High-resolution study of excited states in Gd-158 with the (p, t) reaction

Levon, A.; Bucurescu, D.; Costache, C.; Faestermann, T.; Hertenberger, R.; Ionescu, A.; Lica, R.; Magner, A. G.; Mihai, C.; Mihai, R.; Nita, C. R.; Pascu, S.; Shevchenko, K. P.; Shevchuk, A. A.; Turturica, A. und Wirth, H-F (2020): High-resolution study of excited states in Gd-158 with the (p, t) reaction. In: Physical Review C, Bd. 102, Nr. 1, 014308

Abstract

The excitation spectra in the deformed nucleus Gd-158 have been studied with high energy resolution for the extended spin and parity range by means of the (p, t) reaction using the Q3D spectrograph facility at the Munich Tandem accelerator. The angular distributions of tritons were measured for more than 200 excited states seen in the triton spectra up to 4.3 MeV. Spins and parities of states were assigned by comparison of experimental angular distributions with the calculated ones with the help of the CHUCK3 code. Differential cross-section calculations for multistep processes were required in order to make spin assignments for spins greater than zero and so that different pathways were inferred for different states. In addition to the previously studied multiple 0(+) excitations, in this study, the assignments for levels with higher spins are the following: 95 for 2(+) states, 64 for 4(+) states, 14 for 6(+) states, and about 20 for negative parity states. Selected sequences of states with energies following I (I+ 1) systematics and suitable cross section variations are treated as rotational bands. An analysis of the moments of inertia defined for these bands is carried out. This high number of excited states in a deformed nucleus, close to a complete level scheme, constitutes a very good ground to check models of nuclear structure. The large ensembles of states with the same spin-parity offer unique opportunities for statistical analysis. Such an analysis for the 0(+) and 2(+) states sequences, for all K values and for well-determined projections K of the angular momentum is performed. The obtained data may indicate on a K symmetry breaking. Experimental data are compared with interacting boson model (IBM) calculations using the spdf version of the model. The energies of the low-lying levels, the transition probabilities in the first bands, and the distribution in transfer intensity of the 0(+) states are calculated and compared with experiment.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0556-2813
• Sprache: Englisch