Hadron-Hadron Interaction In A Chiral Quark Model

QCD is widely believed to be the underlying theory of strong interactions. Due to the non-perturbative property of QCD in low energy region, people still need various QCD-inspired models in the study of low energy hadron physics. Among these models, the chiral SU(3) quark model and the extended chiral SU(3) quark model have been quite successful in reproducing the energies of the baryon ground states, the binding energy of deuteron, the nucleon-nucleon scattering phase shifts, and the nucleon-hyperon scattering cross sections, and have also made remarkable progress in the study of the baryon-meson interactions, e.g. interactions of KN,∧K,∑K,△K, NΦandΩπ. In this thesis, by using these chiral quark models, we further dynamically study the interactions of KN,ΞK,ωΦand K*K* within the framework of resonating group method. Following are the main results we have achieved:●TheΞEK interaction is dynamically investigated. The results show that the S-wave isospin I=0ΞK interaction is attractive, and in the extended chiral SU(3) quark model such an attraction can make for aΞK bound state with 3 MeV binding energy. Further analysis shows that inΞK system the one-gluon exchange offers strong repulsion while vector meson exchange is weekly attractive, which leads the EK system to be one of the ideal places to help us examine the short range quark-quark interaction mechanism.●TheωΦstates with spin S= 0,1 and 2 are dynamically studied. It is found that though theωΦinteraction is attractive, the strength of the attraction is not strong enough to formωΦbound state or resonance state. Our results do not support the explanation that the X(1812), recently observed by BES II collaboration in theωΦinvariant mass spectrum in J/Φ→γωΦdoubly OZI suppressed decay, is structured byωΦbound state or resonance.●The K*K* interaction is dynamically investigated. The results show that in the chiral SU(3) quark model an S= 2 K*K* bound state can be obtained, and in the extended chiral SU(3) quark model the K*K* bound states can be obtained for all the spin cases. The experimental information about these states can help us test our model and further to understand the short range interaction mechanism.●The cross sections for K-p scattering into K-p, K0n,π+∑-,π-∑+,π0∑0 andπ0∧channels and the KN scattering phase shifts are dynamically stud-ied. The results show that for the short range interaction, if we only con-sider one-gluon exchange or vector meson exchange besides quark exchange effects, no simultaneous description for KN cross sections and KN phase shifts can be obtained by use of one set of parameters. Later we construct a new model where both one-gluon exchange and vector meson exchange are included and within such a mode we achieve a satisfactory description for both KN and KN scattering data. We conclude that both one-gluon exchange and vector meson exchange should be considered in the quark-quark interaction if one wants to describe the KN and KN scattering with one set of parameters in the constituent quark model.More systems with strong interactions will be investigated in our future work with the purpose to test our model by a comparison of our theoretical results with the experiments and, on the other hand, to predict unknown properties of strong interaction systems by using the model tested already by NN and KN scattering.