Search for the radiative $\Xi_b^-\to\Xi^-\gamma$ decay

TL;DR

This paper reports the first search for the rare radiative decay of the $ ext{Xi}_b^-$ baryon into $ ext{Xi}^- ext{gamma}$ using LHCb data, setting an upper limit on its branching fraction.

Contribution

It presents the first experimental search for the $ ext{Xi}_b^- o ext{Xi}^- ext{gamma}$ decay and establishes an upper limit on its branching ratio.

Findings

No signal observed for the decay.

Upper limit on branching fraction set at $1.3 imes 10^{-4}$.

Abstract

The first search for the rare radiative decay $\Xi_b^- \to \Xi^- \gamma$ is performed using data collected by the LHCb experiment in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb$^{-1}$. The $\Xi_b- \to \Xi^- J/\psi$ channel is used as normalization. No $\Xi_b^- \to \Xi^- \gamma$ signal is found and an upper limit of $\mathcal{B}(\Xi_b^- \to \Xi^- \gamma) < 1.3 \times 10^{-4}$ at 95% confidence level is obtained.