Dodelson-Widrow Mechanism in the Presence of Self-Interacting Neutrinos

Abstract

keV-scale gauge-singlet fermions, allowed to mix with the active neutrinos, are elegant dark matter (DM) candidates. They are produced in the early universe via the Dodelson-Widrow mechanism and can be detected as they decay very slowly, emitting X-rays. In the absence of new physics, this hypothesis is virtually ruled out by astrophysical observations. Here, we show that new interactions among the active neutrinos allow these sterile neutrinos to make up all the DM while safely evading all current experimental bounds. The existence of these new neutrino interactions may manifest itself in next-generation experiments, including DUNE.

The Forward Physics Facility: Sites, Experiments, and Physics Potential

“…A well-known example is the Majoron [106]. Another scenario with a mediator mass below the weak scale has been proposed to address the relic density of the sterile neutrino DM [107][108][109], which otherwise is in severe tension with existing constraints [110]. The thermal freeze-out mechanism for DM via the neutrino-philic mediator has also been explored in Ref.…”

New constraints on the mass of fermionic dark matter from dwarf spheroidal galaxies

“…There are, how- ever, several other possibilities for sterile neutrino dark matter production. A sample of alternative possibilities are: sterile neutrino production from the decays of heavier particles, including singlet scalars (Shaposhnikov & Tkachev 2006;Kusenko 2006;König et al 2016), Dirac fermions (Asaka et al 2006;Abada et al 2014) or charged scalars (Frigerio & Yaguna 2015), and sterile neutrino production assisted by neutrinophilic scalars (De Gouvêa et al 2020) or gauge bosons (Nemevsek et al 2012). Importantly, regardless of the production mechanism, the very same procedure to set bounds on the sterile neutrino mass described in Sec.…”

“…Although it is beyond the scope of this paper to set constraints on each of these production mechanisms, we note that our procedure typically yields a bound s O (1) keV for sterile neutrinos produced via these alternative mechanisms. As an illustrative example of how to use our derived bounds, one can consider the recent model of De Gouvêa et al (2020). Taking the benchmark scenario denoted as B in that reference, the maximum of the distribution is B max 2 × 10 −3 for = 7.1 keV.…”

Sterile neutrino dark matter: impact of active-neutrino opacities

“…Combined constraints for keV sterile-neutrino dark matter. The X-ray constraints are taken from [30], see also [10,[31][32][33]. Phase space density constraints are from [29].…”