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In the present paper we investigate the onset of the pasta phase with different parametrisations of the density dependent hadronic model and compare the results with one of the usual parametrisation of the non-linear Walecka model. The influence of the scalar-isovector virtual δ meson is shown. At zero temperature two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature only the coexistence phases method is used. npe matter with fixed proton fractions and in β-equilibrium are studied. We compare our results with restrictions imposed on the the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations.PACS number(s): 21.65.+f, 24.10.Jv, 26.60.+c, 95.30.Tg

In the present work, we investigate the main differences in the lead neutron skin thickness, binding energy, surface energy, and density profiles obtained with two different density dependent hadron models. Our results are calculated within the Thomas-Fermi approximation with two different numerical prescriptions and compared with results obtained with a common parametrization of the nonlinear Walecka model. The neutron skin thickness is a reflex of the equation of state properties. Hence, a direct correlation is found between the neutron skin thickness and the slope of the symmetry energy. We show that within the present approximations, the asymmetry parameter for low momentum transfer polarized electron scattering is not sensitive to the model differences. DOI: 10.1103/PhysRevC.75.055805 PACS number(s): 21.65.+f, 24.10.Jv, 95.30.Tg, 26.60.+c 055805-2 DENSITY DEPENDENT HADRONIC MODELS AND THE . . . PHYSICAL REVIEW C 75, 055805 (2007)

Small deviations from purely bosonic behavior of trapped atomic Bose-Einstein condensates are investigated with the help of the quon algebra, which interpolates between bosonic and fermionic statistics. A previously developed formalism is employed to obtain a generalized version of the Gross-Pitaeviskii equation. Two extreme situations are considered, the collapse of the condensate for attractive forces and the depletion of the amount of condensed atoms with repulsive forces.Experimental discrepancies observed in the parameters governing the collapse and the depletion of the condensates can be accounted for by universal fittings of the deformation parameter for each case.

We use the Peierls-Yoccoz projection method to study the motion of a relativistic system of nucleons interacting with sigma and omega mesons, generalizing a method developed for the alpha particle. The nuclear system is described in a mean-field Hartree approach, including explicitly the meson contribution. The formalism is applied to 4 He, 16 O and 40 Ca. The center-of-mass correction makes the system too much bounded. It turns out that a new set of model parameters is needed when the center-of-mass motion is consistently treated with respect to the traditional approaches.An appropriate refitting of the model brings the radii and binding energies to reasonable values for the oxygen and calcium. PACS number(s): 21.10.-k, 21.10.Dr, 21.60.-n I. INTRODUCTIONRelativistic models for finite nuclei, with nucleons and mesons are usually treated in the Hartree or Hartree-Fock approximations. In these approximations the total linear momentum is no longer a conserved quantity and the spurious center of mass (CM) motion gives rise to unphysical contributions in the calculated nuclear observables. As already discussed for non-relativistic nuclear models, using the same kind of mean-field approximation, the correct treatment for the CM motion introduces a modest modification in the total binding energy for intermediate mass nuclei, but relatively large contributions in other observables, e.g., charge distributions and spectral functions [1], [2]. In relativistic treatments, the CM correction is up to now limited to the harmonic approximation for the energy or to the subtraction of <ˆ P 2 A > 2AM from the total energy, whereˆ P A is the total nucleonic momentum operator, M is the nucleon mass and the mean-value is taken using the Hartree self-consistent state for A nucleons.More recently [3], the CM energy correction was estimated within the σ − ω model, using the Peierls-Yoccoz projection procedure [4], for N = Z spherical nuclei within the Hartree approximation. Although the correction obtained in this way is of the same order of magnitude of the harmonic approximation, only the nucleonic degrees of freedom were taken into account in that calculation. In reference [5], a formalism has been developed to include the mesonic degrees of freedom in the CM projection within σ − ω models and an