Phenomenological Woods-Saxon Research Articles

SHELLS AND SUPERSHELLS IN METAL CLUSTERS

We analyze the shell and supershell structure of valence electrons in large metal clusters. For this purpose we use the spherical jellium model for the ions, treat the many-body problem of the interacting valence electrons selfconsistently in local-density approximation and solve numerically the Kohn-Sham equations for up to N ~ 6000 electrons. We investigate the influence of temperature effects on the shell structure and compare our results to experimental data and other calculations performed with phenomenological Woods–Saxon potentials.

Scattering of polarized protons from 6Li at 200 MeV.

New cross section and analyzing power data are presented for elastic and inelastic scattering of 200 MeV protons from $^{6}\mathrm{Li}$. The elastic data are well described by a standard, spherical, 12-parameter phenomenological Woods-Saxon (WS) optical potential. Microscopic folding-model optical potentials, obtained by convoluting free and Pauli-corrected effective nucleon-nucleon (NN) interactions with $^{6}\mathrm{Li}$ ground-state densities constrained by electromagnetic data, produce satisfactory descriptions of the elastic data. The effects of the spin-spin optical potential, estimated via the distorted wave approximation (DWA), are small but not negligible. The inelastic transitions leading to the ${3}^{+}$,T=0 state at 2.18 MeV and the ${0}^{+}$,T=1 state at 3.56 MeV are also examined within the framework of the microscopic folding model using the DWA. Transition potentials are generated by convoluting the two effective NN interactions considered with target transition densities constrained by weak and electromagnetic data. These are employed in DWA calculations using both folded optical potentials consistent with the transition potentials and the WS optical potential. The self-consistent calculation with the Pauli-corrected interaction provides a good description of the data for the ${3}^{+}$ excitation. The results for the ${0}^{+}$ excitation provide a clear indication that shell model configurations outside the p shell are important for a complete description of this transition.