Sterile neutrino dark matter with supersymmetry

Abstract

Sterile neutrino dark matter, a popular alternative to the WIMP paradigm, has generally been studied in non-supersymmetric setups. If the underlying theory is supersymmetric, we find that several interesting and novel dark matter features can arise. In particular, in scenarios of freeze-in production of sterile neutrino dark matter, its superpartner, the sterile sneutrino, can play a crucial role in early Universe cosmology as the dominant source of cold, warm, or hot dark matter, or of a subdominant relativistic population of sterile neutrinos that can contribute to the effective number of relativistic degrees of freedom N eff during Big Bang nucleosynthesis. MOTIVATION

Right-handed neutrinos and R(D(∗))

“…[17]. In contrast to traditionally studied frameworks of sterile neutrino dark matter, where the relic abundance is produced via freeze-in mechanisms (see, e.g., [60][61][62][63][64][65]), the W model involves the sterile neutrino freezing out as a relativistic species, leading to too large of a relic abundance for masses greater than O(keV). This can be fixed with appropriate entropy dilution from, for instance, late decays of GeV scale sterile neutrinos [58,58,66,67], which also makes the dark matter colder, improving compatibility with warm dark matter constraints.…”

The dawn of FIMP Dark Matter: A review of models and constraints

“…More recent studies have considered similar scenarios where the scalar s either decays into sterile neutrinos while in equilibrium [271,280,283,285,306,340,[354][355][356][357][358][359][360][361][362][363], or where it first undergoes a freeze-in itself [271, 279, 281-285, 330, 354, 358, 361, 362]. Recently, sterile neutrinos undergoing or related to freeze-in have also been studied in supersymmetric models [272,278,361,364]. A useful estimate for the DM abundance in these scenarios can be given as [17,18] Ω ν R h 2 0.12…”

R(D(∗)) from W ′ and right-handed neutrinos

“…Sterile neutrino dark matter is generally studied in frameworks where its abundance freezes in rather than freezes out [73][74][75][76][77]; however, this is not true in the current scenario. It is well known that without other additional modifications of the standard cosmology, a species that undergoes relativistic freezeout around T ∼ m τ overcloses the Universe if its mass is greater than O(keV).…”