The Nuclear Matter Saturation Problem

Abstract

The general systematics of nuclear binding energies are well parameterised by the semi empirical mass formula. The volume term in this formula predicts that, in absence of coulomb interactions, an infinite, homogeneous fluid of equal numbers of neutrons and protons will be self bound with a binding energy per nucleon of E₀ ≃ 16±0.5 MeV. Measurements of the central densities of heavy nuclei suggest that the infinite nuclear matter fluid will saturate at a density p ₀ ≃ 0.17±0.01 nucleons per fm³ corresponding to a Fermi wave number k_F ≃ 1.37±0.03 fm^-1. While it is difficult to unambiguously separate bulk and surface effects, the observation of ’breathing mode’ excitations at 12–25 MeV excitation energy in nuclei suggests a bulk compressibility modulus for the nuclear matter fluid