Angular analysis and differential branching fraction of the decay $B^0_s\to\phi\mu^+\mu^-$

TL;DR

This paper presents an angular analysis and differential branching fraction measurement of the decay $B^0_s\to\phi\mu^+\mu^-$ using LHCb data, revealing deviations from the Standard Model in certain $q^2$ ranges.

Contribution

It provides the first detailed angular and differential branching fraction analysis of this decay mode with new experimental data.

Findings

Results are consistent with the Standard Model for angular distributions.

Differential branching fraction is more than 3 sigma below predictions for $1<q^2<6$ GeV$^2$/c$^4$.

Data covers $pp$ collisions at 7 and 8 TeV with 3.0 fb$^{-1}$ luminosity.

Abstract

An angular analysis and a measurement of the differential branching fraction of the decay $B^0_s\to\phi\mu^+\mu^-$ are presented, using data corresponding to an integrated luminosity of $3.0\, {\rm fb^{-1}}$ of $pp$ collisions recorded by the LHCb experiment at $\sqrt{s} = 7$ and $8\, {\rm TeV}$. Measurements are reported as a function of $q^{2}$, the square of the dimuon invariant mass and results of the angular analysis are found to be consistent with the Standard Model. In the range $1<q^2<6\, {\rm GeV}^{2}/c^{4}$, where precise theoretical calculations are available, the differential branching fraction is found to be more than $3\,\sigma$ below the Standard Model predictions.