2006/02/28 by H. Iida, Hidehiro Iida, Takumi Doi +6 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-lat #hep-ph
paper · pdf · doi:10.1103/physrevd.74.074502
published as Phys.Rev. D74 (2006) 074502 · 13 pages, 11 figures
arxiv created 2006/06/14 · openalex publication_date 2006/10/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
J/\ensuremathΨ and \ensuremathηc above the QCD critical temperature Tc are studied in anisotropic quenched lattice QCD, considering whether the cc systems above Tc are spatially compact (quasi-)bound states or scattering states. We adopt the standard Wilson gauge action and O(a)-improved Wilson quark action with renormalized anisotropy as/at=4.0 at \ensuremathβ=6.10 on 163\ifmmode×\else\texttimes\fi(14--26) lattices, which correspond to the spatial lattice volume V\ensuremath≡L3\ensuremath≃(1.55 fm)3 and temperatures T\ensuremath≃(1.11--2.07)Tc. We investigate the cc system above Tc from the temporal correlators with spatially extended operators, where the overlap with the ground state is enhanced. To clarify whether compact charmonia survive in the deconfinement phase, we investigate spatial boundary-condition dependence of the energy of cc systems above Tc. In fact, for low-lying S-wave cc scattering states, it is expected that there appears a significant energy difference \ensuremathΔE\ensuremath≡E(APBC)\ensuremath-E(PBC)\ensuremath≃2√mc2+3\ensuremathπ2/L2\ensuremath-2mc (mc: charm quark mass) between periodic and antiperiodic boundary conditions on the finite-volume lattice. In contrast, for compact charmonia, there is no significant energy difference between periodic and antiperiodic boundary conditions. As a lattice QCD result, almost no spatial boundary-condition dependence is observed for the energy of the cc system in J/\ensuremathΨ and \ensuremathηc channels for T\ensuremath≃(1.11--2.07)Tc. This fact indicates that J/\ensuremathΨ and \ensuremathηc would survive as spatially compact cc (quasi-)bound states below 2Tc. We also investigate a P-wave channel at high temperature with maximal entropy method and find no low-lying peak structure corresponding to \ensuremathχc1 at 1.62Tc.