Analysis of FCNC $\Xi_{QQ} \to \Lambda_Q l^+ l^-$ decay in light-cone sum rules

TL;DR

This paper calculates the decay rates of doubly heavy baryons via flavor-changing neutral currents using light-cone sum rules, providing predictions for branching ratios relevant for experimental searches.

Contribution

It introduces a novel application of light-cone sum rules to analyze FCNC decays of $ ext{Xi}_{QQ}$ baryons and estimates their branching ratios.

Findings

Branching ratio for $b o d$ transition is around $10^{-9}$.

Branching ratio for $c o u$ transition is around $10^{-13}$.

Potential for $ ext{Xi}_{bb} o ext{Lambda}_b l^+ l^-$ detection at LHCb.

Abstract

The weak decays of doubly heavy $\Xi_{QQ}$ baryon induced by flavor changing $b \to d$ and $ c \to u$ flavor changing neutral current within the light cone sum rules are studied. Using the parallel components of the light cone distribution amplitudes for $\Lambda_Q$ baryon, the sum rules are constructed and analyzed for the corresponding transition form factors. Having the results for the form factors, the corresponding branching ratios for $\Xi_{QQ} \to \Lambda_Q l^+ l^-$ decays are estimated. While the branching ratio due to $b \to d$ transition is around $10^{-9}$, in $c \to u$ transition case, it is found as around $10^{-13}$. Hence, $\Xi_{bb} \to \Lambda_b l^+ l^-$ decay has the potential of being discovered at LHCb. However, $\Xi_{bb} \to \Lambda_b l^+ l^-$ is difficult to be measured due to the extremely small values of obtained branching ratio. Our results on the branching ratio are also compared with the results of the light-front approach.