出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Charmonium dissociation temperatures are studied in a quenched anisotropic lattice QCD with
standard plaquette gauge action and O(a) improved Wilson fermion action. Simulations are carried
out at temperatures in the range 0:88 Tc to 2:3 Tc. From the meson correlators, we first
subtract the contribution of constant mode, which was reported to mislead the analysis of, in particular,
P wave signals. We then calculate effective masses and Bethe-Salpeter wave functions
for ground (1S, 1P) and excited states (2S, 2P) using the multi-state variational analysis. To distinguish
between bound states and scattering states, we apply two methods: First, we compare
effective masses for charmonium correlation functions with finite spatial momenta under different
spatial boundary conditions. Since the scattering state energies are sensitive to the boundary
conditions, we expect finite volume effects when the charmonium dissociates. Second, we study
the Bethe-Salpeter wave function, which should become broad when the charmonium bound state
turns into a scattering state. With both methods, we have fond no clear evidences of dissociation
for the ground and exited charmonium states up to 2:3 Tc so far.
