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arXiv · 0806.0126

Survival of charmonia above Tc in anisotropic lattice QCD

H. Iida·T. Doi·N. Ishii·H. Suganuma·K. Tsumura
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Abstract

We find a strong evidence for the survival of $J/Ψ$ and $η_c$ as spatially-localized $c\bar c$ (quasi-)bound states above the QCD critical temperature $T_c$, by investigating the boundary-condition dependence of their energies and spectral functions. In a finite-volume box, there arises a boundary-condition dependence for spatially spread states, while no such dependence appears for spatially compact states. In lattice QCD, we find almost {\it no} spatial boundary-condition dependence for the energy of the $c\bar c$ system in $J/Ψ$ and $η_c$ channels for $T\simeq(1.11-2.07)T_c$. We also investigate the spectral function of charmonia above $T_c$ in lattice QCD using the maximum entropy method (MEM) in terms of the boundary-condition dependence. There is {\it no} spatial boundary-condition dependence for the low-lying peaks corresponding to $J/Ψ$ and $η_c$ around 3GeV at $1.62T_c$. These facts indicate the survival of $J/Ψ$ and $η_c$ as compact $c\bar c$ (quasi-)bound states for $T_c < T < 2T_c$.

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H. Iida, T. Doi, N. Ishii, H. Suganuma, K. Tsumura. 2008-06-01. Survival of charmonia above Tc in anisotropic lattice QCD. https://doi.org/10.1143/ptps.174.238

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