相对论夸克模型和N-Δ能量劈裂

Relativistic Quark Model and the N-Δ Mass Splitting

基于相对论夸克模型 ,在夸克层次上研究了N Δ的质量和二者的能量劈裂 ,通过引入了赝标量π介子云效应 ,得到了π和核子之间的耦合常数gπNN,以及单胶子交换势和单π介子交换势分别对N Δ能量劈裂的贡献 ,计算结果较好地与实验值得到了吻合 .另外我们还比较了相对论与非相对论夸克模型在处理上的不同 .

In the constituent quark model, light baryons are considered as the systems of the constituent quarks with confining interaction and with a chiral interaction mediated by Goldstone bosons. Here the masses of the N and Δ and their splitting are investigated based on a relativistic quark model approach with inclusion of pion meson cloud. Pseudoscalar π-quark interaction is employed to study the coupling between the mucleon and the π. The results show the contributions of the one-gluon-exchange potential and of the pion meson cloud to the N-Δ mass splitting. Moreover, our numerical analyses indicate a difference between the relativistic and the nonrelativistic treatments.