2,513 research outputs found
Superfluid Properties of the Inner Crust of Neutron Stars
Superfluid properties of the inner crust matter of neutron stars, formed by
nuclear clusters immersed in a dilute neutron gas, are analysed in a self-
consistent HFB approach. The calculations are performed with two pairing
forces, fixed so as to obtain in infinite nuclear matter the pairing gaps
provided by the Gogny force or by induced interactions. It is shown that the
nuclear clusters can either suppress or enhance the pairing correlations inside
the inner crust matter, depending on the density of the surrounding neutrons.
The profile of the pairing field in the inner crust is rather similar for both
pairing forces, but the values of the pairing gaps are drastically reduced for
the force which simulates the polarisation effects in infinite neutron matter.Comment: 13 pages, 6 figures. Corrected typos and new format. To appear in
Phys. Rev.
Treatment of pairing correlations in nuclei close to drip lines
We discuss the HFB equations in coordinate representation,a suitable method
for handling the full effects of the continuous quasiparticle spectrum. We show
how the continuum HFB equations can be solved with the correct asymptotic
conditions instead of the discretization conditions which are commonly used in
the literature. The continuum HFB method is illustrated with a model where the
mean field and pairing field have simple forms. The relationship with the
continuum Hartree-Fock-BCS (HF-BCS) approximation is also discussed. Realistic
HFB and HF-BCS calculations based on Skyrme interactions are compared for the
case of a neutron-rich nucleus.Comment: 12 pages, 4 Postscript figures, uses KapProc.cls, to appear in
Proceedings of NATO School " Nuclei far from stability and astrophysics",
Predeal, Romania, 200
Two-Particle Resonant States in a Many-Body Mean Field
A formalism to evaluate the resonant states produced by two particles moving
outside a closed shell core is presented. The two particle states are
calculated by using a single particle representation consisting of bound
states, Gamow resonances and scattering states in the complex energy plane
(Berggren representation). Two representative cases are analysed corresponding
to whether the Fermi level is below or above the continuum threshold. It is
found that long lived two-body states (including bound states) are mostly
determined by either bound single-particle states or by narrow Gamow
resonances. However, they can be significantly affected by the continuum part
of the spectrum.Comment: 11 pages, 4 figure
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