Experimental equation of state in proton-proton and proton-antiproton collisions and phase transition to quark gluon plasma

We deduce approximate equations of state from experimental measurements in pp and p¯p collisions. Thermodynamic quantities are estimated combining the measure of transverse momentum pT vs pseudorapidity density dNch/deta with the estimation of the interaction region size from measures of Bose Einstein correlation, or from a theoretical model which relates dNch/deta 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 dNch/deta about 6 and end at dNch/deta about 24