Heidelberg 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 25: Structure and Dynamics of Nuclei 5

HK 25.3: Vortrag

Dienstag, 24. März 2015, 15:15–15:30, T/HS2

Dipole strength distribution of ⁵⁰Ti * — •Udo Gayer, Tobias Beck, Jacob Beller, Laura Mertes, Haridas Pai, Norbert Pietralla, Philipp Ries, Christopher Romig, Volker Werner, and Markus Zweidinger — Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt

A first nuclear resonance fluorescence (NRF) experiment with a 68% isotopically enriched ⁵⁰Ti target has been performed at the superconducting Darmstadt electron linear accelerator S-DALINAC to investigate particle-bound dipole excitations in this nucleus. The target was irradiated with an unpolarized bremsstrahlung photon beam at endpoint energies of 7.5 MeV and 9.7 MeV. The observed excited states are analyzed with respect to their excitation energies, spin quantum numbers and transition strengths. A complementary NRF experiment with polarized photons will be conducted at the High Intensity gamma-ray Source in Durham, NC, USA to determine the polarity of the dipole transitions. Data will be analyzed with regard to the Pygmy Dipole Resonance, a weakly-collective electric dipole excitation which starts to form in nuclei of this mass region. The measured transition strengths will be compared to microscopic calculations in the quasiparticle-phonon model. The investigation of the magnetic dipole strength distribution will focus on strong spin-flip transitions between the p,f spin-orbit partners expected in the nuclear shell model. First results of the measurements and the evaluation will be presented and discussed.
* Supported by the DFG under contract No. SFB 634