-07-2023
Abstract: Measurements of Higgs boson production cross-sections are carried out in the diphoton decay channel using 139 fb − 1 of pp collision data at $$ \\sqrt{s} $$ s = 13 TeV collected by the ATLAS experiment at the LHC. The analysis is based on the definition of 101 distinct signal regions using machine-learning techniques. The inclusive Higgs boson signal strength in the diphoton channel is measured to be $$ {1.04}_{-0.09}^{+0.10} $$ 1.04 − 0.09 + 0.10 . Cross-sections for gluon-gluon fusion, vector-boson fusion, associated production with a W or Z boson, and top associated production processes are reported. An upper limit of 10 times the Standard Model prediction is set for the associated production process of a Higgs boson with a single top quark, which has a unique sensitivity to the sign of the top quark Yukawa coupling. Higgs boson production is further characterized through measurements of Simplified Template Cross-Sections (STXS). In total, cross-sections of 28 STXS regions are measured. The measured STXS cross-sections are compatible with their Standard Model predictions, with a p -value of 93%. The measurements are also used to set constraints on Higgs boson coupling strengths, as well as on new interactions beyond the Standard Model in an effective field theory approach. No significant deviations from the Standard Model predictions are observed in these measurements, which provide significant sensitivity improvements compared to the previous ATLAS results.
Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at
Publisher:
Elsevier BV
Date:
07-2023
Publisher: Elsevier BV
Date: 07-2023
On frame and orientation localization for relative sensing networks
Publisher: Elsevier BV
Date: 2013
Target localization and circumnavigation by a non-holonomic robot
Publisher: IEEE
Date: 10-2012
A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
Publisher: Springer Science and Business Media LLC
Date: 04-07-2022
DOI: 10.1038/S41586-022-04893-W
Abstract: The standard model of particle physics 1–4 describes the known fundamental particles and forces that make up our Universe, with the exception of gravity. One of the central features of the standard model is a field that permeates all of space and interacts with fundamental particles 5–9 . The quantum excitation of this field, known as the Higgs field, manifests itself as the Higgs boson, the only fundamental particle with no spin. In 2012, a particle with properties consistent with the Higgs boson of the standard model was observed by the ATLAS and CMS experiments at the Large Hadron Collider at CERN 10,11 . Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, enabling much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and W and Z bosons—the carriers of the strong, electromagnetic and weak forces—are studied in detail. Interactions with three third-generation matter particles (bottom ( b ) and top ( t ) quarks, and tau leptons ( τ )) are well measured and indications of interactions with a second-generation particle (muons, μ ) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the standard model.
Emulating the impact of additional proton–proton interactions in the ATLAS simulation by presampling sets of inelastic Monte Carlo events
Publisher: Springer Science and Business Media LLC
Date: 27-01-2022
DOI: 10.1007/S41781-021-00062-2
Abstract: The accurate simulation of additional interactions at the ATLAS experiment for the analysis of proton–proton collisions delivered by the Large Hadron Collider presents a significant challenge to the computing resources. During the LHC Run 2 (2015–2018), there were up to 70 inelastic interactions per bunch crossing, which need to be accounted for in Monte Carlo (MC) production. In this document, a new method to account for these additional interactions in the simulation chain is described. Instead of s ling the inelastic interactions and adding their energy deposits to a hard-scatter interaction one-by-one, the inelastic interactions are pres led, independent of the hard scatter, and stored as combined events. Consequently, for each hard-scatter interaction, only one such pres led event needs to be added as part of the simulation chain. For the Run 2 simulation chain, with an average of 35 interactions per bunch crossing, this new method provides a substantial reduction in MC production CPU needs of around 20%, while reproducing the properties of the reconstructed quantities relevant for physics analyses with good accuracy.
Measurement of $$Z\gamma \gamma $$ production in pp collisions at $$\sqrt{s}= 13$$ TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 27-06-2023
DOI: 10.1140/EPJC/S10052-023-11579-8
Abstract: Cross-sections for the production of a Z boson in association with two photons are measured in proton–proton collisions at a centre-of-mass energy of 13 TeV. The data used correspond to an integrated luminosity of 139 fb $$^{-1}$$ - 1 recorded by the ATLAS experiment during Run 2 of the LHC. The measurements use the electron and muon decay channels of the Z boson, and a fiducial phase-space region where the photons are not radiated from the leptons. The integrated $$Z(\\rightarrow \\ell \\ell )\\gamma \\gamma $$ Z ( → ℓ ℓ ) γ γ cross-section is measured with a precision of 12% and differential cross-sections are measured as a function of six kinematic variables of the $$Z\\gamma \\gamma $$ Z γ γ system. The data are compared with predictions from MC event generators which are accurate to up to next-to-leading order in QCD. The cross-section measurements are used to set limits on the coupling strengths of dimension-8 operators in the framework of an effective field theory.
Measurement of the CP properties of Higgs boson interactions with $$\tau $$-leptons with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 04-07-2023
DOI: 10.1140/EPJC/S10052-023-11583-Y
Abstract: A study of the charge conjugation and parity ( $$\\textit{CP}$$ CP ) properties of the interaction between the Higgs boson and $$\\tau $$ τ -leptons is presented. The study is based on a measurement of $$\\textit{CP}$$ CP -sensitive angular observables defined by the visible decay products of $$\\tau $$ τ -leptons produced in Higgs boson decays. The analysis uses 139 fb $$^{-1}$$ - 1 of proton–proton collision data recorded at a centre-of-mass energy of $$\\sqrt{s}= 13$$ s = 13 TeV with the ATLAS detector at the Large Hadron Collider. Contributions from $$\\textit{CP}$$ CP -violating interactions between the Higgs boson and $$\\tau $$ τ -leptons are described by a single mixing angle parameter $$\\phi _{\\tau }$$ ϕ τ in the generalised Yukawa interaction. Without constraining the $$H\\rightarrow \\tau \\tau $$ H → τ τ signal strength to its expected value under the Standard Model hypothesis, the mixing angle $$\\phi _{\\tau }$$ ϕ τ is measured to be $$9^{\\circ } \\pm 16^{\\circ }$$ 9 ∘ ± 16 ∘ , with an expected value of $$0^{\\circ } \\pm 28^{\\circ }$$ 0 ∘ ± 28 ∘ at the 68% confidence level. The pure $$\\textit{CP}$$ CP -odd hypothesis is disfavoured at a level of 3.4 standard deviations. The results are compatible with the predictions for the Higgs boson in the Standard Model.
Sensitivity analysis for bottleneck assignment problems
Publisher: Elsevier BV
Date: 11-2022
Search for type-III seesaw heavy leptons in leptonic final states in pp collisions at $$\sqrt{s} = 13~\text {TeV}$$ with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 03-11-2022
DOI: 10.1140/EPJC/S10052-022-10785-0
Abstract: A search for the pair production of heavy leptons as predicted by the type-III seesaw mechanism is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV, corresponding to $$139\\,\\text {fb}^{-1}$$ 139 fb - 1 of integrated luminosity recorded by the ATLAS detector during Run 2 of the Large Hadron Collider. The analysis focuses on final states with three or four electrons or muons from the possible decays of new heavy leptons via intermediate electroweak bosons. No significant deviations above the Standard Model expectation are observed upper and lower limits on the heavy lepton production cross-section and masses are derived respectively. These results are then combined for the first time with the ones already published by ATLAS using the channel with two leptons in the final state. The observed lower limit on the mass of the type-III seesaw heavy leptons combining two, three and four lepton channels together is 910 GeV at the 95% confidence level.
Charged-hadron production in pp, p+Pb, Pb+Pb, and Xe+Xe collisions at $$ \sqrt{s_{\textrm{NN}}} $$ = 5 TeV with the ATLAS detector at the LHC
Publisher: Springer Science and Business Media LLC
Date: 10-07-2023
Abstract: This paper presents measurements of charged-hadron spectra obtained in pp , p +Pb, and Pb+Pb collisions at $$ \sqrt{s} $$ s or $$ \sqrt{s_{\textrm{NN}}} $$ s NN = 5 . 02 TeV, and in Xe+Xe collisions at $$ \sqrt{s_{\textrm{NN}}} $$ s NN = 5 . 44 TeV. The data recorded by the ATLAS detector at the LHC have total integrated luminosities of 25 pb − 1 , 28 nb − 1 , 0.50 nb − 1 , and 3 μ b − 1 , respectively. The nuclear modification factors R p Pb and R AA are obtained by comparing the spectra in heavy-ion and pp collisions in a wide range of charged-particle transverse momenta and pseudorapidity. The nuclear modification factor R p Pb shows a moderate enhancement above unity with a maximum at p T ≈ 3 GeV the enhancement is stronger in the Pb-going direction. The nuclear modification factors in both Pb+Pb and Xe+Xe collisions feature a significant, centrality-dependent suppression. They show a similar distinct p T -dependence with a local maximum at p T ≈ 2 GeV and a local minimum at p T ≈ 7 GeV. This dependence is more distinguishable in more central collisions. No significant | η |-dependence is found. A comprehensive comparison with several theoretical predictions is also provided. They typically describe R AA better in central collisions and in the p T range from about 10 to 100 GeV.
Search for exotic decays of the Higgs boson into long-lived particles in pp collisions at $$ \sqrt{s} $$ = 13 TeV using displaced vertices in the ATLAS inner detector
Publisher: Springer Science and Business Media LLC
Date: 11-2021
Abstract: A novel search for exotic decays of the Higgs boson into pairs of long-lived neutral particles, each decaying into a bottom quark pair, is performed using 139 fb − 1 of $$ \\sqrt{s} $$ s = 13 TeV proton-proton collision data collected with the ATLAS detector at the LHC. Events consistent with the production of a Higgs boson in association with a leptonically decaying Z boson are analysed. Long-lived particle (LLP) decays are reconstructed from inner-detector tracks as displaced vertices with high mass and track multiplicity relative to Standard Model processes. The analysis selection requires the presence of at least two displaced vertices, effectively suppressing Standard Model backgrounds. The residual background contribution is estimated using a data-driven technique. No excess over Standard Model predictions is observed, and upper limits are set on the branching ratio of the Higgs boson to LLPs. Branching ratios above 10% are excluded at 95% confidence level for LLP mean proper lifetimes cτ as small as 4 mm and as large as 100 mm. For LLP masses below 40 GeV, these results represent the most stringent constraint in this lifetime regime.
Optimal scaling of the ADMM algorithm for distributed quadratic programming
Publisher: IEEE
Date: 12-2013
Search for pair-production of vector-like quarks in pp collision events at s
Publisher: Elsevier BV
Date: 08-2023
Cohesive motion control of autonomous formations in three dimensions
Publisher: IEEE
Date: 12-2010
MITL Verification Under Timing Uncertainty
Publisher: Springer International Publishing
Date: 2022
Asynchronous Distributed Optimization via Dual Decomposition and Block Coordinate Subgradient Methods
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2021
Minimum-energy distributed consensus of uncertain agents
Publisher: IEEE
Date: 12-2014
Safe Formation Control with Obstacle Avoidance
Publisher: Elsevier BV
Date: 2011
An Expressiveness Hierarchy of Behavior Trees and Related Architectures
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2021
Accelerated gradient methods for networked optimization
Publisher: IEEE
Date: 06-2011
Measurements of Zγ+jets differential cross sections in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 10-07-2023
Abstract: Differential cross-section measurements of Zγ production in association with hadronic jets are presented, using the full 139 fb − 1 dataset of $$ \\sqrt{s} $$ s = 13 TeV proton–proton collisions collected by the ATLAS detector during Run 2 of the LHC. Distributions are measured using events in which the Z boson decays leptonically and the photon is usually radiated from an initial-state quark. Measurements are made in both one and two observables, including those sensitive to the hard scattering in the event and others which probe additional soft and collinear radiation. Different Standard Model predictions, from both parton-shower Monte Carlo simulation and fixed-order QCD calculations, are compared with the measurements. In general, good agreement is observed between data and predictions from MATRIX and MiNNLO PS , as well as next-to-leading-order predictions from M ad G raph 5_ a MC@NLO and S herpa .
