The Effect of Charge, Isospin, and Strangeness in the QCD Phase Diagram Critical End Point

Abstract

In this work, we discuss the deconfinement phase transition to quark matter in hot/dense matter. We examine the effect that different charge fractions, isospin fractions, net strangeness, and chemical equilibrium with respect to leptons have on the position of the coexistence line between different phases. In particular, we investigate how different sets of conditions that describe matter in neutron stars and their mergers, or matter created in heavy-ion collisions affect the position of the critical end point, namely where the first-order phase transition becomes a crossover. We also present an introduction to the topic of critical points, including a review of recent advances concerning QCD critical points.

Temperature and strong magnetic field effects in dense matter

“…This has been previously discussed within the CMF model at B ¼ 0 in Ref. [100]. The exact values of the differences in energy density between the beginning and end of the phase transition are given in Table III.…”

“…An exception is the case of T ¼ 100 MeV, where heavy-ion matter becomes softer just prior to the phase transition and the phase transition is weaker. This is related to the proximity of the critical point, shown to appear at much lower temperatures for heavy-ion matter in the CMF model [100] (without magnetic-field effects). For the PNJL model, heavy-ion matter is overall softer, reaches a lower energy density prior to the phase transition and a higher-energy density after, and presents a stronger phase transition (compared to neutron star matter) in all temperature and magnetic field cases analyzed.…”

Dense and Hot QCD at Strong Coupling

“…2 mark the location (T c ,n bc ) of the critical point in the respective models whose precise values are listed in Table I. The critical point has been analyzed in various models in the literature, and the results for the location vary in a wide range depending on the model [26,[76][77][78]. Recent results in a simpler holographic approach [26], which extrapolates results for thermodynamics of QCD from lattice QCD to higher values of baryon chemical potential by using a bottom-up setup, are given by {T c , µ bc } = {112, 612} MeV [27] and {T c , µ bc } = {89, 724} MeV [28,29].…”