Quark Gluon Plasma Bags as Reggeons

Within an exactly solvable model I discuss the influence of the medium dependent finite width of quark gluon plasma (QGP) bags on their equation of state. It is shown that the large width of the QGP bags not only explains the observed deficit in the number of hadronic resonances, but also clarifies the reason why the heavy QGP bags cannot be directly observed as metastable states in a hadronic phase. I show how the model allows one to estimate the minimal value of the width of QGP bags being heavier than 2.5 GeV from a variety of the lattice QCD data and to get the minimal resonance width at zero temperature of about 600 MeV. The Regge trajectories of large and heavy QGP bags are established both in a vacuum and in a strongly interacting medium. It is shown that at high temperatures the average mass and width of the QGP bags behave in accordance with the upper bound of the Regge trajectory asymptotics (the linear asymptotics), whereas at low temperatures (below a half of the Hagedorn temperature T_H [1] they obey the lower bound of the Regge trajectory asymptotics (the square root one). Thus, for temperatures below T_H/2 the spin of the QGP bags is restricted from above, whereas for temperatures above T_H/2 these bags demonstrate the typical Regge behavior consistent with the string models.