Study Of Y-N Interaction And Light Hypernuclei Based On The Chiral SU(3) Quark Model

The phenomenological interactions have frequently been employed as a generalinput in studying of Y-N interactions. So many free parameters make it inadequatelyin describing the nonpertubative QCD behavior in the short and medium ranges of theinteractions. Although the calculations succeed in explaining some properties ofsome hypernucleis, it is impossible for it to agree with all the experimental data.A general model is always one of the goals of the study of hypernuclei. Now, the theoretical studying in hypernuclei physics go deep into the quark levelfrom the bayon level with the developent of particle physics. The research of nearseveral decades enunciated that The meson featured in the atomic nucleus phenomenons.dynamics of quantum based on the hardons' free degree is a very successful theoryand it can explain many phenomenons of nuclon physics experimental phenomenons. On the other hand according to the common ground of nowadays, the basic theoriesof the strong interaction is based on the Quantum Chromdynamics of free degree ofquark and gumson and norm field theory. This theory is very successful at high energyregion, but how to apply it to the low energy region is far from solving.We knowthat QCD at low energy far region is deep non pertubative. In recent years, despiteusing latticesite norm theories to calculate the non-perturbative effect has alreadyobtained some greate progress, it can't resolve this problem and still need to fallback on the model theories in the actual application. Among these model, theconstituent quark model(CQM) is quite successful. In principle, the constituentquark mass mq and the quark-quark interaction should be derived from the QCDlagrangian. As long as the quark carries constituent mass, which is about severalhundred MeV, the chiral symmetry of the lagrangian is broken. It is well known that 3广西师范大学硕士学位论文the chiral symmetry is a very important symmetry reqired in hadronic physics.Therefore, restoring the chiral symmetry in lagrangian come out to be very important.That is to say,it is necessary to found a lagrangian which can give constituent quarkmass and quark-chiral interaction and match request of QCD theory. How to restorethe chiral symmetry of Lagrangian has contained many works. In 1960, GellMann andLevy gave the method to restore the chiral symmetry in σ model on the nuclei Levelof structure. nuclei field changed into quark field , the old σ model would comeout to be σ model on quark level and it got to be origin for the chiral symmetrymodel.Recently, Fernandez et. gave a quark-quark interaction potential whichincluded not only the spontaneous chiral symmetry breaking, but considered changingin π and σ as nonpertubative effect from QCD vacuum son. In this model, thecoupling constants for σ changing is determinate completely ,so the freeparameters was reduced. They used the potential in the N-N interaction and calculatedN-N scattering phase shift in GCM method and the result was meaningful. But in thesetwo model, they only gave consideration to π and σ fields interaction. In facta common form can concludes scalar field for isospin being vector and pseudoscalarfield for isospin being scalar. As a model with QCD's inspirit, the constituentquark model(CQM) turned out to be quite successful in studding the N-N interactiondynamically. But in this model, there are still some problems. For example, thesource of the constituent quark mass is not clear. Recently, it is an aware thatrestoring the chiral symmetry in the lagrangian, which is an important symmetry ofthe quark-chiral interaction ,can resolve some of these problems. In 1992, Fernandez et. gave quark-chiral interaction based on the linearrelation in σ model and consequently improve the calculated N-N scattering result.To study Y-N interaction, Zhang et al. further expanded this model to chiral SU(3)quark model. With a unified set of model parameters...