Weekly seminars

Hierarchion - A Unified Framework to Address the Standard Model’s Hierarchies

by Gilad Perez (Weizmann)

Auditorium (Annecy-le-Vieux)



9 chemin de Bellevue 74940 ANNECY LE VIEUX

We present a framework that addresses the electroweak, the strong CP, and the flavor hierar- chies of the Standard Model, including neutrino masses. The naturalness of the electroweak scale is accounted for by the cosmological relaxation mechanism. The relaxion field is identified with the pseudo-Nambu-Goldstone boson of an abelian flavor symmetry, explaining the Standard Model’s mass hierarchies through the Froggatt-Nielsen mechanism. If the flavor symmetry has no QCD anomaly, the relaxion field can also solve the strong CP problem a` la Nelson-Barr, with its vac- uum expectation value at the stopping point being mapped to the Cabibbo-Kobayashi-Maskawa phase. The “rolling” potential of the relaxion is generated by the Nelson-Barr sector while the “backreaction” potential is induced by a sterile neutrino sector. The relaxion of our construction can be probed in variety of ways, in particular, in flavor-violating decays of the Standard Model fermions, motivating a further experimental effort in looking for new physics in rare decays of leptons and mesons.