Tau Decays to Mu + Eta in Supersymmetric Models

Abstract

The existence of large ν_μ-ν_τmixing suggests the likelihood of large smuon-stau mixing in supersymmetric models, leading to μand τnumber violation. In addition to interesting signatures in slepton and neutralino production and decay, this will lead to rare τdecays, such as τ--> mu γ. Recently, it has been pointed out that the τ--> 3μbranching ratio could be substantial in the large \tanβregion of parameter space, due to an induced μ-τ-Higgs vertex. In this paper, another signature, τ--> μηis considered. In the large \tanβregion, it is shown that the branching ratio of τ--> μηis 8.4 times the branching ratio of τ--> 3μ, independent of any unknown parameters, and it will thus give the most stringent bound on Higgs-mediated lepton flavor violation, and may provide its first signature. In the other regions of parameter space, where τ--> μγis the most prominent decay, the branching ratio for τ--> μηis always substantially lower.

5 pages, 2 figures. Paragraph about CLEO measurements added. Version to appear in PRD