2005/02/23 by F. Barranco, P. F. Bortignon, R. A. Broglia +7 · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Nuclear physics research studies #Quantum, superfluid, helium dynamics #nucl-th
paper · pdf · doi:10.1103/physrevc.72.054314
published as Phys.Rev. C72 (2005) 054314
arxiv created 2005/02/23 · openalex publication_date 2005/11/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The dependence on the single-particle states of the pairing matrix elements of the Gogny force and of the bare low-momentum nucleon-nucleon potential v_low\text\ensuremath-k---designed so as to reproduce the low-energy observables avoiding the use of a repulsive core---is studied for a typical finite, superfluid nucleus (120Sn). It is found that the matrix elements of v_low\text\ensuremath-k follow closely those of vGogny on a wide range of energy values around the Fermi energy eF, those associated with v_low\text\ensuremath-k being less attractive. This result explains the fact that around eF the pairing gap \ensuremathΔGogny associated with the Gogny interaction (and with a density of single-particle levels corresponding to an effective k mass mk\ensuremath≈0.7 m) is a factor of about 2 larger than \ensuremathΔ_low\text\ensuremath-k, being in agreement with \ensuremathΔexp=1.4 MeV. The exchange of low-lying collective surface vibrations among pairs of nucleons moving in time-reversal states gives rise to an induced pairing interaction vind peaked at eF. The interaction (v_low\text\ensuremath-k+vind) Z_\ensuremathω arising from the renormalization of the bare nucleon-nucleon potential and of the single-particle motion (\ensuremathω-mass and quasiparticle strength Z_\ensuremathω) associated with the particle-vibration coupling mechanism, leads to a value of the pairing gap at the Fermi energy \ensuremathΔren that accounts for the experimental value. An important question that remains to be studied quantitatively is to what extent \ensuremathΔGogny, which depends on average parameters, and \ensuremathΔren, which explicitly depends on the parameters describing the (low-energy) nuclear structure, display or not a similar isotopic dependence and whether this dependence is borne out by the data.