Lepton-flavour violation in hadronic tau decays and $\mu-\tau$ conversion in nuclei

TL;DR

This paper analyzes lepton-flavour-violating tau decays and mu-tau conversion in nuclei within the Standard Model Effective Field Theory, establishing constraints on new physics operators based on current experimental limits and future prospects.

Contribution

It provides a model-independent analysis of lepton-flavour violation in tau decays and mu-tau conversion, deriving constraints on Wilson coefficients from existing data and outlining future experimental implications.

Findings

Constraints on Wilson coefficients from current experimental limits.

Framework applicable to future Belle II and other experiments.

Analysis within the Standard Model Effective Field Theory up to dimension 6.

Abstract

Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$--$\tau$ conversion in nuclei, with $\ell = e,\mu$. Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing to these processes. Our work paves the way to extract the related information from Belle II and foreseen future experiments.