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

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

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

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

Glueball properties in anisotropic SU(3) lattice QCD with improved action

We study the glueballs properties at finite temperature using SU(3) lattice QCD at the quenched level with the anisotropic lattice. We use the tree-level Symanzik O(a^2) improved action. We present our preliminary results which shows the slight reduction of the scalar glueball mass near T_cComment: 8 pages, 13 figures, Talk given at Joint Workshop of the Special Research Center for the Subatomic Structure of Matter and the National Institute for Theoretical Physics (Workshop on Lepton Scattering, Hadrons and QCD), Adelaide, Australia 26 March - 6 April 200