[Submitted on 9 Jan 2023]
Constraints on Nuclear Symmetry Energy Parameters
A review is made of constraints on the nuclear symmetry energy parameters arising from nuclear binding energy measurements, theoretical chiral effective field predictions of neutron matter properties, the unitary gas conjecture, and measurements of neutron skin thicknesses and dipole polarizabilities. While most studies have been confined to the parameters and , the important roles played by, and constraints on , or, equivalently, the neutron matter incompressibility , are discussed. Strong correlations among , and are found from both nuclear binding energies and neutron matter theory. However, these correlations somewhat differ in the two cases, and those from neutron matter theory have smaller uncertainties. To 68\% confidence, it is found from neutron matter theory that MeV, MeV and MeV. Theoretical predictions for neutron skin thickness and dipole polarizability measurements of the neutron-rich nuclei Ca, Sn, and Pb are compared to recent experimental measurements, most notably the CREX and PREX neutron skin experiments from Jefferson Laboratory. By themselves, PREX I+II measurements of Pb and CREX measurement of Ca suggest MeV and MeV, respectively, to 68\% confidence. However, we show that nuclear interactions optimally satisfying both measurements imply MeV, nearly the range suggested by either nuclear mass measurements or neutron matter theory, and is also consistent with nuclear dipole polarizability measurements. This small parameter range implies km and , which are consistent with NICER X-ray and LIGO/Virgo gravitational wave observations of neutron stars.
- Comments:
- This article belongs to the Special Issue Selected Papers from The Modern Physics of Compact Stars and Relativistic Gravity 2021, Ed. Armen Sedrakian
- Subjects:
- Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
- arXiv:
- 2301.03666 [pdf]