Second leptogenesis: Unraveling the baryon-lepton asymmetry discrepancy

We propose a novel scenario to explain the matter-antimatter asymmetry by twofold leptogenesis, wherein heavy Majorana neutrinos exhibit temperature-dependent masses and engage in \(CP\)-violating decays. This scenario envisages two distinct phases of leptogenesis: one occurring above the electrowea...

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Bibliographic Details
Published inarXiv.org
Main Authors ChoeJo, YeolLin, Enomoto, Kazuki, Kim, Yechan, Lee, Hye-Sung
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 13.02.2024
Subjects
Antimatter
Asymmetry
Baryons
Decoupling
Leptons
Neutrinos
Temperature dependence
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Summary:We propose a novel scenario to explain the matter-antimatter asymmetry by twofold leptogenesis, wherein heavy Majorana neutrinos exhibit temperature-dependent masses and engage in \(CP\)-violating decays. This scenario envisages two distinct phases of leptogenesis: one occurring above the electroweak scale and the other below it. The sphaleron process converts the first lepton asymmetry to baryon asymmetry, but not the second one due to its decoupling. This mechanism potentially explains the significant discrepancy between baryon and lepton asymmetries, as suggested by recent observations of Helium-4. Furthermore, our model implies that the present masses of Majorana neutrinos are lighter than the electroweak scale, offering a tangible avenue for experimental verification in various terrestrial settings.
ISSN:2331-8422