Rethinking the properties of the quark-gluon plasma at T_c < T < 4T_c

We argue that although at asymptotically high temperatures the quark-gluon plasma (QGP) in bulk behaves as a gas of weakly interacting quasiparticles (modulo long-range magnetism), it is different at temperatures up to few times the critical temperature T_c. In particular, we emphasize the role of several zero binding lines on the phase diagrams, below which c̄c, light quarks, gg as well as exotic gq,qq bound states exist. Near these lines quasiparticle rescattering is enhanced dramatically, possibly explaining why heavy-ion collisions at the relativistic heavy-ion collider exhibit robust collective phenomena. Although in QCD the coupling constant in the QGP phase reaches only values g ∼ 1, using Maldacena duality one may study these phenomena in the strong coupling limit g²N_c ≪ 1 in conformal gauge theories at finite temperature [e.g., N=4 supersymmetric Yang-Mills (SUSY YM)]. Trapped atoms is another system which allows us to study strongly interacting matter, in the limit of infinite scattering length.