Search for Rare b-hadron Decays at CDF

TL;DR

This paper reports on searches for rare B-hadron decays involving muons using data from the CDF II detector, setting upper limits and measuring branching fractions to test the Standard Model and probe new physics.

Contribution

It provides the first upper limits on B_s and B_d to mu+ mu- decays and measures branching fractions for B+ and B0_d decays involving muons, using data from the CDF II detector.

Findings

Upper limits on B(B_s to mu+ mu-) and B(B_d to mu+ mu-) at 95% confidence level.

Measured branching fractions for B+ to mu+ mu- K+ and B0_d to mu+ mu- K*0.

Constraints on new physics contributions to rare B-hadron decays.

Abstract

We report on searches for B^0_s to \mu^+ \mu^-, B^0_d to \mu^+ \mu^- decays and b to s \mu^+\mu^- transitions in exclusive decays of B mesons. Using 2 fb^{-1} of data collected by the CDF II detector we find upper limits on the branching fractions B(B^0_s to \mu^+ \mu^-) < 5.8 x 10^{-8} and B(B^0_d to \mu^+ \mu^-) < 1.8 x 10^{-8} at 95% confidence level. Using 924 pb^{-1} of data we measure the branching fractions B(B^+ to \mu^+ \mu^- K^+) = (0.60 \pm 0.15 \pm 0.04) x 10^{-6}, B(B^0_d to \mu^+ \mu^- K^{*0}) = (0.82 \pm 0.31 \pm 0.10) x 10^{-6} and the limit B(B^0_s to \mu^+ \mu^- phi)/B(B^0_s to J/\psi\phi) < 2.61(2.30) x 10^{-3} at 95(90)% confidence level.