A Search for the Flavor-Changing Neutral Current Decay B0_s -> mu^+mu^- in pp(bar) Collisions at \sqrt{s} = 1.96 TeV with the D0 Detector

TL;DR

This paper reports a search for the rare decay B0_s -> mu+ mu- in proton-antiproton collisions, setting the most stringent upper limit to date on its branching fraction, thus constraining new physics models.

Contribution

First search for B0_s -> mu+ mu- decay at Tevatron with D0 detector, establishing the tightest upper limit on its branching fraction to date.

Findings

Upper limit on Br(B0_s -> mu+ mu-) ≤ 5.0 x 10^{-7} at 95% C.L.

No evidence of the decay observed.

Results constrain new physics models predicting enhanced decay rates.

Abstract

We present the results of a search for the flavor-changing neutral current decay B0_s -> mu+ mu- using a data set with integrated luminosity of 240 pb^{-1} of pp(bar) collisions at sqrt{s}=1.96 TeV collected with the D0 detector in Run II of the Fermilab Tevatron collider. We find the upper limit on the branching fraction to be Br(B0_s -> mu+ mu-) \leq 5.0 x 10^{-7} at the 95% C.L. assuming no contributions from the decay B0_d -> mu+ mu- in the signal region. This limit is the most stringent upper bound on the branching fraction B0_s -> mu+ mu- to date.