摘要
从协变手征有效理论出发,计算了核子-核子(Nucleon-Nucleon,N-N)散射两圈图振幅.两圈图是以箱图为骨架并对π介子自能进行修正所得.在减除时,采用两种减除方案:MS和EMS(Extended MS).由MS得到的振幅严重破坏手征微扰展开的幂次规则,由EMS得到的振幅中仅余非定域"反常"贡献,剩下的均是满足手征幂次规则的贡献.
The amplitude of the two-loop level in N-N(nucleon-nucleon)scattering is calculated using covariant chiral effective theory.Based on the skeleton of the box diagram,the two-loop diagram results from the correction of pion self-energy.Two subtraction schemes will be employed for comparison:MS and EMS.The loop amplitude obtained with MS contains terms that violate chiral power counting rules;with EMS,the results are entirely chiral contributions with the exception of non-local"anomalous"ones that must be retained.
作者
孙进
杨继锋
SUN Jin;YANG Jifeng(School of Physics and Electronic Science,East China Normal University,Shanghai 200241,China)
出处
《华东师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第2期90-97,共8页
Journal of East China Normal University(Natural Science)
基金
国家自然科学基金(11435005).
关键词
协变手征有效场论
MS方案
EMS方案
手征幂次规则
covariant chiral effective field theory
MS scheme
EMS scheme
chiral power counting rules
作者简介
通信作者:杨继锋,男,副教授,硕士生导师,研究方向为粒子物理与场论.E-mail:jfyang@phy.ecnu.edu.cn
