Search for rare and forbidden charm meson decays D0 → Vl+l- and hhll

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton number violating decays of the D-0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho (0), (K) over bar (*0) or phi vector meson or a nonresonant pi pi, K pi, or KK 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).