Measurement of the t$$ \overline{t} $$t$$ \overline{t} $$ production cross section in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 11-2021
Abstract: A measurement of four-top-quark production using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider corresponding to an integrated luminosity of 139 fb − 1 is presented. Events are selected if they contain a single lepton (electron or muon) or an opposite-sign lepton pair, in association with multiple jets. The events are categorised according to the number of jets and how likely these are to contain b -hadrons. A multivariate technique is then used to discriminate between signal and background events. The measured four-top-quark production cross section is found to be $$ {26}_{-15}^{+17} $$ 26 − 15 + 17 fb, with a corresponding observed (expected) significance of 1.9 (1.0) standard deviations over the background-only hypothesis. The result is combined with the previous measurement performed by the ATLAS Collaboration in the multilepton final state. The combined four-top-quark production cross section is measured to be $$ {24}_{-6}^{+7} $$ 24 − 6 + 7 fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12 . 0 ± 2 . 4 fb.
On reconstructability of quadratic utility functions from the iterations in gradient methods
Publisher: Elsevier BV
Date: 04-2016
Promoting Truthful Behavior in Participatory-Sensing Mechanisms
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2015
Scheduling rigid demands on continuous-time linear shift-invariant systems
Publisher: IEEE
Date: 12-2016
Search for long-lived, massive particles in events with displaced vertices and multiple jets in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 29-06-2023
Abstract: A search for long-lived particles decaying into hadrons is presented. The analysis uses 139 fb − 1 of pp collision data collected at $$ \\sqrt{s} $$ s = 13 TeV by the ATLAS detector at the LHC using events that contain multiple energetic jets and a displaced vertex. The search employs dedicated reconstruction techniques that significantly increase the sensitivity to long-lived particles decaying in the ATLAS inner detector. Background estimates for Standard Model processes and instrumental effects are extracted from data. The observed event yields are compatible with those expected from background processes. The results are used to set limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model, and on scenarios with pair-production of supersymmetric particles with long-lived electroweakinos that decay via a small R -parity-violating coupling. The pair-production of electroweakinos with masses below 1.5 TeV is excluded for mean proper lifetimes in the range from 0.03 ns to 1 ns. When produced in the decay of $$ m\\left(\\overset{\\sim }{g}\\right) $$ m g ~ = 2 . 4 TeV gluinos, electroweakinos with $$ m\\left({\\overset{\\sim }{\\chi}}_1^0\\right) $$ m χ ~ 1 0 = 1 . 5 TeV are excluded with lifetimes in the range of 0.02 ns to 4 ns.
A secure control framework for resource-limited adversaries
Publisher: Elsevier BV
Date: 2015
Measurement of the polarisation of single top quarks and antiquarks produced in the t-channel at $$ \sqrt{s} $$ = 13 TeV and bounds on the tWb dipole operator from the ATLAS experiment
Publisher: Springer Science and Business Media LLC
Date: 09-11-2022
Abstract: A simultaneous measurement of the three components of the top-quark and top-antiquark polarisation vectors in t -channel single-top-quark production is presented. This analysis is based on data from proton–proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 139 fb − 1 , collected with the ATLAS detector at the LHC. Selected events contain exactly one isolated electron or muon, large missing transverse momentum and exactly two jets, one being b -tagged. Stringent selection requirements are applied to discriminate t -channel single-top-quark events from the background contributions. The top-quark and top-antiquark polarisation vectors are measured from the distributions of the direction cosines of the charged-lepton momentum in the top-quark rest frame. The three components of the polarisation vector for the selected top-quark event s le are $$ {P}_{x^{\\prime }} $$ P x ′ = 0 . 01 ± 0 . 18, $$ {P}_{y^{\\prime }} $$ P y ′ = − 0 . 029 ± 0 . 027, $$ {P}_{z^{\\prime }} $$ P z ′ = 0 . 91 ± 0 . 10 and for the top-antiquark event s le they are $$ {P}_{x^{\\prime }} $$ P x ′ = − 0 . 02 ± 0 . 20, $$ {P}_{y^{\\prime }} $$ P y ′ = − 0 . 007 ± 0 . 051, $$ {P}_{z^{\\prime }} $$ P z ′ = 0 . 79 ± 0 . 16. Normalised differential cross-sections corrected to a fiducial region at the stable-particle level are presented as a function of the charged-lepton angles for top-quark and top-antiquark events inclusively and separately. These measurements are in agreement with Standard Model predictions. The angular differential cross-sections are used to derive bounds on the complex Wilson coefficient of the dimension-six $$ \\mathcal{O} $$ O tW operator in the framework of an effective field theory. The obtained bounds are C tW ∈ [ − 0 . 9 , 1 . 4] and C itW ∈ [ − 0 . 8 , 0 . 2], both at 95% confidence level.
Second-Order Online Nonconvex Optimization
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2021
Measurements of the Higgs boson inclusive and differential fiducial cross-sections in the diphoton decay channel with pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 02-08-2022
Abstract: A measurement of inclusive and differential fiducial cross-sections for the production of the Higgs boson decaying into two photons is performed using 139 fb − 1 of proton-proton collision data recorded at $$ \\sqrt{s} $$ s = 13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio, in a fiducial region closely matching the experimental selection, is measured to be 67 ± 6 fb, which is in agreement with the state-of-the-art Standard Model prediction of 64 ± 4 fb. Extrapolating this result to the full phase space and correcting for the branching ratio, the total cross-section for Higgs boson production is estimated to be 58 ± 6 pb. In addition, the cross-sections in four fiducial regions sensitive to various Higgs boson production modes and differential cross-sections as a function of either one or two of several observables are measured. All the measurements are found to be in agreement with the Standard Model predictions. The measured transverse momentum distribution of the Higgs boson is used as an indirect probe of the Yukawa coupling of the Higgs boson to the bottom and charm quarks. In addition, five differential cross-section measurements are used to constrain anomalous Higgs boson couplings to vector bosons in the Standard Model effective field theory framework.
Robust Model Predictive Control of Unmanned Aerial Vehicles Using Waysets
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 10-2015
DOI: 10.2514/1.G000787
Exclusive dimuon production in ultraperipheral
Pb + Pb
Publisher: American Physical Society (APS)
Date: 19-08-2021
Safe autonomous agent formation operations via obstacle collision avoidance
Publisher: Wiley
Date: 26-09-2015
DOI: 10.1002/ASJC.1005
Determination of the parton distribution functions of the proton from ATLAS measurements of differential W± and Z boson production in association with jets
Publisher: Springer Science and Business Media LLC
Date: 07-2021
Abstract: This article presents a new set of proton parton distribution functions, ATLASepWZVjet20, produced in an analysis at next-to-next-to-leading order in QCD. The new data sets considered are the measurements of W + and W − boson and Z boson production in association with jets in pp collisions at $$ \\sqrt{s} $$ s = 8 TeV performed by the ATLAS experiment at the LHC with integrated luminosities of 20 . 2 fb − 1 and 19 . 9 fb − 1 , respectively. The analysis also considers the ATLAS measurements of differential W ± and Z boson production at $$ \\sqrt{s} $$ s = 7 TeV with an integrated luminosity of 4 . 6 fb − 1 and deep-inelastic-scattering data from e ± p collisions at the HERA accelerator. An improved determination of the sea-quark densities at high Bjorken x is shown, while confirming a strange-quark density similar in size to the up- and down-sea-quark densities in the range x ≲ 0 . 02 found by previous ATLAS analyses.
Model-independent search for the presence of new physics in events including H → γγ with $$ \sqrt{s} $$ = 13 TeV pp data recorded by the ATLAS detector at the LHC
Publisher: Springer Science and Business Media LLC
Date: 24-07-2023
Abstract: A model-independent search for new physics leading to final states containing a Higgs boson, with a mass of 125.09 GeV, decaying to a pair of photons is performed with 139 fb − 1 of $$ \\sqrt{s} $$ s = 13 TeV pp collision data recorded by the ATLAS detector at the Large Hadron Collider at CERN. This search examines 22 final states categorized by the objects that are produced in association with the Higgs boson. These objects include isolated electrons or muons, hadronically decaying τ -leptons, additional photons, missing transverse momentum, and hadronic jets, as well as jets that are tagged as containing a b -hadron. No significant excesses above Standard Model expectations are observed and limits on the production cross section at 95% confidence level are set. Detector efficiencies are reported for all 22 signal regions, which can be used to convert detector-level cross-section limits reported in this paper to particle-level cross-section constraints.
Corrections to “Rigid Network Design Via Submodular Set Function Optimization”
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2020
Measurement of Higgs boson decay into b-quarks in associated production with a top-quark pair in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 17-06-2022
Abstract: The associated production of a Higgs boson and a top-quark pair is measured in events characterised by the presence of one or two electrons or muons. The Higgs boson decay into a b -quark pair is used. The analysed data, corresponding to an integrated luminosity of 139 fb − 1 , were collected in proton-proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV. The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is $$ {0.35}_{-0.34}^{+0.36} $$ 0.35 − 0.34 + 0.36 . This result is compatible with the Standard Model prediction and corresponds to an observed (expected) significance of 1.0 (2.7) standard deviations. The signal strength is also measured differentially in bins of the Higgs boson transverse momentum in the simplified template cross-section framework, including a bin for specially selected boosted Higgs bosons with transverse momentum above 300 GeV.
Search in diphoton and dielectron final states for displaced production of Higgs or
Z
Publisher: American Physical Society (APS)
Date: 19-07-2023
Noisy network localization via optimal measurement refinement part 2: Distance-only network localization
Publisher: Elsevier BV
Date: 2011
Rigid-Profile Input Scheduling Under Constrained Dynamics With a Water Network Application
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2021
Distributed Cohesive Motion Control of Quadrotor Vehicle Formations
Publisher: ASMEDC
Date: 2010
Abstract: In this paper, we focus on distributed cohesive motion control of 3-dimensional multi-vehicle systems considering in idual agent dynamic behaviors as well as the overall multi-vehicle system. In this context, we examine maintenance of geometric formation of a swarm of autonomous quadrotor vehicles, i.e. maintenance of the distance between each agent pair in the swarm, during arbitrary maneuvers. A distributed scheme for the formation maintenance task is developed first. This coordination scheme is integrated with low level dynamic controllers designed for the agents considering practical kinematic and dynamic models for quadrotor vehicles. The distributed motion control scheme is implemented to move the vehicles whose initial positions satisfying the desired formation maintenance constraints are specified, to a set of final desired positions satisfying the same constraints cohesively without deviating from the desired geometric formation during motion. The developed coordination and control schemes are tested via a number of simulations.
