Light cone QCD sum rules study of the rare radiative ${\mathrm{\Xi }}_{bb}^{\ast }\to {\mathrm{\Xi }}_b\gamma$ decay

The rare radiative decay ${\mathrm{\Xi }}_{bb}^{\ast }\to {\mathrm{\Xi }}_b\gamma$ is investigated within the light cone QCD sum rules approach. This decay proceeds through the flavor changing neutral current $b\to s$ transition in the Standard Model. The hadronic matrix element of the considered decay is parameterized in terms of four tensor form factors $T_1^V(q^2)$, $T_2^V(q^2)$, $T_1^A(q^2)$ and $T_2^A(q^2)$. The sum rules for these form factors describing the ${\mathrm{\Xi }}_{bb}^{\ast }\to {\mathrm{\Xi }}_b\gamma$ decay are derived at $q^2=0$ point using the ${\mathrm{\Xi }}_b$ distribution amplitudes. The results of the form factors are employed to calculate the corresponding decay width. Our finding indicates that this weak radiative decay could be within reach of future high statistics studies of doubly heavy baryons at LHCb and upcoming facilities.