Form factors and differential distributions in rare radiative leptonic B-decays

TL;DR

This paper analyzes rare radiative leptonic B-decays using a relativistic quark model, estimating branching ratios and distributions for different photon energy thresholds relevant to collider experiments.

Contribution

It provides new estimations of branching ratios for B-decays with photon energy cuts, extending previous analyses within a relativistic quark model framework.

Findings

Branching ratios are stable across different photon energy thresholds.

Highest branching ratios are approximately 18.5×10^{-9} for electrons and 11.9×10^{-9} for muons.

Distribution of the forward-backward asymmetry is presented.

Abstract

We study rare radiative leptonic decays $B_{(s)}\to e^+e^-\gamma$ and $B_{(s)}\to \mu^+\mu^-\gamma$ within relativistic quark model. In addition to previous analysis we give the estimations of the branching ratios for four values of the minimal photon energy, which correspond to photon selection criteria of the Belle and LHCb detectors. We find out that the branching ratios only slightly change. The highest values corresponding to $E^\gamma_{min}=80 \textrm{MeV}$ are ${\cal B}(\bar B^0_s\to e^+e^-\gamma)=18.5\times10^{-9}$ and ${\cal B}(B^0_s\to \mu^+\mu^-\gamma)=11.9\times10^{-9}$. We present the distribution of the forward-backward asymmetry.