Stability of oblate shapes in the vicinity of N= Z = 34 {sup 68}Se : bands in {sup 69}Se and {sup 67}As.

Journal Article · Sat Dec 01 04:00:00 EST 2001 · Phys. Rev. C

DOI:https://doi.org/10.1103/PhysRevC.64.064311· OSTI ID:949428

Jenkins, D G; Balamuth, D P; Carpenter, M P; Lister, C J; Fischer, S M; Clark, R M; Macchiavelli, A O; Fallon, P; Svensson, C E; Kelsall, N S; Wadsworth, R; LBNL,

The {gamma}-ray decay schemes of {sup 69}Se and {sup 67}As have been considerably extended using the {sup 40}Ca({sup 32}S,2pn){sup 69}Se and {sup 40}Ca({sup 32}S,{alpha}p){sup 67}As reactions at 100 MeV and {sup 40}Ca({sup 36}Ar,{alpha}2pn){sup 69}Se and {sup 40}Ca({sup 36}Ar,2{alpha}p){sup 67}As reactions at 145 MeV, with the aim of studying oblate bands arising from the strong coupling of a valence g9/2 particle (or hole) to the oblate deformed ground state band of {sup 68}Se. A new T{sub 1/2}=12{+-}2 ns J{sup {pi}}=9/2+ isomeric bandhead was identified in {sup 67}As. A transitional quadrupole moment of Q{sub 0}=-2.7(6) eb was deduced for the band built on the 9/2{sup +} isomer in {sup 69}Se, corresponding to a rigid oblate deformation of {beta}{sub 2}=-0.4(1), consistent with theoretical predictions. However, it appears that the relevant oblate configurations in {sup 69}Se and {sup 67}As are not nearly so favored as they are in {sup 68}Se, and are rapidly crossed by prolate configurations that form the high spin yrast lines.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: NATO; SC; NSF; FOR
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 949428
• Report Number(s): ANL/PHY/JA-40825
• Journal Information: Phys. Rev. C, Journal Name: Phys. Rev. C Journal Issue: 06 ; Dec. 2001 Vol. 64; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DECAY
DEFORMATION
GROUND STATES
ISOMERS
QUADRUPOLE MOMENTS
SELENIUM ISOTOPES
SHAPE
SPIN
STABILITY
VALENCE