Polynomial methods in noisy network localization
Publisher: IEEE
Date: 06-2009
On the Optimal Step-size Selection for the Alternating Direction Method of Multipliers
Publisher: Elsevier BV
Date: 09-2012
Measurements of Higgs boson production cross-sections in the H → τ+τ− decay channel in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 18-08-2022
Abstract: Measurements of the production cross-sections of the Standard Model (SM) Higgs boson ( H ) decaying into a pair of τ -leptons are presented. The measurements use data collected with the ATLAS detector from pp collisions produced at the Large Hadron Collider at a centre-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 139 fb − 1 . Leptonic ( τ → ℓν ℓ ν τ ) and hadronic ( τ → hadrons ν τ ) decays of the τ -lepton are considered. All measurements account for the branching ratio of H → ττ and are performed with a requirement |y H | 2 . 5, where y H is the true Higgs boson rapidity. The cross-section of the pp → H → ττ process is measured to be 2 . 94 ± $$ 0.21{\left(\mathrm{stat}\right)}_{-0.32}^{+0.37} $$ 0.21 stat − 0.32 + 0.37 (syst) pb, in agreement with the SM prediction of 3 . 17 ± 0 . 09 pb. Inclusive cross-sections are determined separately for the four dominant production modes: 2 . 65 ± $$ 0.41{\left(\mathrm{stat}\right)}_{-0.67}^{+0.91} $$ 0.41 stat − 0.67 + 0.91 (syst) pb for gluon-gluon fusion, 0 . 197 ± $$ 0.028{\left(\mathrm{stat}\right)}_{-0.026}^{+0.032} $$ 0.028 stat − 0.026 + 0.032 (syst) pb for vector-boson fusion, 0 . 115 ± $$ 0.058{\left(\mathrm{stat}\right)}_{-0.040}^{+0.042} $$ 0.058 stat − 0.040 + 0.042 (syst) pb for vector-boson associated production, and 0 . 033 ± $$ 0.031{\left(\mathrm{stat}\right)}_{-0.017}^{+0.022} $$ 0.031 stat − 0.017 + 0.022 (syst) pb for top-quark pair associated production. Measurements in exclusive regions of the phase space, using the simplified template cross-section framework, are also performed. All results are in agreement with the SM predictions.
Towards more efficient building energy management systems
Publisher: IEEE
Date: 11-2012
Search for resonant and non-resonant Higgs boson pair production in the $$ b\overline{b}{\tau}^{+}{\tau}^{-} $$ decay channel using 13 TeV pp collision data from the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 05-07-2023
Abstract: A search for Higgs boson pair production in events with two b -jets and two τ -leptons is presented, using a proton–proton collision dataset with an integrated luminosity of 139 fb − 1 collected at $$ \\sqrt{s} $$ s = 13 TeV by the ATLAS experiment at the LHC. Higgs boson pairs produced non-resonantly or in the decay of a narrow scalar resonance in the mass range from 251 to 1600 GeV are targeted. Events in which at least one τ -lepton decays hadronically are considered, and multivariate discriminants are used to reject the backgrounds. No significant excess of events above the expected background is observed in the non-resonant search. The largest excess in the resonant search is observed at a resonance mass of 1 TeV, with a local (global) significance of 3 . 1 σ (2 . 0 σ ). Observed (expected) 95% confidence-level upper limits are set on the non-resonant Higgs boson pair-production cross-section at 4.7 (3.9) times the Standard Model prediction, assuming Standard Model kinematics, and on the resonant Higgs boson pair-production cross-section at between 21 and 900 fb (12 and 840 fb), depending on the mass of the narrow scalar resonance.
Measurements of observables sensitive to colour reconnection in $$t{\bar{t}}$$ events with the ATLAS detector at $$\sqrt{s} =$$ 13 TeV
Publisher: Springer Science and Business Media LLC
Date: 20-06-2023
DOI: 10.1140/EPJC/S10052-023-11479-X
Abstract: A measurement of observables sensitive to effects of colour reconnection in top-quark pair-production events is presented using 139 $$\\hbox {fb}^{-1}$$ fb - 1 of 13 TeV proton–proton collision data collected by the ATLAS detector at the LHC. Events are selected by requiring exactly one isolated electron and one isolated muon with opposite charge and two or three jets, where exactly two jets are required to be b -tagged. For the selected events, measurements are presented for the charged-particle multiplicity, the scalar sum of the transverse momenta of the charged particles, and the same scalar sum in bins of charged-particle multiplicity. These observables are unfolded to the stable-particle level, thereby correcting for migration effects due to finite detector resolution, acceptance and efficiency effects. The particle-level measurements are compared with different colour reconnection models in Monte Carlo generators. These measurements disfavour some of the colour reconnection models and provide inputs to future optimisation of the parameters in Monte Carlo generators.
Searches for lepton-flavour-violating decays of the Higgs boson into eτ and μτ in $$ \sqrt{s} $$ = 13 TeV pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 21-07-2023
Abstract: This paper presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → μτ , performed using data collected with the ATLAS detector at the LHC. The searches are based on a data s le of proton-proton collisions at a centre-of-mass energy $$ \\sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 138 fb − 1 . Leptonic ( τ → ℓν ℓ ν τ ) and hadronic ( τ → hadrons ν τ ) decays of the τ -lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation s les, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, $$ \\mathcal{B} $$ B ( H → eτ ) 0 . 20% (0 . 12%) and $$ \\mathcal{B} $$ B ( H → μτ ) 0 . 18% (0 . 09%), are obtained with the MC-template method from a simultaneous measurement of potential H → eτ and H → μτ signals. The best-fit branching ratio difference, $$ \\mathcal{B} $$ B ( H → μτ ) → $$ \\mathcal{B} $$ B ( H → eτ ), measured with the Symmetry method in the channel where the τ -lepton decays to leptons, is (0 . 25 ± 0 . 10)%, compatible with a value of zero within 2 . 5 σ .
Observation of gauge boson joint-polarisation states in W±Z production from pp collisions at s
Publisher:
Elsevier BV
Date:
08-2023
Publisher: Elsevier BV
Date: 08-2023
Search for bottom-squark pair production in
p p
Publisher:
American Physical Society (APS)
Date:
31-08-2021
Publisher: American Physical Society (APS)
Date: 31-08-2021
Two-particle Bose–Einstein correlations in $${ pp }$$ collisions at $$\mathbf {\sqrt{s} = 13}$$ TeV measured with the ATLAS detector at the LHC
Publisher: Springer Science and Business Media LLC
Date: 11-07-2022
DOI: 10.1140/EPJC/S10052-022-10472-0
Abstract: This paper presents studies of Bose–Einstein correlations (BEC) in proton–proton collisions at a centre-of-mass energy of 13 TeV, using data from the ATLAS detector at the CERN Large Hadron Collider. Data were collected in a special low-luminosity configuration with a minimum-bias trigger and a high-multiplicity track trigger, accumulating integrated luminosities of 151 $$\upmu $$ μ b $$^{-1}$$ - 1 and 8.4 nb $$^{-1}$$ - 1 , respectively. The BEC are measured for pairs of like-sign charged particles, each with $$|\eta | 2.5$$ | η | 2.5 , for two kinematic ranges: the first with particle $$p_{\mathrm {T}} 100$$ p T 100 MeV and the second with particle $$p_{\mathrm {T}} 500$$ p T 500 MeV. The BEC parameters, characterizing the source radius and particle correlation strength, are investigated as functions of charged-particle multiplicity (up to 300) and average transverse momentum of the pair (up to 1.5 GeV). The double-differential dependence on charged-particle multiplicity and average transverse momentum of the pair is also studied. The BEC radius is found to be independent of the charged-particle multiplicity for high charged-particle multiplicity (above 100), confirming a previous observation at lower energy. This saturation occurs independent of the transverse momentum of the pair.
Collective Circumnavigation
Publisher: World Scientific Pub Co Pte Lt
Date: 07-2014
DOI: 10.1142/S2301385014400019
Abstract: This paper considers the problem of localization and circumnavigation of a slowly drifting target with an unknown speed by a group of autonomous agents while they form a regular polygon at a known distance from the target. The goal is achieved in a distributed way where each of the agents coordinates its motion knowing its own position and either the bearing angle of the target or the distance to the target, and the position of one of its neighbors. First, we solve the problem for the case where the target is stationary and propose a two-stage control law that forces the agents to move on a circular trajectory around the target and form a regular polygon formation. Then, we consider the case where the target is undergoing a slow but possibly persistent movement. Later, we consider the case where only one of the agents know the desired distance from the target. In the end, the case in which only a subset of agents can measure either the bearing or the distance to the target is considered. The performance of the controllers proposed is verified analytically, through simulations, and in an experimental setup.
Search for New Phenomena in Final States with Two Leptons and One or No
b
Publisher:
American Physical Society (APS)
Date:
10-2021
Publisher: American Physical Society (APS)
Date: 10-2021
Stabilization of rigid formations with direction-only constraints
Publisher: IEEE
Date: 12-2011
An algorithm for the selection of linearisation points in non-linear systems: a diesel air-path case study
Publisher: Informa UK Limited
Date: 25-10-2022
Adaptive Source Localization Based Station Keeping of Autonomous Vehicles
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2016
A search for an unexpected asymmetry in the production of e+μ− and e−μ+ pairs in proton–proton collisions recorded by the ATLAS detector at
Publisher:
Elsevier BV
Date:
07-2022
Publisher: Elsevier BV
Date: 07-2022
Target localization and circumnavigation using bearing measurements in 2D
Publisher: IEEE
Date: 12-2010
Search for boosted diphoton resonances in the 10 to 70 GeV mass range using 138 fb−1 of 13 TeV pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 20-07-2023
Abstract: A search for diphoton resonances in the mass range between 10 and 70 GeV with the ATLAS experiment at the Large Hadron Collider (LHC) is presented. The analysis is based on pp collision data corresponding to an integrated luminosity of 138 fb − 1 at a centre-of-mass energy of 13 TeV recorded from 2015 to 2018. Previous searches for diphoton resonances at the LHC have explored masses down to 65 GeV, finding no evidence of new particles. This search exploits the particular kinematics of events with pairs of closely spaced photons reconstructed in the detector, allowing examination of invariant masses down to 10 GeV. The presented strategy covers a region previously unexplored at hadron colliders because of the experimental challenges of recording low-energy photons and estimating the backgrounds. No significant excess is observed and the reported limits provide the strongest bound on promptly decaying axion-like particles coupling to gluons and photons for masses between 10 and 70 GeV.
Measurement of the Higgs boson mass in the H → ZZ⁎ → 4ℓ decay channel using 139 fb−1 of s
Publisher:
Elsevier BV
Date:
08-2023
Publisher: Elsevier BV
Date: 08-2023
Conditions and strategies for uniqueness of the solutions to cooperative localization and mapping problems using rigidity theory
Publisher: IEEE
Date: 12-2016
Reduction of Self-localization Errors in Multi-Agent Autonomous Formations
Publisher: Elsevier BV
Date: 2008
Search for Higgs boson pair production in association with a vector boson in pp collisions at $$\sqrt{s}=13\,\text {TeV}$$ with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 20-06-2023
DOI: 10.1140/EPJC/S10052-023-11559-Y
Abstract: This paper reports a search for Higgs boson pair ( hh ) production in association with a vector boson ( $$W\\ {\\text {o}r}\\ Z$$ W o r Z ) using 139 fb $$^{-1}$$ - 1 of proton–proton collision data at $$\\sqrt{s}=13\\,\\text {TeV}$$ s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The search is performed in final states in which the vector boson decays leptonically ( $$W\\rightarrow \\ell \\nu ,\\, Z\\rightarrow \\ell \\ell ,\\nu \\nu $$ W → ℓ ν , Z → ℓ ℓ , ν ν with $$\\ell =e, \\mu $$ ℓ = e , μ ) and the Higgs bosons each decay into a pair of b -quarks. It targets Vhh signals from both non-resonant hh production, present in the Standard Model (SM), and resonant hh production, as predicted in some SM extensions. A 95% confidence-level upper limit of 183 (87) times the SM cross-section is observed (expected) for non-resonant Vhh production when assuming the kinematics are as expected in the SM. Constraints are also placed on Higgs boson coupling modifiers. For the resonant search, upper limits on the production cross-sections are derived for two specific models: one is the production of a vector boson along with a neutral heavy scalar resonance H , in the mass range 260–1000 GeV, that decays into hh , and the other is the production of a heavier neutral pseudoscalar resonance A that decays into a Z boson and H boson, where the A boson mass is 360–800 GeV and the H boson mass is 260–400 GeV. Constraints are also derived in the parameter space of two-Higgs-doublet models.
