Perturbative corrections to power suppressed effects in semileptonic B decays

We compute the O(αs) corrections to the Wilson coefficient of the chromomagnetic operator in inclusive semileptonic B decays. The results are employed to evaluate the complete \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ {{{{\alpha_s}\Lambda_{\mathrm{QCD}}^2}} \left/ {{m_b^2}} \right.} $\end{document} correction to the semileptonic width and to the first moments of the lepton energy distribution.