New approach for amplitudes with multiple fermion lines  

作　　者：Feng Zhang Bin Gong Jian-Xiong Wang 张丰;Bin Gong;王建雄(Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China [2]University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics C》2022年第8期63-71,共9页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China (12135013,11975242);supported in part by National Key Research and Development Program of China (2020YFA0406400)。

摘　　要：A new approach for tree-level amplitudes with multiple fermion lines is presented.It primarily focuses on the simplification of fermion lines.By calculating two vectors recursively without any matrix multiplications,the result of a fermion line is reduced to a very compact form depending only on the two vectors.Comparisons with other packages are presented,and the results show that our package FDC provides a very good performance in the processes of multiple fermion lines with this new approach and some other improvements.A further comparison with WHIZARD shows that this new approach has a competitive efficiency in computing pure amplitude squares without phase space integration.

关 键 词：multi-particle process scattering amplitude fermion line tree level 

分 类 号：O572.2[理学—粒子物理与原子核物理]