8,078 research outputs found
QCD phase transitions via a refined truncation of Dyson-Schwinger equations
We investigate both the chiral and deconfinement phase transitions of QCD
matter in a refined scheme of Dyson-Schwinger equations, which have been shown
to be successful in giving the meson mass spectrum and matching the interaction
with the results from ab initio computation. We verify the equivalence of the
chiral susceptibility criterion with different definitions for the
susceptibility and confirm that the chiral susceptibility criterion is
efficient to fix not only the chiral phase boundary but also the critical end
point (CEP), especially when one could not have the effective thermodynamical
potential. We propose a generalized Schwinger function criterion for the
confinement. We give the phase diagram of both phase transitions and show that
in the refined scheme the position of the CEP shifts to lower chemical
potential and higher temperature. Based on our calculation and previous results
of the chemical freeze out conditions, we propose that the CEP locates in the
states of the matter generated by the Au--Au collisions with
GeV.Comment: 12 pages, 6 figures, 1 tabl
Interface Effect in QCD Phase Transitions via Dyson-Schwinger Equation Approach
With the chiral susceptibility criterion we obtain the phase diagram of
strong-interaction matter in terms of temperature and chemical potential in the
framework of Dyson-Schwinger equations (DSEs) of QCD.After calculating the
pressure and some other thermodynamic properties of the matter in the DSE
method, we get the phase diagram in terms of temperature and baryon number
density. We also obtain the interface tension and the interface entropy density
to describe the inhomogeneity of the two phases in the coexistence region of
the first order phase transition. After including the interface effect, we find
that the total entropy density of the system increases in both the
deconfinement (dynamical chiral symmetry restoration) and the hadronization
(dynamical chiral symmetry breaking) processes of the first order phase
transitions and thus solve the entropy puzzle in the hadronization process.Comment: 9 pages, 9 figures, and 1 tabl
A Universal Constraint on the Infrared Behavior of the Ghost Propagator in QCD
With proposing a unified description of the fields variation at the level of
generating functional, we obtain a new identity for the quark-gluon interaction
vertex based on gauge symmetry, which is similar to the Slavnov-Taylor
Identities(STIs) based on the Becchi-Rouet-Stora-Tyutin transformation. With
these identities, we find that in Landau gauge, the dressing function of the
ghost propagator approaches to a constant as its momentum goes to zero, which
provides a strong constraint on the infrared behaviour of ghost propagator.Comment: 4 pages, no figur
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