Properties of Thermal Glueballs

We study the properties of the 0++ glueball at finite temperature using SU(3) quenched lattice QCD. We find a significant thermal effects near T_c. We perform the \chi^2 fit analyses adopting two Ansaetze for the spectral function, i.e., the conventional narrow-peak Ansatz and an advanced Breit-Wigner Ansatz. The latter is an extension of the former, taking account of the appearance of the thermal width at T>0. We also perform the MEM analysis. These analyses indicate that the thermal effect on the glueball is a significant thermal-width broadening \Gamma(T_c) \sim 300 MeV together with a modest reduction in the peak center \Delta\omega_0(T_c) \sim 100 MeV.Comment: A talk presented at International Conference on Color Confinement and Hadrons in Quantum Chromodynamics --Confinement 2003--, Wako, Japan, 21-24 July 2003, 5 pages, 3 figure

Charmonium-nucleon interactions from the time-dependent HAL QCD method

The charmonium-nucleon effective central interactions have been computed by the time-dependent HAL QCD method. This gives an updated result of a previous study based on the time-independent method, which is now known to be problematic because of the difficulty in achieving the ground-state saturation. We discuss that the result is consistent with the heavy quark symmetry. No bound state is observed from the analysis of the scattering phase shift; however, this shall lead to a future search of the hidden-charm pentaquarks by considering channel-coupling effects.Comment: 8 pages, 8 figure

Lattice QCD Study of the Nucleon-Charmonium Interaction

The $J/\psi$-nucleon interaction is studied by lattice QCD calculations. At the leading order of the derivative expansion, the interaction consists of four terms: the central, the spin-spin, and two types of tensor forces. We determine these spin-dependent forces quantitatively by using the time-dependent HAL QCD method. We find that the spin-spin force is the main cause of the hyperfine splitting between the $J=1/2$ and the $J=3/2$ states, while the two tensor forces have much smaller effects on the S-wave scattering processes.Comment: 5 pages, 4 figure

Thermal Width Broadening of the 0++ Glueball Spectrum near Tc

We study the 0++ glueball correlator constructed with SU(3) anisotropic quenched lattice QCD at various temperature taking into account the possible existence of the thermal width in the ground-state peak. For this purpose, we adopt the Breit-Wigner ansatz, analysing the lattice data obtained with 5,500-9,900 gauge configurations at each T. The results indicate the significant thermal width broadening as Gamma(Tc) \sim 300 MeV with a reduction in the peak center as Delta omega_0(Tc) \sim 100 MeV in the vicinity of the critical temperature Tc.Comment: Talk given at Tokyo-Adelaide Joint Workshop on Quarks, Astrophysics and Space Physics, Tokyo, Japan, 6-10 January 2003, 5 pages, Latex2e, 2 figure

Theoretical Foundation of the Nuclear Force in QCD and its applications to Central and Tensor Forces in Quenched Lattice QCD Simulations

We present full accounts of a method to extract nucleon-nucleon (NN) potentials from the Bethe-Salpter amplitude in lattice QCD. The method is applied to two nucleons on the lattice with quenched QCD simulations. By disentangling the mixing between the S-state and the D-state, we obtain central and tensor potentials in the leading order of the velocity expansion of the non-local NN potential. The spatial structure and the quark mass dependence of the potentials are analyzed in detail.Comment: 40 pages, 11 figures. Prog. Theor. Phys. accepted versio