Study of the Lepton Flavor Violating Decay ${\tau }^{-}\to {\mu }^{-}\eta$

Abstract

We present the preliminary results from the search of the non-conservation of lepton flavor number in the decay of a $\tau$ to a lighter mass lepton and a pseudo-scalar meson, performed using $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$ events collected at a center-of-mass energy near 10.58 GeV with the BABAR detector at the SLAC PEP-II $e^{+}{e}^{-}$ storage ring. No evidence of such a signal has been found in the data sample corresponding to a luminosity of 314.5 fb${}^{-1}$, and we set an upper limit of $1.6\times 10^{-7}$ at 90% confidence level on the decay of ${\tau }^{-}\to {\mu }^{-}\eta$.

16 pages, 6 postscript figues, submitted to ICHEP2006