[en] This book offers an introduction to topics of current interest in nuclear structure research, as part of Plenum's NATO Advanced Study Institute Series. Includes introductions to the shell model, to effective interactions, and to the interacting boson model. Gives detailed treatment of the interactions of nuclei with electrons, muons, protons, pions, and heavy ions. Discusses applications in the areas of exotic nuclei, fission, astrophysics, and proton-induced X-rays. Examines the application of the shell model to nuclear spectroscopy, pion-nuclear many-body problems, and nuclear structure and heavy-ion reactions. Recommended for researchers and workers in nuclear structure, astrophysics, atomic physics, high-energy physics, and theoretical physics

No abstract available

No abstract available

No abstract available

[en] It is demonstrated that a mean-field approximation, in combination with the generator coordinate method, may yield a simple and accurate representation of certain IBA-2 eigenstates for deformed nuclei. These may then be considered as rotational states based on intrinsic excitations. This model is excellent for the Ksup(π)=1⁺ ''scissors'' band but must be used with care for higher members of β-vibrational bands. The accuracy of a few even simpler approximations is discussed. (orig.)

No abstract available

No abstract available

No abstract available

[en] A microscopic calculation of interacting-boson model (IBM) parameters is performed for Xe isotopes within the framework of the broken-pair model. We employ a shell-model hamiltonian which reproduces the spectra of near-magic and semi-magic nuclei. As a first approximation we adopt the idea of Otsuka, Arima and Iachello, that IBM states represent fermion states built from collective S- and D-pairs - the SD space. We show that at least two effects are needed to explain the empirical values of IBM parameters. Firstly there is a reduction in collectivity of S- and D-pairs in states with several broken pairs, due to the Pauli-blocking effect of the latter. Secondly the shell-model hamiltonian mixes the SD space with other fermion states which are not explicitly represented in the IBM. Among the latter, states with a collective G-pair (J=4) are the most important, but they contribute less than half of the total renormalization of the parameters. The calculated IBM parameters chi of the E2 transition operators exhibit similar trends to those which occur in the IBM hamiltonian. We explain the IBM Majorana force as a renormalization effect on states with even J; not as a repulsion in states with odd J. The latter emerge as rather pure states with mix little with the non-collective fermion space. This indicates that they may be experimentally observable. With our calculated parameters the IBM spectra and E2 transitions are of comparable quality to those obtained in IBM fits of the data. (orig.)

[en] The low-energy properties of ⁸⁹Y, ⁹¹Nb and ⁹³Tc are described in a broken-pair model. The shell model space for the protons consists of one major shell and for the neutrons particle-hole states within two major shells are taken into account. The effective interaction is assumed to be a simple Gaussian Serber force, which has proved to be the most successful in adjacent even nuclei. Energy spectra up to about 3 MeV excitation energy and one-nucleon transfer data can be described very well. Also electromagnetic properties can be reproduced rather well if reasonable effective charges are used. No indication for deformed states, as found in Sn nuclei, is observed. (orig.)