Low-energy scattering processes of vector meson and nucleon are an important window for studying non-perturbative QCD. The interaction with nucleon, meson-nucleon length $|\alpha_{VN}|$, is component the study hadronic interactions. Nowadays many values $|\alpha_{VN}|$ have been reported using recent photoproduction experiment data or quasi data. In addition, trace anomalous energy contribution...

As has been confirmed meanwhile by lattice-QCD calculations (see e.g. Ref. [1]), the confinement spectrum of non-exotic quark-antiquark systems has its ground state for scalar mesons well above 1 GeV in the Resonance Spectrum Expansion (RSE). For instance, in the S-wave Kπ RSE amplitude, a broad resonance was predicted slightly above 1.4 GeV [2], which is confirmed by experiment as the K 0 (143...

The chiral symmetry is applied to an extended constituent quark potential model. With random phase approximation (RPA), a small component effect is added to the constituent quark model. To obtain the pseudoscalar π meson as a Goldstone boson, the quark effective potentials are modified in the model to account for the dynamical breaking of chiral symmetry. Also the vector ρ meson is calculated a...

Vector meson photoproduction and electroproduction have been suggested as a tool to find or confirm the nucleon resonances. In order to extract more reliable informations on the nucleon resonances, understanding the non-resonant background is indispensable. We consider final state interactions in ω photoproduction as a background production mechanism. For the intermediate states, we consider nu...

Polarized flavor asymmetry ∆¯ u/∆ ¯ d is investigated in a meson-cloud model. A polarized nucleon splits into a ρ meson and a baryon, then the polarized ρ meson interacts with the virtual photon. Because of the difference between the longitudinally polarized distributions ∆¯ u and ∆ ¯ d in ρ, the polarized flavor asymmetry is produced in the nucleon. In addition, we show that the g 2 part of ρ ...