Core collapse supernovae in the QCD phase diagram

TL;DR

This study compares two hybrid equations of state with different quark matter phase transition models in core collapse supernova simulations, revealing how transition density temperature dependence influences quark matter formation and supernova evolution.

Contribution

It introduces and contrasts two distinct quark matter models in supernova simulations, highlighting the impact of their temperature-dependent transition densities on supernova dynamics.

Findings

Quark matter forms only with low-density phase transitions in the bag model.

Higher critical densities in the PNJL model prevent quark matter formation.

The bag model leads to a second neutrino burst during supernova evolution.

Abstract

We compare two classes of hybrid equations of state with a hadron-to-quark matter phase transition in their application to core collapse supernova simulations. The first one uses the quark bag model and describes the transition to three-flavor quark matter at low critical densities. The second one employs a Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model with parameters describing a phase transition to two-flavor quark matter at higher critical densities. These models possess a distinctly different temperature dependence of their transition densities which turns out to be crucial for the possible appearance of quark matter in supernova cores. During the early post bounce accretion phase quark matter is found only if the phase transition takes place at sufficiently low densities as in the study based on the bag model. The increase critical density with increasing temperature, as obtained for our PNJL parametrization, prevents the formation of quark matter. The further evolution of the core collapse supernova as obtained applying the quark bag model leads to a structural reconfiguration of the central proto-neutron star where, in addition to a massive pure quark matter core, a strong hydrodynamic shock wave forms and a second neutrino burst is released during the shock propagation across the neutrinospheres. We discuss the severe constraints in the freedom of choice of quark matter models and their parametrization due to the recently observed 2 solar mass pulsar and their implications for further studies of core collapse supernovae in the QCD phase diagram.