We study the properties of charmonium states at finite temperature in quenched QCD on large and fine isotropic lattices. We perform a detailed analysis of charmonium correlation and spectral functions both below and above $T_c$. Our analysis suggests that both $S$ wave states ($J/\psi$ and ${\eta }_c$) and $P$ wave states (${\chi }_{c0}$ and ${\chi }_{c1}$) disappear already at about $1.5T_c$. The charm diffusion coefficient is estimated through the Kubo formula and found to be compatible with zero below $T_c$ and approximately $1/\pi T$ at $1.5T_c\lesssim T\lesssim 3T_c$.

• Received 23 April 2012

DOI:https://doi.org/10.1103/PhysRevD.86.014509