Search for Lepton Flavour Violation at HERA

TL;DR

This paper reports a search for lepton flavor violating leptoquarks at HERA, finding no evidence and setting mass exclusion limits up to 712 GeV for muon-quark and 479 GeV for tau-quark couplings.

Contribution

First search for second and third generation leptoquarks via lepton flavor violation at HERA with full data sample.

Findings

No evidence for leptoquark production observed.

Excluded leptoquarks with masses up to 712 GeV (muon) and 479 GeV (tau) at 95% CL.

Abstract

A search for second and third generation scalar and vector leptoquarks produced in ep collisions via the lepton flavour violating processes ep -> mu X and ep -> tau X is performed by the H1 experiment at HERA. The full H1 ep data sample taken at a centre-of-mass energy of 319 GeV is used for the analysis. No evidence for the production of such leptoquarks is observed in the H1 data. Leptoquarks produced in ep collisions with a coupling strength of 0.3 and decaying with the same coupling strength to a muon-quark pair or a tau-quark pair are excluded at 95% confidence level up to leptoquark masses of 712 GeV and 479 GeV, respectively.