Thermometric signals of quark-gluon plasma

It is shown that the ratio of the production rates (μ+μ-/γ) and (π0±/μ+μ-) are suitable thermometric signals for detection of a possible phase transition from the hadronic world to a quark-gluon plasma; saturation of the ratio (μ+μ-/γ) is a signal of the phase transition most suitably picked up in the high MT∝pT regime, while the ratio (π0±/μ+μ-μ-) as a function of MT changes over from the hadronic world to a quark-gluon plasma with a clear decrease in the slope. Possible methods to test the validity of thermodynamic equilibrium are also explored. (orig.)