Numerical evaluation of multi-gluon amplitudes for High Energy Factorization

Abstract We present a program to evaluate tree-level multi-gluon amplitudes with up to two of them off-shell. Furthermore, it evaluates squared amplitudes summed over colors and helicities for up to six external gluons. It employs both analytic expressions, obtained via BCFW recursion, and numerical BCFW recursion. It has been validated numerically with the help of an independent program employing numerical Dyson–Schwinger recursion. Title of program: AMP4HEF Catalogue Id: AEXF_v1_0 Nature of problem The numerical evaluation of matrix elements applicable in factorization prescriptions for the cross section calculation of hadron scattering processes that require off-shell partonic initial states. Versions of this program held in the CPC repository in Mendeley Data AEXF_v1_0; AMP4HEF; 10.1016/j.cpc.2015.06.023 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)摘要 本文提出一款可评估至多包含两个离壳胶子的树级多胶子振幅的程序。此外，该程序可对至多6个外胶子的颜色与螺旋度求和后的平方振幅进行数值求值。程序同时采用了基于BCFW递推得到的解析表达式与数值BCFW递推方法，并通过采用数值Dyson–施温格递推的独立程序完成了数值验证。 程序名称：AMP4HEF 目录编号：AEXF_v1_0 问题属性 针对需要离壳部分子初态的强子散射过程截面计算的因子化方案，实现其适用矩阵元的数值求解。 Mendeley数据中的CPC库收录版本 AEXF_v1_0；AMP4HEF；10.1016/j.cpc.2015.06.023 本程序源自贝尔法斯特女王大学馆藏的CPC程序库（1969-2018年）