Niels Bohr Institutet > Kalender - det sker på NBI > 2010 > PhD defense by Christi...
PhD defense by Christina Losa
To first order, the motion of nucleons in atomic nuclei is well described by a mean field. The same nucleon-nucleon force, which generates the field, further induces correlations among the nucleons, resulting in superfluidity and in collective excitations. A consistent treatment of the different types of correlations is furnished by the quasiparticle-random-phase approximation (QRPA).
In my work I investigate theoretically excitations in light deformed nuclei by developing a fully self-consistent QRPA method. The underlying nucleon-nucleon interaction is treated in terms of Skyrme energy density functionals. The aim is to accurately describe excited states of different multipoles in axially symmetric deformed even-even nuclei, including nuclei with weakly bound neutrons close to the neutron drip-line. In my talk I will present theoretical results for the lowest and most important multipole excitations in which the neutrons and protons are either vibrating together or vibrating opposite to each other. The results are compared to available experimental data and to very recent calculations present in the literature. For the nucleus 20 O will investigate the importance of achieving self--consistency by showing what happens when technically involved terms are included in the mean field but neglected in the QRPA calculations. For the nuclei 24-26 Mg and 34 Mg I will focus on the influence that the ground state intrinsic deformation has on these nuclear systems.
Supervisor: Thomas Døssing