Singularities and accumulation of singularities ofπN scattering amplitudes  

作　　者：Qu-Zhi Li Han-Qing Zheng 

机构地区：[1]Department of Physics Peking University,Beijing 100871,China [2]College of Physics,Sichuan University,Chengdu,Sichuan 610065,China [3]Collaborative Innovation Center of Quantum Matter,Beijing,China

出　　处：《Communications in Theoretical Physics》2022年第11期136-139,共4页理论物理通讯（英文版）

基　　金：supported in part by National Nature Science Foundations of China under contract numbers 11975028 and 10925522。

摘　　要：It is demonstrated that for the isospin I=1/2πN scattering amplitude,T^(I=1/2)(s,t),s=(m_(N)^(2)-m_(π)^(2))^(2)/m_(N)^(2)and s=m_(N)^(2)+2m_(π)^(2)are two accumulation points of poles on the second sheet of complex s plane,and are hence accumulation of singularities of T^(I=1/2)(s,t).For T^(I=3/2)(s,t),s=(m_(N)^(2)-m_(π)^(2))^(2)/m_(N)^(2)is the accumulation point of poles on the second sheet of the complex s plane.The proof is valid up to all orders of chiral expansions.

关 键 词：dispersion relations partial wave ANALYTICITY 

分 类 号：O572[理学—粒子物理与原子核物理]