Search for the Flavor-Changing Neutral-Current Decays $D^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ and $D^{+}\to {\pi }^{+}{e}^{+}{e}^{-}$

Abstract

We report the results of a search for the flavor-changing neutral-current decays $D^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ and $D^{+}\to {\pi }^{+}{e}^{+}{e}^{-}$ in data from Fermilab charm hadroproduction experiment E791. No signal above background is found, and we obtain upper limits on branching fractions, $B(D^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-})<1.8\times 10^{-5}$ and $B(D^{+}\to {\pi }^{+}{e}^{+}{e}^{-})<6.6\times 10^{-5}$, at the 90\% confidence level.

nine pages with figures; compressed, uuencoded postscript