Top quark decay at next-to-leading order in the standard model effective field theory
Top quark decay at next-to-leading order in the standard model effective field theory
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DOI：
10.1103/physrevd.100.056023
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发表时间：
2019-07
影响因子：
5
通讯作者：
R. Boughezal;Chien‐Yi Chen;F. Petriello;D. Wiegand
中科院分区：
文献类型：
--
作者：
R. Boughezal;Chien‐Yi Chen;F. Petriello;D. Wiegand
我们在标准模型有效场论（SMEFT）中考虑顶夸克衰变。我们提出了一个计算的总衰变宽度和$W$-玻色子螺旋分数在下一个领先的顺序（NLO）在SMEFT。我们的结果除了包括QCD偶极算符和底质量抑制效应外，还包括了完整的四费米子算符。我们发现，在SMEFT中首次出现在NLO的算子可以被当前数据以及来自高光度LHC和潜在的$e^+e^-$对撞机的未来数据所约束，这表明了在研究SMEFT时超越领先阶的重要性。我们讨论了我们的计算技术方面，我们相信这将是有用的，在未来的高阶研究的SMEFT，特别是治疗的$\gamma_5$在回路图。
We consider top quark decay in the Standard Model Effective Field Theory (SMEFT). We present a calculation of the total decay width and the $W$-boson helicity fractions at next-to-leading order (NLO) in SMEFT. Our result includes the complete set of contributing four-fermion operators in addition to QCD dipole operators and bottom-mass suppressed effects. We show that operators that first appear at NLO in the SMEFT can be bounded by the current data as well as future data from both a high-luminosity LHC and a potential $e^+e^-$ collider, demonstrating the importance of going beyond leading order when studying the SMEFT. We discuss technical aspects of our calculation that we believe will be useful in future higher-order studies of the SMEFT, in particular the treatment of $\gamma_5$ in loop diagrams.