ORCID Profile
0000-0002-3543-2183
Current Organisation
Institute for Basic Science
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Publisher: Elsevier BV
Date: 10-2018
Publisher: Oxford University Press (OUP)
Date: 11-2016
DOI: 10.1093/PTEP/PTW155
Publisher: IOP Publishing
Date: 06-2021
DOI: 10.1088/1475-7516/2021/06/049
Abstract: We investigate whether successful Gravitational Leptogenesis can take place during an Ekpyrotic contraction phase. Two possible paths by which this can occur are coupling the Ekpyrotic scalar to a gravitational Chern-Simons term, or to a U(1) gauge field Chern-Simons term. These couplings lead to the production of chiral gravitational waves, which generate a lepton number asymmetry through the gravitational-lepton number anomaly. This lepton asymmetry is subsequently reprocessed by equilibrium sphaleron processes to produce a baryon asymmetry. We find successful Gravitational Leptogenesis to be possible in Ekpyrotic bounce cosmologies through both of these mechanisms.
Publisher: Elsevier BV
Date: 02-2020
Publisher: American Physical Society (APS)
Date: 06-04-2022
Publisher: Elsevier BV
Date: 05-2016
Publisher: Springer Science and Business Media LLC
Date: 08-2020
Abstract: We consider the introduction of a complex scalar field carrying a global lepton number charge to the Standard Model and the Higgs inflation framework. The conditions are investigated under which this model can simultaneously ensure Higgs vacuum stability up to the Planck scale, successful inflation, non-thermal Leptogenesis via the pendulum mechanism, and light neutrino masses. These can be simultaneously achieved when the scalar lepton is minimally coupled to gravity, that is, when standard Higgs inflation and reheating proceed without the interference of the additional scalar degrees of freedom. If the scalar lepton also has a non-minimal coupling to gravity, a multi-field inflation scenario is induced, with interesting interplay between the successful inflation constraints and those from vacuum stability and Leptogenesis. The parameter region that can simultaneously achieve the above goals is explored.
Publisher: World Scientific Pub Co Pte Lt
Date: 02-05-2017
DOI: 10.1142/S0217732317500870
Abstract: We propose a new mechanism for generating both luminous and dark matter during cosmic inflation. According to this mechanism, ordinary and dark matter carry common charge which is associated with an anomalous U(1)[Formula: see text] group. Anomaly terms source [Formula: see text] and U(1)[Formula: see text] charge violating processes during inflation, producing corresponding nonzero Chern–Simons numbers which are subsequently reprocessed into baryon and dark matter densities. The general framework developed is then applied to two possible extensions of the Standard Model with anomalous gauged [Formula: see text] and [Formula: see text], each with an additional dark matter candidate. In each scenario, we consider the parameter choices that predict the correct dark matter to baryonic matter density ratio and baryon asymmetry. Interestingly, under these conditions, for the U(1)[Formula: see text] extension we obtain a prediction for the mass of the dark matter candidate which is independent of the other choice of parameters, when assuming an [Formula: see text] and [Formula: see text].
Publisher: Elsevier BV
Date: 06-2018
Publisher: Springer Science and Business Media LLC
Date: 17-05-2022
Abstract: The Type II Seesaw Mechanism provides a minimal framework to explain the neutrino masses involving the introduction of a single triplet Higgs to the Standard Model. However, this simple extension was believed to be unable to successfully explain the observed baryon asymmetry of the universe through Leptogenesis. In our previous work ( Phys. Rev. Lett. 128 (2022) 141801), we demonstrated that the triplet Higgs of the Type II Seesaw Mechanism alone can simultaneously generate the observed baryon asymmetry of the universe and the neutrino masses while playing a role in setting up Inflation. This is achievable with a triplet Higgs mass as low as 1 TeV, and predicts that the neutral component obtains a small vacuum expectation value v ∆ 10 keV. We find that our model has very rich phenomenology and can be tested by various terrestrial experiments as well as by astronomical observations. Particularly, we show that the successful parameter region may be probed at a future 100 TeV collider, upcoming lepton flavor violation experiments such as Mu3e, and neutrinoless double beta decay experiments. Additionally, the tensor-to-scalar ratio from the inflationary scenario will be probed by the LiteBIRD telescope, and observable isocurvature perturbations may be produced for some parameter choices. In this article, we present all the technical details of our calculations and further discussion of its phenomenological implications.
Publisher: Elsevier BV
Date: 09-1970
Publisher: Springer International Publishing
Date: 2017
Publisher: Springer Science and Business Media LLC
Date: 03-01-2023
Abstract: Upcoming Lepton Flavour Violation experiments searching for μ → 3 e and μ to e conversion in nuclei processes will provide new opportunities to test the fundamental properties of the neutrino sector, and possibly the origin of matter. In recent work, it was shown that the Type II Seesaw mechanism alone can simultaneously explain the neutrino masses, Leptogenesis, and inflation. A key prediction of this model was the possibility of signals being produced in Lepton Flavour Violation decays. Searches at future experiments such as Mu3e and COMET will be integral to determining the properties of the associated triplet Higgs, and will complement other terrestrial experimental searches and cosmological measurements. In this work, we survey the detection prospects for the ingredients of the Type II Seesaw Leptogenesis scenario, and discuss the corresponding dependencies on the neutrino oscillation parameters and $$ \\mathcal{CP} $$ CP phases.
Publisher: IOP Publishing
Date: 04-08-2020
Publisher: World Scientific Pub Co Pte Lt
Date: 07-06-2018
DOI: 10.1142/S0217732318500979
Abstract: A new scenario of baryogenesis via the ratchet mechanism is proposed based on an analogy with the forced pendulum. The oscillation of the inflaton field during the reheating epoch after inflation plays the role of the driving force, while the phase [Formula: see text] of a scalar baryon field (a complex scalar field with baryon number) plays the role of the angle of the pendulum. When the inflaton is coupled to the scalar baryon, the behavior of the phase [Formula: see text] can be analogous to that of the angle of the forced pendulum. If the oscillation of the driving force is adjusted to the pendulum’s motion, a directed rotation of the pendulum is obtained with a nonvanishing value of [Formula: see text], which models successful baryogenesis since [Formula: see text] is proportional to the baryon number density. Similar ratchet models which lead to directed motion have been used in the study of molecular motors in biology. There, the driving force is supplied by chemical reactions, while in our scenario this role is played by the inflaton during the reheating epoch.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 04-2016
Publisher: Springer Science and Business Media LLC
Date: 09-2014
Location: Japan
No related grants have been discovered for Neil Barrie.