Eur. Phys. J. A 15, 285-289 (2002)
DOI: 10.1140/epja/i2002-10076-x

Short Note

Rotational bands in

X.H. Zhou¹, M. Oshima², Y. Toh², Y.H. Zhang¹, Y. Zheng¹, M. Koizumi², A. Osa², T. Hayakawa², Y. Hatsukawa², T. Shizuma² and M. Sugawara<sup>3

1</sup>  Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, PRC
²  Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195, Japan
³  Chiba Institute of Technology, Narashino, Chiba 275-0023, Japan

zxh@impcas.ac.cn

(Received: 10 May 2002 / Revised version: 8 July 2002 / Published online: 19 November 2002)

Abstract
High-spin states in ¹⁶⁹Re have been investigated by means of in-beam -ray spectroscopy techniques with the ¹⁴⁴Sm( ²⁸Si, 1p2n ) ¹⁶⁹Re reaction. X- and - - t coincidences, -ray anisotropies, and DCO ratios were measured. A strongly coupled band based on the 9/2 ^-[514] Nilsson state and a decoupled band built on the h_9/2 intruder proton orbital (nominally 1/2 ^-[541]) have been established. The AB neutron crossings are observed at and 0.27 MeV for the 9/2 ^-[514] and 1/2 ^-[541] bands, respectively. The 9/2 ^-[514] band in ¹⁶⁹Re shows the largest signature splitting at low spin among the odd-mass Re isotopes. Band properties of the AB neutron crossing frequencies, alignment gains, and signature splittings are discussed, and compared with those in the heavier odd- A Re isotopes. Additionally, a three-quasipariticle band is observed, and the 9/2 configuration is proposed tentatively.

PACS
21.10.Re - Collective levels.
23.20.-g - Electromagnetic transitions.
23.20.Lv - Gamma transitions and level energies.
27.70.+q - .

© Società Italiana di Fisica, Springer-Verlag 2002