Chiral invariant mass and scale symmetry in dense matter from a dilaton compensated parity doublet model
Abstract
In the parity doublet model the nucleon mass includes a chiral invariant part m0, which is conventionally assumed to be medium independent. We promote this assumption to a dynamical question by making the model scale invariant using a dilaton compensator χ, so that the effective chiral invariant mass minv∗ = m0χ̃, with χ̃= χ/fχ, responds to the partial restoration of scale symmetry in the medium. We fit the model parameters by using vacuum spectra, nuclear matter properties, and NICER mass--radius posteriors---with the hadronic equation of state connected to 2+1-flavor Nambu--Jona-Lasinio quark matter by an interpolation. The best fit gives m0 = 657 MeV, a maximum neutron-star mass of 2.30 M⊙ and R1.4 = 12.22 km, with the mass--radius sequence passing through all three NICER credible regions. The resulting tidal deformabilities, Λ1.4 = 387 and Λ̃= 463, are consistent with GW170817 measurements. The in-medium analysis separates the two restorations: at the hadron--quark matching density the chiral condensate falls to 56% of its vacuum value, while the dilaton decreases only to 94%, so the nucleon arrives at the matching density with 90% of its mass carried by the invariant part. The order parameters of chiral and scale symmetries organize the in-medium probes, making the ω an almost pure probe of scale symmetry and the ρ of chiral restoration, which gives us a clue on the origin of hadron mass.
Related
- Spin splitting without symmetry: a nearly compensated ferrimagnet and the origin of altermagnetism
- Statistical Symmetry Breaking and Emergent Colored Noise in a Stochastic Scalar-Doublet Field Theory
- A gauge-invariant measure for lattice chiral fermions
- NJL-Chiral Soliton and the Nucleon Equation of State at supra-saturation density: Impact of Chiral Symmetry Restoration
- Classification of chiral domain-wall dynamics through symmetry analysis
BibTeX
@misc{ma2026chiral,
title = {{Chiral invariant mass and scale symmetry in dense matter from a dilaton compensated parity doublet model}},
author = {Yao Ma and Bikai Gao and Masayasu Harada and Yong-Liang Ma},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.08163},
eprint = {2611.08163},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.08163},
}
RIS
TY - UNPB
TI - Chiral invariant mass and scale symmetry in dense matter from a dilaton compensated parity doublet model
AU - Yao Ma
AU - Bikai Gao
AU - Masayasu Harada
AU - Yong-Liang Ma
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2611.08163
UR - https://arxiv.org/abs/2611.08163
AB - In the parity doublet model the nucleon mass includes a chiral invariant part m_0, which is conventionally assumed to be medium independent. We promote this assumption to a dynamical question by making the model scale invariant using a dilaton compensator χ, so that the effective chiral invariant mass m_inv^∗ = m_0χ̃, with χ̃= χ/f_χ, responds to the partial restoration of scale symmetry in the medium. We fit the model parameters by using vacuum spectra, nuclear matter properties, and NICER mass--radius posteriors---with the hadronic equation of state connected to 2+1-flavor Nambu--Jona-Lasinio quark matter by an interpolation. The best fit gives m_0 = 657 MeV, a maximum neutron-star mass of 2.30 M_⊙ and R_1.4 = 12.22 km, with the mass--radius sequence passing through all three NICER credible regions. The resulting tidal deformabilities, Λ_1.4 = 387 and Λ̃= 463, are consistent with GW170817 measurements. The in-medium analysis separates the two restorations: at the hadron--quark matching density the chiral condensate falls to 56% of its vacuum value, while the dilaton decreases only to 94%, so the nucleon arrives at the matching density with 90% of its mass carried by the invariant part. The order parameters of chiral and scale symmetries organize the in-medium probes, making the ω an almost pure probe of scale symmetry and the ρ of chiral restoration, which gives us a clue on the origin of hadron mass.
ER -