Where does the ρ go? Chirally symmetric vector mesons in the quark-gluon plasma

If the phase transition of QCD at nonzero temperature is dominated by the (approximate) restoration of chiral symmetry, then the transition might be characterized using a gauged linear {σ} model. Assuming that vector meson dominance holds, such {σ} models predict that at the temperature of chiral restoration, the pole mass of the thermal {ρ} meson is greater than that at zero temperature; in the chiral limit and in weak coupling this mass is {~}962 MeV. The width of the thermal {ρ}-a₁ peak is estimated to be about 200--250 MeV.