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Baryogenesis from the Kobayashi-Maskawa Phase

Micha Berkooz·Yosef Nir·Tomer Volansky
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Abstract

The Standard Model fulfills the three Sakharov conditions for baryogenesis. The smallness of quark masses suppresses, however, the CP violation from the Kobayashi-Maskawa phase to a level that is many orders of magnitude below what is required to explain the observed baryon asymmetry. We point out that if, as a result of time variation in the Yukawa couplings, quark masses were large at the time of the electroweak phase transition, then the Kobayashi-Maskawa mechanism could be the source of the asymmetry. The Froggatt-Nielsen mechanism provides a plausible framework where the Yukawa couplings could all be of order one at that time, and settle to their present values before nucleosynthesis. The problems related to a strong first order electroweak phase transition may also be alleviated in this framework. Our scenario reveals a loophole in the commonly held view that the Kobayashi-Maskawa mechanism cannot be the dominant source of CP violation to play a role in baryogenesis.

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Micha Berkooz, Yosef Nir, Tomer Volansky. 2004-01-04. Baryogenesis from the Kobayashi-Maskawa Phase. https://doi.org/10.1103/physrevlett.93.051301

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