Eur. Phys. J. A 13, 411-418 (2002)
DOI: 10.1140/epja/iepja1344

Gamow-Teller transitions from to discrete states of

The study of isospin symmetry in atomic nuclei

Y. Fujita¹, H. Fujita¹, T. Adachi¹, G.P.A. Berg², E. Caurier³, H. Fujimura², K. Hara², K. Hatanaka², Z. Janas^{4, 5}, J. Kamiya², T. Kawabata⁶, K. Langanke⁷, G. Martínez-Pinedo⁷, T. Noro², E. Roeckl⁴, Y. Shimbara¹, T. Shinada¹, S.Y. van der Werf⁸, M. Yoshifuku¹, M. Yosoi⁶ and R.G.T. Zegers<sup>9

1</sup>  Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
²  Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
³  Institut de Recherches Subatomiques (IN2P3-CNRS-Université Louis Pasteur), F-67037 Strasbourg Cedex 2, France
⁴  Gesellschaft für Schwerionenforschung, D-64291 Darmstadt, Germany
⁵  Institute of Experimental Physics, Warsaw University, PL-00-681 Warsaw, Poland
⁶  Department of Physics, Kyoto University, Sakyo, Kyoto 606-8502, Japan
⁷  Institute of Physics and Astronomy, University of Århus, DK-8000 Århus C, Denmark
⁸  Kernfysisch Versneller Instituut, NL-9747 AA Groningen, The Netherlands
⁹  SPring-8, JAERI, Mikazuki, Sayo, Hyogo 679-5148, Japan

fujita@rcnp.osaka-u.ac.jp

(Received: 24 November 2001 / Revised version: 15 January 2002 Communicated by J. Äystö)

Abstract
Under the assumption that isospin is a good quantum number, symmetry is expected for the transitions from the ground states of nuclei to the common excited states of the T_z=0 nucleus situated between the two nuclei. The symmetry can be studied by comparing the strengths of Gamow-Teller (GT) transitions obtained from a (p,n)-type charge-exchange reaction on a target nucleus with T_z=1 with those from the -decay of the T_z=-1 nucleus. The A=58 system is the heaviest for which such a comparison is possible. As a part of the symmetry study, we measured the GT transitions from ⁵⁸Ni ( T_z=1) to ⁵⁸Cu ( T_z=0) by using the zero-degree reaction at 150 MeV/nucleon. With the achieved resolution of 50 keV, many hitherto unresolved GT states have been identified. The GT transition strengths were obtained for states up to 8 MeV excitation, i.e., near to the Q window limitation ( MeV) of the -decay from ⁵⁸Zn ( T_z=-1) to ⁵⁸Cu. The strength distribution is compared with that from shell-model calculations.

PACS
21.10.Hw - Spin, parity and isobaric spin.
21.60.Cs - Shell model.
25.55.Kr - Charge-exchange reactions.
27.40.+z - .

© Società Italiana di Fisica, Springer-Verlag 2002