Search for single production of a vectorlike
T
Publisher: American Physical Society (APS)
Date: 25-05-2022
Distributed relative clock synchronization for wireless sensor networks
Publisher: Elsevier BV
Date: 2011
On the Use of Convex Optimization in Sensor Network Localization and Synchronization
Publisher: Elsevier BV
Date: 09-2009
Search for exotic decays of the Higgs boson into b$$ \overline{b} $$ and missing transverse momentum in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 2022
Abstract: A search for the exotic decay of the Higgs boson ( H ) into a b $$ \\overline{b} $$ b ¯ resonance plus missing transverse momentum is described. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb − 1 of pp collisions at $$ \\sqrt{s} $$ s = 13 TeV. The search targets events from ZH production in an NMSSM scenario where H → $$ {\\overset{\\sim }{\\chi}}_2^0{\\overset{\\sim }{\\chi}}_1^0 $$ χ ~ 2 0 χ ~ 1 0 , with $$ {\\overset{\\sim }{\\chi}}_2^0 $$ χ ~ 2 0 → $$ a{\\overset{\\sim }{\\chi}}_1^0 $$ a χ ~ 1 0 , where a is a light pseudoscalar Higgs boson and $$ {\\overset{\\sim }{\\chi}}_{1,2}^0 $$ χ ~ 1 , 2 0 are the two lightest neutralinos. The decay of the a boson into a pair of b -quarks results in a peak in the dijet invariant mass distribution. The final-state signature consists of two leptons, two or more jets, at least one of which is identified as originating from a b -quark, and missing transverse momentum. Observations are consistent with Standard Model expectations and upper limits are set on the product of cross section times branching ratio for a three-dimensional scan of the masses of the $$ {\\overset{\\sim }{\\chi}}_2^0 $$ χ ~ 2 0 , $$ {\\overset{\\sim }{\\chi}}_1^0 $$ χ ~ 1 0 and a boson.
Inclusive and differential cross-sections for dilepton $$ t\overline{t} $$ production measured in $$ \sqrt{s} $$ = 13 TeV pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 17-07-2023
Abstract: Differential and double-differential distributions of kinematic variables of leptons from decays of top-quark pairs ( $$ t\\overline{t} $$ t t ¯ ) are measured using the full LHC Run 2 data s le collected with the ATLAS detector. The data were collected at a pp collision energy of $$ \\sqrt{s} $$ s = 13 TeV and correspond to an integrated luminosity of 140 fb − 1 . The measurements use events containing an oppositely charged eμ pair and b -tagged jets. The results are compared with predictions from several Monte Carlo generators. While no prediction is found to be consistent with all distributions, a better agreement with measurements of the lepton p T distributions is obtained by reweighting the $$ t\\overline{t} $$ t t ¯ s le so as to reproduce the top-quark p T distribution from an NNLO calculation. The inclusive top-quark pair production cross-section is measured as well, both in a fiducial region and in the full phase-space. The total inclusive cross-section is found to be $$ {\\sigma}_{t\\overline{t}}=829\\pm 1\\ \\left(\\textrm{stat}\\right)\\pm 13\\ \\left(\\textrm{syst}\\right)\\pm 8\\ \\left(\\textrm{lumi}\\right)\\pm 2\\ \\left(\\textrm{beam}\\right)\\ \\textrm{pb}, $$ σ t t ¯ = 829 ± 1 stat ± 13 syst ± 8 lumi ± 2 beam pb , where the uncertainties are due to statistics, systematic effects, the integrated luminosity and the beam energy. This is in excellent agreement with the theoretical expectation.
Search for new phenomena in final states with photons, jets and missing transverse momentum in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 03-07-2023
Abstract: A search for new phenomena has been performed in final states with at least one isolated high-momentum photon, jets and missing transverse momentum in proton–proton collisions at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV. The data, collected by the ATLAS experiment at the CERN LHC, correspond to an integrated luminosity of 139 fb − 1 . The experimental results are interpreted in a supersymmetric model in which pair-produced gluinos decay into neutralinos, which in turn decay into a gravitino, at least one photon, and jets. No significant deviations from the predictions of the Standard Model are observed. Upper limits are set on the visible cross section due to physics beyond the Standard Model, and lower limits are set on the masses of the gluinos and neutralinos, all at 95% confidence level. Visible cross sections greater than 0.022 fb are excluded and pair-produced gluinos with masses up to 2200 GeV are excluded for most of the NLSP masses investigated.
Fault Detection and Mitigation in Kirchhoff Networks
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2012
Relative clock synchronization in wireless networks
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2010
Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector
Publisher: Elsevier BV
Date: 06-2022
Microfluidic characteristics of a multi-holed baffle plate micro-reactor
Publisher: Elsevier BV
Date: 12-2006
Constraints on Higgs boson production with large transverse momentum using
H →
Publisher:
American Physical Society (APS)
Date:
11-05-2022
Publisher: American Physical Society (APS)
Date: 11-05-2022
Search for long-lived charginos based on a disappearing-track signature using 136 fb$$^{-1}$$ of pp collisions at $$\sqrt{s}$$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 11-07-2022
DOI: 10.1140/EPJC/S10052-022-10489-5
Abstract: A search for long-lived charginos produced either directly or in the cascade decay of heavy prompt gluino states is presented. The search is based on proton–proton collision data collected at a centre-of-mass energy of $$\\sqrt{s}$$ s = 13 T $$\\text {eV}$$ eV between 2015 and 2018 with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 136 fb $$^{-1}$$ - 1 . Long-lived charginos are characterised by a distinct signature of a short and then disappearing track, and are reconstructed using at least four measurements in the ATLAS pixel detector, with no subsequent measurements in the silicon-microstrip tracking volume nor any associated energy deposits in the calorimeter. The final state is complemented by a large missing transverse-momentum requirement for triggering purposes and at least one high-transverse-momentum jet. No excess above the expected backgrounds is observed. Exclusion limits are set at 95% confidence level on the masses of the chargino and gluino for different chargino lifetimes. Chargino masses up to 660 (210) G $$\\text {eV}$$ eV are excluded in scenarios where the chargino is a pure wino (higgsino). For charginos produced during the cascade decay of a heavy gluino, gluinos with masses below 2.1 T $$\\text {eV}$$ eV are excluded for a chargino mass of 300 G $$\\text {eV}$$ eV and a lifetime of 0.2 ns.
Preserving Privacy of Finite Impulse Response Systems
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2017
Search for resonant pair production of Higgs bosons in the
b b
Publisher:
American Physical Society (APS)
Date:
11-05-2022
Publisher: American Physical Society (APS)
Date: 11-05-2022
Cyberattack and Machine-Induced Fault Detection and Isolation Methodologies for Cyber-Physical Systems
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Zeroth-Order Optimization on Subsets of Symmetric Matrices With Application to MPC Tuning
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2022
Water-level reference planning for automated irrigation channels via robust MPC
Publisher: IEEE
Date: 06-2014
Distributed Fault Detection and Isolation Resilient to Network Model Uncertainties
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2014
Agents misbehaving in a network: a vice or a virtue?
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2012
Learning Safety Filters for Unknown Discrete-Time Linear Systems
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Active influence in dynamical models of structural balance in social networks
Publisher: IOP Publishing
Date: 07-2013
A Distributed Augmenting Path Approach for the Bottleneck Assignment Problem
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Differential $$ t\overline{t} $$ cross-section measurements using boosted top quarks in the all-hadronic final state with 139 fb−1 of ATLAS data
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Abstract: Measurements of single-, double-, and triple-differential cross-sections are presented for boosted top-quark pair-production in 13 TeV proton–proton collisions recorded by the ATLAS detector at the LHC. The top quarks are observed through their hadronic decay and reconstructed as large-radius jets with the leading jet having transverse momentum ( p T ) greater than 500 GeV. The observed data are unfolded to remove detector effects. The particle-level cross-section, multiplied by the $$ t\\overline{t}\\to WWb\\overline{b} $$ t t ¯ → WWb b ¯ branching fraction and measured in a fiducial phase space defined by requiring the leading and second-leading jets to have p T 500 GeV and p T 350 GeV, respectively, is 331 ± 3(stat.) ± 39(syst.) fb. This is approximately 20% lower than the prediction of $$ {398}_{-49}^{+48} $$ 398 − 49 + 48 fb by P owheg +P ythia 8 with next-to-leading-order (NLO) accuracy but consistent within the theoretical uncertainties. Results are also presented at the parton level, where the effects of top-quark decay, parton showering, and hadronization are removed such that they can be compared with fixed-order next-to-next-to-leading-order (NNLO) calculations. The parton-level cross-section, measured in a fiducial phase space similar to that at particle level, is 1 . 94 ± 0 . 02(stat.) ± 0 . 25(syst.) pb. This agrees with the NNLO prediction of $$ {1.96}_{-0.17}^{+0.02} $$ 1.96 − 0.17 + 0.02 pb. Reasonable agreement with the differential cross-sections is found for most NLO models, while the NNLO calculations are generally in better agreement with the data. The differential cross-sections are interpreted using a Standard Model effective field-theory formalism and limits are set on Wilson coefficients of several four-fermion operators.
Measurement of the production cross section of pairs of isolated photons in pp collisions at 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 11-2021
Abstract: A measurement of prompt photon-pair production in proton-proton collisions at $$ \\sqrt{s} $$ s = 13 TeV is presented. The data were recorded by the ATLAS detector at the LHC with an integrated luminosity of 139 fb − 1 . Events with two photons in the well-instrumented region of the detector are selected. The photons are required to be isolated and have a transverse momentum of $$ {p}_{\\mathrm{T}{,}_{\\gamma 1(2)}} $$ p T , γ 1 2 40 (30) GeV for the leading (sub-leading) photon. The differential cross sections as functions of several observables for the diphoton system are measured and compared with theoretical predictions from state-of-the-art Monte Carlo and fixed-order calculations. The QCD predictions from next-to-next-to-leading-order calculations and multi-leg merged calculations are able to describe the measured integrated and differential cross sections within uncertainties, whereas lower-order calculations show significant deviations, demonstrating that higher-order perturbative QCD corrections are crucial for this process. The resummed predictions with parton showers additionally provide an excellent description of the low transverse-momentum regime of the diphoton system.
Search for events with a pair of displaced vertices from long-lived neutral particles decaying into hadronic jets in the ATLAS muon spectrometer in
Publisher:
American Physical Society (APS)
Date:
09-08-2022
Publisher: American Physical Society (APS)
Date: 09-08-2022
A New Intelligent Traffic Shaper for High Speed Networks
Publisher: IEEE
Date: 11-2006
Observation of
W W W
Publisher:
American Physical Society (APS)
Date:
04-08-2022
Publisher: American Physical Society (APS)
Date: 04-08-2022
Measurements of Higgs boson production by gluon-gluon fusion and vector-boson fusion using
H
Publisher:
American Physical Society (APS)
Date:
08-08-2023
Publisher: American Physical Society (APS)
Date: 08-08-2023
Measurements of jet observables sensitive to
b
Publisher:
American Physical Society (APS)
Date:
09-08-2022
Publisher: American Physical Society (APS)
Date: 09-08-2022
Erratum to: Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb−1 of Pb+Pb data with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 11-2021
Noisy Network Localization via Optimal Measurement Refinement Part 1: Bearing-Only Orientation Registration and Localization
Publisher: Elsevier BV
Date: 2011
Minimization of the effect of noisy measurements on localization of multi-agent autonomous formations
Publisher: Elsevier BV
Date: 04-2009
Combustion prevention of iron powders by a novel coating method
Publisher: Wiley
Date: 2006
Online Optimization Using Zeroth Order Oracles
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2020
Tuning of multivariable model predictive controllers through expert bandit feedback
Publisher: Informa UK Limited
Date: 27-02-2020
Measurement of the nuclear modification factor of b-jets in 5.02 TeV Pb+Pb collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 25-05-2023
DOI: 10.1140/EPJC/S10052-023-11427-9
Abstract: This paper presents a measurement of b -jet production in Pb+Pb and pp collisions at $$\\sqrt{s_{_\\text {NN}}}=5.02$$ s NN = 5.02 TeV with the ATLAS detector at the LHC. The measurement uses 260 $$\\text {pb}^{-1}$$ pb - 1 of pp collisions collected in 2017 and 1.4 $$\\text {nb}^{-1}$$ nb - 1 of Pb+Pb collisions collected in 2018. In both collision systems, jets are reconstructed via the anti- $$k_{t}$$ k t algorithm. The b -jets are identified from a s le of jets containing muons from the semileptonic decay of b -quarks using template fits of the muon momentum relative to the jet axis. In pp collisions, b -jets are reconstructed for radius parameters $$R= 0.2$$ R = 0.2 and $$R= 0.4$$ R = 0.4 , and only $$R= 0.2$$ R = 0.2 jets are used in Pb+Pb collisions. For comparison, inclusive $$R= 0.2$$ R = 0.2 jets are also measured using 1.7 $$\\text {nb}^{-1}$$ nb - 1 of Pb+Pb collisions collected in 2018 and the same pp collision data as the b -jet measurement. The nuclear modification factor, $$R_\\text {AA}$$ R AA , is calculated for both b -jets and inclusive jets with $$R= 0.2$$ R = 0.2 over the transverse momentum range of 80–290 GeV. The nuclear modification factor for b -jets decreases from peripheral to central collisions. The ratio of the b -jet $$R_\\text {AA}$$ R AA to inclusive jet $$R_\\text {AA}$$ R AA is also presented and suggests that the $$R_\\text {AA}$$ R AA for b -jets is larger than that for inclusive jets in central Pb+Pb collisions. The measurements are compared with theoretical calculations and suggest a role for mass and colour-charge effects in partonic energy loss in heavy-ion collisions.
