Competing proton and neutron rotational alignments: Band structures in sup 131 Ba

Journal Article · Wed Jan 31 23:00:00 EST 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.41.717· OSTI ID:7243370

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

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1. Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794 (USA)
2. The Manne Siegbahn Institute of Physics, Frescativaegen 24, S 104 05 Stockholm 50, (Sweden)

High-spin states in the odd-neutron {sup 131}Ba nucleus have been populated following the {sup 122}Sn({sup 13}C,4{ital n}) reaction. Several rotational bands were established using {gamma}-{gamma} coincidence techniques. The yrast band, built on a {nu}{ital h}{sub 11/2} orbital, has a relatively large signature splitting ({similar to}160 keV). Cranking calculations suggest a significant triaxial shape with {gamma}{much lt}0{degree} for this configuration. A pair of {ital h}{sub 11/2} protons align at a rotational frequency {h bar}{omega}{similar to}0.43 MeV and drive the nucleus towards a near-prolate shape ({gamma}{ge}0{degree}), which is manifest by the observation of a {Delta}{ital I}=1 band with strong dipole transitions and a small signature inversion. At a similar frequency, pairs of {ital h}{sub 11/2} neutrons align and drive the nucleus to near-oblate ({gamma}{similar to}{minus}60{degree}) shapes, resulting in the observation of decoupled {Delta}{ital I}=2 bands.

• OSTI ID: 7243370
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Journal Name: Physical Review, C (Nuclear Physics); (USA) Vol. 41:2; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651720* -- Nuclear Properties & Reactions
A=90-149
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALINE EARTH ISOTOPES
BARIUM 131
BARIUM ISOTOPES
BARYONS
BETA DECAY RADIOISOTOPES
CARBON 13 REACTIONS
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
CRANKING MODEL
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
EVEN-ODD NUCLEI
EXCITED STATES
FERMIONS
HADRONS
HEAVY ION REACTIONS
HIGH SPIN STATES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
NEUTRONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
RADIOISOTOPES
ROTATIONAL STATES
TARGETS
TIN 122 TARGET
YRAST STATES