Numerical evaluation of multi-loop integrals by sector decomposition
Numerical evaluation of multi-loop integrals by sector decomposition
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DOI：
10.1016/j.nuclphysb.2003.12.023
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发表时间：
2003-05
期刊：
影响因子：
--
通讯作者：
T. Binoth;G. Heinrich
中科院分区：
文献类型：
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作者：
T. Binoth;G. Heinrich
在最近的论文[核物理B 585（2000）741]中，我们提出了一个自动减法发散多回路/腿积分的维数正则化，允许他们的数值计算，并将其应用到图与无质量的内部线。在这里，我们将展示如何将此算法扩展到费曼图与大规模传播和任意传播的权力。作为应用，我们提出了主2-loop 4-point拓扑的数值结果与大量的内部线发生在Bhabha散射在两个循环，和主积分的平面和非平面无质量双盒图与两个离壳腿。我们还数值计算了一些两点函数的β函数计算相关的5个循环，和一个3循环4点函数，无质量的壳平面三重盒。而4点函数的评估在非物理运动学区域，传播函数的结果是有效的任意运动学。
In a recent paper [Nucl. Phys. B 585 (2000) 741] we have presented an automated subtraction method for divergent multi-loop/leg integrals in dimensional regularisation which allows for their numerical evaluation, and applied it to diagrams with massless internal lines. Here we show how to extend this algorithm to Feynman diagrams with massive propagators and arbitrary propagator powers. As applications, we present numerical results for the master 2-loop 4-point topologies with massive internal lines occurring in Bhabha scattering at two loops, and for the master integrals of planar and non-planar massless double box graphs with two off-shell legs. We also evaluate numerically some two-point functions up to 5 loops relevant for beta-function calculations, and a 3-loop 4-point function, the massless on-shell planar triple box. Whereas the 4-point functions are evaluated in non-physical kinematic regions, the results for the propagator functions are valid for arbitrary kinematics.