Eur. Phys. J. A 14, 279-285 (2002)
First evidence for the two-proton decay ofM. Pfützner1, E. Badura2, C. Bingham3, B. Blank4, M. Chartier5, H. Geissel2, J. Giovinazzo4, L.V. Grigorenko2, R. Grzywacz1, M. Hellström2, Z. Janas1, J. Kurcewicz1, A.S. Lalleman4, C. Mazzocchi2, I. Mukha2, G. Münzenberg2, C. Plettner2, E. Roeckl2, K.P. Rykaczewski6, 1, K. Schmidt7, R.S. Simon2, M. Stanoiu8 and J.-C. Thomas4
1 Institute of Experimental Physics, Warsaw University, PL-00-681 Warszawa, Poland
2 GSI, Planckstrasse 1, D-64291 Darmstadt, Germany
3 Department of Physics and Astronomy, University of Tennessee, Knoxville 37996 TN, USA
4 CEN Bordeaux-Gradignan, F-33175 Gradignan Cedex, France
5 Oliver Lodge Laboratory, Department of Physics, University of Liverpool, Liverpool, L69 3BX, UK
6 Physics Division, ORNL, Oak Ridge, TN 37831-6371, USA
7 Department of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, UK
8 GANIL, BP 5027, F-14021 Caen Cedex, France
(Received: 17 May 2002 Communicated by J. Äystö)
Decays of five 45Fe atoms have been observed at the fragment separator of GSI. Whereas one event is consistent with the -decay of 45Fe accompanied by the emission of a 10 MeV proton, four decays are consistent with the emission of particle(s) of total energy MeV. This observation represents the first evidence for two-proton ground-state radioactivity, a decay mode predicted for 45Fe. The time distribution of the observed decay events corresponds to a half-life of 3.2+2.6-1.0 ms.
21.10.Tg - Lifetimes.
23.50.+z - Decay by proton emission.
29.30.Ep - Charged-particle spectroscopy.
© Società Italiana di Fisica, Springer-Verlag 2002