Beta decay of exotic T_Z = -1, -2 nuclei: the interesting case of ⁵⁶Zn

¹ Instituto de Física Corpuscular, CSIC-Universidad de Valencia, E-46071 Valencia, Spain
² Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
³ Centre d’Etudes Nucléaires de Bordeaux Gradignan CNRS/IN2P3 - Université Bordeaux 1, 33175 Gradignan Cedex France
⁴ Department of Physics, University of Surrey, Guilford GU2 7XH, Surrey, UK
⁵ Inst. of Nuclear Research of the Hung. Acad. of Sciences, Debrecen, H-4026, Hungary
⁶ Department of Physics, Istanbul University, Istanbul, Turkey
⁷ Grand Accélérateur National d’Ions Lourds, BP 55027, F-14076 Caen, France
⁸ Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
⁹ Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago, Chile
¹⁰ SCK.CEN, Boeretang 200, 2400 Mol, Belgium
¹¹ Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA

^a e-mail: Sonja.Orrigo@ific.uv.es

Published online: 20 March 2014

Abstract

The β decay properties of the T_z = -2, ⁵⁶Zn isotope and other proton-rich nuclei in the fp-shell have been investigated in an experiment performed at GANIL. The ions were produced in fragmentation reactions and implanted in a double-sided silicon strip detector surrounded by Ge EXOGAM clovers. Preliminary results for ⁵⁶Zn are presented .The ⁵⁶Zn decay proceeds mainly by β delayed proton emission, but β delayed gamma rays were also detected. Moreover, the exotic β delayed gamma-proton decay was observed for the first time. The ⁵⁶Zn half-life and the energy levels populated in the ⁵⁶Cu daughter have been determined. Knowledge of the gamma de-excitation of the mirror states in ⁵⁶Co and the comparison with the results of the mirror charge exchange process, the ⁵⁶Fe(³He,t) reaction (where ⁵⁶Fe has T_z = +2), were important in the interpretation of the ⁵⁶Zn decay data. The absolute Fermi and Gamow-Teller strengths have been deduced.