Distributed fault detection for interconnected second-order systems
Publisher: Elsevier BV
Date: 12-2011
Constraints on spin-0 dark matter mediators and invisible Higgs decays using ATLAS 13 TeV pp collision data with two top quarks and missing transverse momentum in the final state
Publisher: Springer Science and Business Media LLC
Date: 13-06-2023
DOI: 10.1140/EPJC/S10052-023-11477-Z
Abstract: This paper presents a statistical combination of searches targeting final states with two top quarks and invisible particles, characterised by the presence of zero, one or two leptons, at least one jet originating from a b -quark and missing transverse momentum. The analyses are searches for phenomena beyond the Standard Model consistent with the direct production of dark matter in pp collisions at the LHC, using 139 fb $$^{-\\text {1}}$$ - 1 of data collected with the ATLAS detector at a centre-of-mass energy of 13 TeV. The results are interpreted in terms of simplified dark matter models with a spin-0 scalar or pseudoscalar mediator particle. In addition, the results are interpreted in terms of upper limits on the Higgs boson invisible branching ratio, where the Higgs boson is produced according to the Standard Model in association with a pair of top quarks. For scalar (pseudoscalar) dark matter models, with all couplings set to unity, the statistical combination extends the mass range excluded by the best of the in idual channels by 50 (25) GeV, excluding mediator masses up to 370 GeV. In addition, the statistical combination improves the expected coupling exclusion reach by 14% (24%), assuming a scalar (pseudoscalar) mediator mass of 10 GeV. An upper limit on the Higgs boson invisible branching ratio of 0.38 ( $$\\text {0.30}^{+\\text {0.13}}_{-\\text {0.09}}$$ 0.30 - 0.09 + 0.13 ) is observed (expected) at 95% confidence level.
Search for Higgs boson decays into a pair of pseudoscalar particles in the
b b μ
Publisher:
American Physical Society (APS)
Date:
11-01-2022
Publisher: American Physical Society (APS)
Date: 11-01-2022
Search for high-mass Wγ and Zγ resonances using hadronic W/Z boson decays from 139 fb−1 of pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 14-07-2023
Abstract: A search for high-mass charged and neutral bosons decaying to Wγ and Zγ final states is presented in this paper. The analysis uses a data s le of $$ \\sqrt{s} $$ s = 13 TeV proton-proton collisions with an integrated luminosity of 139 fb − 1 collected by the ATLAS detector during LHC Run 2 operation. The sensitivity of the search is determined using models of the production and decay of spin-1 charged bosons and spin-0/2 neutral bosons. The range of resonance masses explored extends from 1.0 TeV to 6.8 TeV. At these high resonance masses, it is beneficial to target the hadronic decays of the W and Z bosons because of their large branching fractions. The decay products of the high-momentum W/Z bosons are strongly collimated and boosted-boson tagging techniques are employed to improve the sensitivity. No evidence of a signal above the Standard Model backgrounds is observed, and upper limits on the production cross-sections of these bosons times their branching fractions to Wγ and Zγ are derived for various boson production models.
Measurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with t
Publisher: Springer Science and Business Media LLC
Date: 13-06-2022
Abstract: Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented using 139 fb − 1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at $$ \\sqrt{s} $$ s = 13 TeV is measured to be σ = 1 . 267 ± 0 . 005 ± 0 . 053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4 . 2%. The cross-section is measured differentially as a function of variables characterising the $$ t\\overline{t} $$ t t ¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators O tG and $$ {O}_{tq}^{(8)} $$ O tq 8 , where the limits on the latter are the most stringent to date.
Close target reconnaissance with guaranteed collision avoidance
Publisher: Wiley
Date: 05-11-2011
DOI: 10.1002/RNC.1663
Network design via modular set function optimization in localization problems
Publisher: IEEE
Date: 06-2014
Distributed Leader Selection without Direct Inter-agent Communication
Publisher: Elsevier BV
Date: 2010
Secure and Private Implementation of Dynamic Controllers Using Semihomomorphic Encryption
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2020
Structured computation of constrained quadratic optimal controls for heterogeneous networks
Publisher: Elsevier BV
Date: 2013
Study of $$ {\mathrm{B}}_{\mathrm{c}}^{+}\to \mathrm{J}/\psi {\mathrm{D}}_{\mathrm{s}}^{+} $$ and $$ {\mathrm{B}}_{\mathrm{c}}^{+}\to \mathrm{J}/\psi {\mathrm{D}}_{\mathrm{s}}^{\ast +} $$ decays in pp
Publisher: Springer Science and Business Media LLC
Date: 05-08-2022
Abstract: A study of $$ {B}_c^{+}\\to J/\\psi {D}_s^{+} $$ B c + → J / ψ D s + and $$ {B}_c^{+}\\to J/\\psi {D}_s^{\\ast +} $$ B c + → J / ψ D s ∗ + decays using 139 fb − 1 of integrated luminosity collected with the ATLAS detector from $$ \\sqrt{s} $$ s = 13 TeV pp collisions at the LHC is presented. The ratios of the branching fractions of the two decays to the branching fraction of the $$ {B}_c^{+} $$ B c + → J/ψπ + decay are measured: $$ \\mathcal{B}\\left({B}_c^{+}\\to J/\\psi {D}_s^{+}\\right)/\\mathcal{B}\\left({B}_c^{+}\\to J/{\\psi \\pi}^{+}\\right) $$ B B c + → J / ψ D s + / B B c + → J / ψπ + = 2 . 76 ± 0 . 47 and $$ \\mathcal{B}\\left({B}_c^{+}\\to J/\\psi {D}_s^{\\ast +}\\right)/\\mathcal{B}\\left({B}_c^{+}\\to J/{\\psi \\pi}^{+}\\right) $$ B B c + → J / ψ D s ∗ + / B B c + → J / ψπ + = 5 . 33 ± 0 . 96. The ratio of the branching fractions of the two decays is found to be $$ \\mathcal{B}\\left({B}_c^{+}\\to J/\\psi {D}_s^{\\ast +}\\right)/\\mathcal{B}\\left({B}_c^{+}\\to J/\\psi {D}_s^{\\ast +}\\right) $$ B B c + → J / ψ D s ∗ + / B B c + → J / ψ D s ∗ + = 1 . 93 ± 0 . 26. For the $$ {B}_c^{+}\\to J/\\psi {D}_s^{\\ast +} $$ B c + → J / ψ D s ∗ + decay, the transverse polarization fraction, Γ ±± / Γ, is measured to be 0 . 70 ± 0 . 11. The reported uncertainties include both the statistical and systematic components added in quadrature. The precision of the measurements exceeds that in all previous studies of these decays. These results supersede those obtained in the earlier ATLAS study of the same decays with $$ \\sqrt{s} $$ s = 7 and 8 TeV pp collision data. A comparison with available theoretical predictions for the measured quantities is presented.
Modelling and computational improvements to the simulation of single vector-boson plus jet processes for the ATLAS experiment
Publisher: Springer Science and Business Media LLC
Date: 05-08-2022
Abstract: This paper presents updated Monte Carlo configurations used to model the production of single electroweak vector bosons ( W , Z/γ ∗ ) in association with jets in proton-proton collisions for the ATLAS experiment at the Large Hadron Collider. Improvements pertaining to the electroweak input scheme, parton-shower splitting kernels and scale-setting scheme are shown for multi-jet merged configurations accurate to next-to-leading order in the strong and electroweak couplings. The computational resources required for these set-ups are assessed, and approximations are introduced resulting in a factor three reduction of the per-event CPU time without affecting the physics modelling performance. Continuous statistical enhancement techniques are introduced by ATLAS in order to populate low cross-section regions of phase space and are shown to match or exceed the generated effective luminosity. This, together with the lower per-event CPU time, results in a 50% reduction in the required computing resources compared to a legacy set-up previously used by the ATLAS collaboration. The set-ups described in this paper will be used for future ATLAS analyses and lay the foundation for the next generation of Monte Carlo predictions for single vector-boson plus jets production.
Operation and performance of the ATLAS semiconductor tracker in LHC Run 2
Publisher: IOP Publishing
Date: 2022
DOI: 10.1088/1748-0221/17/01/P01013
Abstract: The semiconductor tracker (SCT) is one of the tracking systems for charged particles in the ATLAS detector. It consists of 4088 silicon strip sensor modules. During Run 2 (2015–2018) the Large Hadron Collider delivered an integrated luminosity of 156 fb -1 to the ATLAS experiment at a centre-of-mass proton-proton collision energy of 13 TeV. The instantaneous luminosity and pile-up conditions were far in excess of those assumed in the original design of the SCT detector. Due to improvements to the data acquisition system, the SCT operated stably throughout Run 2. It was available for 99.9% of the integrated luminosity and achieved a data-quality efficiency of 99.85%. Detailed studies have been made of the leakage current in SCT modules and the evolution of the full depletion voltage, which are used to study the impact of radiation damage to the modules.
Search for new phenomena in three- or four-lepton events in pp collisions at s
Publisher:
Elsevier BV
Date:
2022
Publisher: Elsevier BV
Date: 2022
A computationally advantageous reparameterisation of a robust model predictive control scheme
Publisher: IEEE
Date: 11-2014
Search for third-generation vector-like leptons in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 13-07-2023
Abstract: A search for vector-like leptons in multilepton (two, three, or four-or-more electrons plus muons) final states with zero or more hadronic τ -lepton decays is presented. The search is performed using a dataset corresponding to an integrated luminosity of 139 fb − 1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the LHC. To maximize the separation of signal and background, a machine-learning classifier is used. No excess of events is observed beyond the Standard Model expectation. Using a doublet vector-like lepton model, vector-like leptons coupling to third-generation Standard Model leptons are excluded in the mass range from 130 GeV to 900 GeV at the 95% confidence level, while the highest excluded mass is expected to be 970 GeV.
