Nonperturbative quark matter equations of state with vector interactions
Institut für Theoretische Physik, Justus-Liebig-Universität Gießen,
2 LUTH, Observatoire de Paris, PSL Research University, CNRS, Université de Paris, 5 place Jules Janssen, 92195 Meudon, France
3 Helmholtz Forschungsakademie Hessen für FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung, Campus Gießen, Germany
Accepted: 27 October 2020
Published online: 21 December 2020
Nonperturbative equations of state (EoSs) for two and three quark flavors are constructed with the functional renormalization group (FRG) within a quark-meson model truncation augmented by vector mesons for low temperature and high density. Based on previous FRG studies without repulsive vector meson interactions the influence of isoscalar vector ω- and ϕ-mesons on the dynamical fluctuations of quarks and (pseudo)scalar mesons is investigated. The grand potential as well as vector meson condensates are evaluated as a function of quark chemical potential and the quark matter EoS in β-equilibrium is applied to neutron star (NS) physics. The tidal deformability and mass-radius relations for hybrid stars from combined hadronic and quark matter EoSs are compared for different vector couplings. We observe a significant impact of the vector mesons on the quark matter EoS such that the resulting EoS is sufficiently stiff to support two-solar-mass neutron stars.
© The Author(s) 2020
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