Top Quark Decay at Next-to-Next-to Leading Order in QCD.

摘要

We present the complete calculations of top quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and W boson width effects. Especially we also show the first results of the fully differential decay rates for top-quark semileptonic decay t W+(l+ )b at next-to-next-to-leading order in QCD. Our method is based on the understanding of the invariant mass distribution of final-state jet in the singular limit from effective field theory. Our result can be used to study arbitrary infrared-safe observables of top quark decay with the highest perturbative accuracy.