华东师范大学学报（自然科学版） ›› 2020, Vol. 2020 ›› Issue (2): 90-97.doi: 10.3969/j.issn.1000-5641.201922008

• 物理学与电子学 • 上一篇    下一篇

核子-核子散射协变手征有效场论的两圈图研究

孙进, 杨继锋   

  1. 华东师范大学 物理与电子科学学院, 上海　200241
  • 收稿日期:2019-03-25 发布日期:2020-03-16
  • 通讯作者: 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 E-mail:jfyang@phy.ecnu.edu.cn
  • 基金资助:
    国家自然科学基金（11435005）

A study of nucleon-nucleon scattering in covariant chiral effective field theory at the two-loop level

SUN Jin, YANG Jifeng   

  1. School of Physics and Electronic Science, East China Normal University, Shanghai　200241, China
  • Received:2019-03-25 Published:2020-03-16

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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: $\overline {{\rm{MS}}}$和${\rm{E}}\overline {{\rm{MS}}} \left( {{\rm{Extended}}\;\overline {{\rm{MS}}} } \right)$. 由$\overline {{\rm{MS}}}$得到的振幅严重破坏手征微扰展开的幂次规则, 由${\rm{E}}\overline {{\rm{MS}}}$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.

关键词: 协变手征有效场论, $\scriptstyle\overline {{\rm{MS}}}$方案, $\scriptstyle{\rm{E}}\overline {{\rm{MS}}}$方案, 手征幂次规则

Abstract: 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: $\overline {{\rm{MS}}}$ and ${\rm{E}}\overline {{\rm{MS}}}$. The loop amplitude obtained with $\overline {{\rm{MS}}}$ contains terms that violate chiral power counting rules; with ${\rm{E}}\overline {{\rm{MS}}}$, the results are entirely chiral contributions with the exception of non-local “anomalous” ones that must be retained.

Key words: covariant chiral effective field theory, $\scriptstyle\overline {{\rm{MS}}}$ scheme, $\scriptstyle{\rm{E}}\overline {{\rm{MS}}}$ scheme, chiral power counting rules

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