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arXiv · 1705.03858

Flavoured $B-L$ Local Symmetry and Anomalous Rare $B$ Decays

Rodrigo Alonso·Peter Cox·Chengcheng Han·Tsutomu T. Yanagida
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Abstract

We consider a flavoured $B-L$ gauge symmetry under which only the third generation fermions are charged. Such a symmetry can survive at low energies (~TeV) while still allowing for two superheavy right-handed neutrinos, consistent with neutrino masses via see-saw and leptogenesis. We describe a mechanism for generating Yukawa couplings in this model and also discuss the low-energy phenomenology. Interestingly, the new gauge boson could explain the recent hints of lepton universality violation at LHCb, with a gauge coupling that remains perturbative up to the Planck scale. Finally, we discuss more general $U(1)$ symmetries and show that there exist only two classes of vectorial $U(1)$ that are both consistent with leptogenesis and remain phenomenologically viable at low-energies.

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Rodrigo Alonso, Peter Cox, Chengcheng Han, Tsutomu T. Yanagida. 2017-05-10. Flavoured $B-L$ Local Symmetry and Anomalous Rare $B$ Decays. https://doi.org/10.1016/j.physletb.2017.10.027

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