Data di Pubblicazione:
2008
Citazione:
Vortex–nucleus interaction in the inner crust
of neutron stars / P. Avogadro, F. Barranco, R.A. Broglia, E. Vigezzi. - In: NUCLEAR PHYSICS. A. - ISSN 0375-9474. - 811:3-4(2008 Oct 15), pp. 378-412. [10.1016/j.nuclphysa.2008.07.010]
Abstract:
The structure of a vortex in the inner crust of neutron stars is calculated up to density equal to one fourth
of the nuclear saturation density, within the framework of quantum mean field theory, taking into account
the interaction with the nuclei composing the Coulomb lattice. Vortices are associated with Coopers pairs
formed out of single-particle levels of opposite parity and, due to (quantal-size) shell effects, their formation
is hindered within the nuclear volume, by an amount that depends on the Fermi energy and on the effective
mass associated with the adopted nuclear two-body interaction. When the vortex axis goes through the
center of a nucleus, the typical linear rise of the pairing gap away from the vortex axis is delayed by about
8 fm, as compared to the case of a vortex in uniform matter. Also the velocity field is suppressed in a large
region close to the interface between the nucleus and the neutron gas. As a consequence, pinning of a vortex
on a nucleus leads to a loss of condensation energy, contrary to the predictions of all previous models. This
result strongly influences the density dependence of the pinning energy, relevant in the study of glitches.
We find that pinning of vortices on nuclei is favoured at low density.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Inner crust; Neutron star; Pinning energy; Superfluidity; Vortex
Elenco autori:
P. Avogadro, F. Barranco, R.A. Broglia, E. Vigezzi
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