Differential branching fraction and angular analysis of the $B^{+} \rightarrow K^{+}\mu^{+}\mu^{-}$ decay

TL;DR

This paper presents a detailed analysis of the decay $B^{+} ightarrow K^{+}$ using LHCb data, measuring its angular distribution and branching fraction with high precision, consistent with Standard Model predictions.

Contribution

It provides the most precise measurements to date of the differential branching fraction and angular distribution for the $B^{+} ightarrow K^{+}$ decay, using a large dataset.

Findings

Angular distribution consistent with Standard Model

Total branching fraction measured as (4.36 ± 0.15 ± 0.18)×10^{-7}

Most precise measurement of this decay to date

Abstract

The angular distribution and differential branching fraction of the decay $B^{+} \rightarrow K^{+}\mu^{+}\mu^{-}$ are studied with a dataset corresponding to $1.0\,\mathrm{fb}^{-1}$ of integrated luminosity, collected by the LHCb experiment. The angular distribution is measured in bins of dimuon invariant mass squared and found to be consistent with Standard Model expectations. Integrating the differential branching fraction over the full dimuon invariant mass range yields a total branching fraction of $\mathcal{B}(B^{+} \rightarrow K^{+}\mu^{+}\mu^{-}) = (4.36 \pm 0.15 \pm 0.18)\times 10^{-7}$. These measurements are the most precise to date of the $B^{+} \rightarrow K^{+}\mu^{+}\mu^{-}$ decay.