Abstract The formation of clusters at subsaturation densities, as a result of manybody correlations, constitutes an essential feature for a reliable modelization of the nuclear matter equation of state (EoS). Phenomenological models that make use of energy density functionals (EDFs) offer a convenient approach to account for the presence of these bound states of nucleons when introduced as additional degrees of freedom. However, in these models clusters dissolve, by construction, when the nuclear saturation density is approached from below, revealing inconsistencies with recent findings that evidence the existence of shortrange correlations (SRCs) even at larger densities. The idea of this work is to incorporate SRCs in established models for the EoS, in light of the importance of these features for the description of heavyion collisions, nuclear structure and in the astrophysical context. Our aim is to describe SRCs at suprasaturation densities by using effective quasiclusters immersed in dense matter as a surrogate for correlations, in a regime where cluster dissolution is usually predicted in phenomenological models. Within the EDF framework, we explore a novel approach to embed SRCs within a relativistic meanfield model with density dependent couplings through the introduction of suitable inmedium modifications of the cluster properties, in particularmore »
Equation of state of hot dense hyperonic matter in the Quark–MesonCoupling (QMCA) model
ABSTRACT We report a new equation of state (EoS) of cold and hot hyperonic matter constructed in the framework of the quark–mesoncoupling (QMCA) model. The QMCA EoS yields results compatible with available nuclear physics constraints and astrophysical observations. It covers the range of temperatures from T = 0 to 100 MeV, entropies per particle S/A between 0 and 6, lepton fractions from YL = 0.0 to 0.6, and baryon number densities nB = 0.05–1.2 fm−3. Applications of the QMCA EoS are made to cold neutron stars (NSs) and to hot protoneutron stars (PNSs) in two scenarios: (i) leptonrich matter with trapped neutrinos (PNSI) and (ii) deleptonized chemically equilibrated matter (PNSII). We find that the QMCA model predicts hyperons in amounts growing with increasing temperature and density, thus suggesting not only their presence in PNS but also, most likely, in NS merger remnants. The nucleon–hyperon phase transition is studied through the adiabatic index and the speed of sound cs. We observe that the lowering of (cs/c)2 to and below the conformal limit of 1/3 is strongly correlated with the onset of hyperons. Rigid rotation of cold and hot stars, their moments of inertia and Kepler frequencies are also explored. The QMCA model results are compared with two more »
 Award ID(s):
 1748621
 Publication Date:
 NSFPAR ID:
 10221854
 Journal Name:
 Monthly Notices of the Royal Astronomical Society
 Volume:
 502
 Issue:
 3
 Page Range or eLocationID:
 3476 to 3490
 ISSN:
 00358711
 Sponsoring Org:
 National Science Foundation
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