Seesaw model with hidden $SU(2{)}_H\times U(1{)}_X$ gauge symmetry

Abstract

We propose a seesaw model with a hidden gauge symmetry $SU(2{)}_H\times U(1{)}_X$ where two types of standard model singlet fermions in realizing a seesaw mechanism are organized into $SU(2{)}_H$ doublet. Then we formulate scalar and gauge sector, neutrino mass matrix and lepton flavor violations. In our gauge sector, $Z$-$Z^{\prime }$ mixing appears after spontaneous symmetry breaking and we investigate constraint from $\rho$-parameter. In addition we discuss $Z^{\prime }$ production at the large hadron collider via $Z$-$Z^{\prime }$ mixing, where $Z^{\prime }$ tends to dominantly decay into heavy neutrinos.

Comments: 16 pages, 2 figures, version accepted for publication in PRD