Singlet-Doublet Self-interacting Dark Matter and Radiative Neutrino Mass

Abstract

Self-interacting dark matter (SIDM) with a light mediator is a promising scenario to alleviate the small-scale problems of the cold dark matter paradigm while being consistent with the latter at large scales, as suggested by astrophysical observations. This, however, leads to an under-abundant SIDM relic due to large annihilation rates into mediator particles, often requiring an extension of the simplest thermal or non-thermal relic generation mechanism. In this work, we consider a singlet-doublet fermion dark matter scenario where the singlet fermion with a light scalar mediator gives rise to the velocity-dependent dark matter self-interaction through a Yukawa type attractive potential. The doublet fermion, by virtue of its tiny mixing with the singlet, can be long-lived and can provide a non-thermal contribution to the singlet relic at late epochs, filling the deficit in the thermal relic of singlet SIDM. The light scalar mediator, due to its mixing with the standard model Higgs, paves the path for detecting such SIDM at terrestrial laboratories leading to constraints on model parameters from CRESST-III and XENON1T experiments. Enlarging the dark sector particles by two more singlet fermions and one scalar doublet, all odd under an unbroken Z2 symmetry can also explain non-zero neutrino mass in scotogenic fashion.

CDF-II $W$ Boson Mass Anomaly in the Canonical Scotogenic Neutrino-Dark Matter Model

“…In this section, we discuss in details the canonical Scotogenic model [71] which is a simple extension of SM intimately linking the neutrino mass generation with WIMP dark matter. Since, the initial proposal, the scotogenic mechanism has proved immensely popular and many different extensions of the basic mechanism have been proposed over the years, for 3 some recent works see [72][73][74][75][76][77][78][79][80][81][82][83][84][85]. However, the original Scotogenic model of Ma [71] still stands out for its simplicity and elegance.…”

Impact of dark matter self-scattering on its relic abundance

“…Quite commonly particle physics models with the DM candidate(s) contain heavier particles that can decay with a production of one or several DM states. If the lifetime of these heavy particles is sufficiently long, the contribution from the decays does not simply annihilate away and return the distribution to the equilibrium, but can noticeably alter the evolution of DM distribution, its density and other properties [15,[29][30][31][32]. This additional non-thermal contribution can also arise, for example, from the bubble collisions following a first-order phase transition [33] or primordial black holes evaporation [34].…”