Implication of neutron star observations to the origin of nucleon mass

TL;DR

This paper uses neutron star observations and a multi-approach theoretical framework to constrain the origin of nucleon mass, suggesting that over half of it comes from sources beyond spontaneous chiral symmetry breaking.

Contribution

It introduces a combined framework using parity doublet, NJL model, and fundamental principles to constrain the nucleon mass origin from astrophysical data.

Findings

More than half of nucleon mass originates beyond chiral symmetry breaking.

Constraints are derived solely from fundamental principles and observational data.

Results are independent of assumptions about the quark-hadron transition.

Abstract

We investigate the implications of neutron star observations for understanding the origin of nucleon mass using a framework that combines three complementary approaches: the equation of state based on parity doublet structure for hadronic matter below $2n_0$, the Nambu-Jona-Lasinio (NJL) model for quark matter above $5n_0$, and a model-independent analysis of the intermediate density region based on fundamental physical principles. By systematically exploring parameter spaces and comparing theoretical predictions with recent observational constraints, we establish constraints on the chiral invariant mass. Our results suggest that more than a half of the nucleon mass originates from sources beyond spontaneous chiral symmetry breaking, challenging conventional understanding of nucleon mass generation. These constraints arise solely from fundamental physical principles and observational data, independent of specific assumptions about the nature of the quark-hadron transition, providing robust insights into the microscopic origin of hadron masses.