Eur. Phys. J. C (2025) 85: 825
https://doi.org/10.1140/epjc/s10052-025-14557-4

Regular Article - Theoretical Physics

Correlations between maximum mass of neutron stars and the nuclear matter properties and the constraints from PSR J0740+6620 and GW190814

¹ School of Physics and Information Technology, Shaanxi Normal University, 710119, Xi’an, People’s Republic of China
² School of Physics, Xi’an Jiaotong University, 710049, Shaanxi, Xi’an, People’s Republic of China
³ The Research Center for Theoretical Physics, Science School, Qingdao University of Technology, 266033, Qingdao, People’s Republic of China
⁴ Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Sichuan University, 610064, Chengdu, People’s Republic of China
⁵ Institute of Modern Physics, Key Laboratory of Nuclear Physics and Ion-Beam Application, MOE, Fudan University, 200433, Shanghai, People’s Republic of China
⁶ Laboratori Nazionali del Sud, INFN, 95123, Catania, Italy
⁷ Cyclotron Institute, Texas A&M University, 77843, College Station, USA

^a liuhongming13@126.com

Received: 8 April 2025
Accepted: 23 July 2025
Published online: 31 July 2025

Abstract

The correlations between the maximum mass of neutron stars (NSs) with the properties of nuclear matter at saturation density ${\rho }_0$, i.e., the incompressibility $K_0$, the symmetry energy $E_{\text{sym}}({\rho }_0$), and its slope $L({\rho }_0)$, the isoscalar effective mass $m_{s0}^{\ast }$, and the parameter $f_I$, have been investigated using several sets of Skyrme interactions based on the momentum-dependent (MD) Skyrme interactions SAMi-J27 (soft), SAMi-J31 (stiff), and SAMi-J35 (super-stiff), as well as the momentum-independent (MI) Skyrme interaction SkT5. Only one physical quantity is varied at a time for a given set of Skyrme interactions. It is found that the maximum mass of NSs has (1) a strong positive linear correlation with $K_0$ for stiff and super-stiff equation of state (EOS) and no correlation with $K_0$ for soft EOS; (2) a negative logarithm correlation with the symmetry energy $E_{\text{sym}}({\rho }_0$) for all the EOSs; (3) a positive logarithm correlation with the slope $L({\rho }_0)$ for all the EOSs; (4) a positive logarithm correlation with the parameter $f_I$ for MD EOS; (5) a negative power-law correlation with $m_{s0}^{\ast }$ for MD EOS. Based on these established correlations, the constraints to the nuclear matter properties from the mass of PSR J0740+6620 and GW190814 are investigated. Furthermore, we find that while rotation enhances the maximum mass of NSs, it does not effect the underlying correlations between the maximum mass and the aforementioned nuclear matter parameters.