Interactions Between S-wave ? And Zero-strangeness Mesons

In this thesis,by using the chiral SU(3)quark model and the extended chiral SU(3)quark model and the resonance group method,we dynamically study the S-wave pentaquark systems composed of the baryon ?(*),and the meson or and anti-mesons (?)(*)or (?)(*).First of all,we have done research on the pentaquark system composed of the baryon ?(*)and the meson D(*)or B(*).The binding energies,the matrix elements of the Hamilton and each parts of the interactions inside S-wave systems with all possible quantum numbers are calculated.The numerical results indicate that(1)different quantum S-wave ?D,?D*,?*D and ?*D*systems can form 11 weak bound states with the binding energies in the range of 0.2?10.6MeV,while deferent quantum S-wave ?B,?B*,?*B and ?*B*systems can form 21 weak bound states with the binding energies in the range of 0.4?20.6MeV.(2)The interactions inside ?(*)D(*)and ?(*)B(*)systems are attractive in the middle range,and attractions in the ?(*)D(*)systems are weaker than those in the ?(*)B(*)systems.These attractions are dominantly from scalar meson ?.(3)When isospin is I=1/2,the middle-range attractions in the chiral SU(3)quark model are stronger than those in the extended chiral SU(3)quark model,while the attractions are stronger in the extended chiral SU(3)quark model when isospin is I=3/2.The reason is that in the extended chiral SU(3)quark model,the vector mesons ? and ? provide repulsive forces when isospin is I=1/2,while when isospin is I=3/2,the vector mesons p provides attractive interaction though ? still provides repulsive force.The behavior of the scalar and pseudoscalar mesons are similar in these two models.Then we have done research on the S-wave pentaquark systems composed of ?(*)and anti-mesons (?)(*)or (?)(*).We find that ?(*)and anti-mesons (?)(*)or (?)(*)systems can not obtain bound states in the two models(three groups of parameters).The further calculations show that(1)when isospin is I=1/2,the interactions between ?(*)and anti-mesons (?)(*)or (?)(*)are weak attractions,which are not strong enough to form bound states.When isospin is I=3/2,the interactions inside systems are repulsive.(2)Although the scalar meson ? provides considerable attractive force both in the chiral SU(3)quark model and the extended chiral SU(3)quark model,the confinement potential with isospin I=1/2,the one gluon exchange potential(the chiral SU(3)quark model)or the vector exchange potential(the extended chiral SU(3)quark model)with isospin I=3/2 will provide repulsive forces.(3)For the short-range interaction mechanism of the two models,the behavior of the one gluon exchange potential in the chiral SU(3)quark model and that of the vector meson exchange potential in the extended chiral SU(3)quark model is similar.