Universal Seesaw and $0\nu \beta \beta$ in new 3331 left-right symmetric model

Abstract

We consider a class of left-right symmetric model with enlarged gauge group $SU(3{)}_c\times SU(3{)}_L\times SU(3{)}_R\times U(1{)}_X$ without having scalar bitriplet. In the absence of scalar bitriplet, there is no Dirac mass term for fermions including usual quarks and leptons. We introduce new isosinglet vector-like fermions so that all the fermions get their masses through a universal seesaw mechanism. We extend our discussion to neutrino mass and its implications in neutrinoless double beta decay ($0\nu \beta \beta$). We show that for TeV scale $SU(3{)}_R$ gauge bosons, the heavy-light neutrino mixing contributes dominantly to $0\nu \beta \beta$ that can be observed at ongoing experiments. Towards the end we also comment on different possible symmetry breaking patterns of this enlarged gauge symmetry to that of the standard model.

Comments: 9 pages, Added discussion on effect of light-heavy neutrino mixing on $0\nu \beta \beta$ decay