title: Top-quark decay at next-to-next-to-leading order in QCD.
abstract: We present the complete calculation of the 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. In particular, we also show the first results of the fully differential decay rates for the top-quark semileptonic decay t → W(+)(l(+)ν)b at next-to-next-to-leading order in QCD. Our method is based on the understanding of the invariant mass distribution of the 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.
authors.affiliation: Department of Physics, Southern Methodist University, Dallas, Texas 75275-0175, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China and Center for High Energy Physics, Peking University, Beijing 100871, China.
authors.forename: Chong Sheng
authors.initials: CS
authors.lastname: Li
authors.affiliation: SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94309, USA.
authors.forename: Hua Xing
authors.initials: HX
authors.lastname: Zhu