通过J/Ψ→NM衰变研究N~*时的核子极点效应

N-pole Effect in Studying N* via J/Ψ→NM Decays

摘要: 研究了J／Ψ→pp^-π衰变过程中核子极点图的贡献，特别是由离壳效应带来的贡献．发现衰变宽度对形状因子是敏感的．在通过用J／Ψ→pp^-π衰变研究N^*时，核子极点图作为背景道的贡献是非常重要的；在通过J／Ψ→pp^-η和pp^-η研究N^*时，核子极点图的贡献可忽略不计；在通过J／Ψ→pp^-ω研究N^*时，核子极点图有明显的贡献．
N-pole contributions, especially due to off shell effect, in J/Ψ→ NM decays are
carefully studied. It is found that the decay width is sensitive to the form factor. The Npole contribution as a background is important in the J/Ψ→Nπ decay, ignorable in the J/Ψ→Nη and Nη' decays, and sizable in the J/Ψ→Nω decay.

Abstract: N-pole contributions, especially due to off shell effect, in J/Ψ→ NM decays are
carefully studied. It is found that the decay width is sensitive to the form factor. The Npole contribution as a background is important in the J/Ψ→Nπ decay, ignorable in the J/Ψ→Nη and Nη' decays, and sizable in the J/Ψ→Nω decay.