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]

---

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

Related Subjects

651720* -- Nuclear Properties & Reactions
A=90-149
Experimental
653001 -- Nuclear Theory-- Nuclear Structure
Moments
Spin
& Models
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCELERATORS
ALKALI METAL ISOTOPES
ANGULAR DISTRIBUTION
BAND THEORY
BARYONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BORON 11 REACTIONS
CESIUM 127
CESIUM ISOTOPES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
CRANKING MODEL
DEFORMED NUCLEI
DISTRIBUTION
DOPPLER EFFECT
ELECTROMAGNETIC RADIATION
ELECTRON CAPTURE RADIOISOTOPES
ELECTROSTATIC ACCELERATORS
ELEMENTARY PARTICLES
ENERGY LEVELS
EVAPORATION MODEL
EXCITED STATES
FERMIONS
GAMMA RADIATION
HADRONS
HEAVY ION REACTIONS
HOURS LIVING RADIOISOTOPES
IONIZING RADIATIONS
ISOTOPES
MATHEMATICAL MODELS
NEUTRONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
QUADRUPOLE MOMENTS
QUASI PARTICLES
RADIATIONS
RADIOISOTOPES
RECOILS
ROTATIONAL STATES
SHELL MODELS
TARGETS
TIN 120 TARGET
VAN DE GRAAFF ACCELERATORS