Feynman loop numerical integral expansions for 3-loop vertex diagrams
Feynman loop numerical integral expansions for 3-loop vertex diagrams
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3 环顶点图的费曼环数值积分展开
DOI：
10.1016/j.procs.2017.05.253
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Yuasa F
中科院分区：
文献类型：
--
作者：
de Doncker E;Yuasa F
在高能相互作用的精确理论计算中，微扰法需要用多圈图进行高阶修正。我们解决3圈顶点费曼图与无质量的内部线，并可能表现出紫外线（UV）奇点。计算方法的目标是自动数值积分和外推，以逼近相对于维度正则化参数的积分展开的主要系数。通过对积分展开式应用线性外推法来加速收敛。多变量积分是用ParInt软件包进行的，分层在MPI（消息传递接口）上，以加快计算速度。被积函数变换导致被积函数中奇异行为的影响减小。
The inclusion of higher order corrections by multi-loop diagrams is required in perturbation methods for precise theoretical calculations of high energy interactions. We address 3-loop vertex Feynman diagrams with massless internal lines, and which may exhibit ultra-violet (UV) singularities. The computational methods target automatic numerical integration and extrapolation to approximate the leading coefficients of the integral expansion with respect to the dimensional regularization parameter. Convergence acceleration is achieved by applying linear extrapolation on the integral expansion. Multivariate integration is performed with the ParInt software package, layered over MPI (Message Passing Interface) to speed up the computations. Integrand transformations result in diminishing the effect of singular behavior in the integrand.