ORCID Profile
0000-0002-6491-8131
Current Organisations
Hiroshima University
,
University of Colorado at Boulder
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Publisher: Springer Science and Business Media LLC
Date: 03-2021
Abstract: We present measurements of the branching fractions for the decays B → Kμ + μ − and B → Ke + e − , and their ratio ( R K ), using a data s le of 711 fb − 1 that contains 772 × 10 6 $$ B\\overline{B} $$ B B ¯ events. The data were collected at the ϒ(4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e + e − collider. The ratio R K is measured in five bins of dilepton invariant-mass-squared ( q 2 ): q 2 ∈ (0 . 1 , 4 . 0) , (4 . 00 , 8 . 12) , (1 . 0 , 6 . 0), (10 . 2 , 12 . 8) and ( 14 . 18) GeV 2 /c 4 , along with the whole q 2 region. The R K value for q 2 ∈ (1 . 0 , 6 . 0) GeV 2 /c 4 is $$ {1.03}_{-0.24}^{+0.28} $$ 1.03 − 0.24 + 0.28 ± 0 . 01. The first and second uncertainties listed are statistical and systematic, respectively. All results for R K are consistent with Standard Model predictions. We also measure CP -averaged isospin asymmetries in the same q 2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q 2 ∈ (1 . 0 , 6 . 0) GeV 2 /c 4 bin in the mode with muon final states. The measured differential branching fractions, $$ d\\mathrm{\\mathcal{B}} $$ d ℬ /dq 2 , are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ ± e ∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10 − 8 for B + → K + μ ± e ∓ , and B 0 → K 0 μ ± e ∓ modes.
Publisher: American Physical Society (APS)
Date: 22-04-2021
Publisher: American Physical Society (APS)
Date: 12-2020
Publisher: American Physical Society (APS)
Date: 03-06-2021
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 29-01-2019
Publisher: American Physical Society (APS)
Date: 14-10-2020
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 21-02-2023
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 19-11-2021
Publisher: American Physical Society (APS)
Date: 12-07-2021
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 23-03-2021
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 30-11-2018
Publisher: American Physical Society (APS)
Date: 15-10-2019
Publisher: arXiv
Date: 2022
Publisher: Oxford University Press (OUP)
Date: 02-2020
DOI: 10.1093/PTEP/PTAA008
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 26-10-2020
Publisher: American Physical Society (APS)
Date: 15-03-2021
Publisher: Springer Science and Business Media LLC
Date: 04-2021
Abstract: We present a search for the dark photon A ′ in the B 0 → A ′ A ′ decays, where A ′ subsequently decays to e + e − , μ + μ − , and π + π − . The search is performed by analyzing 772 × 10 6 $$ B\\overline{B} $$ B B ¯ events collected by the Belle detector at the KEKB e + e − energy-asymmetric collider at the ϒ(4 S ) resonance. No signal is found in the dark photon mass range 0 . 01 GeV /c 2 ≤ m A ′ ≤ 2 . 62 GeV /c 2 , and we set upper limits of the branching fraction of B 0 → A ′ A ′ at the 90% confidence level. The products of branching fractions, $$ \\mathrm{\\mathcal{B}}\\left({B}^0\\to A^{\\prime }A^{\\prime}\\right)\\times \\mathrm{\\mathcal{B}}{\\left(A\\prime \\to {e}^{+}{e}^{-}\\right)}^2 $$ ℬ B 0 → A ′ A ′ × ℬ A ′ → e + e − 2 and $$ \\mathrm{\\mathcal{B}}\\left({B}^0\\to A^{\\prime }A^{\\prime}\\right)\\times \\mathrm{\\mathcal{B}}{\\left(A\\prime \\to {\\mu}^{+}{\\mu}^{-}\\right)}^2 $$ ℬ B 0 → A ′ A ′ × ℬ A ′ → μ + μ − 2 , have limits of the order of 10 − 8 depending on the A ′ mass. Furthermore, considering A ′ decay rate to each pair of charged particles, the upper limits of $$ \\mathrm{\\mathcal{B}}\\left({B}^0\\to A^{\\prime }A^{\\prime}\\right) $$ ℬ B 0 → A ′ A ′ are of the order of 10 − 8 –10 − 5 . From the upper limits of $$ \\mathrm{\\mathcal{B}}\\left({B}^0\\to A^{\\prime }A^{\\prime}\\right) $$ ℬ B 0 → A ′ A ′ , we obtain the Higgs portal coupling for each assumed dark photon and dark Higgs mass. The Higgs portal couplings are of the order of 10 − 2 –10 − 1 at $$ {m}_{h\\prime}\\simeq {m}_{B^0} $$ m h ′ ≃ m B 0 ± 40 MeV /c 2 and 10 − 1 –1 at $$ {m}_{h\\prime}\\simeq {m}_{B^0} $$ m h ′ ≃ m B 0 ± 3 GeV /c 2 .
Publisher: Elsevier BV
Date: 10-2023
Publisher: American Physical Society (APS)
Date: 16-02-2023
Publisher: American Physical Society (APS)
Date: 27-10-2021
Publisher: American Physical Society (APS)
Date: 16-06-2021
Publisher: American Physical Society (APS)
Date: 02-08-2023
Publisher: arXiv
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 02-2022
Abstract: We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle ϕ 3 (also known as γ ) using a model-independent Dalitz plot analysis of B + → D ( $$ {K}_S^0 $$ K S 0 h + h − ) h + , where D is either a D 0 or $$ \\overline{D} $$ D ¯ 0 meson and h is either a π or K . This is the first measurement that simultaneously uses Belle and Belle II data, combining s les corresponding to integrated luminosities of 711 fb − 1 and 128 fb − 1 , respectively. All data were accumulated from energy-asymmetric e + e − collisions at a centre-of-mass energy corresponding to the mass of the Υ(4 S ) resonance. We measure ϕ 3 = (78 . 4 ± 11 . 4 ± 0 . 5 ± 1 . 0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the D -decay strong-phase parameters.
Publisher: American Physical Society (APS)
Date: 30-11-2020
Publisher: American Physical Society (APS)
Date: 10-07-2019
Publisher: American Physical Society (APS)
Date: 29-03-2021
Location: Japan
No related grants have been discovered for ZACHARY LIPTAK.