Critique of fermionic RνMDM and its scalar variants

Abstract

We examine the stability of minimal dark matter (MDM) particle-candidates in the setup in which they participate in radiative neutrino (Rν) masses. We first point out the existence of an additional renormalizable term in recently proposed RνMDM Lagrangian, which violates the claimed accidental Z₂ symmetry and spoils the stability of the fermionic MDM quintuplet component. We then explore the viability of RνMDM variants based on scalar MDM multiplets. There are ubiquitous super-renormalizable terms in the scalar potential which make these scalar multiplets unstable.