Penguin-Induced Radiative Baryonic B Decays

Abstract

Weak radiative baryonic B decays $B\to\B_1\ov \B_2γ$ mediated by the electromagnetic penguin process $b\to sγ$ have appreciable rates larger than their two-body counterparts $B\to\B_1\ov \B_2$. The branching ratios for $B^-\toΛ\bar pγ$ and $B^-\toΞ^0\barΣ^-γ$ 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 $Λ_b\toΛγ$ and $Ξ_b\toΞγ$ due to the large short-distance enhancement for $b\to sγ$ 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.

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