Parametrization of the surface energy in the ETF approximation. (17th November 2020)

• Record Type: Journal Article
• Authors: Furtado, U J; Gulminelli, F
• Is Part Of: Journal of physics. Volume 48:Number 1(2021)
• Publication Date: 2020-11-17
• Subjects: surface energy -- neutron star crust -- neutron skin -- semi-classical methods -- compressible liquid drop -- extended Thomas–Fermi -- Wigner–Seitz; Nuclear physics -- Periodicals; Particles (Nuclear physics) -- Periodicals; Physique nucléaire -- Périodiques; Particules (Physique nucléaire) -- Périodiques; Kernfysica; Elementaire deeltjes; 539.7
• DOI: 10.1088/1361-6471/abb44b
• Languages: English
• ISSNs: 0954-3899

Abstract

Abstract: We perform extended Thomas–Fermi calculations in the Wigner–Seitz cell below and above neutron drip with realistic functionals. The resulting energy density is decomposed as a sum of bulk terms and a surface term, and a compressible liquid drop analytical formula is used to fit the surface tension. The effect of curvature terms and neutron skin is studied in detail. A very good reproduction of the microscopic data is obtained using an expression that depends only on the mass and charge of the cluster, showing that the in-medium modifications of the nuclear energy in the presence of an external neutron gas can be effectively accounted for in the isospin dependence of the surface tension. In this first application, aimed at establishing the fitting protocol, we concentrate on the Sly4 energy functional, but the study can be easily generalized to different functionals, and the resulting parametrizations can be used for direct applications in pasta calculations in neutron star crusts and supernova matter.