Search for Flavor-Changing-Neutral-Current D Meson Decays

Abstract

We study the flavor-changing-neutral-current process c→uμ(+)μ(−) using 1.3 fb(−1) of pp-bar collisions at s√=1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated D(+)s and D(+)→ϕπ(+)→μ(+)μ(−)π(+) final states with significance greater than 4 standard deviations above background for the D+ state. We search for the continuum neutral-current decay of D(+)→π(+)μ(+)μ(−) in the dimuon invariant mass spectrum away from the ϕ resonance. We see no evidence of signal above background and set a limit of B(D(+)→π(+)μ(+)μ(−))<3.9×10−6 at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c→uμ(+)μ(−) transition.