Sterile neutrino dark matter with dipole interaction

TL;DR

This paper explores sterile neutrinos with dipole interactions as viable dark matter candidates, demonstrating their potential to produce the correct relic abundance and explaining neutrino oscillations within certain mass ranges.

Contribution

It introduces a model where sterile neutrinos with dipole interactions serve as dark matter, detailing conditions for their longevity and relic abundance, and linking heavier sterile neutrinos to active neutrino oscillations.

Findings

MeV-scale sterile neutrino with dipole interaction can be dark matter

Relic abundance can be achieved without violating constraints

Heavier GeV-scale sterile neutrinos explain active neutrino oscillations

Abstract

We consider the possibility of the lightest sterile neutrino dark matter which has dipole interaction with heavier sterile neutrinos. The lifetime can be long enough to be a dark matter candidate without violating other constraints and the correct amount of relic abundance can be produced in the early Universe. We find that a sterile neutrino with the mass of around MeV and the dimension-five non-renormalisable dipole interaction suppressed by $\Lambda_5 \gtrsim 10^{15}$ GeV can be a good candidate of dark matter, while heavier sterile neutrinos with masses of the order of GeV can explain the active neutrino oscillations.