The v R -philic scalar dark matter

Abstract

Right-handed neutrinos (v R ) offer an intriguingportal to new physics in hidden sectors where dark matter (DM) mayreside. In this work, we delve into the simplest hidden sector involvingonly a real scalar exclusively coupled to v R , referred toas the v R -philic scalar. We investigate the viability of thev R -philic scalar to serve as a DM candidate, under the constraintthat the coupling of v R to the standard model is determinedby the seesaw relation and is responsible for the observed DM abundance.By analyzing the DM decay channels and solving Boltzmann equations,we identify the viable parameter space. In particular, our study revealsa lower bound (2.6 × 105 GeV) on the mass of v R forthe v R -philic scalar to be DM. The DM mass may vary from sub-MeVto sub-GeV. Within the viable parameter space, monochromatic neutrinolines from DM decay can be an important signal for DM indirect detection.