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The structures of Ωω states with spin-parity Jp = 5/2−, 3/2−, and 1/2− are dynamically studied in both the chiral SU(3) quark model and the extended chiral SU(3) quark model by solving a resonating group method (RGM) equation. The model parameters are taken from our previous work, which gave a satisfactory description of the energies of the baryon ground states, the binding energy of the deuteron, the nucleon-nucleon (NN) scattering phase shifts, and the hyperon-nucleon (YN) cross sections. The calculated results show that the Ωω state has an attractive interaction, and in the extended chiral SU(3) quark model such attraction can make for a Ωω quasi-bound state with spin-parity Jp = 3/2− or 5/2− and the binding energy of about several MeV.

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 (ΩΩ)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 (ΩΩ)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 |CCstr = −6,ST = 00 is much higher than that of the (ΩΩ)ST = 00 state, thus the CC channel has little effect on the binding energy of (ΩΩ)ST = 00 state. When the error function confinement potential is considered, the bound state property would not change largely. Further, scalar meson mixing is considered. No matter whether θS = −18° or ideal mixing is taken, (ΩΩ)ST = 00 state is still a bound state.

The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters are taken to be the values fitted by the energies of the baryon ground states and the kaon-nucleon elastic scattering phase shifts of different partial waves. As a preliminary study the s-channel q(-q) annihilation interactions are not included since they only act in the very short range and are subsequently assumed to be unimportant in the low-energy domain. The numerical results are in qualitative agreement with the experimental data.

The structures of (ΩΩ)0+ and (([1])Ω)1+ are studied in the extended chiral SU(3) quark model in whichvector meson exchanges are included. The effect from the vector meson fields is very similar to that from the one-gluonexchange (OGE) interaction. Both in the chiral SU(3) quark model and in the extended chiral SU(3) quark model,di-omega (ΩΩ)0+ is always deeply bound, with over one hundred MeV binding energy, and (([1])Ω)1+ 's binding energyis around 20 MeV. An analysis shows that the quark exchange effect plays a very important role for making di-omega(ΩΩ)0+ deeply bound.

The chiral SU(3) quark model is extended by including the vector meson exchanges to describe the short range interactions. The phase shifts of NN scattering are studied in this model. Compared with the results of the chiral SU(3) quark model in which only the pseudo-scalar and scalar chiral fields are considered, the phase shifts of 1S0 wave are obviously improved.

The cross sections of Ω + Ω→ (ΩΩ)Jx+ X are studied by using an effective Hamiltonian method.The results are ern+ΩΩ→(nΩ)0++ = 0.03 ～ 0.16 × 10- cm2 for pn = 100 ~ 400 MeV,and the cross sections ofη production are about 10-28 cm2 for pΩ＞ 880 MeV.

The structure of a new dibaryon (ΩΩ)0+ is studied and predicted in the framework of the chiral SU(3) quark model by solving a resonating group method equation. The binding energy of this dibaryon is around 100 MeV, the mean root square of the distance between two Ωs is 0.84 fm and the preliminary estimated mean lifetime is about two times longer than that of the free Ω. All these interesting properties and also the two negative charge units it carried could make it be easily identified experimentally in the heavy-ion collision process. The production probability of this new dibaryon in 158A GeV Pb+Pb collision is estimated using the thermal model, which is of the order of 10-6 to 10-5 per event; And it is expected, that with the increase of temperature, the production rate will also be increased.

We discuss the structure of deltaron dibaryon in the chiral quark model. The energy of deltaron is obtained by considering the coupling of the and CC (hidden color) channels. It is shown that the mass of deltaron is lower than the mass of but higher than the mass of .

The leptonic decay of charmonium is studied by using an error function confinement potential in which the color-screening effect is considered. The relativistic correction of the quark-antiquark potential is also included in the calculation. The discrepancy means that there should be some other effects in explaining charmonium high-lying states.

Nucleon-nucleon interaction is studied in the non-relativistic quark model with a flat bottom linear confinement potential. The results are consistent with the calculated ones from the lattice quantum chromodynamics. The quark-quark interaction also consists of those caused by the one gluon exchange and the one pion exchange. The phenomenological sigma meson exchange between two nucleons is also included to fit the S-wave N-N scattering data. The calculated NN channel S-wave phase shifts show that the flat bottom linear confinement potential can provide part of the medium range attraction.

The N-N interaction is studied in the framework of non-relativistic quark model using the resonating group method (RGM). The ΔΔ channel is taken into account in addition to the NN channel. The calculated S-wave phase shifts show that the channel coupling effect is increased if the quadratic or the linear confinement is replaced by the flat-bottom-linear confinement. This result is quite different from that in the case of the quadratic confinement or the linear confinement, in which this channel coupling effect is negligible.