Risk bounded nonlinear robot motion planning with integrated perception & control
Publisher: Elsevier BV
Date: 2023
Measurement of the polarisation of W bosons produced in top-quark decays using dilepton events at
Publisher:
Elsevier BV
Date:
08-2023
Publisher: Elsevier BV
Date: 08-2023
Quadratic Gaussian privacy games
Publisher: IEEE
Date: 12-2016
Circumnavigation using distance measurements under slow drift
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2012
Direct constraint on the Higgs–charm coupling from a search for Higgs boson decays into charm quarks with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 18-08-2022
DOI: 10.1140/EPJC/S10052-022-10588-3
Abstract: A search for the Higgs boson decaying into a pair of charm quarks is presented. The analysis uses proton–proton collisions to target the production of a Higgs boson in association with a leptonically decaying W or Z boson. The dataset delivered by the LHC at a centre-of-mass energy of "Equation missing" and recorded by the ATLAS detector corresponds to an integrated luminosity of 139 $$\text{ fb}^{-1}$$ fb - 1 . Flavour-tagging algorithms are used to identify jets originating from the hadronisation of charm quarks. The analysis method is validated with the simultaneous measurement of WW , WZ and ZZ production, with observed (expected) significances of 2.6 (2.2) standard deviations above the background-only prediction for the $$(W/Z)Z(\rightarrow c{\bar{c}})$$ ( W / Z ) Z ( → c c ¯ ) process and 3.8 (4.6) standard deviations for the $$(W/Z)W(\rightarrow cq)$$ ( W / Z ) W ( → c q ) process. The $$(W/Z)H(\rightarrow c {\bar{c}})$$ ( W / Z ) H ( → c c ¯ ) search yields an observed (expected) upper limit of 26 (31) times the predicted Standard Model cross-section times branching fraction for a Higgs boson with a mass of "Equation missing" , corresponding to an observed (expected) constraint on the charm Yukawa coupling modifier $$|\kappa _c| 8.5~(12.4)$$ | κ c | 8.5 ( 12.4 ) , at the 95% confidence level. A combination with the ATLAS $$(W/Z)H, H\rightarrow b{\bar{b}}$$ ( W / Z ) H , H → b b ¯ analysis is performed, allowing the ratio $$\kappa _c / \kappa _b$$ κ c / κ b to be constrained to less than 4.5 at the 95% confidence level, smaller than the ratio of the b- and c-quark masses, and therefore determines the Higgs-charm coupling to be weaker than the Higgs-bottom coupling at the 95% confidence level.
Search for neutral long-lived particles in pp collisions at $$ \sqrt{s} $$ = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter
Publisher: Springer Science and Business Media LLC
Date: 06-2022
Abstract: A search for decays of pair-produced neutral long-lived particles (LLPs) is presented using 139 fb − 1 of proton-proton collision data collected by the ATLAS detector at the LHC in 2015–2018 at a centre-of-mass energy of 13 TeV. Dedicated techniques were developed for the reconstruction of displaced jets produced by LLPs decaying hadronically in the ATLAS hadronic calorimeter. Two search regions are defined for different LLP kinematic regimes. The observed numbers of events are consistent with the expected background, and limits for several benchmark signals are determined. For a SM Higgs boson with a mass of 125 GeV, branching ratios above 10% are excluded at 95% confidence level for values of c times LLP mean proper lifetime in the range between 20 mm and 10 m depending on the model. Upper limits are also set on the cross-section times branching ratio for scalars with a mass of 60 GeV and for masses between 200 GeV and 1 TeV.
A model for optimal and robust control with time-varying computing constraints
Publisher: IEEE
Date: 12-2010
Observation of electroweak production of two jets and a Z-boson pair
Publisher: Springer Science and Business Media LLC
Date: 09-02-2023
Search for Higgs bosons decaying into new spin-0 or spin-1 particles in four-lepton final states with the ATLAS detector with 139 fb−1 of pp collision data at $$ \sqrt{s} $$ = 13 TeV
Publisher: Springer Science and Business Media LLC
Date: 03-2022
Abstract: Searches are conducted for new spin-0 or spin-1 bosons using events where a Higgs boson with mass 125 GeV decays into four leptons ( ℓ = e , μ ). This decay is presumed to occur via an intermediate state which contains two on-shell, promptly decaying bosons: H → XX/ZX → 4 ℓ , where the new boson X has a mass between 1 and 60 GeV. The search uses pp collision data collected with the ATLAS detector at the LHC with an integrated luminosity of 139 fb − 1 at a centre-of-mass energy $$ \\sqrt{s} $$ s = 13 TeV. The data are found to be consistent with Standard Model expectations. Limits are set on fiducial cross sections and on the branching ratio of the Higgs boson to decay into XX/ZX , improving those from previous publications by a factor between two and four. Limits are also set on mixing parameters relevant in extensions of the Standard Model containing a dark sector where X is interpreted to be a dark boson.
Heterologous Expression of the Grapevine JAZ7 Gene in Arabidopsis Confers Enhanced Resistance to Powdery Mildew but Not to Botrytis cinerea
Publisher: MDPI AG
Date: 05-12-2018
DOI: 10.3390/IJMS19123889
Abstract: Jasmonate ZIM-domain (JAZ) family proteins comprise a class of transcriptional repressors that silence jasmonate-inducible genes. Although a considerable amount of research has been carried out on this gene family, there is still very little information available on the role of specific JAZ gene members in multiple pathogen resistance, especially in non-model species. In this study, we investigated the potential resistance function of the VqJAZ7 gene from a disease-resistant wild grapevine, Vitis quinquangularis cv. “Shang-24”, through heterologous expression in Arabidopsis thaliana. VqJAZ7-expressing transgenic Arabidopsis were challenged with three pathogens: the biotrophic fungus Golovinomyces cichoracearum, necrotrophic fungus Botrytis cinerea, and semi-biotrophic bacteria Pseudomonas syringae pv. tomato DC3000. We found that plants expressing VqJAZ7 showed greatly reduced disease symptoms for G. cichoracearum, but not for B. cinerea or P. syringae. In response to G cichoracearum infection, VqJAZ7-expressing transgenic lines exhibited markedly higher levels of cell death, superoxide anions (O2¯, and H2O2 accumulation, relative to nontransgenic control plants. Moreover, we also tested the relative expression of defense-related genes to comprehend the possible induced pathways. Taken together, our results suggest that VqJAZ7 in grapevine participates in molecular pathways of resistance to G. cichoracearum, but not to B. cinerea or P. syringae.
Search for Displaced Leptons in
s = 13
Publisher:
American Physical Society (APS)
Date:
27-07-2021
Publisher: American Physical Society (APS)
Date: 27-07-2021
Measurements of azimuthal anisotropies of jet production in
Pb +
Publisher:
American Physical Society (APS)
Date:
07-06-2022
Publisher: American Physical Society (APS)
Date: 07-06-2022
Externally excited coordination of autonomous formations
Publisher: IEEE
Date: 06-2007
Measurement of b-quark fragmentation properties in jets using the decay B± → J/ψK± in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 12-2021
Abstract: The fragmentation properties of jets containing b -hadrons are studied using charged B mesons in 139 fb − 1 of pp collisions at $$ \\sqrt{s} $$ s = 13 TeV, recorded with the ATLAS detector at the LHC during the period from 2015 to 2018. The B mesons are reconstructed using the decay of B ± into J/ψK ± , with the J/ψ decaying into a pair of muons. Jets are reconstructed using the anti- k t algorithm with radius parameter R = 0 . 4. The measurement determines the longitudinal and transverse momentum profiles of the reconstructed B hadrons with respect to the axes of the jets to which they are geometrically associated. These distributions are measured in intervals of the jet transverse momentum, ranging from 50 GeV to above 100 GeV. The results are corrected for detector effects and compared with several Monte Carlo predictions using different parton shower and hadronisation models. The results for the longitudinal and transverse profiles provide useful inputs to improve the description of heavy-flavour fragmentation in jets.
Measurement of the energy asymmetry in $$t{\bar{t}}j$$ production at $$13\,$$TeV with the ATLAS experiment and interpretation in the SMEFT framework
Publisher: Springer Science and Business Media LLC
Date: 04-2022
DOI: 10.1140/EPJC/S10052-022-10101-W
Abstract: A measurement of the energy asymmetry in jet-associated top-quark pair production is presented using $$139\\,{\\mathrm {fb}}^{-1}$$ 139 fb - 1 of data collected by the ATLAS detector at the Large Hadron Collider during pp collisions at $$\\sqrt{s}=13\\,\\text {TeV}$$ s = 13 TeV . The observable measures the different probability of top and antitop quarks to have the higher energy as a function of the jet scattering angle with respect to the beam axis. The energy asymmetry is measured in the semileptonic $$t{\\bar{t}}$$ t t ¯ decay channel, and the hadronically decaying top quark must have transverse momentum above $$350\\,\\text {GeV}$$ 350 GeV . The results are corrected for detector effects to particle level in three bins of the scattering angle of the associated jet. The measurement agrees with the SM prediction at next-to-leading-order accuracy in quantum chromodynamics in all three bins. In the bin with the largest expected asymmetry, where the jet is emitted perpendicular to the beam, the energy asymmetry is measured to be $$-0.043\\pm 0.020$$ - 0.043 ± 0.020 , in agreement with the SM prediction of $$-0.037\\pm 0.003$$ - 0.037 ± 0.003 . Interpreting this result in the framework of the Standard Model effective field theory (SMEFT), it is shown that the energy asymmetry is sensitive to the top-quark chirality in four-quark operators and is therefore a valuable new observable in global SMEFT fits.
A Logistic Regression Approach to Field Estimation Using Binary Measurements
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Constraints on Higgs boson properties using $$WW^{*}(\rightarrow e\nu \mu \nu )jj$$ production in $$36.1\,\mathrm{fb}^{-1}$$ of $$\sqrt{s}=13$$ TeV pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 18-07-2022
DOI: 10.1140/EPJC/S10052-022-10366-1
Abstract: This article presents the results of two studies of Higgs boson properties using the $$WW^*(\\rightarrow e\\nu \\mu \\nu )jj$$ W W ∗ ( → e ν μ ν ) j j final state, based on a dataset corresponding to $${36.1}{{\\mathrm{fb}}^{-1}}$$ 36.1 fb - 1 of $$\\sqrt{s}=13$$ s = 13 TeV proton–proton collisions recorded by the ATLAS experiment at the Large Hadron Collider. The first study targets Higgs boson production via gluon–gluon fusion and constrains the CP properties of the effective Higgs–gluon interaction. Using angular distributions and the overall rate, a value of $$\\tan (\\alpha ) = 0.0 \\pm 0.4 (\\mathrm {stat.}) \\pm 0.3 (\\mathrm {syst.})$$ tan ( α ) = 0.0 ± 0.4 ( stat . ) ± 0.3 ( syst . ) is obtained for the tangent of the mixing angle for CP-even and CP-odd contributions. The second study exploits the vector-boson fusion production mechanism to probe the Higgs boson couplings to longitudinally and transversely polarised W and Z bosons in both the production and the decay of the Higgs boson these couplings have not been directly constrained previously. The polarisation-dependent coupling-strength scale factors are defined as the ratios of the measured polarisation-dependent coupling strengths to those predicted by the Standard Model, and are determined using rate and kinematic information to be $$a_\\mathrm {L}=0.91^{+0.10}_{-0.18}$$ a L = 0 . 91 - 0.18 + 0.10 (stat.) $$^{+0.09}_{-0.17}$$ - 0.17 + 0.09 (syst.) and $$a_{\\mathrm {T}}=1.2 \\pm 0.4 $$ a T = 1.2 ± 0.4 (stat.) $$ ^{+0.2}_{-0.3} $$ - 0.3 + 0.2 (syst.). These coupling strengths are translated into pseudo-observables, resulting in $$\\kappa _{VV}= 0.91^{+0.10}_{-0.18}$$ κ VV = 0 . 91 - 0.18 + 0.10 (stat.) $$^{+0.09}_{-0.17}$$ - 0.17 + 0.09 (syst.) and $$\\epsilon _{VV} =0.13^{+0.28}_{-0.20}$$ ϵ VV = 0 . 13 - 0.20 + 0.28 (stat.) $$^{+0.08}_{-0.10}$$ - 0.10 + 0.08 (syst.). All results are consistent with the Standard Model predictions.
