Rotational bands in neutron-rich {sup 169,171,172}Er
- Nuclear Structure Research Laboratory, Department of Physics, University of Rochester, Rochester, New York 14627 (United States)
The neutron-rich {sup 169,171,172}Er nuclei were populated by few-neutron transfer reactions between {sup 170}Er and {sup 238}U at a near barrier energy. The spectroscopy of these Er isotopes was studied using prompt {gamma} rays correlated with delayed transitions or events involving at least three prompt transitions. The ground-state band of {sup 172}Er was populated up to spin 22{sup +} at an excitation energy of 5528 keV. Rotational bands built on the 1/2{sup -}[521], 5/2{sup -}[512], and 7/2{sup +}[633] neutron configurations in {sup 169,171}Er were extended to substantially higher spins than previously known. The signature splitting observed in these rotational bands is addressed within the framework of the particle-rotor model in terms of triaxiality and Coriolis attenuation. The signature inversion observed in the 5/2{sup -}[512] band is well reproduced by including the triaxial degree of freedom in the calculation. Attenuating the Coriolis interaction in the calculation is found to be necessary to reproduce the signature splitting observed in the 7/2{sup +}[633] band. A similar Coriolis attenuation also is needed to account for the signature splitting as well as the B(M1)/B(E2) ratios in the 7/2{sup +}[633] ground-state band in the neighboring N=99 isotones, {sup 167}Er and {sup 169}Yb.
- OSTI ID:
- 20695590
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 70, Issue 1; Other Information: DOI: 10.1103/PhysRevC.70.014313; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COLLECTIVE MODEL
ERBIUM 167
ERBIUM 170
ERBIUM 171
ERBIUM 172
EXCITATION
GAMMA SPECTRA
GAMMA SPECTROSCOPY
GROUND STATES
HEAVY ION REACTIONS
ISOTONIC NUCLEI
KEV RANGE
NEUTRON TRANSFER
NEUTRONS
PARTICLE-CORE COUPLING MODEL
ROTATIONAL STATES
SPIN
URANIUM 238
YTTERBIUM 169