0000000000547699
AUTHOR
Hanzhe Liu
Searches for Lepton Flavor Violation in the Decaysτ±→e±γandτ±→μ±γ
Searches for lepton-flavor-violating decays of a tau lepton to a lighter mass lepton and a photon have been performed with the entire data set of (963 +/- 7) x 10(6) tau decays collected by the BABAR detector near the Y(4S), Y(3S) and Y(2S) resonances. The searches yield no evidence of signals and we set upper limits on the branching fractions of B(tau(+/-) -> e(+/-)gamma) mu(+/-)gamma) < 4.4 X 10(-8) at 90% confidence level.
Search for charged lepton flavor violation in narrow Y decays
Charged-lepton flavor-violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 × 10 6 Υ ( 2 S ) decays and 117 × 10 6 Υ ( 3 S ) decays collected with the BABAR detector. We place upper limits on the branching fractions B ( Υ ( n S ) → e ± τ ∓ ) and B ( Υ ( n S ) → μ ± τ ∓ ) ( n = 2 , 3 ) at the 10 − 6 level and use these results to place lower limits of order 1 TeV on the mass scale of charged-lepton flavor-violating effective operators.