https://doi.org/10.1140/epja/i2008-10587-4
Regular Article - Experimental Physics
Evidence for an isomeric 3/2- state in 53Co
1
Department of Physics, Lund University, S-221 00, Lund, Sweden
2
Gesellschaft für Schwerionenforschung mbH, D-64291, Darmstadt, Germany
3
Department of Physics, University of Surrey, GU2 7XH, Guildford, United Kingdom
4
Wright Nuclear Structure Laboratory, Yale University, 06520-8124, New Haven, CT, USA
5
Institute of Nuclear Physics (IFJ PAN), The Henryk Niewodniczański, PL-31342, Kraków, Poland
6
Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049, Madrid, Spain
7
Institut für Kernphysik, Universität zu Köln, D-50937, Köln, Germany
8
Faculty of Physics, University of Sofia, BG-1164, Sofia, Bulgaria
9
Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
10
Department of Physics, University of York, YO10 5DD, York, UK
* e-mail: Dirk.Rudolph@nuclear.lu.se
Received:
4
March
2008
Accepted:
5
May
2008
Published online:
21
May
2008
The fragmentation of a 550MeV/u primary beam of 58Ni on a 9Be target has been used to measure time- and energy-correlated γ decays following the implantation of event-by-event discriminated secondary fragments into a 9Be stopper plate. A new isomeric γ decay with T
1/2 = 14() ns and E
γ = 646.2(2) keV is observed and attributed to the decay of the yrast 3/2- state in 53
27Co26 . This short-lived isomeric state has been populated by means of nuclear reactions during the stopping process of the secondary fragments. The experimental findings are discussed in the framework of large-scale spherical shell model calculations in conjunction with isospin symmetry-breaking residual interactions for the A = 53 , T
z = ±1/2 mirror nuclei 53Co and 53Fe .
PACS: 21.60.Cs Shell model – / 23.20.-g Electromagnetic transitions – / 25.70.Mn Projectile and target fragmentation – / 27.40.+z 39 ⩽ A ⩽ 58 –
© Società Italiana di Fisica and Springer-Verlag, 2008