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

Journal Article · Thu Feb 01 00:00:00 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), Vol. 41:2; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

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