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arXiv · 1408.2498

Leptogenesis and the Higgs Portal

Matthias Le Dall·Adam Ritz
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Abstract

We study the impact on leptogenesis of Higgs portal couplings to a new scalar singlet. These couplings open up additional $CP$-violating decay channels for the higher mass singlet neutrinos $N_2$ and $N_3$. We analyze the simplest case of two-level $N_1-N_2$ leptogenesis, including significant mass hierarchies, in which the $CP$ asymmetry is generated in part by singlet-mediated decays of $N_2$. For these models, provided the lightest singlet neutrino $N_1$ is sufficiently weakly coupled to avoid excessive washout, its mass scale is not directly constrained by the Davidson-Ibarra bound.

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Matthias Le Dall, Adam Ritz. 2014-08-11. Leptogenesis and the Higgs Portal. https://doi.org/10.1103/physrevd.90.096002

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