论文标题
$ s_ {11} $ $ n^*（890）$从天真的$ k $矩阵拟合中出现？
How does the $S_{11}$ $N^*(890)$ state emerge from a naive $K$ matrix fit?
论文作者
论文摘要
我们对描述$πn$散射幅度的$ k $矩阵模型进行了教学分析，以低能在$ s_ {11} $ Channel中。我们展示了在$ s $频道中正确使用分析性和在$ t $和$ u $ channels中的交叉对称性如何导致负$ s $区域的分析行为，这与手性扰动幅度在其有效性区域的预测一致。该分析再次得出结论，即存在真正的$ n^*（890）$共振。
We give a pedagogical analysis on $K$ matrix models describing the $πN$ scattering amplitude, in $S_{11}$ channel at low energies. We show how the correct use of analyticity in the $s$ channel and crossing symmetry in $t$ and $u$ channels leads to a much improved analytic behavior in the negative $s$ region, in agreement with the prediction from chiral perturbation amplitudes in its validity region. The analysis leads again to the conclusion that a genuine $N^*(890)$ resonance exists.
