Charmonium spectral functions at finite temperature from a Bayesian analysis of QCD sum rules

Abstract

Charmonium spectral functions at finite temperature are investigated, making use of a recently developed method of analyzing QCD sum rules. This method employs the Maximum Entropy Method, which enables us to directly obtain the spectral function from the sum rules, without having to introduce any specific assumption about its functional form. QCD sum rules incorporate finite temperature effects by the change of the various gluonic condensates that appear in the operator product expansion. These changes depend on the energy density and pressure at finite temperature, which we extract from lattice QCD. As a result, J/ψ and ηc appear to dissolve into the continuum already at temperatures sightly above the critical temperature Tc.