Weak Radiative Decays of Beauty Baryons

Abstract

Weak radiative decays of beauty baryons into strange baryons, induced by the electroweak penguin, are estimated by using a quark model approach. Relations between formfactors in the semileptonic and in the weak radiative decays are derived within the heavy quark effective theory. The partial decay widths are found to be of the order of $10^{-15}{\rm MeV}$ for $Λ_b\rightarrowΛγ$ and $Ξ_b\rightarrowΞγ$ and of the oder of $10^{-13}{\rm MeV}$ for $Ω_b\rightarrowΩγ$. The $Ω_b$ radiative decay is thus expected at the sizable branching ratio of approximately $10^{-4}$.