skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evidence for particle-hole excitations in the triaxial strongly-deformed well of {sup 163}Tm.

Abstract

Two interacting, strongly-deformed triaxial (TSD) bands have been identified in the Z=69 nucleus {sup 163}Tm. This is the first time that interacting TSD bands have been observed in an element other than the Z=71 Lu nuclei, where wobbling bands have been previously identified. The observed TSD bands in {sup 163}Tm appear to be associated with particle--hole excitations, rather than wobbling. Tilted-axis cranking (TAC) calculations reproduce all experimental observables of these bands reasonably well and also provide an explanation for the presence of wobbling bands in the Lu nuclei, and their absence in the Tm isotopes.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); FOR
OSTI Identifier:
915325
Report Number(s):
ANL/PHY/JA-56692
Journal ID: ISSN 0370-2693; PYLBAJ; TRN: US0804924
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Lett. B; Journal Volume: 647; Journal Issue: 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; DEFORMED NUCLEI; HOLES; THULIUM 163; EXCITATION

Citation Formats

Pattabiraman, N. S., Gu, Y., Frauendorf, S., Garg, U., Li, T., Nayak, B. K., Zhu, S., Wang, X., Ghugre, S. S., Janssens, R. V. F., Chakrawarthy, R. S., Whitehead, M., Macchiavelli, A. O., Physics, Univ. of Notre Dame, Kolkata Center, Schuster LLNL, and BNL. Evidence for particle-hole excitations in the triaxial strongly-deformed well of {sup 163}Tm.. United States: N. p., 2007. Web. doi:10.1016/j.physletb.2007.01.057.
Pattabiraman, N. S., Gu, Y., Frauendorf, S., Garg, U., Li, T., Nayak, B. K., Zhu, S., Wang, X., Ghugre, S. S., Janssens, R. V. F., Chakrawarthy, R. S., Whitehead, M., Macchiavelli, A. O., Physics, Univ. of Notre Dame, Kolkata Center, Schuster LLNL, & BNL. Evidence for particle-hole excitations in the triaxial strongly-deformed well of {sup 163}Tm.. United States. doi:10.1016/j.physletb.2007.01.057.
Pattabiraman, N. S., Gu, Y., Frauendorf, S., Garg, U., Li, T., Nayak, B. K., Zhu, S., Wang, X., Ghugre, S. S., Janssens, R. V. F., Chakrawarthy, R. S., Whitehead, M., Macchiavelli, A. O., Physics, Univ. of Notre Dame, Kolkata Center, Schuster LLNL, and BNL. Mon . "Evidence for particle-hole excitations in the triaxial strongly-deformed well of {sup 163}Tm.". United States. doi:10.1016/j.physletb.2007.01.057.
@article{osti_915325,
title = {Evidence for particle-hole excitations in the triaxial strongly-deformed well of {sup 163}Tm.},
author = {Pattabiraman, N. S. and Gu, Y. and Frauendorf, S. and Garg, U. and Li, T. and Nayak, B. K. and Zhu, S. and Wang, X. and Ghugre, S. S. and Janssens, R. V. F. and Chakrawarthy, R. S. and Whitehead, M. and Macchiavelli, A. O. and Physics and Univ. of Notre Dame and Kolkata Center and Schuster LLNL and BNL},
abstractNote = {Two interacting, strongly-deformed triaxial (TSD) bands have been identified in the Z=69 nucleus {sup 163}Tm. This is the first time that interacting TSD bands have been observed in an element other than the Z=71 Lu nuclei, where wobbling bands have been previously identified. The observed TSD bands in {sup 163}Tm appear to be associated with particle--hole excitations, rather than wobbling. Tilted-axis cranking (TAC) calculations reproduce all experimental observables of these bands reasonably well and also provide an explanation for the presence of wobbling bands in the Lu nuclei, and their absence in the Tm isotopes.},
doi = {10.1016/j.physletb.2007.01.057},
journal = {Phys. Lett. B},
number = 2007,
volume = 647,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • With the Doppler Shift Attenuation Method, quadrupole transition moments Qt were determined for the two recently proposed triaxial strongly deformed (TSD) bands in {sup 163}Tm. The measured Qt values indicate that the deformation of these bands is larger than that of the yrast signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the region.
  • With the Doppler Shift Attenuation Method, quadrupole transition moments Q{sub t} were determined for the two recently proposed triaxial strongly deformed (TSD) bands in {sup 163}Tm. The measured Q{sub t} values indicate that the deformation of these bands is larger than that of the yrast signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the region.
  • An unexpected strong interaction between normal deformed and triaxial strongly deformed levels at high spin, {approx}32({Dirac_h}/2{pi}), is observed in {sup 167}Lu. This constitutes the first observation of accidental degeneracy, at such high spins, causing cross talk between levels in the normal deformed and in the second potential well in any known mass region. Furthermore, evidence of quasi-particle excitations highly competing with the wobbling excitation mode in a triaxial superdeformed well has been established in {sup 167}Lu.
  • No abstract prepared.
  • High-spin states in {sup 160,161}Tm were populated using the {sup 128}Te({sup 37}Cl, 5n and 4n) reactions at a beam energy of 170 MeV. Emitted {gamma} rays were detected in the Gammasphere spectrometer. Two rotational bands with high moments of inertia were discovered, one assigned to {sup 160}Tm, while the other tentatively assigned to {sup 161}Tm. These sequences display features similar to bands observed in neighboring Er, Tm, Yb, and Lu nuclei which have been discussed in terms of triaxial strongly deformed structures. Cranked Nilsson Strutinsky calculations have been performed that predict well-deformed triaxial shapes at high spin in {sup 160,161}Tm.