Hadronic modes and quark properties in the quark-gluon plasma

Based on interaction potentials between a heavy quark and antiquark as extracted from recent QCD lattice calculations, we set up a Brueckner-type many-body scheme to study the properties of light (anti-) quarks in a quark-gluon plasma at moderate temperatures, T 1–2 Tc. The quark-antiquark T matrix, including both color-singlet and color-octet channels, and corresponding quark self-energies and spectral functions are calculated self-consistently. The repulsive octet potential induces quasiparticle masses of up to 150 MeV, whereas the attractive color-singlet part generates resonance structures in the q-q̄ T matrix, which in turn lead to quasiparticle widths of ∼200 MeV. This corresponds to scattering rates of ∼1 fm−1 and may reflect liquid-like properties of the system.