Chiral Symmetry of Baryon and Baryon Resonances

点击翻译按钮获取中文摘要

Researches targeting the study of the chiral symmetry realization of the baryons and baryon excitations are performed. The main results are itemized in the following.(A) QCD sum rule approaches to the hadrons : Roles of chiral symmetry in the mass difference of the positive and negative parity baryons are clarified. The meson-baryon coupling constants under the SU(3) symmetry is also studied in the QCD sum rule. The F/D ratio is found to agree with the SU(6) quark model prediction.(B) Chiral effective theories for the baryon and baryon resonances : Baryons under chiral symmetry are classified and the mirror assignment is considered in detail. The N*(1535) is studied from the viewpoint of the mirror baryon candidate.(C) Lattice QCD and ladder QCD : Quenched lattice QCD calculation of the quark-gluon mixed condensate at finite temperature shows that the behavior coincides with the quark condensate, which indicates a universal structure of the chiral restoration. The roles of the instanton induced interaction in the scalar meson spectrum is studied in the ladder QCD.