Angular Distribution and Polarization of Photons in the Inclusive Decay $\Lambda_b\to X_s\,\gamma$

Abstract

We study the angular distribution of photons produced in the inclusive decay of a polarized $\Lambda_b$, $\Lambda_b\to X_s\,\gamma$, using the technique of Heavy Quark Effective Theory. Finite non-perturbative corrections are obtained relative to the free quark decay $b\to s\gamma$. These corrections affect significantly the intensity and polarization of photons emitted at small angles relative to the $\Lambda_b$ spin direction.