SPECTRUM OF QUARK GLUON PLASMA

The dispersive properties of both Bose and Fermi collective excitations in hot quark-gluon plasma are analysed. We show that in the momenta region k ≫ gT only transverse oscillations corresponding to quarks and gluons survive. The longitudinal Bose and Fermi oscillations discussed earlier in the literature are overdamped at k ≳ gT due to Landau mechanism. We discovered also new quasimassless fermion mode with frequency ω ∼ -ig2T which exists at low momenta k ≲ g2T. The appearance of this mode reflects an approximate supersymmetry of massless QCD lagrangian in the high energy limit where interaction terms are small. The damping of all types of oscillations is also discussed. It is estimated as Im ω(k) ∼ g2T in the region of existence of the modes. © 1990.