Holographic QCD phase diagram with critical point from Einstein–Maxwell-dilaton dynamics

Abstract

Supplementing the holographic Einstein-Maxwell-dilaton model of [1,2] by input of lattice QCD data for 2+1 flavors and physical quark masses for the equation of state and quark number susceptibility at zero baryo-chemical potential we explore the resulting phase diagram over the temperature-chemical potential plane. A first-order phase transition sets in at a temperature of about 112 MeV and a baryo-chemical potential of 612 MeV. We estimate the accuracy of the critical point position in the order of approximately 5 − 8 % by considering parameter variations and different low-temperature asymptotics for the second-order quark number susceptibility. The critical pressure as a function of the temperature has a positive slope, i.e. the entropy per baryon jumps up when crossing the phase border line from larger values of temperature/baryo-chemical potential, thus classifying the phase transition as a gas-liquid one. The updated holographic model exhibits in-and outgoing isentropes in the vicinity of the first-order phase transition.

Cool baryon and quark matter in holographic QCD

“…The backgrounds resulting from this fit will be the starting point for this article, on top of which the baryon dynamics will be added. Extrapolated EoSs for QCD on the (µ, T )-plane have also been considered earlier using holography [60][61][62][63] and field theory [64][65][66].…”

Holographic QCD in the Veneziano limit and neutron stars

“…Earlier related works considered fitting QCD lattice data at µ = 0 using a somewhat simpler holographic model based on Einstein-Maxwell-dilaton actions and studying the continuation of the equations of state to the (µ, T )-plane [27][28][29][30]. These articles concentrate on the physics near the critical point, whereas in the current article 1 Notice that while ordinary QCD does not have a well defined order parameter for the deconfinement transition, there is such a parameter at large N c : the pressure in the confined (deconfined) phase scales as N 0 c (N 2 c ).…”

Holographic vector mesons in a dilaton background

“…[61]), often employed in including a conserved charge density (e.g. [62,63]), such a term refers to the gauge coupling. For the relation to truncated string (M) theory and supergravity, see remarks in [64].…”