The Severity Of The Child's Coupled Channel Effects

At present, the world’s experimental cooperation group accumulated a large amount of experimental data.Since2003, BaBar, Belle, BES, CLEO, CDF experiment cooperative groups have reported a lot of new hadronic states, the so-called "X, Y, Z" particles. Such as X(1835), X(3872), Y(3940), Z(4160), Z(3930), Zb(10610). These hadrons state explained by traditional quark model has met with some difficulties. This phenomenon has aroused wide interest around theorists and experimenters. They put forward various interpretations:multi-quark state, molecular state and mixed state, etc.For multi-quark state, although so far, there is no more than a quark hadronic states were experimentally;But the basic theory of hadron physics quantum chromodynamics theory itself does not rule out the existence of multi-quark system. Some researchers think these new hadronic states may not be a simple two quarks or three quark system, but may be some of the meson and baryon molecular state, multi-quark state, etc.In baryons section, we think baryon is composed of three quarks in traditional quark model. Description using three quark system. But there are exceptions to the rule, such as N(1440), A(1405)These particles’parity is positive, the quality given by experiment is significantly lower than the quark model calculated energy.Therefore, three quark system has a problem when explaining these baryons. Inspired by theoretical workers to the explanation of meson. Whether the baryons can be explained by multi-quark system Or the state may be three quarks and five mixed state of quark is our assumption.In this paper, we will do some research for this assumption.In the Constituent Quark Model framework, we usie the3P0model and the Coupling the effect to calculate the effect of five quark composition to the baryon spectra.3P0quark Model is the quark producing model which was firstly Putted forward by QPC,L. Micu,and is improved and promoted by Le Yaouanc, Ackleh, Roberts.3P0quark Model is applied to OZI (Okubo, Zweg and Iizuka) rules described in the two body decay inside. People have used3P0quark Model for a series of research and calculation in the Baryon meson which could be with u, d, s, c, b quark meson, and the decay of amplitude and partial wave width, these were matched well with the experimental data.Many gaussian expansion method (GEM) is putted forward by Kamimura when they doing the research of umolecules and atoms μ, non adiabatic calculation of three body.The algorithm in the nuclear physics has proven to be an effective less precise calculation method. In recent years, people have given the algorithm a successfully apply to the study of hadron physics. The basic thought of The GEM methods is:Divides the wave function of system with multiple gaussian wave function expansion, via the variational method to solve the eigen energy and wave function of the system.The main characteristic of this method is:when select the appropriate number of gauss, it will get high calculation precision, convergence speed is fast; so it can be easily applied to multi-quark hadronic physics problems.Our work is calculating the mass change caused by the five quark under the3P0model,using gaussian considering the coupling effect. And our further research is whether five quark effect can be absorbed by the model parameters.First of all, we use gaussian expansion method to calculate the energy and wave function of three quarks group, then the model was used to study the given five quark composition, the exotic baryon mass movement. As a preliminary work, five composition of quarks bound for two color singleton group:3quarks group and two quarks, and all color singleton group in the ground state, namely all the orbital angular momentum is zero. If using fitting of three quarks baryonic mass with the experimental data, the N and△quality mobile respectively:-315.04MeV and-523.1MeV, poor quality of the resulting△and N of130.3MeV, greater deviation from the experimental data. To test whether the coupling way effect can be absorbed by model parameters, we have to adjust the parameters, is to think about after five quark composition of baryonic quality conforms to the experimental value, for the singular ground state baryons, we can achieve a goal, but for in a singular number of baryon excited baryons and belt, we have no current calculation, and this is our next step.