Rotational band structures in sup 127 Cs: Shape changes induced by h sub 11/2 neutron alignment

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.42.890· OSTI ID:6421624

Liang, Y; Ma, R; Paul, E S; Xu, N; Fossan, D B ^[1]; Wyss, R A ^[2]

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1. Department of Physics, State University of New York at Stony Brook, Stony Brook, NY (USA)
2. The Manne Siegbahn Insitute of Physics, Stockholm (Sweden)

Several rotational bands have been populated to high spin in {sup 127}Cs following the {sup 120}Sn({sup 11}B,4{ital n}) reaction. Rotational bands built on low-lying proton {ital g}{sub 7/2}, {ital d}{sub 5/2}, and {ital g}{sub 9/2} (hole) orbitals, and the unique-parity {ital h}{sub 11/2} orbital were observed and identified. For the {pi}{ital g}{sub 9/2} (hole) case, both signatures were seen in a strongly coupled {Delta}{ital I}=1 band, while for the other cases, decoupled {Delta}{ital I}=2 bands were observed with strong in-band quadrupole transitions. Through comparisons with cranked-shell-model calculations, these band structures are understood to be associated with a prolate ({gamma}{approximately}0{degree}) deformed nuclear shape. At frequencies above {h bar}{omega}=0.3 MeV, the rotational alignment of a pair of {ital h}{sub 11/2} neutrons was observed for each of the {ital h}{sub 11/2}, {ital g}{sub 7/2}, and {ital d}{sub 5/2} bands. This neutron alignment is predicted to drive the nuclear core away from a prolate shape towards the collectively rotating oblate ({gamma}={minus}60{degree}) shape. Changes in the measured signature splittings for the bands below and above the alignment are consistent with the shape changes.

• OSTI ID: 6421624
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Vol. 42:3; ISSN 0556-2813
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BORON 11 REACTIONS
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ROTATIONAL STATES
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ANGULAR DISTRIBUTION
BAND THEORY
COINCIDENCE SPECTROMETRY
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DEFORMED NUCLEI
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BETA-PLUS DECAY RADIOISOTOPES
CESIUM ISOTOPES
CHARGED-PARTICLE REACTIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRON CAPTURE RADIOISOTOPES
ELECTROSTATIC ACCELERATORS
ELEMENTARY PARTICLES
ENERGY LEVELS
EXCITED STATES
FERMIONS
HADRONS
HEAVY ION REACTIONS
HOURS LIVING RADIOISOTOPES
IONIZING RADIATIONS
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MATHEMATICAL MODELS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
RADIATIONS
RADIOISOTOPES
TARGETS
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