Speaker
Description
I present an analysis of the inclusive $H_b \to X_s \gamma$ decay with $H_b$ a beauty baryon, in particular $\Lambda_b$, employing an expansion in the heavy quark mass at ${\cal O}(m_b^{-3})$ at leading order in $\alpha_s$.
For a polarized baryon I show the results for the distribution $\displaystyle\frac{d^2\Gamma}{dy \, d \cos \theta_P}$, with $y=2E_\gamma/m_b$, $E_\gamma$ the photon energy and $\theta_P$ the angle between the baryon spin vector and the photon momentum in the $H_b$ rest-frame.
I discuss the correlation between the baryon spin and the photon polarization, and show how effects of physics beyond the Standard Model can modify the photon polarization asymmetry.
I also present a method to treat the singular terms in the photon energy distribution.
