Model-independent analysis of Tau -> lll' decays

TL;DR

This paper provides a model-independent analysis of tau lepton decays into three charged leptons, classifying operators by chirality and exploring decay distributions to distinguish new physics models.

Contribution

It introduces a generic effective-field-theory framework for tau -> lll' decays, including interference effects and decay distributions, aiding the identification of new physics.

Findings

Dalitz plot distributions for tau decays derived

Interference effects from four-lepton operators analyzed

Potential to differentiate new physics models discussed

Abstract

Many models for physics beyond the Standard Model predict lepton-flavour violating decays of charged leptons at a level which may become observable very soon. We investigate the decays of a Tau-lepton into three charged leptons (Tau -> lll', l(') = e,\mu in a generic way. Using effective-field-theory methods, the relevant operators are classified according to their chirality structure. For each case, we work out the Dalitz plots for the decay distributions, including interference terms which arise from four-lepton operators and radiatively induced processes. We discuss phenomenological implications, in particular the potential to distinguish different new physics models.