Detecting Majorana nature of neutrinos in muon and tau decay

TL;DR

This paper explores how the Majorana nature of neutrinos could be detected through precise measurements of muon decay processes influenced by charged Higgs interactions, offering a potential experimental signature.

Contribution

It introduces the impact of charged Higgs boson interactions on muon decay processes within the Higgs triplet model, highlighting a novel interference effect due to Majorana neutrinos.

Findings

Interference effects between W boson and charged Higgs diagrams could be observable.

Neutrino Yukawa couplings significantly affect muon decay rates.

Potential for near-future experiments to detect Majorana neutrino signatures.

Abstract

The Majorana nature of neutrinos can be detected by the precise measurement of muon decay. This possibility comes from the presence of charged Higgs boson interaction for Majorana neutrinos. We study the effects of the neutrino Yukawa interaction via charged Higgs bosons in muon decay processes such as $\mu\to e\nu\bar{\nu}$ and $\mu\to e\gamma$. The Higgs triplet model with small vacuum expectation value is of special importance whose neutrino Yukawa coupling can affect significantly muon decays. External neutrino lines in the Feynman diagrams of $\mu\to e\nu\bar{\nu}$ can be crossed because of its Majorana nature. This fact provides the interference contribution between the W boson exchange diagram and that of charged Higgs boson, which may be detectable in near future experiments.