Dark matter andU(1)′symmetry for the right-handed neutrinos

Abstract

We consider a $U{(1)}^{\ensuremath{'}}$ gauge symmetry acting on three generations of right-handed neutrinos. The $U{(1)}^{\ensuremath{'}}$ symmetry is broken at the TeV scale, and its remnant discrete symmetry makes one of the right-handed neutrinos stable. As a natural consequence of the anomaly cancellation, the neutrino mass matrix consists of a combination of type I (TeV scale) seesaw and radiative corrections. The stable right-handed neutrino communicates with the Standard Model via $s$-channel exchange of the Higgs field and the $U{(1)}^{\ensuremath{'}}$ gauge boson, so that the observed relic density for dark matter is obtained in a wide range of the parameter space. The experimental signatures in collider and other experiments are briefly discussed.