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Leptogenesis from Split Fermions

Yukinori Nagatani·Gilad Perez
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Abstract

We present a new type of leptogenesis mechanism based on a two-scalar split-fermions framework. At high temperatures the bulk scalar vacuum expectation values (VEVs) vanish and lepton number is strongly violated. Below some temperature, $T_c$, the scalars develop extra dimension dependent VEVs. This transition is assumed to proceed via a first order phase transition. In the broken phase the fermions are localized and lepton number violation is negligible. The lepton-bulk scalar Yukawa couplings contain sizable CP phases which induce lepton production near the interface between the two phases. We provide a qualitative estimation of the resultant baryon asymmetry which agrees with current observation. The neutrino flavor parameters are accounted for by the above model with an additional approximate U(1) symmetry.

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Yukinori Nagatani, Gilad Perez. 2004-01-11. Leptogenesis from Split Fermions. https://doi.org/10.1088/1126-6708%2F2005%2F02%2F068

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