Eur. Phys. J. A 11, 279-284 (2001)

Analysis of decay data from neutron-rich nuclei

U.C. Bergmann¹, M.J.G. Borge², J. Cederkäll³, C. Forssén¹, E. Fumero⁴, H.O.U. Fynbo³, H. Gausemel⁵, H. Jeppesen⁶, B. Jonson¹, K. Markenroth¹, T. Nilsson³, G. Nyman¹, K. Riisager⁶, H. Simon⁷, O. Tengblad², L. Weissman³, F. Wenander¹, K. Wilhelmsen Rolander⁴ and the ISOLDE Collaboration<sup>3

1</sup>  Experimentell Fysik, Chalmers Tekniska Högskola, S-412 96 Göteborg, Sweden
²  Instituto Estructura de la Materia, CSIC, E-28006 Madrid, Spain
³  EP Division, CERN, CH-1211 Genève 23, Switzerland
⁴  Fysiska Institutionen, Stockholms Universitet, Box 6730, S-113 85 Stockholm, Sweden
⁵  Kjemisk Institutt, Universitetet i Oslo, Postboks 1033, Blindern, N-0315 Oslo, Norway
⁶  Institut for Fysik og Astronomi, Aarhus Universitet, DK-8000 Aarhus C, Denmark
⁷  Institut für Kernphysik, Technische Universität, D-64289 Darmstadt, Germany

kvr@ifa.au.dk

(Received: 3 May 2001 / Revised version: 26 June 2001 Communicated by J. Äystö )

Abstract
The -decays of the neutron-rich nuclei ¹²Be and ²⁹Ne have been studied. The statistical correlations between the almost identical half-lives of ¹²Be and its daughter ¹²B are analysed for a large sample of ¹²Be decay data. Stringent mutual bounds are obtained on the parameter set, leading to a precise determination of the ¹²Be half-life of ms. From a simultaneous detection of -particles and neutrons from the decay of ²⁹Ne the neutron emission probability, P_n, is determined to % . No indication of two-neutron emission is seen from this nucleus. An upper limit of 2.2% (90% confidence level) is established for P_2n.

PACS
23.40.-s - Beta decay; double beta decay; electron and muon capture.
27.20.+n - .
27.30.+t - .
07.05.Kf - Data analysis: algorithms and implementation; data management.

© Società Italiana di Fisica, Springer-Verlag 2001