Search for the decay $B^0\to\phi\mu^+\mu^-$

TL;DR

This paper reports a search for the rare decay $B^0\to\phi\mu^+\mu^-$ using LHCb data, setting upper limits on its branching fraction due to no observed evidence, thus constraining new physics models.

Contribution

First search for $B^0\to\phi\mu^+\mu^-$ decay using LHCb data at multiple energies, establishing upper limits on its branching fraction.

Findings

No evidence for the decay was observed.

An upper limit on the branching fraction was set at $4.4 \times 10^{-3}$.

The absolute branching fraction is constrained to be less than $3.2 \times 10^{-9}$.

Abstract

A search for the decay $B^0\to\phi\mu^+\mu^-$ is performed using proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV collected by the LHCb experiment and corresponding to an integrated luminosity of 9 fb$^{-1}$. No evidence for the $B^0\to \phi \mu^+ \mu^-$ decay is found and an upper limit on the branching fraction, excluding the $\phi$ and charmonium regions in the dimuon spectrum, of $4.4 \times 10^{-3}$ at a 90$\%$ credibility level, relative to that of the $B^0_s \to \phi \mu^+ \mu^-$ decay, is established. Using the measured $B^0_s\to\phi\mu^+\mu^-$ branching fraction and assuming a phase-space model, the absolute branching fraction of the decay $B^0\to \phi \mu^+ \mu^-$ in the full $q^2$ range is determined to be less than $3.2 \times 10^{-9}$ at a 90$\%$ credibility level.