QCD corrections to the weak radiative anti B-meson decay

The anti B→Xsγ decay, which is sensitive to the top-quark mass, has become now particularly interesting as we expect a t-mass greater than 80 GeV. The QCD corrections play a relevant role, enhancing the GIM suppressed vertex: Their computation presents many technical difficulties, which have led to different results in the previous literature. We have performed the calculation off-shell, in all gauges, in the leading logarithmic approximation; we confirm the strong enhancement of the QCD corrected branching ratios. (orig.)