Search for the rare decay Bs0→μ+μ−

Abstract We present the results of a search for the flavor changing neutral current decay B s 0 → μ + μ − using 6.1 fb − 1 of p p ¯ collisions at s = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B s 0 candidates is consistent with background expectations. The resulting upper limit on the branching fraction is B ( B s 0 → μ + μ − ) 5.1 × 10 − 8 at the 95% C.L. This limit is a factor of 2.4 better than that of the previous D0 analysis and the best limit to date.