An N/D study of the S11 channel πN scattering amplitude

• 作者: Qu-Zhi Li Yao Ma Wen-Qi Niu Yu-Fei Wang Han-Qing Zheng
• 来源期刊: 中国物理C（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: PARTICLES AND FIELDS
• 页码范围: 35-48
• 页数: 14页
• 语种: 英文
• DOI: 10.1088/1674-1137/ac31a4

摘要

Extensive dynamical N/D calculations are conducted in the study of S 11 channel low energy πN scat-terings,based on various phenomenological model inputs of left cuts at the tree level.The subtleties of the singular behavior of the partial wave amplitude,at the origin of the complex s plane,are analysed in detail.Furthermore,it is found that the dispersion representation for the phase shift,δ,must be modified in the case of πN scatterings.An ad-ditional contribution from the dispersion integral exists,which approximately cancels the contribution of the two vir-tual poles located near the end points of the segment cut,induced by u channel nucleon exchanges.With limited reli-ance on the details of the dynamical inputs,the subthreshold resonance N*(890) survives.