Interactions Between A Baryon ? And Heavy Zero-strangeness Mesons

In this thesis,we dynamically investigate the pentaquark systems composed of a ground-state a baryon(?)and a heavy meson(D(*),B(*),D(*)and B(*))within the chiral SU(3)and extended chiral SU(3)quark models by solving a resonating group method equationFirstly,the bound states are investigated.(1)We have obtained sixteen bound states of AD(*)systems and twenty bound states of ?B(*)systems.The number of bound-states in the extended chiral SU(3)quark model is larger than that in the chiral SU(3)quark model.In addition,the binding energies of the corresponding systems are greater in the extended chiral SU(3)quark model.(2)The systems ?D(*)and?B(*)with different quantum numbers cannot form bound statesSecondly,the properties of interactions inside the systems are further analyzed(1)The interactions inside the systems ?D(*)and ?B(*)are attractive.The attractions in the chiral SU(3)quark model dominantly come from the scalar meson(?),and in the extended chiral SU(3)quark model dominantly come from the scalar meson(?)and the vector mesons(?,?).What is more,the attractions in the extended chiral??SU(3)quark model are stronger than those in the chiral SU(3)quark model Attractions of low-spin states are larger when isospins are 1,and attractions of high-spin states are greater when isospins are 2.(2)For systems ?D(*)and ?B(*):(?)When insospins are 1(except for(?D*)5/2,1 and(?B*)5/2,1),internal interactions show a trend of weak attraction.These attractions in the chiral SU(3)quark model dominantly come from the scalar meson(?)and one-gluon exchange potential,and in the extended chiral SU(3)quark model dominantly come from the scalar meson(?)and the vector mesons(?,?).The results in the chiral SU(3)quark model are similar to those in the extended chiral SU(3)quark model,indicating that the contributions of one-gluon exchange potential and the vector mesons exchange potential in their models are similar.(?)Internal interactions of(?D*)5/2,1 and(?B*)5/2,1 systems show a trend of weak repulsion,which dominantly come from the confinement potential.In addition,the repulsions in the chiral SU(3)quark model are slightly larger.(?)When isospins are 2,internal interactions are strongly repulsive in short range,and weakly attractive in the middle-long range.Under the chiral SU(3)quark model,the repulsions in short range dominantly come from one-gluon exchange potential,while under the extended chiral SU(3)quark model,the repulsions in short range dominantly come from vector mesons exchange potential.The weak attractions of the middle-long range dominantly come from the scalar meson(?)in both modelsFinally,the S-wsave elastic scattering phase shifts of systems are studied.(1)In the systems ?D(*)and ?B(*),the signs of elastic scattering phase shifts are positive,indicating that internal interactions of systems are attractions.The amplitudes of phase shifts in the extended chiral SU(3)quark model are higher than those in the chiral SU(3)quark model,which shows that the former has great attractions.(2)For systems ?D(*)and AB(*):(?)When insospins are 1(except for(?D*)5/2,1 and(AB*)5/2,1),the signs of elastic scattering phase shifts are positive,indicating that internal interactions of systems are attractive.The signs of elastic scattering phase shifts are negative in(?D*)5/2,1 and(AB*)5/2,1 systems,indicating that internal interactions of systems are repulsive.(?)When isospins are 2(except(AB*)3/2,2),the signs of elastic scattering phase shifts are negative,internal interactions of systems are repulsive.The signs of elastic scattering phase shifts are positive in(AB/)3/2,2 system,indicating that internal interactions of systems are attractive.