Search for rare b-meson decays at CDF

TL;DR

This paper reports on a search for rare B-meson decays involving muons using data from the CDF II detector, setting upper limits on their branching fractions and measuring some decay rates.

Contribution

The study provides new upper limits on the branching fractions of rare B-meson decays and measures specific decay rates using the CDF II detector data.

Findings

Upper limits on $ ext{B}(B_s^0 o \mu^+\mu^-)$ and $ ext{B}(B_d^0 o \\mu^+\mu^-)$

Measured branching fractions for $b o s \\mu^+\\mu^-$ transitions

Constraints on rare decay processes at 95% confidence level

Abstract

We report on the search 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 the CDF II detector at the Fermilab Tevatron Collider. Using 2 fb$^{-1}$ of Run II data we find upper limits on the branching fractions $\mathcal{B}(B^0_s\to\mu^+\mu^-)<5.8\times 10^{-8}$ and $\mathcal{B}(B^0_d\to\mu^+\mu^-)<1.8\times 10^{-8}$ at 95% confidence level. The results for the branching fractions of the $b\to s \mu^+\mu^-$ transitions using 924 pb$^{-1}$ of Run II data are $\mathcal{B}(B^+\to\mu^+\mu^-K^+)=(0.60\pm0.15\pm0.04)\times 10^{-6}$, $\mathcal{B}(B^0_d\to\mu^+\mu^-K^{*0})=(0.82\pm0.31\pm0.10)\times 10^{-6}$ and $\mathcal{B}(B^0_s\to \mu^+\mu^-\phi)/\mathcal{B}(B^0_s\to J/\psi\phi) < 2.61\times 10^{-3}$ at 95% confidence level.