Thermal Width For Heavy Quarkonium In The Static Limit

The accuracy of hard thermal loop (HTL) approximation for the thermal width mechanism of heavy quarkonium dissociation is discussed. Thermal width mechanism is proposed as the main reason for quarkonium dissociation in ther-mal medium, but the gauge-dependent problem is emerged in the calculation. The HTL approximation is adopted in the literature to solve this problem, but the assumption of HTL approximation conflicts with the fact that the thermal medium, which generated with the present experiment condition, is not a weak-coupling medium. In order to test the accuracy of HTL thermal width results, we calculate the complete results of thermal width for charmonium and bottonium, and make a comparison between them with the HTL ones. The numerical re-sults show that the difference between HTL results and complete ones are about 50 MeV. It can be seen that, the HTL approximation can only provide semi-quantitative results, and the gauge-dependent problem can not be neglected in the current research.