CutTools：实现OPP归约方法以计算单回路振幅的程序
CutTools: a program implementing the OPP reduction method to compute one-loop amplitudes
摘要：
我们提出了一个程序，实现了降阶方法提取的系数的单圈标量积分从用户定义的（子）振幅或费曼图，以及合理的条款来自4维部分的分子。来自分子的ε维部分的有理部分被视为外部输入，并且可以在专用树级（如费曼规则）的帮助下计算。可能的数值不稳定性是在任意精度例程的帮助下处理的，这些例程仅在需要时激活。
英文摘要：
We present a program that implements the OPP reduction method to extract the coefficients of the one-loop scalar integrals from a user defined (sub)-amplitude or Feynman Diagram, as well as the rational terms coming from the 4-dimensional part of the numerator. The rational pieces coming from the epsilon-dimensional part of the numerator are treated as an external input, and can be computed with the help of dedicated tree-level like Feynman rules. Possible numerical instabilities are dealt with the help of arbitrary precision routines, that activate only when needed.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
