Liaoning Normal Univ, Dept Phys, Dalian 116029, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
Previously, we extended our chiral SU(3) quark model to include the coupling between the quark and vector chiral fields. [Nucl. Phys. A 727(2003)321]. Here we further study the structure of (Omega Omega)(ST=00) dibaryon in the extended chiral SU(3) quark model by solving a resonating group method equation. The vector meson exchanges effect, hidden colour channel and colour screening effect are investigated, respectively. The results show that the (Omega Omega)(ST=00) system is still the deeply bound state in the extended chiral SU(3) quark model in which the vector meson exchanges control the short-range quark-quark interaction, which is similar to the results obtained from the chiral SU(3) quark model. When the model space is enlarged by including the hidden colour channel, it is found that the energy of the hidden colour state vertical bar CC >(str=-6),(ST=00) is much higher than that of the (Omega Omega)(ST=00) state, thus the CC channel has little effect on the binding energy of (Omega Omega)(ST=00) state. When the error function confinement potential is considered, the bound state would not change largely. Further, scalar meson mixing is considered. No matter whether theta(S) = -18 degrees or ideal mixing is taken, (Omega Omega)(ST=00) is still a bound state.