Search for lepton-flavor violating decays of the Higgs boson in the $\mu\tau$ and e$\tau$ final states in proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This study searches for lepton-flavor violating decays of the Higgs boson into mu-tau and e-tau final states using 13 TeV proton-proton collision data, setting upper limits on these rare decay probabilities.

Contribution

First search to set experimental upper limits on Higgs lepton-flavor violating decays in mu-tau and e-tau channels at 13 TeV.

Findings

No significant excess observed.

Upper limits on branching fractions: 0.15% for H→μτ and 0.22% for H→eτ.

Results constrain new physics models predicting lepton-flavor violation.

Abstract

A search is presented for lepton-flavor violating decays of the Higgs boson to $\mu\tau$ and e$\tau$. The data set corresponds to an integrated luminosity of 137 fb$^{-1}$ collected at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. No significant excess has been found, and the results are interpreted in terms of upper limits on lepton-flavor violating branching fractions of the Higgs boson. The observed (expected) upper limits on the branching fractions are, respectively, $\mathcal{B}($H $\to\mu\tau)$ $\lt$ 0.15 (0.15)% and $\mathcal{B}($H$\to$e$\tau)$ $\lt$ 0.22 (0.16)% at 95% confidence level.