Two-loop QCD corrections to top quark decay

Abstract

We present a determination of a new class of Feynman diagrams relevant for second-order QCD corrections to the top quark decay t -> b W. Modern computing techniques allow us to perform a reduction of the original loop integrals to master integrals. We obtain the analytical value of the top decay rate as an expansion around the limit of massless b and W.Comment: 3 pages, to appear in the proceedings of Lake Louise Winter Institute 2004, Lake Louise, Alberta, Canada, 15-21 Feb 200