Phase transitions of hadronic to quark matter at finite T and \mu_B

TL;DR

This paper investigates the phase transition from hadronic to quark matter at finite temperature and baryon chemical potential using two equations of state, highlighting the sensitivity of transition boundaries to model parameters and implications for neutron stars and heavy ion collisions.

Contribution

It provides a detailed analysis of the hadron-quark phase boundary using combined models and explores the dependence on model parameters like the Bag constant and isospin effects.

Findings

Critical temperatures depend on the Bag parameter and can be modeled by a fermion ultrarelativistic gas.

Critical chemical potentials are highly sensitive to the hadronic equation of state.

No solutions to Gibbs conditions exist for small Bag constants at low temperature.

Abstract

The phase transition of hadronic to quark matter and the boundaries of the mixed hadron-quark coexistence phase are studied within the two Equation of State (EoS) model. The relativistic effective mean field approach with constant and density dependent meson-nucleon couplings is used to describe hadronic matter, and the MIT Bag model is adopted to describe quark matter. The boundaries of the mixed phase for different Bag constants are obtained solving the Gibbs equations. We notice that the dependence on the Bag parameter of the critical temperatures (at zero chemical potential) can be well reproduced by a fermion ultrarelativistic quark gas model, without contribution from the hadron part. At variance the critical chemical potentials (at zero temperature) are very sensitive to the EoS of the hadron sector. Hence the study of the hadronic EoS is much more relevant for the determination of the transition to the quark-gluon-plasma at finite baryon density and low-T. Moreover in the low temperature and finite chemical potential region no solutions of the Gibbs conditions are existing for small Bag constant values, B < (135 MeV)^4. Isospin effects in asymmetric matter appear relevant in the high chemical potential regions at lower temperatures, of interest for the inner core properties of neutron stars and for heavy ion collisions at intermediate energies.