Analytic formulation of Leptogenesis with neutrino oscillation data employing the general parametrization for neutrino mass matrix

Fuente: arXiv
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Autores principales: Okada, Nobuchika, Raut, Digesh
Formato: Preprint
Publicado: 2025
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author Okada, Nobuchika
Raut, Digesh
author_facet Okada, Nobuchika
Raut, Digesh
contents The observed neutrino oscillations and baryon asymmetry, unexplained by the Standard Model (SM), can both be accounted for by extending the SM to include Majorana right-handed neutrinos (RHNs). Tiny neutrino masses naturally arise through the Type-I seesaw mechanism, which involves lepton number violation. Meanwhile, the baryon asymmetry can be generated via leptogenesis, where the out-of-equilibrium decay of RHNs produces a lepton asymmetry that is partially converted into a baryon asymmetry through sphaleron processes. The Dirac Yukawa couplings play the crucial role for both Type-I seesaw and leptogenesis. In this work, we derive an analytic expression for the CP asymmetry parameter in a general parametrization. Focusing on a hierarchical RHN mass spectrum, we evaluate the lowest mass of the lightest RHN that reproduce both neutrino oscillation data and the observed baryon asymmetry. We study the case with two and three generations of RHNs for both thermal and non-thermal leptogenesis scenarios. Besides the standard Type-I seesaw involving SM Higgs doublet, we also examine the Type-I seesaw with a new neutrinophillic Higgs doublet. In this case for non-thermal leptogenesis, the minimum value for the lightest RHN mass can be as low as sphaleron decoupling temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2506_20580
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Analytic formulation of Leptogenesis with neutrino oscillation data employing the general parametrization for neutrino mass matrix
Okada, Nobuchika
Raut, Digesh
High Energy Physics - Phenomenology
High Energy Physics - Theory
The observed neutrino oscillations and baryon asymmetry, unexplained by the Standard Model (SM), can both be accounted for by extending the SM to include Majorana right-handed neutrinos (RHNs). Tiny neutrino masses naturally arise through the Type-I seesaw mechanism, which involves lepton number violation. Meanwhile, the baryon asymmetry can be generated via leptogenesis, where the out-of-equilibrium decay of RHNs produces a lepton asymmetry that is partially converted into a baryon asymmetry through sphaleron processes. The Dirac Yukawa couplings play the crucial role for both Type-I seesaw and leptogenesis. In this work, we derive an analytic expression for the CP asymmetry parameter in a general parametrization. Focusing on a hierarchical RHN mass spectrum, we evaluate the lowest mass of the lightest RHN that reproduce both neutrino oscillation data and the observed baryon asymmetry. We study the case with two and three generations of RHNs for both thermal and non-thermal leptogenesis scenarios. Besides the standard Type-I seesaw involving SM Higgs doublet, we also examine the Type-I seesaw with a new neutrinophillic Higgs doublet. In this case for non-thermal leptogenesis, the minimum value for the lightest RHN mass can be as low as sphaleron decoupling temperature.
title Analytic formulation of Leptogenesis with neutrino oscillation data employing the general parametrization for neutrino mass matrix
topic High Energy Physics - Phenomenology
High Energy Physics - Theory
url https://arxiv.org/abs/2506.20580