Recently, an O(3) type of effective action was presented for the quantum Hall ferromagnet, which accounts for bag formation observed in microscopic Hartree-Fock calculations. We apply this action in the soliton sector and compare with Hartree-Fock results. We find good agreement over the whole parameter range where skyrmions exist. The standard minimal O(3) model cannot explain the bag and has ...

We perform continuous-choice Brueckner-Hartree-Fock calculations of hypernuclear matter, using the recent Nijmegen potentials for hyperon-nucleon and hyperon-hyperon interactions. Single-particle observables of the various hyperons in bulk matter, as well as properties of singleand double-lambda hypernuclei, employing an extended Skyrme-Hartree-Fock scheme, are presented. We find that the poten...

Charge-density distributions and the associated nuclear radii are calculated with the Hartree-Fock method for comparison with available data from electron scattering. Two forms of Skyrme interactions are used for the calculations. As a further refinement the single-particle occupancies are constrained to values obtained from shell-model calculations. A significant improvement in the agreement i...