Multi-quark Baryon Spectrum In The Chiral SU(3) Quark Model

In 2003, the Japanese LEPS experimental group claimed that they have found a particles with the smallest quark constituent, what is uudds. It caused a wave climax of research of multi-quark states in physics. DORiska, Jia-Lun Ping, who study the pentaquark state, can not find a good interpretation in pentaquark baryon spectrum.Proton magnetic moment, excited baryon state ect. issues has been failed to resolve, and non-elastic scattering experiments show that the baryon not only contains three quarks component, but so there have five quarks component. These have prompted us to re-examine the nature and structure of baryons. We constructed the five-quark system wave function which is met to the physical requirements by group theory in chiral SU (3) constituent quark model. The final baryon spectrum was obtained by a linear combination of quality in the three-quark model and in the five-quark model. This paper primarily calculated the octet baryon spectrum.This paper argues that a baryon contains three quarks and pentaquark state, which in part three quark baryon energy near zero energy.While the five-quark baryon state energy is the quality of an approximation. And a pentaquark baryon in the composition is inspired from the three quarks in a pair of quark and anti-quark formation. Pentaquark is composed of four quarks and one anti-quark. And four quarks are fermions, which symmetry meets the S4 group. All four are in the anti-symmetric state base on the Pauli exclusion principle. the anti-quark is not all the same fermion.Therefore, the five-quark wave function with four quarks and an anti-quark function be constructed by outer product. A baryon wave function is composed of the orbit, flavor, spin and color wave functions. Therefore, we shall decompose wave function of four quarks by the inner product in accordance with the requirements of decomposition. In order to construct the structure of the qqq-qq wave function,we shall be part every space of four-quark wave function to isolate a positive quark, which is coupled of quark and anti-quark wave function in various space.The orbit and spin space is SU (2) symmetry, while the flavor and color space is SU (3) symmetry. So flavor and color wave function of anti-quark can be with two quarks that are all antisymmetric. Young tableau of the decomposition is corresponding with the Weyle disk, we can get the final five-quark wave function. Then we calculate of matrix elements of each space and the pentaquark energy.However, the paper didn't consider the impact of the three quarks and the five-quark creation and annihilation mechanism because of the lack of the mechanism understanding. we have found that this model can explain some nature of the baryons, but there are some deviations. We need to consider the excited state and the quark-anti-quark pair production and annihilation effects in the future.