Rho-meson resonance broadening in QCD at finite temperature

TL;DR

This paper uses finite energy QCD sum rules to analyze how the properties of the rho meson, such as its width, change with temperature, providing insights into quark-gluon deconfinement relevant for nuclear collision experiments.

Contribution

It introduces a method to determine the temperature dependence of rho meson resonance parameters using QCD sum rules, linking hadronic and quark-gluon descriptions at finite temperature.

Findings

Rho meson width increases with temperature.

Deconfinement occurs near T_c ≈ 197 MeV.

Results align with quark-gluon plasma formation evidence.

Abstract

Thermal Finite Energy QCD sum rules for the vector current correlator are used to study quark-gluon deconfinement. Assuming $\rho$-meson saturation of the correlator in the hadronic sector, and the Operator Product Expansion in QCD, we obtain the temperature behavior of the resonance parameters (coupling, mass, and width), and of the leading vacuum condensates, as well as the perturbative QCD threshold in the complex squared energy plane. The results are consistent with quark-gluon deconfinement at a critical temperature $T_c \simeq 197 MeV$. The temperature dependence of the $\rho$-meson width is of importance for current experiments on dimuon production in nuclear collisions.