First observation of the decay $B^{+} \rightarrow \pi^{+} \mu^{+} \mu^{-}$

TL;DR

This paper reports the first observation of the rare decay $B^{+} ightarrow ^{+} ^{+} ^{-}$ with a significance of 5.2 sigma, measuring its branching fraction and ratio to a similar decay using LHCb data.

Contribution

First observation of the decay $B^{+} ightarrow ^{+} ^{+} ^{-}$ with measured branching fraction and ratio, expanding knowledge of rare B meson decays.

Findings

Decay observed with 5.2 sigma significance

Branching fraction measured as (2.3 ± 0.6 ± 0.1)×10^{-8}

Branching ratio to $B^{+} ightarrow K^{+} ^{+} ^{-}$ is 0.053 ± 0.014 ± 0.001

Abstract

A discovery of the rare decay $B^{+} \rightarrow \pi^{+} \mu^{+} \mu^{-}$ is presented. This decay is observed for the first time, with 5.2 $\sigma$ significance. The observation is made using $pp$ collision data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected with the LHCb detector. The measured branching fraction is (2.3 $\pm$ 0.6 (stat.) $\pm$ 0.1 (syst.))$\times 10^{-8}$, and the ratio of the $B^{+} \rightarrow \pi^{+} \mu^{+} \mu^{-}$ and $B^{+} \rightarrow \K^{+} \mu^{+} \mu^{-}$ branching fractions is measured to be 0.053 $\pm$ 0.014 (stat.) $\pm$ 0.001 (syst.).