Electron exchange and polarization effects on electron captures and neutron emissions by nuclei in white dwarfs and neutron stars

In dense stellar environments, nuclei may become unstable against electron captures and/or neutron emissions. These processes are of particular importance for determining the internal constitution of white-dwarf cores and neutron-star crusts. In this paper, the role of electron exchange and polariza...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. D 2016-03, Vol.93 (6), Article 063001
Main Authors: Chamel, N., Fantina, A. F.
Format: Article
Language:English
Subjects:
Astrophysics
Beta decay
Crusts
Electron capture
Exchange
Neutron emission
Neutron stars
Nuclear Theory
Nuclei
Physics
Polarization
Solar and Stellar Astrophysics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In dense stellar environments, nuclei may become unstable against electron captures and/or neutron emissions. These processes are of particular importance for determining the internal constitution of white-dwarf cores and neutron-star crusts. In this paper, the role of electron exchange and polarization effects is studied. In particular, the instability condition for the onset of electron captures and neutron emissions is extended so as to account for electron exchange and polarization. Moreover, general analytical expressions for the corresponding density and pressure are derived. The corrections to the electron-capture threshold in white-dwarf cores are found to be very small. Likewise, the neutron-drip density and pressure in the crusts of accreting and nonaccreting neutron stars are only slightly shifted. Depending on the nuclear mass model employed, electron polarization may change the composition of the crust of nonaccreting neutron stars. On the other hand, the current uncertainties in the masses of neutron-rich Kr and Sr isotopes are found to be more important than electron exchange and polarization effects.
ISSN:2470-0010
2470-0029
DOI:10.1103/PhysRevD.93.063001