Quark Gluon Bags as Reggeons

TL;DR

This paper presents a solvable model analyzing how medium-dependent widths of QGP bags influence their equation of state, explaining resonance deficits and the non-observability of heavy QGP bags, with estimates consistent across lattice QCD data.

Contribution

It introduces a model incorporating finite widths of QGP bags, linking Regge trajectory behavior to temperature-dependent properties, and resolves contradictions in hadronic mass spectrum theories.

Findings

Minimal resonance width at zero temperature is about 600 MeV.

At high temperatures, QGP bag properties align with linear Regge asymptotics.

Lattice QCD pressure includes T-linear and T^4 ln T terms between 240-420 MeV.

Abstract

The influence of the medium dependent finite width of QGP bags on their equation of state is analyzed within an exactly solvable model. It is argued 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. The model allows us to estimate the minimal value of the width of QGP bags from a variety of the lattice QCD data and get that the minimal resonance width at zero temperature is about 600 MeV, whereas the minimal resonance width at the Hagedorn temperature is about 2000 MeV. As shown these estimates are almost insensitive to the number of the elementary degrees of freedom. The recent lattice QCD data are analyzed and it is found that besides sigma T**4 term the lattice QCD pressure contains T-linear and T**4 ln T terms in the range of temperatures between 240 MeV and 420 MeV. The presence of the last term in the pressure bears almost no effect on the width estimates. Our analysis shows that at hight 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 they obey the lower bound of the Regge trajectory asymptotics (the square root one). Since the model explicitly contains the Hagedorn mass spectrum, it allows us to remove an existing contradiction between the finite number of hadronic Regge families and the Hagedorn idea of the exponentially growing mass spectrum of hadronic bags.