Reconciling multi-messenger constraints with chiral symmetry restoration

Abstract

We analyze the recent astrophysical constraints in the context of a hadronic equation of state (EoS), in which the baryonic matter is subject to chiral symmetry restoration. We show that with such EoS it is possible to reconcile the modern constraints on the neutron star (NS) mass, radius, and tidal deformability (TD). We find that the softening of the EoS, required by the TD constraint of a canonical $1.4M_{\odot }$ NS, followed by a subsequent stiffening, required by the $2M_{\odot }$ constraint, is driven by the appearance of $\Delta$ matter due to partial restoration of chiral symmetry. Consequently, a purely hadronic EoS that accounts for the fundamental properties of quantum chromodynamics linked to the dynamical emergence of parity doubling with degenerate masses of nucleons and $\Delta$ resonances can be fully consistent with multi-messenger data. Therefore, with the present constraints on the EoS, the conclusion about the existence of the quark matter in the stellar core may still be premature.

version accepted for publication ApJ Letters

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Cited by in corpus (15)

• Heavy Baryons in Compact Stars
• Reaching percolation and conformal limits in neutron stars
• The slope, the hill, the drop, and the swoosh: Learning about the nuclear matter equation of state from the binary Love relations
• Chiral symmetry restoration and the $\Delta$ matter formation in neutron stars
• Neutron star matter based on a parity doublet model including the $a_0(980)$ meson
• Topology and emergent symmetries in dense compact star matter
• Fluctuations near the liquid-gas and chiral phase transitions in hadronic matter
• Fluctuations and correlations of baryonic chiral partners
• Anatomy of critical fluctuations in hadronic matter
• Conformality and percolation threshold in neutron stars
• Investigating the Impact of Higher-Order Phase Transitions in Binary Neutron-Star Mergers
• Emergent chirality and superfluidity of parity-doubled baryons in neutron stars
• A TESS View of Post-Eruption Variability in the Novae V1405 Cas,V1716 Sco, and V1674 Her
• Recurring region for neutron-star observables
• Parity-doubled nucleons can rapidly cool neutron stars