Non-Abelian family symmetries as portals to dark matter

Abstract

Non-Abelian family symmetries offer a very promising explanation for the flavour structure in the Standard Model and its extensions. We explore the possibility that dark matter consists in fermions that transform under a family symmetry, such that the visible and dark sector are linked by the familons -Standard Model gauge singlet scalars, responsible for spontaneously breaking the family symmetry. We study three representative models with non-Abelian family symmetries that have been shown capable to explain the masses and mixing of the Standard Model fermions.One of our central results is the possibility to have dark matter fermions and at least one familon with masses on and even below the experimentally accessible TeV scale. In particular we discuss the characteristic signatures in collider experiments from light familon fields with a non-Abelian family symmetry, and we show that run I of the LHC is already testing this class of models.

Fermion masses and mixings and dark matter constraints in a model with radiative seesaw mechanism

“…The solutions to the DM and the flavour problems have indeed often been approached separately in the literature. Nevertheless one could entertain the idea that they have a common origin, whether because some residual flavour symmetry stabilizes it [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52], or where there is a dark sector which communicates to the visible sector only through family symmetry mediators [53,54].…”

Collider constraints and prospects of a scalar singlet extension to Higgs portal dark matter

“…The new scalar here acquires a vacuum expectation value (vev) and mixes with the SM Higgs field, giving two scalar mediators that act as the portal to the dark fermion. The case of a dark fermion with its SM interactions mediated by a new scalar or pseudoscalar has also been considered, but in the context of a bottom-up, effective field theory (EFT) approach, without considering the mixing of the scalar and SM Higgs [18], or embedded in a more complex model with additional extensions [19] .…”

Seesaw scale discrete dark matter and two-zero texture Majorana neutrino mass matrices

“…Finally, it is worth mentioning that there have been works tackling the problem of the vanishing reactor mixing angle within the A 4 DDM model [20], but in such a case the A 4 symmetry has to be explicitly broken in the scalar potential. For models in which dark matter transforms nontrivially under a non-Abelian flavor symmetry, see, for instance, [21][22][23].…”

“…23 , and the sum of light neutrino masses, m ν = m ν 1 + m ν 2 + m ν 3 , for model A on the left panels and model B on the right ones. In these graphics, the allowed 3σ regions in sin 2 θ 23 vs.m ν for the normal hierarchy (NH) is plotted in magenta and for the inverse hierarchy (IH) in cyan.…”