Research On Mixing Baryon Spectrum Of Three Quark And Pentaquark In The ³P₀ Model

In this paper,we have studied the energy spectral structures of light-weight baryon's octahe-dral,decuplet and singlet.The work consists of two parts:First,we calcu-lated the spectra of three quarks and five quarks by using chiral SU?3?quark model.For the three quark States,We calculated the energy spectra of even parity states?JP =1/2+,3/2⁺,5/2⁺,7/2⁺?and odd parity states?JP = 1/2^-,3/2^-,5/2^-?· Secondly,combining the ³P₀ model and considering the coupled channel effect,we calculated the baryon spectra of the mix of three quark states and five quark states.By analyzing the structure of the energy spectra,we can obtain some conclusions as follows.The process of using chiral SU?3?quark model to describe the energy of ground state baryon has little dependence on parameters.The model can well describe the energy of baryon octet and decuplet which are at the ground state.For the energy of the high excited state,the deviation between the theoretical and experimental values is large.This is partly because the harmonic wave function can ' t describe the high excited state well.We try to solve the problem by mixing the three quark states with the five quark states in the 3P0 model,but the problem of the inversion of energy levels has not been solved by this method.Combined with the 3P0 model,analysing the spectra of the mix of three quark states and five quark states.The results show that the annihilation fraction contributes little to the three quark energy spectrum and the five quark state energy spectrum.By solving the intrinsic equation of the Hamiltonian of the mixed system,the mixing states of three quark States and five quark states are obtained.In a mixed state,the three quark states are mixed by three quark States and five quark States,and the three quark States occupy a large proportion in the mixed states.Originally a five quark state,after mixing three quark states with five quark States,the five quark States occupy a large proportion in the mixed states.This shows that the probability of the transition of the three quark state to the five quark state and the probability of the five quark state transition to the three quark state are very low.