Majorana neutrino decay in an Effective Approach

TL;DR

This paper investigates the decay of light Majorana neutrinos using an effective theory approach, exploring their potential to explain anomalies and suggesting search strategies at colliders.

Contribution

It introduces a model-independent effective theory framework for Majorana neutrino decays below the W mass, analyzing decay channels and potential explanations for neutrino anomalies.

Findings

The neutrino plus photon channel could explain MiniBooNE and SHALON anomalies.

Decay length and branching ratios are characterized for neutrinos with masses below the W.

Heavy neutral leptons could be detected at the LHC via displaced vertices.

Abstract

The search strategy or the finding of new effects for heavy neutrinos often relies 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 $\Lambda$. 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 $\Lambda\sim 1$ T$e$V, the neutrino plus photon channel could give explanation to 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. This kind of heavy neutral leptons could be searched for in the LHC with the use of displaced vertices techniques. \