Lepton flavor violating Higgs boson decay H --> mu tau at muon colliders

Abstract

We consider an effective nondiagonal coupling $H\barμτ$ and present the analysis of the Higgs boson mediated lepton-flavor violating (LFV) reaction $μ^-μ^+ --> μτ$. For a Higgs boson mass around 115 GeV and convenient values of the strength of the coupling $H\barμτ$, which are within the bounds obtained from the experimental limits on the LFV decays $τ-->ημ$ and $τ-->μγ$, we found that there would be up to a few hundreds of $μτ$ events per year at a muon collider running with an integrated luminosity of $1 fb^{-1}$. We paid special attention on the background for this LFV reaction, which arises from the standard model process $μ^-μ^+ --> μτ\barν_μν_τ$, and discuss how it can be separated from the main signal.