Scalar Quarkonia at Finite Temperature

TL;DR

This paper investigates how the masses and decay constants of scalar quarkonia change with temperature using QCD sum rules, showing stability up to 100 MeV and significant reductions near the deconfinement point.

Contribution

It provides the first detailed analysis of scalar quarkonia properties at finite temperature within the QCD sum rules framework, including temperature dependence of masses and decay constants.

Findings

Masses decrease by about 6% (bottom) and 23% (charm) near critical temperature.

Decay constants drop to approximately 25% of their vacuum values near deconfinement.

Results align with existing experimental data and other nonperturbative approaches.

Abstract

Masses and decay constants of the scalar quarkonia, $\chi_{Q0} (Q=b,c)$ with quantum numbers $I^G(J^{PC})=0^{+}(0^{++})$ are calculated in the framework of the QCD sum rules approach both in vacuum and finite temperature. The masses and decay constants remain unchanged up to $T\simeq100~MeV$ but they start to diminish with increasing the temperature after this point. At near the critic or deconfinement temperature, the decay constants reach approximately to 25% of their values in vacuum, while the masses are decreased about 6% and 23% for bottom and charm cases, respectively. The results at zero temperature are in a good consistency with the existing experimental values and predictions of the other nonperturbative approaches. Our predictions on the decay constants in vacuum as well as the behavior of the masses and decay constants with respect to the temperature can be checked in the future experiments.