Gao Jun, Li Chong Sheng, Zhu Hua Xing
Department of Physics, Southern Methodist University, Dallas, Texas 75275-0175, USA.
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.
Phys Rev Lett. 2013 Jan 25;110(4):042001. doi: 10.1103/PhysRevLett.110.042001. Epub 2013 Jan 24.
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.
我们给出了在 QCD 下次到次领头阶的顶夸克衰变宽度的完整计算，包括次领头阶电弱修正以及有限的底夸克质量和 W 玻色子宽度效应。特别地，我们还展示了在 QCD 下次到次领头阶时顶夸克半轻子衰变 t → W(+)(l(+)ν)b 的全微分衰变率的首个结果。我们的方法基于从有效场论对奇异极限下末态喷注不变质量分布的理解。我们的结果可用于以最高的微扰精度研究顶夸克衰变的任意红外安全可观测量。
