Effects of the short-range part of the baryon-baryon interaction from a quark model on properties of nuclei

我们从一个夸克模型出发研究了重子-重子相互作用的短程部分，该模型可以同时描述正、负宇称重子以及双重子系统。此外，我们还研究了它对强子少体系统性质的影响。通过比较原始相互作用得到的散射波函数和壳上等效局域势得到的散射波函数，研究并澄清了由夸克自由度引起的重子-重子相互作用的非定域性效应。研究了奇异性为+1的重子--五夸克。我们假设它有4-夸克-1-反夸克组态相互关联。角动量-1/2态被认为是最轻的，它的衰变宽度太宽，不能被认为是观测到的。另一方面，角动量-3/2态的宽度较小，它被认为是下一个最轻的状态，因为它只受张量力的衰减。此外，我们还证明了瞬子诱导的相互作用可能会降低态的质量。研究了出现在B衰变中的重介子X(3872)。我们假设它具有qqbar-ccbar组态，并证明了该态可以描述为具有短距离多夸克分量的双介子分子态，该多夸克分量由吸引夸克相互作用形成。我们还研究了Lambda(1405)和其他负宇称激发的重子。如果散射用夸克-团簇模型处理，如果味-单重态3q态被引入为嵌入在连续体中的极点，那么这个粒子可以描述为Sigma-pi散射中的共振，它通过有效的单胶子交换势耦合。

We have investigated the short-range part of the baryon-baryon interaction from a quark model, which can describe the positive- and negative-parity baryons as well as two-baryon systems simltaniously. Also, we have investigated its effects on the properties of hadron few-body systems.1. Effects of the nonlocality of the baryon-baryon interaction arising from the quark degrees of freedom have been investigated and clarified by comparing the scattering wave functions obtained from the original interaction and those from the on-shell equivalent local potential.2. Pentaquark, a baryon with strangeness +1, has been investigated. We assume that it has 4-quark-1-antiquark configuration correlating each other. The decay width of the angular-momentum-1/2 state, which is considered to be the lightest, is too broad to be considered as the observed one. On the other hand, the width is small for the angular-momentum-3/2 state, which is considered to be the next lightest one, because it decays only by a tensor force. Also, we show the possibility that the instanton-induced interaction may lower the mass of the state.3. X(3872), a heavy meson which appears in the B-decay, has been investigated. We assume that it has qqbar-ccbar configuration and have shown that the state can be described as a two-meson molecular state with a short-ranged multiquark component forming from the attractive quark interaction.4. Lambda(1405) and other negative-parity excited baryons have also been investigated. This particle can be described as a resonance in the Sigma-pi scattering if the scattering is treated by a quark-cluster model and if the flavor-singlet 3q state is introduced as a pole embedded in the continuum, which couples by the effective one-gluon-exchange potential.