标题： 零喷注性软函数在微扰QCD中的三阶形式 显示英文标题

标题： Zero-jettiness soft function to third order in perturbative QCD

摘要： 我们给出了在微扰QCD中下一阶下一阶下一阶领先顺序（N3LO）下零喷注性软函数的高精度结果。 在这一微扰阶数下，软函数是使用零喷注性变量作为切片参数计算强子色单态产生或色单态衰变为两个喷注时所需的最后一个缺失成分。 此外，对N3LO软函数的了解使得能够通过下一阶下一阶下一阶领先对数阶次对过程$e^+ e^- \to \textrm{hadrons}$中的推力分布进行重求和描述，这对于利用该形状变量提取强耦合常数非常重要。 在方法论方面，零喷注性变量的复杂性迫使我们开发了一种新的半解析方法，在通过Heaviside函数参数化的约束条件下进行相空间积分，希望这种方法将有助于进一步发展$N$-喷注性切片方案。 显示英文摘要

摘要： We present the high-precision result for the zero-jettiness soft function at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. At this perturbative order, the soft function is the last missing ingredient required for the computation of a hadronic colour singlet production or a colour singlet decay into two jets using the zero-jettiness variable as the slicing parameter. Furthermore, the knowledge of the N3LO soft function enables the re-summed description of the thrust distribution in the process $e^+ e^- \to \textrm{hadrons}$ through next-to-next-to-next-to-leading logarithmic order, which is important for the extraction of the strong coupling constant using this shape variable. On the methodological side, the complexity of the zero-jettiness variable forced us to develop a new semi-analytic method for phase-space integration in the presence of constraints parameterized through Heaviside functions which, hopefully, will be useful for further development of the $N$-jettiness slicing scheme.