2018 Impact factor 2.481
Hadrons and Nuclei


Eur. Phys. J. A 11, 25-38 (2001)

High-spin spectroscopy of 6331 Ga 32 and 6531 Ga 34

M. Weiszflog1, G. de Angelis2, A. Axelsson3, D. Bazzacco4, F. Becker5, M. De Poli2, J. Eberth5, C. Fahlander2, 6, A. Gadea2, S. Lunardi4, D.R. Napoli2, J. Nyberg1, C. Rossi Alvarez4, B. Rubio7, D. Rudolph6, S. Skoda5, H.G. Thomas5 and R. Wyss8

1  Department of Neutron Research, Uppsala University, 75121 Uppsala, Sweden
2  INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
3  Department of Radiation Sciences, Uppsala University, 75121 Uppsala, Sweden
4  Dipartimento di Fisica dell'Università and INFN, 35131 Padova, Italy
5  Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
6  Lund University, 22100 Lund, Sweden
7  Instituto de Física Corpuscular, Valencia, Spain
8  The Royal Institute of Technology, 10044 Stockholm, Sweden

matthias@tsl.uu.se

(Received: 20 December 2000 / Revised version: 9 April 2001 Communicated by D. Guerreau)

Abstract
High-spin states in the nuclei 63Ga and 65Ga were studied following the reaction 32S + 40Ca at a reaction energy of 125 MeV and using the GASP $\gamma$-ray spectrometer in combination with the ISIS charged-particle detector system. In addition to low-lying negative-parity states with single-particle character, rotational-like cascades built on the 9/2+ and 19/2- states have been observed in both nuclei. Sidebands with negative parity in 63Ga and positive parity in 65Ga could be established. The experimental results are compared with Total Routhian Surface calculations which describe the nuclei as moderately deformed ($\beta_2$ $\approx 0.25$) and $\gamma$ soft at low rotational frequencies. The highest experimentally observed positive-parity state in 65Ga (41/2+) is in good agreement with the calculated crossing of the collective band with a non-collective one terminating at this spin.

PACS
21.60.Ev - Collective models.
23.20.En - Angular distribution and correlation measurements.
23.20.Lv - Gamma transitions and level energies.
27.50.+e - $59 \leq A \leq 89$ .

© Società Italiana di Fisica, Springer-Verlag 2001