In 1979 laboratory evidence for a change o velocity of sound with temperature in p-p reactions was reported (E

In 1979 laboratory evidence for a change o velocity of sound with temperature in p-p reactions was reported (E. M. Friedlander and R. M. Weiner, Phys. Rev. Lett. 43, 15 (1979) and interpreted as due to the formation of quark-gluon plasma.

In 1984 it was found (M. Plümer, S. Raha and R. M. Weiner, Nucl. Phys. A418, 549c, (1984)) that due to the remnant confinement effect quark-gluon plasma continues to interact strongly beyond the critical temperature. This property has been recently confirmed experimentally in heavy ion reactions at the relativistic heavy ion collider (RHIC).