Nuclear $0\nu2β$ decays in $B-L$ symmetric SUSY model and in TeV scale left-right symmetric model

Abstract

In this paper we take B-L supersymmetric standard model (B-LSSM) and TeV scale left-right symmetric model (LRSM) as two types of typical ones beyond SM to study the nuclear neutrinoless double beta decays (0ν2β) and to see the senses for the present data and the expected data in the near future of the decays. In the study we pay much attention onto the QCD corrections in the energy-scale region from µ = M W to µ ≃ 1.0 GeV, but we treat the nuclear effects in the decays as done in the relevant literatures. For these two models the decay half-life of the nuclei, 76 Ge and 136 Xe, T 0ν 1/2 ( 76 Ge, 136 Xe), are precisely estimated with the model parameters allowed by experiments and the results are presented properly. Results show that the concerned QCD corrections to the half-life of the 0ν2β decays for the two models are quite sizable. The interference effects between the different contributions happened only in the model LRSM are specially analyzed. According to the numerical results, an optimistic conclusion is obtained that the 0ν2β decays for the models may be observed in the next generation of the underground observations.