Leptogenesis and gravity: Baryon asymmetry without decays

A popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we discovered a new source of leptogenesis in these models, namely that the same Yukawa phases which provide the CP violation fo...

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Main Authors: J.I. McDonald, G.M. Shore
Format: Article
Language:English
Published: Elsevier 2017-03-01
Series:Physics Letters B
Online Access:http://www.sciencedirect.com/science/article/pii/S0370269316307316
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author J.I. McDonald
G.M. Shore
author_facet J.I. McDonald
G.M. Shore
author_sort J.I. McDonald
collection DOAJ
description A popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we discovered a new source of leptogenesis in these models, namely that the same Yukawa phases which provide the CP violation for decays, combined with curved-spacetime loop effects, lead to an entirely new gravitational mechanism for generating an asymmetry, driven by the expansion of the Universe and independent of the departure of the heavy particles from equilibrium. In this Letter, we build on previous work by analysing the full Boltzmann equation, exploring the full parameter space of the theory and studying the time-evolution of the asymmetry. Remarkably, we find regions of parameter space where decays play no part at all, and where the baryon asymmetry of the Universe is determined solely by gravitational effects.
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spelling doaj.art-0c8ec49b02c14874b63891e5dd0bebc92022-12-21T23:59:13ZengElsevierPhysics Letters B0370-26931873-24452017-03-01766C16216910.1016/j.physletb.2016.11.057Leptogenesis and gravity: Baryon asymmetry without decaysJ.I. McDonaldG.M. ShoreA popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we discovered a new source of leptogenesis in these models, namely that the same Yukawa phases which provide the CP violation for decays, combined with curved-spacetime loop effects, lead to an entirely new gravitational mechanism for generating an asymmetry, driven by the expansion of the Universe and independent of the departure of the heavy particles from equilibrium. In this Letter, we build on previous work by analysing the full Boltzmann equation, exploring the full parameter space of the theory and studying the time-evolution of the asymmetry. Remarkably, we find regions of parameter space where decays play no part at all, and where the baryon asymmetry of the Universe is determined solely by gravitational effects.http://www.sciencedirect.com/science/article/pii/S0370269316307316
spellingShingle J.I. McDonald
G.M. Shore
Leptogenesis and gravity: Baryon asymmetry without decays
Physics Letters B
title Leptogenesis and gravity: Baryon asymmetry without decays
title_full Leptogenesis and gravity: Baryon asymmetry without decays
title_fullStr Leptogenesis and gravity: Baryon asymmetry without decays
title_full_unstemmed Leptogenesis and gravity: Baryon asymmetry without decays
title_short Leptogenesis and gravity: Baryon asymmetry without decays
title_sort leptogenesis and gravity baryon asymmetry without decays
url http://www.sciencedirect.com/science/article/pii/S0370269316307316
work_keys_str_mv AT jimcdonald leptogenesisandgravitybaryonasymmetrywithoutdecays
AT gmshore leptogenesisandgravitybaryonasymmetrywithoutdecays