Search for flavor-changing-neutral-current $D$ meson decays

Abstract

We study the flavor-changing-neutral-current process c to u mu_s16 mu- using 1.3 fb^-1 of p p bar collisions at sqrt(s) = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the Ds_s16 and D_s16 to phi pi_s16 to mu_s16 mu- pi_s16 final states with significance greater than four standard deviations above background for the D_s16 state. We search for the continuum decay of D_s16 to pi_s16mu_s16mu- in the dimuon invariant mass spectrum away from the phi resonance. We see no evidence of signal above background and set a limit of B(D_s16 to pi_s16mu_s16mu-) < 3.9 x 10^-6 at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c to u mu_s16 mu- transition.