Eur. Phys. J. A 12, 269-277 (2001)

First measurement of -decay properties of the proton drip-line nucleus

C. Mazzocchi^{1, 2}, Z. Janas^{1, 3}, J. Döring¹, M. Axiotis⁴, L. Batist⁵, R. Borcea¹, D. Cano-Ott⁶, E. Caurier⁷, G. de Angelis⁴, E. Farnea^{4, 8}, A. Faßbender¹, A. Gadea^{4, 9}, H. Grawe¹, A. Jungclaus¹⁰, M. Kapica¹, R. Kirchner¹, J. Kurcewicz¹, S.M. Lenzi⁸, T. Martínez^{4, 9}, I. Mukha¹, E. Nácher⁹, D.R. Napoli⁴, E. Roeckl¹, B. Rubio⁹, R. Schwengner¹¹, J.L. Tain⁹ and C.A. Ur<sup>8

1</sup>  Gesellschaft für Schwerionenforschung, Darmstadt, D-64291 Darmstadt, Germany
²  Universitá degli Studi di Milano, I-20133 Milano, Italy
³  Institute of Experimental Physics, University of Warsaw, PL-00681 Warsaw, Poland
⁴  Laboratori Nazionali di Legnaro - INFN, I-35020 Legnaro, Italy
⁵  St. Petersburg Nuclear Physics Institute, RU-188-350 Gatchina, Russia
⁶  Department of Nuclear Fission, CIEMAT, E-28040 Madrid, Spain
⁷  Institut de Recherches Subatomiques (IN2P3-CNRS-Université Louis Pasteur), F-67037 Strasbourg Cedex 2, France
⁸  Dipartimento di Fisica dell'Universitá di Padova and INFN, I-35131 Padova, Italy
⁹  Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, E-46100 Burjassot-Valencia, Spain
¹⁰  Departamento de Fisica Teórica, Universidad Autónoma de Madrid, E-28049 and Instituto Estructura de la Materia, CSIC, E-28006 Madrid, Spain
¹¹  Forschungszentrum Rossendorf, D-01314 Dresden, Germany

c.mazzocchi@gsi.de

(Received: 4 September 2001 / Revised version: 23 October 2001 Communicated by J. Äystö )

Abstract
By using the fusion-evaporation reaction ²⁸Si( ³⁶Ar,p3n) and spectroscopy of -delayed -rays and charged particles on mass-separated sources, -decay properties of the neutron-deficient isotope ⁶⁰Ga were studied for the first time. The half-life of ⁶⁰Ga was determined to be 70(15) ms, and, based on coincidences, the isobaric-analogue state in ⁶⁰Zn was identified at 4851.9(7) keV. A semiempirical proton separation energy value of 40(70) keV was deduced for ⁶⁰Ga. The experimental results on half-life, mass excess, proton separation energy, and structure of the ⁶⁰Zn daughter states are discussed in comparison with various model predictions, including large-scale shell model calculations.

PACS
21.10.-k - Properties of nuclei; nuclear energy levels.
23.40.-s - Beta decay; double beta decay; electron and muon capture.
21.60.Cs - Shell model.

© Società Italiana di Fisica, Springer-Verlag 2001