We investigate the possibility of neutrinoless double beta decay ($0\nu\beta\beta$) and leptogenesis within the Alternative Left-Right Model (ALRM). Unlike the usual left-right symmetric model, ALRM features a Majorana right-handed neutrino which does not carry any charge. Further, in this picture the down-type quark and the charged leptons receive mass through the additional left-handed scalar field, rather than the usual doublet. Together, these features conspire to generate significant contributions to the $0\nu\beta\beta$ through vector-scalar ($WH$) mediation. For moderate masses of the relevant charged Higgs boson ($M_{ H_1^\pm}\sim 200$ GeV), the half-life of $T_{ \frac{ 1}{ 2}}^{ WH}$ is $\sim 3\times 10^{ 26}~{ \rm yrs}$ for both the case of $^{ 76}$Ge and $^{ 136}$Xe, well within the sensitivity expected by future experiments. Invoking the resonant leptogenesis, CP violation arising from the right-handed neutrino decay could be the required order to generate the correct baryogenesis, $\epsilon\sim 10^{ -6}$, for small Dirac phases and without any fine tuning.
Categories: hep-ph