meson mass and heavy quark potential at finite temperature

有限温度におけるメソンの質量及び重いクオーク間のポテンシャル

Gubler, P. ; Song, T.*; Lee, S. H.*

Gubler, P.; Song, T.*; Lee, S. H.*

Based on the observation that the heavy quark-antiquark potential value at infinity corresponds to twice the meson mass, we constrain the asymptotic value of the heavy quark potential in a hot medium through a QCD sum rule calculation of the meson at finite temperature. We find that to correctly reproduce the QCD sum rule results as well as a recent model calculation for the meson mass near the critical temperature, the heavy quark potential should be composed mostly of the free energy with an addition of a small but non-trivial fraction of the internal energy. Combined with a previous study comparing potential model results for the J/ to a QCD sum rule calculation, we conclude that the composition of the effective heavy quark potential should depend on the inter-quark distance. Namely, the potential is dominated by the free energy at short distance, while at larger separation, it has a fraction of about 20% of internal energy.