Crossover transition in bag-like models

Abstract

We formulate a simple model for a gas of extended hadrons at zero chemical potential by taking inspiration from the compressible bag model. We show that a crossover transition qualitatively similar to lattice QCD can be reproduced by such a system by including some appropriate additional dynamics. Under certain conditions, at high temperature, the system consist of a finite number of infinitely extended bags, which occupy the entire space. In this situation the system behaves as an ideal gas of quarks and gluons.Comment: Corresponds to the published version. Added few references and changed the titl

Hagedorn bag-like model with a crossover transition meets lattice QCD

“…The scan in δ performed here is, therefore, similar to the study presented in Ref. [27]. The temperature dependence of the scaled pressure p/T 4 and the scaled energy density ε/T 4 is depicted in Fig.…”

“…m = 4Bv from the MIT bag model [3], leads to a constant energy density at high temperature, which is incompatible with lattice QCD (see Refs. [24,25,27] for more details).…”

A novel mathematical mechanism of the critical endpoint generation

“…This is obtained by matching the deconfining PT line T c (μ) with the line of vanishing surface tension coefficient T Σ (μ) for μ ≥ μ end and T ≤ T c (μ end ). Such a step unexpectedly leads to a new strong claim that the 1st order PT in QGBSTM2 should not be accompanied by change of the leading singularity type as was argued earlier in [6,7,10,11,15,16,19,[24][25][26]. Then, in contrast to all previous findings, the high density QGP phase is defined by a simple pole of the isobaric partition (1) and not by its essential singularity (compare the panels a and b of Fig.…”

“…(6). Usually the statistical models similar to QGBSTM [6,7,10,11,15,16,19,[24][25][26] are dealing with the following structure of sin gularities. The pressure of low energy density phase (confined) p H (T, μ) is described by the simple pole s = s H (T, μ) = p H (T, μ)/T which is the rightmost singular ity of the isobaric partition (1), whereas the pressure of high energy density phase (deconfined) p Q (T, μ) fixes the system pressure, if the essential singularity s = s Q (T, μ) = p Q (T, μ)/T of this partition becomes the rightmost one (see figure a).…”

Erratum: QCD phase boundary and critical point in a bag model calculation [Phys. Rev. D80, 114508 (2009)]

“…From this critical point to the µ B = 0 line , we find a transitional cross-over region which cannot be described or modelled analytically. Hadronic degrees of freedom are insufficient to give a valid description [18] of this region whereas free quark and gluons start playing a significant role only at much higher temperatures. We have compared our prediction regarding the location of the QCD critical point with those…”