A novel method to test particle ordering and final state alignment in helicity formalism  

作　　者：Mengzhen Wang Yi Jiang Yinrui Liu Wenbin Qian Xiao-Rui Lyu Liming Zhang 王梦臻;蒋艺;刘寅睿;钱文斌;吕晓睿;张黎明(Center for High Energy Physics,Tsinghua University,Beijing 100084,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Center for High Energy Physics,Tsinghua University,Beijing 100084,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics C》2021年第6期29-36,共8页中国物理C（英文版）

基　　金：This work was supported in part by National Key R&D Program of China(2017YFA0402103,2020YFA0406400);National Natural Science Foundation of China(11775122,11822506,11975015);Fundamental Research Funds for the Central Universities。

摘　　要：In this study,the non-trival effect of the selection of reference particles for decay angle definitions is demonstrated when constructing the partial-wave amplitude of multi-body decays using helicity formalism.This issue is often ignored in the standard use case of helicity formalism.A new technique is proposed to test the selection of the particle ordering,and it can also be used as a generalized method to calculate the rotation operators that are used for the final-state alignment between different decay chains.Moreover,numerical validations are performed to support the arguments and to verify the effectiveness of the proposed technique.

关 键 词：helicity formalism PENTAQUARK baryon final state partial-wave amplitude analysis 

分 类 号：O572.2[理学—粒子物理与原子核物理]