Evidence for an isomeric 3/2- state in 53Co

D. Rudolph; R. Hoischen; M. Hellström; S. Pietri; Zs. Podolyák; P. H. Regan; A. B. Garnsworthy; S. J. Steer; F. Becker; P. Bednarczyk; L. Cáceres; P. Doornenbal; J. Gerl; M. Górska; J. Grebosz; I. Kojouharov; N. Kurz; W. Prokopowicz; H. Schaffner; H. J. Wollersheim; L. -L. Andersson; L. Atanasova; D. L. Balabanski; M. A. Bentley; A. Blazhev; C. Brandau; J. R. Brown; C. Fahlander; E. K. Johansson; A. Jungclaus

doi:10.1140/epja/i2008-10587-4

2021 Impact factor 3.131

Hadrons and Nuclei

Eur. Phys. J. A (2008) 36: 131-138
https://doi.org/10.1140/epja/i2008-10587-4

Regular Article - Experimental Physics

Evidence for an isomeric 3/2^- state in ⁵³Co

D. Rudolph¹^*, R. Hoischen¹^,2, M. Hellström¹, S. Pietri³, Zs. Podolyák³, P. H. Regan³, A. B. Garnsworthy³^,4, S. J. Steer³, F. Becker², P. Bednarczyk²^,5, L. Cáceres²^,6, P. Doornenbal²^,7, J. Gerl², M. Górska², J. Grebosz⁵^,2, I. Kojouharov², N. Kurz², W. Prokopowicz²^,5, H. Schaffner², H. J. Wollersheim², L. -L. Andersson¹, L. Atanasova⁸, D. L. Balabanski⁸^,9, M. A. Bentley¹⁰, A. Blazhev⁷, C. Brandau²^,3, J. R. Brown¹⁰, C. Fahlander¹, E. K. Johansson¹ and A. Jungclaus⁶

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

Abstract

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 .