Rare decays $\bar{B}\to X_{s(d)}\gamma$ at the NLO

Abstract

We present an independent calculation of $\mathcal{O}({\alpha }_s)$ matrix elements of the QCD penguin operators for the decays $\bar{B}\to X_{s(d)}\gamma$. The Mellin-Barnes representation technique is applied for the systematic numerical evaluation of involved two-loop diagrams. The numerical effect of the calculated contributions is confirmed to be of order of 1%. We also present an updated numerical analysis for $\bar{B}\to X_{s(d)}\gamma$ decay rates.

Comments: 15 pages, 4 figures