Search for Rare and Forbidden Charm Meson Decays D0--> V l+ l- and h h l l

TL;DR

This study searched for rare charm meson decays involving flavor-changing neutral currents, lepton-flavor, and lepton-number violations, setting upper limits on their branching fractions due to no observed evidence.

Contribution

First comprehensive search for multiple rare D0 decay modes involving leptons, providing new upper limits on their branching fractions.

Findings

No evidence for the decay modes was observed.

Upper limits on branching fractions were established for 27 decay modes.

18 of these decay modes are reported for the first time.

Abstract

We report the results of a search for flavor-changing neutral current, lepton-flavor, and lepton-number violating decays of the 3 and 4-body decay modes of D0 (and its antiparticle) containing muons and electrons. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons and either a Rho(0), Kstar, or Phi vector meson or a non-resonant Pi Pi, K Pi, or K K pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).