A Search for the Rare and Forbidden Decays $D^0 \to V l^+l^-$
E. M. Aitala · 2003
I report the results of a search for flavor-changing neutral current, leptonflavor, and lepton-number violating decays of the 3 and 4-body decay modes of the $D^0$ (and its antiparticle) containing muons and electrons. Using data from Fermilab charm hadroproduction experiment E791, I examine modes with two leptons and either a $p^0, K^{\ast0}$, or $\phi$ vector meson or a non-resonant $\pi\pi, K\pi$, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, branching-fraction upper limits, typically at the $10^{-4}$ level, are presented at the 90% confidence level for the 27 decay modes examined. Of these searches, 18 are investigations of decays without previous published results; several others have significantly improved sensitivity over previous results.