Spontaneously stabilised dark matter from a fermiophobic U(1)′ gauge symmetry

A bstract We consider the possibility that dark matter is stabilised by a discrete Z 2 symmetry which arises from subgroup of U(1)′ gauge symmetry, spontaneously broken integer charged scalars, and under chiral quarks leptons do not carry any charges. fermion χ with half-integer charge odd preserved , hence becomes stable candidate, being produced through couplings to right-handed neutrinos vector-like charges, as in type Ib seesaw mechanism. calculate relic abundance such low energy effective model containing few parameters, then high renormalisable complete fourth family fermions, where quark lepton masses arise seesaw-like With inclusion family, lightest can contribute production, enlarging allowed parameter space we explore.