Penguin-Induced Radiative Baryonic B Decays

Abstract

Weak radiative baryonic B decays $B\to {\text{B}}_1\text{ov}{\text{B}}_2\gamma$ mediated by the electromagnetic penguin process $b\to s\gamma$ have appreciable rates larger than their two-body counterparts $B\to {\text{B}}_1\text{ov}{\text{B}}_2$. The branching ratios for $B^{-}\to \Lambda \bar{p}\gamma$ and $B^{-}\to {\Xi }^0{\bar{\Sigma }}^{-}\gamma$ are sizable, falling into the range of $(1\sim 6)\times 10^{-6}$ with the value preferred to be on the large side, and not far from the bottom baryon radiative decays ${\Lambda }_b\to \Lambda \gamma$ and ${\Xi }_b\to \Xi \gamma$ due to the large short-distance enhancement for $b\to s\gamma$ penguin transition and the large strong coupling of the anti-triplet bottom baryons with the B meson and the light baryon. These penguin-induced radiative baryonic B decay modes should be accessible by B factories.

Comments: 8 pages, 1 figure. Branching ratios are corrected as previous values are too large by a factor of 2 and a new reference is added