Azial charges of N (1535) and N (1650) in two-flavor lattice QCD
We show the lattice QCD results on the axial charge g~(N~*N~*)_A of negative parity nucleon resonances, N~*(1535) and N~*(1650), which are key clues to the chiral structure in baryon sector. The measurements are performed with up and down dynamical quarks employing the renormalization-group improved gauge action at β=1.95 and the ο(a) improved clover quark action with the hopping parameters, κ=0.1375, 0.1390 and 0.1400.In order to properly separate signals of N~*(1535) and N~*(1650), we construct 2×2 correlation matrices and diagonalize them. Wraparound contributions in the correlator, which can be another source of signal contaminations, are eliminated by imposing the Dirichlet boundary condition in the temporal direction. We find that the axial charge of N~* (1535) takes small values as g~(N~*N~*)～ο(0.1), whereas that of N~*(1650) is about 0.5, which is found independent of quark masses and consistent with the predictions by the naive nonrelativistic quark model.
azial charge chiral symmetry negative parity nucleon
Toru T.Takahashi Teiji Kunihiro
Yukawa Institute for Theoretical Physics,Kyoto University,Kyoto 606-8502,Japan Department of Physics,Kyoto University,Kyoto 606-8502,Japan
国际会议
The 12th International Workshop on the Physics Ezcited Nucleon(2009核子共振态物理国际研讨会)
北京
英文
1233-1237
2009-04-19（万方平台首次上网日期，不代表论文的发表时间）