X Conference of Young Scientists "Problems of Theoretical Physics"

Traces of the nuclear liquid-gas phase transition in the analytic properties of hot QCD

24 Dec 2019, 16:55

20m

322 (Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine)

Oral Physics of Nuclei and Elementary Particles Physics of Nuclei and Elementary Particles

Speaker

Mr Oleh Savchuk (Taras Shevchenko National University of Kyiv)

Description

The nuclear liquid-gas transition at normal nuclear densities, n∼n0=0.16 fm−3, and small temperatures, T∼20 MeV, has a large influence on analytic properties of the QCD grand-canonical thermodynamic potential. A classical van der Waals equation is used to determine these unexpected features due to dense cold matter qualitatively. The existence of the nuclear matter critical point results in thermodynamic branch points, which are located at complex chemical potential values, for $T>Tc≃20$ MeV, and exhibit a moderate model dependence up to rather large temperatures $T≲100$ MeV. The behavior at higher temperatures is studied using the van der Waals hadron resonance gas~(vdW-HRG) model. The baryon-baryon interactions have a decisive influence on the QCD thermodynamics close to μB=0. In particular, nuclear matter singularities limit the radius of convergence rμB/T of the Taylor expansion in μB/T, with rμB/T∼2−3 values at T∼140−170 MeV obtained in the vdW-HRG model.