Upper Limit for the Decayμ+→e+γ

Abstract

An examination of 3.6×${10}^{10}$ ${\mu }^{+}$ decays yields an improved upper limit for the branching ratio $\frac{\Gamma ({\mu }^{+}\to e^{+}\gamma )}{\Gamma ({\mu }^{+}\to e^{+}{\nu }_e{\overline{\nu }}_{\mu })}<1.9\mathrm{}\times {10}^{-10\mathrm{}}$ with 90% confidence.