Recent Perturbative Results on Heavy Quark Decays

摘要

We present new results for heavy quark decays at next-to-next-to-leading order.In particular, we discuss the calculation of the charm-quark mass effects andthe expansion in the intermediate recoil limit in semi-leptonic bottom-quarkdecays and the evaluation of the helicity fractions of the W boson from top-quark decays.