2024/06/05 by Cheng-Ming Li, He-Rui Zheng, Shu-Yu Zuo +3 · 1 voice
Physics and Astronomy · #nucl-th #hep-ph
paper · pdf · doi:10.3847/1538-4357/adaf9a
arxiv published 2024/06/05 · arxiv updated 2025/01/28
In this work, under the hypothesis that quark matter may not be strange (Holdom et al. 2018), we adopt a modification of the coupling constant of the four-quark scalar interaction G→ G1+G2⟨ψψ⟩ in the 2-flavor Nambu-Jona-Lasinio (NJL) model to study nonstrange hybrid stars, where G1 and G2 are two parameters constrained by using the lattice QCD simulation results at the critical temperature and zero chemical potential. The Maxwell construction is used to describe the first-order confinement-deconfinement phase transition in hybrid stars. With recent measurements on neutron star mass, radius, and tidal deformability, the hybrid equation of states are constrained. It is found that pure nonstrange quark matter cores can exist in hybrid stars, possessing 0.026-0.04 solar mass. The maximum hybrid star mass in the framework of the modified NJL model is about 0.1 solar mass lighter than that in the conventional 2-flavor NJL model. It is argued that the binary neutron stars in GW170817 should be hadron stars.