Experimental equation of state in pp and pp¯ collisions and phase transition to quark gluon plasma

We deduce approximate equations of state from experimental measurements in pp and pp¯ collisions. Thermodynamic quantities are estimated combining the measure of average transverse momentum 〈pT〉 vs pseudorapidity density dNchdη with the estimation of the interaction region size from measures of Bose Einstein correlation, or from a theoretical model which relates dNchdη to the impact parameter. The results are very similar to theory predictions in case of crossover from hadron gas to quark gluon plasma. According to our analysis, the possible crossover should start at dNchdη≃6 and end at dNchdη≃24.