Measurement of the total cross section and $$\rho $$-parameter from elastic scattering in pp collisions at $$\sqrt{s}=13$$ TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 26-05-2023
DOI: 10.1140/EPJC/S10052-023-11436-8
Abstract: In a special run of the LHC with $$\\beta ^{\\star } = 2.5$$ β ⋆ = 2.5 km, proton–proton elastic-scattering events were recorded at $$\\sqrt{s} = 13$$ s = 13 TeV with an integrated luminosity of $$340~\\upmu {\\text {b}}^{-1}$$ 340 μ b - 1 using the ALFA subdetector of ATLAS in 2016. The elastic cross section was measured differentially in the Mandelstam t variable in the range from $$-t = 2.5 \\cdot 10^{-4}$$ - t = 2.5 · 10 - 4 GeV $$^{2}$$ 2 to $$-t = 0.46$$ - t = 0.46 GeV $$^{2}$$ 2 using 6.9 million elastic-scattering candidates. This paper presents measurements of the total cross section $$\\sigma _{\\text {tot}}$$ σ tot , parameters of the nuclear slope, and the $$\\rho $$ ρ -parameter defined as the ratio of the real part to the imaginary part of the elastic-scattering litude in the limit $$t \\rightarrow 0$$ t → 0 . These parameters are determined from a fit to the differential elastic cross section using the optical theorem and different parameterizations of the t -dependence. The results for $$\\sigma _{\\text {tot}}$$ σ tot and $$\\rho $$ ρ are $$\\begin{aligned} \\sigma _{\\text {tot}}(pp\\rightarrow X) = 104.7 \\pm 1.1 \\ \\text{ mb },\\quad \\rho = 0.098 \\pm 0.011 . \\end{aligned}$$ σ tot ( p p → X ) = 104.7 ± 1.1 mb , ρ = 0.098 ± 0.011 . The uncertainty in $$\\sigma _{\\text {tot}}$$ σ tot is dominated by the luminosity measurement, and in $$\\rho $$ ρ by imperfect knowledge of the detector alignment and by modelling of the nuclear litude.
Revealing stealthy attacks in control systems
Publisher: IEEE
Date: 10-2012
Search for excited τ-leptons and leptoquarks in the final state with τ-leptons and jets in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 29-06-2023
Abstract: A search is reported for excited τ -leptons and leptoquarks in events with two hadronically decaying τ -leptons and two or more jets. The search uses proton-proton ( pp ) collision data at $$ \\sqrt{s} $$ s = 13 TeV recorded by the ATLAS experiment during the Run 2 of the Large Hadron Collider in 2015–2018. The total integrated luminosity is 139 fb − 1 . The excited τ -lepton is assumed to be produced and to decay via a four-fermion contact interaction into an ordinary τ -lepton and a quark-antiquark pair. The leptoquarks are assumed to be produced in pairs via the strong interaction, and each leptoquark is assumed to couple to a charm or lighter quark and a τ -lepton. No excess over the background prediction is observed. Excited τ -leptons with masses below 2.8 TeV are excluded at 95% CL in scenarios with the contact interaction scale Λ set to 10 TeV. At the extreme limit of model validity where Λ is set equal to the excited τ -lepton mass, excited τ -leptons with masses below 4.6 TeV are excluded. Leptoquarks with masses below 1.3 TeV are excluded at 95% CL if their branching ratio to a charm quark and a τ -lepton equals 1. The analysis does not exploit flavour-tagging in the signal region.
Structured computation of optimal controls for constrained cascade systems
Publisher: Informa UK Limited
Date: 31-08-2020
Model predictive control for a class of systems with uncertainty in scheduled load
Publisher: IEEE
Date: 11-2013
AtlFast3: The Next Generation of Fast Simulation in ATLAS
Publisher: Springer Science and Business Media LLC
Date: 11-03-2022
DOI: 10.1007/S41781-021-00079-7
Abstract: The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over the past decade, ATLAS has developed and utilized tools that replace the most CPU-intensive component of the simulation—the calorimeter shower simulation—with faster simulation methods. Here, AtlFast3, the next generation of high-accuracy fast simulation in ATLAS, is introduced. AtlFast3 combines parameterized approaches with machine-learning techniques and is deployed to meet current and future computing challenges, and simulation needs of the ATLAS experiment. With highly accurate performance and significantly improved modelling of substructure within jets, AtlFast3 can simulate large numbers of events for a wide range of physics processes.
Search for charginos and neutralinos in final states with two boosted hadronically decaying bosons and missing transverse momentum in
Publisher:
American Physical Society (APS)
Date:
27-12-2021
Publisher: American Physical Society (APS)
Date: 27-12-2021
Search for the charged-lepton-flavor-violating decay
Z → e <
Publisher: American Physical Society (APS)
Date: 25-08-2023
A search for heavy Higgs bosons decaying into vector bosons in same-sign two-lepton final states in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 26-07-2023
Abstract: A search for heavy Higgs bosons produced in association with a vector boson and decaying into a pair of vector bosons is performed in final states with two leptons (electrons or muons) of the same electric charge, missing transverse momentum and jets. A data s le of proton–proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb − 1 . The observed data are in agreement with Standard Model background expectations. The results are interpreted using higher-dimensional operators in an effective field theory. Upper limits on the production cross-section are calculated at 95% confidence level as a function of the heavy Higgs boson’s mass and coupling strengths to vector bosons. Limits are set in the Higgs boson mass range from 300 to 1500 GeV, and depend on the assumed couplings. The highest excluded mass for a heavy Higgs boson with the coupling combinations explored is 900 GeV. Limits on coupling strengths are also provided.
Genomic Organization of the B3-Domain Transcription Factor Family in Grapevine (Vitis vinifera L.) and Expression during Seed Development in Seedless and Seeded Cultivars
Publisher: MDPI AG
Date: 14-09-2019
DOI: 10.3390/IJMS20184553
Abstract: Members of the plant-specific B3-domain transcription factor family have important and varied functions, especially with respect to vegetative and reproductive growth. Although B3 genes have been studied in many other plants, there is limited information on the genomic organization and expression of B3 genes in grapevine (Vitis vinifera L.). In this study, we identified 50 B3 genes in the grapevine genome and analyzed these genes in terms of chromosomal location and syntenic relationships, intron–exon organization, and promoter cis-element content. We also analyzed the presumed proteins in terms of domain structure and phylogenetic relationships. Based on the results, we classified these genes into five subfamilies. The syntenic relationships suggest that approximately half of the genes resulted from genome duplication, contributing to the expansion of the B3 family in grapevine. The analysis of cis-element composition suggested that most of these genes may function in response to hormones, light, and stress. We also analyzed expression of members of the B3 family in various structures of grapevine plants, including the seed during seed development. Many B3 genes were expressed preferentially in one or more structures of the developed plant, suggesting specific roles in growth and development. Furthermore, several of the genes were expressed differentially in early developing seeds from representative seeded and seedless cultivars, suggesting a role in seed development or abortion. The results of this study provide a foundation for functional analysis of B3 genes and new resources for future molecular breeding of grapevine.
Search for new phenomena in multi-body invariant masses in events with at least one isolated lepton and two jets using $$ \sqrt{s} $$ = 13 TeV proton–proton collision data collected by the ATLAS detec
Publisher: Springer Science and Business Media LLC
Date: 26-07-2023
Abstract: A search for resonances in events with at least one isolated lepton ( e or μ ) and two jets is performed using 139 fb − 1 of $$ \\sqrt{s} $$ s = 13 TeV proton–proton collision data recorded by the ATLAS detector at the LHC. Deviations from a smoothly falling background hypothesis are tested in three- and four-body invariant mass distributions constructed from leptons and jets, including jets identified as originating from bottom quarks. Model-independent limits on generic resonances characterised by cascade decays of particles leading to multiple jets and leptons in the final state are presented. The limits are calculated using Gaussian shapes with different widths for the invariant masses. The multi-body invariant masses are also used to set 95% confidence level upper limits on the cross-section times branching ratios for the production and subsequent decay of resonances predicted by several new physics scenarios.
Measurement of electroweak $$ Z\left(\nu \overline{\nu}\right)\gamma jj $$ production and limits on anomalous quartic gauge couplings in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detecto
Publisher: Springer Science and Business Media LLC
Date: 14-06-2023
Abstract: The electroweak production of $$ Z\\left(\\nu \\overline{\\nu}\\right)\\gamma $$ Z ν ν ¯ γ in association with two jets is studied in a regime with a photon of high transverse momentum above 150 GeV using proton–proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider. The analysis uses a data s le with an integrated luminosity of 139 fb − 1 collected by the ATLAS detector during the 2015–2018 LHC data-taking period. This process is an important probe of the electroweak symmetry breaking mechanism in the Standard Model and is sensitive to quartic gauge boson couplings via vector-boson scattering. The fiducial $$ Z\\left(\\nu \\overline{\\nu}\\right)\\gamma jj $$ Z ν ν ¯ γjj cross section for electroweak production is measured to be $$ {0.77}_{-0.30}^{+0.34} $$ 0.77 − 0.30 + 0.34 fb and is consistent with the Standard Model prediction. Evidence of electroweak $$ Z\\left(\\nu \\overline{\\nu}\\right)\\gamma jj $$ Z ν ν ¯ γjj production is found with an observed significance of 3.2 σ for the background-only hypothesis, compared with an expected significance of 3.7 σ . The combination of this result with the previously published ATLAS observation of electroweak $$ Z\\left(\\nu \\overline{\\nu}\\right)\\gamma jj $$ Z ν ν ¯ γjj production yields an observed (expected) signal significance of 6.3 σ (6.6 σ ). Limits on anomalous quartic gauge boson couplings are obtained in the framework of effective field theory with dimension-8 operators.
Search for $$ t\overline{t}H/A\to t\overline{t}t\overline{t} $$ production in the multilepton final state in proton–proton collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 26-07-2023
Abstract: A search for a new heavy scalar or pseudo-scalar Higgs boson ( H/A ) produced in association with a pair of top quarks, with the Higgs boson decaying into a pair of top quarks ( H/A → $$ t\\overline{t} $$ t t ¯ ) is reported. The search targets a final state with exactly two leptons with same-sign electric charges or at least three leptons. The analysed dataset corresponds to an integrated luminosity of 139 fb − 1 of proton–proton collisions collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Two multivariate classifiers are used to separate the signal from the background. No significant excess of events over the Standard Model expectation is observed. The results are interpreted in the context of a type-II two-Higgs-doublet model. The observed (expected) upper limits at 95% confidence level on the $$ t\\overline{t}H/A $$ t t ¯ H / A production cross-section times the branching ratio of H/A → $$ t\\overline{t} $$ t t ¯ range between 14 (10) fb and 6 (5) fb for a heavy Higgs boson with mass between 400 GeV and 1000 GeV, respectively. Assuming that only one particle, either the scalar H or the pseudo-scalar A , contributes to the $$ t\\overline{t}t\\overline{t} $$ t t ¯ t t ¯ final state, values of tan β below 1.2 or 0.5 are excluded for a mass of 400 GeV or 1000 GeV, respectively. These exclusion ranges increase to tan β below 1.6 or 0.6 when both particles are considered.
