Dynamic and Static Octupole Correlations
Static octupole correlations, which are associated with reflection symmetry breaking at the mean field level, are only present in a handful of nuclei scattered over the periodic table around specific proton and neutron numbers. This is in contrast with the well known prevalence of quadrupole-deformed over spherical shapes in nuclei. However, dynamical correlations, consequence of the relative softness of the nucleus against perturbation of octupole kind, are present in most of the nuclei. They play a role in understanding excitation energies and transition strengths of collective negative parity excitations. In this talk I will address the theoretical description of octupole correlations with techniques beyond the mean field, including symmetry restoration and configuration mixing. The results of calculations along that line will be analyzed.
Frank Leonel Bello Garrote
Monday 2nd November, 3pm GMT
Scissors Resonance in 254No
The nuclear physics group at the University of Oslo primarily dedicates to perform experimental studies of the main average nuclear properties: the nuclear level density and the γ-ray strength function (γ-SF). These quantities are crucial inputs for calculating neutron capture rates relevant for stellar nucleosynthesis simulations. The scissors mode is a collective, magnetic dipole excitation that has been observed in the 2-4 MeV region of the γ-SF in a large group of deformed nuclides. The scissors mode could be of particular importance in the region of the heaviest elements, where the presence of a large resonance in the γ-SF could boost the neutron capture channel relative to fission. In this work, we obtained an experimental spectrum of 254No from which we estimate the strength of the scissors resonance and compare it to theoretical values and empirical formulas used in nuclear reaction codes.
Samuel A. Giuliani
Monday 9th November, 3pm GMT
Nuclear physics and r-process nucleosynthesis of heavy elements
Please get in touch if you are interested in presenting