Electrons from Muon Capture

Abstract

We have searched for the process ${\mu }^{-}+p\to p+e^{-}$ or ${\mu }^{-}+n\to n+e^{-}$ for $\mu$ mesons stopped in a Cu target. Scintillation counters were employed to detect the electrons from the process. No counts attributable to the electrons were obtained and we place an upper limit of ∼5×${10}^{-4\mathrm{}}$ for the relative rate of this process to that for the usual nuclear capture reaction.