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

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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.