2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 3, 133-138

Recoil distance half-life measurements of the excited states in 145Sm

A.M. El-Badry1 - T. Kuroyanagi1 - S. Mitarai1 - A. Odahara1 - Y. Gono1 - S. Morinobu1 - K. Ogawa2

1 Department of Physics,Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan
2 Department of physics, Chiba University, Chiba 263, Japan

Received: 9 September 1997 / Revised version: 12 June 1998 Communicated by K. Nakai

Abstract
A recoil distance method was used to measure half-lives of the excited states of 145Sm. The reaction used was 139La(10B, 4n)145Sm. A plunger system was used. Half-lives were determined for two excited states for the first time. The yrast 27/2+ state was found to have a half-life of 1.1 $\pm$ 0.2 ns corresponding to the retardation of 3.1 $\times$ 10-4 comparing with the single particle estimate of M1. The excitation energy of this state was well reproduced by the shell model calculation having a mixed configuration of [$\pi${h11/2(g7/2)-2 (d5/2)-1 }10-, $\nu$f7/2] + [$\pi${h11/2(g7/2)-1}9-,$\nu$h9/2]. Another retarded E1 transition was also found in a decay of a 21/2+ state. Its retardation was 1.6 $\times$ 10-4 comparing with the single particle value.

PACS
21.10.-kProperties of nuclei; nuclear energy levels - 27.60.+j$90 \le A \le 149$


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