Direct emission of light mesons from quark-gluon plasma surface
  On the basis of hydrodynamic model of evolution of heavy ion collision we consider emission of $\pi,K,\eta,\rho,\omega,K^*$ mesons directly from the surface of quark-gluon plasma, with accounting of their absorption by surrounding plasma hadronic gas. We evaluate upper and lower limits on yields of these direct mesons in Pb+Pb collision at 158 AGeV (SpS) and 3150+3150 AGeV (LHC), and find, that even in the case of the lowest yield, direct $\eta$ and heavier mesons dominate at LHC energy at soft $p_t$ ($p_t\le 0.5 GeV/c$). This enhancement of the low $p_t$ meson production can be considered as a quark-gluon plasma signature. 
D.Yu.Peressounko, Yu.E.Pokrovsky (Russian Research Center ''Kurchatov   Institute'')