Unitarity constraints on effective interaction in pi N scattering

作者：Luo Mingxing^*; Wang Yong; Zhu Guohuai

来源：Physics Letters B, 2007, 649(2-3): 162-165.

DOI：10.1016/j.physletb.2007.03.052

Positivity constraints are derived on pion-nucleon scattering amplitudes and their even-order derivatives inside the Mandelstam triangle with the help of dispersion relations. Fairly interesting constraints are obtained on some of the low-energy constants, by a combination of the chiral perturbation theory for heavy baryons and existing fitting results from available pion-nucleon phase shifts at intermediate energies.

• 出版日期2007-5-31
• 单位浙江大学