Higher-order baryon number susceptibilities: Interplay between the chiral and the nuclear liquid-gas transitions

Abstract

We use an improved version of the SU(3) flavour parity-doublet quark-hadron model to investigate the higher order baryon number susceptibilities near the chiral and the nuclear liquid-gas transitions.The parity-doublet model has been improved by adding higher-order interaction terms of the scalar fields in the effective mean field Lagrangian, resulting in a much-improved description of nuclear ground-state properties, in particular the nuclear compressibility. The resulting phase diagram of the model agrees qualitatively with expectations from lattice QCD, i.e., it shows a crossover at zero net baryo-chemical potential and a critical point at finite density. Using this model, we investigate the dependence of the higher-order baryon number susceptibilities as function of temperature and chemical potential. We observe a strong interplay between the chiral and liquid-gas transition at intermediate baryo chemical potentials. Due to this interplay between the chiral and the nuclear liquid-gas transitions, the experimentally measured cumulants of the net baryon number may show very different beam energy dependence, subject to the actual freeze-out temperature.

Equation of state for hot QCD and compact stars from a mean-field approach

“…The Chiral SU(3)-flavor parity-doublet Polyakov-loop quark-hadron mean-field model, CMF, is an extension of the previously proposed σ-ω model with parity doubling for nuclear and hadron matter [24][25][26][27][28][29]. The CMF model was extended to include quark degrees of freedom [30][31][32][33][34]. This model is a phenomenological effective unified approach to describe interacting hadron-quark matter.…”

A Study of the Properties of the QCD Phase Diagram in High-Energy Nuclear Collisions

“…This is the characteristic experimental signature of the critical point we are looking for in the heavy-ion collision experiment. Theoretically, the properties of QCD phase diagram at finite baryon density and the signatures of conserved charge fluctuations near the QCD critical point have been extensively studied by various model calculations, such as Lattice QCD [10,[18][19][20][21][22]98], NJL, PNJL model [99][100][101][102][103][104][105][106], PQM, FRG model [107][108][109], Dyson-Schwinger Equation (DSE) method [110][111][112][113], chiral hydrodynamics [114] and other effective models [94, [115][116][117][118][119]. However, one should keep in mind that the above results are under the assumption of thermal equilibrium with infinite and static medium.…”

The application of the Quark-Hadron Chiral Parity-Doublet model to neutron star matter

“…In order to theoretically investigate the properties of strongly interacting matter in all of these environments, one has to employ a model approach containing hadrons and quarks in a comprehensive manner. After having analyzed (isospinsymmetric) heavy-ion-collision matter within the aforementioned approach (Mukherjee et al (2017)) based on an extension of the SU(3) parity-doublet model of Steinheimer et al (2011b), we use the same model to investigate the behavior of hybrid stars in the current paper. As an important outcome, we see that not only does this approach lead to a good description of the ground state properties of nuclear matter, but such an approach also leads to heavy hybrid stars with relatively smaller radii.…”