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

Abstract : 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 neutrondrip 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.
Type de document :
Article dans une revue
Physical Review D, American Physical Society, 2016, 93, pp.063001. 〈10.1103/PhysRevD.93.063001〉
Liste complète des métadonnées

http://hal.in2p3.fr/in2p3-01285552
Contributeur : Michel Lion <>
Soumis le : mercredi 9 mars 2016 - 14:22:47
Dernière modification le : jeudi 1 février 2018 - 01:26:41

Identifiants

Collections

Citation

N. Chamel, A.F. Fantina. Electron exchange and polarization effects on electron captures and neutron emissions by nuclei in white dwarfs and neutron stars. Physical Review D, American Physical Society, 2016, 93, pp.063001. 〈10.1103/PhysRevD.93.063001〉. 〈in2p3-01285552〉

Partager

Métriques

Consultations de la notice

78