Observable Gravitational Waves in Minimal Scotogenic Model

Abstract

We scrutinise the widely studied minimal scotogenic model of dark matter and radiative neutrino mass from the requirement of a strong first order electroweak phase transition (EWPT) and observable gravitational waves at future planned space based experiments. The scalar DM scenario is similar to inert scalar doublet extension of standard model where a strong first order EWPT favours the low mass regime of DM, a narrow fine tuned region currently allowed from collider and direct detection bounds. In the fermion DM scenario, we get newer region of parameter space which favours strong first order EWPT as the restriction on mass ordering within inert scalar doublet gets relaxed. While such leptophilic fermion DM remains safe from stringent direct detection bounds, newly allowed low mass regime of charged scalar can leave tantalising signatures at colliders. While we get such new region of parameter space satisfying DM relic, strong first order EWPT with detectable gravitational waves, light neutrino mass and other relevant constraints, we also improve upon previous analysis in similar model by incorporating appropriate resummation effects in effective finite temperature potential.

Dark Sector Assisted Low Scale Leptogenesis from Three Body Decay

“…• Ω 1 h 2 conversion in scotogenic models can be sizeable and saturate experimental upper bounds on corresponding branching ratios for fermion DM scenario [65,137,138], in our model they are likely to be suppressed as the singlet fermions N 1,2 are heavier than the scale of leptogenesis.…”

“…Another interesting prospect of probing our model can be in the form of gravitational waves from a strongly first order phase transition (SFOPT). In a recent work [138], it was shown that in the minimal scotogenic model, the criteria of SFOPT constrains the scalar sector a lot, leading to a scalar DM parameter space in tension with direct detection bounds. Due to the presence of an additional singlet scalar in our model whose mass is not as constrained as the inert doublet components, the SFOPT criteria is likely to be satisfied with more freedom.…”

Self-interacting Dark Matter via Right Handed Neutrino Portal

“…As discussed in subsection II B, for a particular benchmark of SIDM parameter space, one requires a certain freeze-out abundance of N 1 so that correct SIDM relic abundance is generated at the end from non-thermal decay of N 1 . Therefore, we estimate the thermal freeze-out abundance of N 1 in the scotogenic model in a way similar to fermion DM studies in scotogenic model [81][82][83].…”