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Title: Configurations and decay hindrances of high- K states in Hf 180

Abstract

Multi-quasiparticle high-K states, several of which are isomeric, were observed in Hf-180 with the Gammasphere array. We determined the lifetimes in the ns-μs range using centroid-shift and decay measurements within a mu s coincidence time window. The configurations of high-K states involve two and four quasiparticles, with states up to Kπ = (18-) established. High-K excitations are found to be progressively more favored with increasing excitation energy. The K quantum number is quite robust up to the highest spins observed, as evidenced by the large values of the reduced hindrance for isomeric decays. Furthermore, rotational bands built on three high-K states are identified, and the measured branching ratios in these sequences enable the assignment of underlying configurations. Multi-quasiparticle calculations using the Lipkin-Nogami approach for pairing, with blocking included, reproduce the observed high-K energies quite well.

Authors:
 [1];  [2];  [3];  [3];  [3];  [3];  [3];  [4];  [3];  [3];  [5];  [5];  [3];  [6];  [3];  [5]
  1. Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics; Univ. of Mumbai (India). Centre for Excellence in Basic Sciences (DAE)
  2. Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics; Argonne National Lab. (ANL), Argonne, IL (United States)
  5. Univ. of Manchester (United Kingdom)
  6. Univ. of Liverpool (United Kingdom)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP)
OSTI Identifier:
1390818
Alternate Identifier(s):
OSTI ID: 1334221
Grant/Contract Number:  
AC02-06CH11357; FG02-94ER40848; FG02-94ER40834
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 94; Journal Issue: 6; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Tandel, S. K., Chowdhury, P., Kondev, F. G., Janssens, R. V. F., Khoo, T. L., Carpenter, M. P., Lauritsen, T., Lister, C. J., Seweryniak, D., Zhu, S., Deacon, A., Freeman, S. J., Hammond, N. J., Jones, G. D., Moore, E. F., and Smith, J. F. Configurations and decay hindrances of high- K states in Hf180. United States: N. p., 2016. Web. doi:10.1103/PhysRevC.94.064304.
Tandel, S. K., Chowdhury, P., Kondev, F. G., Janssens, R. V. F., Khoo, T. L., Carpenter, M. P., Lauritsen, T., Lister, C. J., Seweryniak, D., Zhu, S., Deacon, A., Freeman, S. J., Hammond, N. J., Jones, G. D., Moore, E. F., & Smith, J. F. Configurations and decay hindrances of high- K states in Hf180. United States. doi:10.1103/PhysRevC.94.064304.
Tandel, S. K., Chowdhury, P., Kondev, F. G., Janssens, R. V. F., Khoo, T. L., Carpenter, M. P., Lauritsen, T., Lister, C. J., Seweryniak, D., Zhu, S., Deacon, A., Freeman, S. J., Hammond, N. J., Jones, G. D., Moore, E. F., and Smith, J. F. Fri . "Configurations and decay hindrances of high- K states in Hf180". United States. doi:10.1103/PhysRevC.94.064304. https://www.osti.gov/servlets/purl/1390818.
@article{osti_1390818,
title = {Configurations and decay hindrances of high- K states in Hf180},
author = {Tandel, S. K. and Chowdhury, P. and Kondev, F. G. and Janssens, R. V. F. and Khoo, T. L. and Carpenter, M. P. and Lauritsen, T. and Lister, C. J. and Seweryniak, D. and Zhu, S. and Deacon, A. and Freeman, S. J. and Hammond, N. J. and Jones, G. D. and Moore, E. F. and Smith, J. F.},
abstractNote = {Multi-quasiparticle high-K states, several of which are isomeric, were observed in Hf-180 with the Gammasphere array. We determined the lifetimes in the ns-μs range using centroid-shift and decay measurements within a mu s coincidence time window. The configurations of high-K states involve two and four quasiparticles, with states up to Kπ = (18-) established. High-K excitations are found to be progressively more favored with increasing excitation energy. The K quantum number is quite robust up to the highest spins observed, as evidenced by the large values of the reduced hindrance for isomeric decays. Furthermore, rotational bands built on three high-K states are identified, and the measured branching ratios in these sequences enable the assignment of underlying configurations. Multi-quasiparticle calculations using the Lipkin-Nogami approach for pairing, with blocking included, reproduce the observed high-K energies quite well.},
doi = {10.1103/PhysRevC.94.064304},
journal = {Physical Review C},
number = 6,
volume = 94,
place = {United States},
year = {2016},
month = {12}
}

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