No abstract available

[en] The population and γ decay of neutron rich nuclei around ⁴⁸Ca has been measured at Legnaro National Laboratory with the PRISMA-CLARA setup, using deep-inelastic collisions on ⁶⁴Ni, at 5.9 MeV/A. The reaction properties of the main products are investigated, focusing on total cross-sections and energy integrated angular distributions. Gamma spectroscopy studies are also performed for the most intense transfer channels, making use of angular distributions and polarization measurements to firmly establish spin and parity of the excited states. In the case of ⁴⁹Ca candidates for particle-core couplings are investigated and interpreted on basis of lifetime measurements and comparison with model predictions. (author)

No abstract available

No abstract available

No abstract available

No abstract available

[en] Recently it has been possible with the new multidetector arrays, GASP in Italy and EUROGRAM in UK, to obtain 3- and higher fold coincidence data with sufficient statistics to perform a statistical analysis of count fluctuations in the γ-spectra. This opens new possibilities in the study of high spin states in the quasi-continuum region of unresolved states. At present, information about discrete band rotation and damped rotation is obtained by analyzing two-dimensional spectra for count fluctuations. It is found that only about 30-50 regular rotational bands exist, before rotational damping sets in at ∼800 keV about the yrast line. The fluctuation analysis also shows that the transition strength through each decay step, at higher excitation energies, is spread over many states within a given energy interval, the damping width, and thus provides direct evidence of the rotational damping picture. Results from the new high-fold data of EUROGAM are shown

[en] Using the ¹⁵⁰Nd(¹⁸O, 5n)¹⁶³Er reaction a multitude of rotational bands have been established with firm spin and parity assignments in ¹⁶³Er. In 16 out of ∼ 23 band crossings E2 cross-band transitions have been observed. The interaction strength varies between ∼ 1 and ∼ 50 keV. These interactions sample a variety of the lowest (multi)-quasiparticle configurations. Some of the band configurations, in particular those with high K-values, can be rather well established. Quite complicated changes in the wavefunctions must occur at these crossings, and, to explain the observed interaction strengths, one may have to invoke coupling to various vibrational degrees of freedom, in addition to possible residual neutron-proton interactions

[en] The rotational motion in thermally excited nuclei and its damping at high excitation energy is discussed here with reference to the role of effects beyond mean-field approximation. The experimental results for different mass regions and deformations are presented and compared with a cranked-shell-model calculation including a two-body residual interaction of surface delta type. Altogether, it is found that the dependence of the mixing process on the nuclear mass and deformation is well reproduced by the data

[en] The excitation spectra of nuclei with one or two particles outside a doubly-magic core are expected to be dominated, at low energy, by the couplings between phonon excitations of the core and valence particles. A survey of the experimental situation is given for some nuclei lying in close proximity of neutron-rich doubly-magic systems, such as ^47,49Ca, ¹³³Sb and ²¹⁰Bi. Data are obtained with various types of reactions (multinucleon transfer with heavy ions, cold neutron capture and neutron induced fission of ²³⁵U and ²⁴¹Pu targets), with the employment of complex detection systems based on HPGe arrays. A comparison with theoretical calculations is also presented, in terms of large shell model calculations and of a phenomenological particle-phonon model. In the case of ¹³³Sb, a new microscopic 'hybrid' model is introduced: it is based on the coupling between core excitations (both collective and non-collective) of the doubly-magic core and the valence nucleon, using the Skyrme effective interaction in a consistent way. (author)