Majorana neutrino decay in an effective approach

Abstract

The search strategy or the discovery of new effects for heavy neutrinos often rely on their different decay channels to detectable particles. In particular, in this work we study the decay of a Majorana neutrino with interactions obtained from an effective general theory modeling new physics at the scale $\mathrm{\ensuremath{\Lambda}}$. The results obtained are general because they are based in an effective theory and not in specific models. We are interested in relatively light-heavy Majorana neutrinos, with masses lower than the $W$ mass (${m}_{N}<{m}_{W}$). This mass range simplifies the study by reducing the possible decay modes. Moreover, we found that for $\mathrm{\ensuremath{\Lambda}}\ensuremath{\sim}1\text{ }\text{ }\mathrm{TeV}$, the neutrino plus photon channel could account for different observations: we analyze the potentiality of the studied interactions to explain some neutrino-related problems like the MiniBooNE and SHALON anomalies. We show in different figures the dominant branching ratios and the decay length of the Majorana neutrino in this approach. These kinds of heavy neutral leptons could be searched for in the LHC with the use of displaced vertices techniques.