Measurement of the production of a
W
Publisher:
American Physical Society (APS)
Date:
14-08-2023
Publisher: American Physical Society (APS)
Date: 14-08-2023
Cross-section measurements for the production of a Z boson in association with high-transverse-momentum jets in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 14-06-2023
Abstract: Cross-section measurements for a Z boson produced in association with high-transverse-momentum jets ( p T ≥ 100 GeV) and decaying into a charged-lepton pair ( e + e − , μ + μ − ) are presented. The measurements are performed using proton–proton collisions at $$ \\sqrt{s} $$ s = 13 TeV corresponding to an integrated luminosity of 139 fb − 1 collected by the ATLAS experiment at the LHC. Measurements of angular correlations between the Z boson and the closest jet are performed in events with at least one jet with p T ≥ 500 GeV. Event topologies of particular interest are the collinear emission of a Z boson in dijet events and a boosted Z boson recoiling against a jet. Fiducial cross sections are compared with state-of-the-art theoretical predictions. The data are found to agree with next-to-next-to-leading-order predictions by NNLO jet and with the next-to-leading-order multi-leg generators M ad G raph 5_ a MC@NLO and S herpa .
Global Convergence and Asymptotic Optimality of the Heavy Ball Method for a Class of Nonconvex Optimization Problems
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Localization and circumnavigation of a slowly moving target using bearing measurements
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2014
Formal Theory of Noisy Sensor Network Localization
Publisher: Society for Industrial & Applied Mathematics (SIAM)
Date: 2010
DOI: 10.1137/100792366
Distributed network size estimation and average degree estimation and control in networks isomorphic to directed graphs
Publisher: IEEE
Date: 10-2012
Search for pair-produced scalar and vector leptoquarks decaying into third-generation quarks and first- or second-generation leptons in pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 27-06-2023
Abstract: A search for pair-produced scalar and vector leptoquarks decaying into quarks and leptons of different generations is presented. It uses the full LHC Run 2 (2015–2018) data set of 139 fb − 1 collected with the ATLAS detector in proton–proton collisions at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV. Scalar leptoquarks with charge −(1 / 3) e as well as scalar and vector leptoquarks with charge +(2 / 3) e are considered. All possible decays of the pair-produced leptoquarks into quarks of the third generation ( t, b ) and charged or neutral leptons of the first or second generation ( e, μ, ν ) with exactly one electron or muon in the final state are investigated. No significant deviations from the Standard Model expectation are observed. Upper limits on the production cross-section are provided for eight models as a function of the leptoquark mass and the branching ratio of the leptoquark into the charged or neutral lepton. In addition, lower limits on the leptoquark masses are derived for all models across a range of branching ratios. Two of these models have the goal of providing an explanation for the recent B -anomalies. In both models, a vector leptoquark decays into charged and neutral leptons of the second generation with a similar branching fraction. Lower limits of 1980 GeV and 1710 GeV are set on the leptoquark mass for these two models.
Learning and information for dual control
Publisher: IEEE
Date: 06-2013
Exclusive dielectron production in ultraperipheral Pb+Pb collisions at $$ \sqrt{s_{\textrm{NN}}} $$ = 5.02 TeV with ATLAS
Publisher: Springer Science and Business Media LLC
Date: 27-06-2023
Abstract: Exclusive production of dielectron pairs, γγ → e + e − , is studied using $$ {\mathcal{L}}_{\textrm{int}} $$ L int = 1 . 72 nb − 1 of data from ultraperipheral collisions of lead nuclei at $$ \sqrt{s_{\textrm{NN}}} $$ s NN = 5 . 02 TeV recorded by the ATLAS detector at the LHC. The process of interest proceeds via photon–photon interactions in the strong electromagnetic fields of relativistic lead nuclei. Dielectron production is measured in the fiducial region defined by following requirements: electron transverse momentum $$ {p}_{\textrm{T}}^e $$ p T e 2 . 5 GeV, absolute electron pseudorapidity |η e | 2 . 5, dielectron invariant mass m ee 5 GeV, and dielectron transverse momentum $$ {p}_{\textrm{T}}^{ee} $$ p T ee 2 GeV. Differential cross-sections are measured as a function of m ee , average $$ {p}_{\textrm{T}}^e $$ p T e , absolute dielectron rapidity | y ee |, and scattering angle in the dielectron rest frame, |cos θ * |, in the inclusive s le, and also with a requirement of no activity in the forward direction. The total integrated fiducial cross-section is measured to be $$ 215\pm 1{\left(\textrm{stat}.\right)}_{-20}^{+23}\left(\textrm{syst}.\right)\pm 4\left(\textrm{lumi}.\right) $$ 215 ± 1 stat . − 20 + 23 syst . ± 4 lumi . μ b. Within experimental uncertainties the measured integrated cross-section is in good agreement with the QED predictions from the Monte Carlo programs S tarlight and S uper C hic , confirming the broad features of the initial photon fluxes. The differential cross-sections show systematic differences from these predictions which are more pronounced at high |y ee | and | cos θ * | values.
Distributed Localization Via Barycentric Coordinates: Finite-Time Convergence*
Publisher: Elsevier BV
Date: 2011
A search for the decays of stopped long-lived particles at $$ \sqrt{\mathrm{s}} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 07-2021
Abstract: A search for long-lived particles, which have come to rest within the ATLAS detector, is presented. The subsequent decays of these particles can produce high-momentum jets, resulting in large out-of-time energy deposits in the ATLAS calorimeters. These de- cays are detected using data collected during periods in the LHC bunch structure when collisions are absent. The analysed dataset is composed of events from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV and recorded by the ATLAS experiment during 2017 and 2018. The dataset used for this search corresponds to a total live time of 579 hours. The results of this search are used to derive lower limits on the mass of gluino R -hadrons, assuming a branching fraction $$ \\mathcal{B}\\left(\\overset{\\sim }{g}\\to q\\overline{q}{\\chi}_1^0\\right) $$ B g ~ → q q ¯ χ 1 0 = 100%, with masses of up to 1 . 4 TeV excluded for gluino lifetimes of 10 − 5 to 10 3 s.
Analysis of Noisy Bearing-Only Network Localization
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2013
Application of Reinforcement Learning in Development of a New Adaptive Intelligent Traffic Shaper
Publisher: IEEE
Date: 12-2006
Rigid Network Design Via Submodular Set Function Optimization
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2015
Search for supersymmetry in events with four or more charged leptons in 139 fb−1 of $$ \sqrt{s} $$ = 13 TeV pp collisions with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 07-2021
Abstract: A search for supersymmetry in events with four or more charged leptons (electrons, muons and τ -leptons) is presented. The analysis uses a data s le corresponding to 139 fb − 1 of proton-proton collisions delivered by the Large Hadron Collider at $$ \\sqrt{s} $$ s = 13 TeV and recorded by the ATLAS detector. Four-lepton signal regions with up to two hadronically decaying τ -leptons are designed to target several supersymmetric models, while a general five-lepton signal region targets any new physics phenomena leading to a final state with five charged leptons. Data yields are consistent with Standard Model expectations and results are used to set upper limits on contributions from processes beyond the Standard Model. Exclusion limits are set at the 95% confidence level in simplified models of general gauge-mediated supersymmetry, excluding higgsino masses up to 540 GeV. In R -parity-violating simplified models with decays of the lightest supersymmetric particle to charged leptons, lower limits of 1 . 6 TeV, 1 . 2 TeV, and 2 . 5 TeV are placed on wino, slepton and gluino masses, respectively.
Observation of four-top-quark production in the multilepton final state with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 12-06-2023
DOI: 10.1140/EPJC/S10052-023-11573-0
Abstract: This paper presents the observation of four-top-quark ( $$t\\bar{t}t\\bar{t}$$ t t ¯ t t ¯ ) production in proton-proton collisions at the LHC. The analysis is performed using an integrated luminosity of 140 $$\\hbox {fb}^{-1}$$ fb - 1 at a centre-of-mass energy of 13 TeV collected using the ATLAS detector. Events containing two leptons with the same electric charge or at least three leptons (electrons or muons) are selected. Event kinematics are used to separate signal from background through a multivariate discriminant, and dedicated control regions are used to constrain the dominant backgrounds. The observed (expected) significance of the measured $$t\\bar{t}t\\bar{t}$$ t t ¯ t t ¯ signal with respect to the standard model (SM) background-only hypothesis is 6.1 (4.3) standard deviations. The $$t\\bar{t}t\\bar{t}$$ t t ¯ t t ¯ production cross section is measured to be $$22.5^{+6.6}_{-5.5}$$ 22 . 5 - 5.5 + 6.6 fb, consistent with the SM prediction of $$12.0 \\pm 2.4$$ 12.0 ± 2.4 fb within 1.8 standard deviations. Data are also used to set limits on the three-top-quark production cross section, being an irreducible background not measured previously, and to constrain the top-Higgs Yukawa coupling and effective field theory operator coefficients that affect $$t\\bar{t}t\\bar{t}$$ t t ¯ t t ¯ production.
Measurement of the total and differential Higgs boson production cross-sections at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector by combining the H → ZZ* → 4ℓ and H → γγ decay channels
Publisher: Springer Science and Business Media LLC
Date: 04-05-2023
Abstract: The total and differential Higgs boson production cross-sections are measured through a combined statistical analysis of the H → ZZ * → 4 ℓ and H → γγ decay channels. The results are based on a dataset of 139 fb − 1 of proton–proton collisions at a centre-of-mass energy of 13 TeV, recorded by the ATLAS detector at the Large Hadron Collider. The measured total Higgs boson production cross-section is $$ {55.5}_{-3.8}^{+4.0} $$ 55.5 − 3.8 + 4.0 pb, consistent with the Standard Model prediction of 55 . 6 ± 2 . 5 pb. All results from the two decay channels are compatible with each other, and their combination agrees with the Standard Model predictions. A combined statistical interpretation of the measured fiducial cross-sections as a function of the Higgs boson transverse momentum is performed in order to probe the Yukawa couplings to the bottom and charm quarks. A similar interpretation is performed by including also the constraints from the measurements of Higgs boson production in association with a W or Z boson in the H → $$ b\\overline{b} $$ b b ¯ and $$ c\\overline{c} $$ c c ¯ decay channels.
Collision Avoidance Based on Robust Lexicographic Task Assignment
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2020
Search for resonant WZ production in the fully leptonic final state in proton–proton collisions at $$\mathbf {\sqrt{s} = 13}$$ TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 18-07-2023
DOI: 10.1140/EPJC/S10052-023-11437-7
Abstract: A search for a WZ resonance, in the fully leptonic final state (electrons or muons), is performed using 139 fb $$^{-1}$$ - 1 of data collected at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The results are interpreted in terms of a singly charged Higgs boson of the Georgi–Machacek model, produced by WZ fusion, and of a Heavy Vector Triplet, with the resonance produced by WZ fusion or the Drell–Yan process. No significant excess over the Standard Model prediction is observed and limits are set on the production cross-section times branching ratio as a function of the resonance mass for these processes.
Search for associated production of a Z boson with an invisibly decaying Higgs boson or dark matter candidates at <
Publisher: Elsevier BV
Date: 06-2022
Online Convex Optimization of Multi-Energy Building-to-Grid Ancillary Services
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2020
Measurement of single top-quark production in the s-channel in proton–proton collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
Publisher: Springer Science and Business Media LLC
Date: 27-06-2023
Abstract: A measurement of single top-quark production in the s-channel is performed in proton–proton collisions at a centre-of-mass energy of 13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The dataset corresponds to an integrated luminosity of 139 fb − 1 . The analysis is performed on events with an electron or muon, missing transverse momentum and exactly two b -tagged jets in the final state. A discriminant based on matrix element calculations is used to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W -boson production in association with jets. The observed (expected) signal significance over the background-only hypothesis is 3.3 (3.9) standard deviations, and the measured cross-section is $$ \\sigma ={8.2}_{-2.9}^{+3.5} $$ σ = 8.2 − 2.9 + 3.5 pb, consistent with the Standard Model prediction of $$ {\\sigma}^{\\textrm{SM}}={10.32}_{-0.36}^{+0.40} $$ σ SM = 10.32 − 0.36 + 0.40 pb.
Search for new phenomena in
p p
Publisher:
American Physical Society (APS)
Date:
21-12-2021
Publisher: American Physical Society (APS)
Date: 21-12-2021
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