Spin dependence of K mixing, strong configuration mixing, and electromagnetic properties of {sup 178}Hf
Abstract
The combined data of two Coulomb excitation experiments has verified the purely electromagnetic population of the K{sup {pi}}=4{sup +},6{sup +},8{sup -}, and 16{sup +} rotational bands in {sup 178}Hf via 2{<=}{nu}{<=}14 K-forbidden transitions, quantifying the breakdown of the K-selection rule with increasing spin in the low-K bands. The {gamma}-, 4{sup +}, and 6{sup +} bands were extended, and four new states in a rotational band were tentatively assigned to a previously known K{sup {pi}}=0{sup +} band. The quasiparticle structure of the 6{sup +} (t{sub (1/2)}=77 ns) and 8{sup -} (t{sub (1/2)}=4 s) isomer bands were evaluated, showing that the gyromagnetic ratios of the 6{sup +} isomer band are consistent with a pure {pi}(7/2){sup +}[404],{pi}(5/2){sup +}[402] structure. The 8{sup -} isomer band at 1147 keV and the second 8{sup -} band at 1479 keV, thought to be predominantly {nu}(7/2){sup -}[514],{nu}(9/2){sup +}[624] and {pi}(9/2){sup -}[514],{pi}(7/2){sup +}[404], respectively, are mixed to a degree approaching the strong-mixing limit. Based on measured <K{sup {pi}}=16{sup +} parallel E 2 parallel K{sup {pi}}=0{sup +}> matrix elements, it was shown that heavy-ion bombardment could depopulate the 16{sup +} isomer at the {approx}1% level, although no states were found that would mediate photodeexcitation of the isomer via low-energy x-raymore »
- Authors:
- more »
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)
- (United States)
- Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)
- Physics Department, University of Richmond, Richmond, Virginia 23173 (United States)
- GSI, Gesellschaft fuer Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt (Germany)
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) (and others)
- Publication Date:
- OSTI Identifier:
- 20995121
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.75.034308; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ABSORPTION; CONFIGURATION MIXING; COULOMB EXCITATION; FORBIDDEN TRANSITIONS; GYROMAGNETIC RATIO; HAFNIUM 178; HEAVY IONS; ISOMERS; KEV RANGE; MATRIX ELEMENTS; MIXING; ROTATIONAL STATES; SELECTION RULES; SPIN; X RADIATION
Citation Formats
Hayes, A. B., Cline, D., Hua, H., Simon, M. W., Teng, R., Wu, C. Y., Lawrence Livermore National Laboratory, Livermore, California 94550, Ai, H., Amro, H., Casten, R. F., Hecht, A. A., Heinz, A., Hughes, R., Meyer, D. A., Beausang, C., Gerl, J., Schlegel, Ch., Wollersheim, H. J., Janssens, R. V. F., Lister, C. J., and Moore, E. F.. Spin dependence of K mixing, strong configuration mixing, and electromagnetic properties of {sup 178}Hf. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVC.75.034308.
Hayes, A. B., Cline, D., Hua, H., Simon, M. W., Teng, R., Wu, C. Y., Lawrence Livermore National Laboratory, Livermore, California 94550, Ai, H., Amro, H., Casten, R. F., Hecht, A. A., Heinz, A., Hughes, R., Meyer, D. A., Beausang, C., Gerl, J., Schlegel, Ch., Wollersheim, H. J., Janssens, R. V. F., Lister, C. J., & Moore, E. F.. Spin dependence of K mixing, strong configuration mixing, and electromagnetic properties of {sup 178}Hf. United States. doi:10.1103/PHYSREVC.75.034308.
Hayes, A. B., Cline, D., Hua, H., Simon, M. W., Teng, R., Wu, C. Y., Lawrence Livermore National Laboratory, Livermore, California 94550, Ai, H., Amro, H., Casten, R. F., Hecht, A. A., Heinz, A., Hughes, R., Meyer, D. A., Beausang, C., Gerl, J., Schlegel, Ch., Wollersheim, H. J., Janssens, R. V. F., Lister, C. J., and Moore, E. F.. Thu .
"Spin dependence of K mixing, strong configuration mixing, and electromagnetic properties of {sup 178}Hf". United States.
doi:10.1103/PHYSREVC.75.034308.
@article{osti_20995121,
title = {Spin dependence of K mixing, strong configuration mixing, and electromagnetic properties of {sup 178}Hf},
author = {Hayes, A. B. and Cline, D. and Hua, H. and Simon, M. W. and Teng, R. and Wu, C. Y. and Lawrence Livermore National Laboratory, Livermore, California 94550 and Ai, H. and Amro, H. and Casten, R. F. and Hecht, A. A. and Heinz, A. and Hughes, R. and Meyer, D. A. and Beausang, C. and Gerl, J. and Schlegel, Ch. and Wollersheim, H. J. and Janssens, R. V. F. and Lister, C. J. and Moore, E. F.},
abstractNote = {The combined data of two Coulomb excitation experiments has verified the purely electromagnetic population of the K{sup {pi}}=4{sup +},6{sup +},8{sup -}, and 16{sup +} rotational bands in {sup 178}Hf via 2{<=}{nu}{<=}14 K-forbidden transitions, quantifying the breakdown of the K-selection rule with increasing spin in the low-K bands. The {gamma}-, 4{sup +}, and 6{sup +} bands were extended, and four new states in a rotational band were tentatively assigned to a previously known K{sup {pi}}=0{sup +} band. The quasiparticle structure of the 6{sup +} (t{sub (1/2)}=77 ns) and 8{sup -} (t{sub (1/2)}=4 s) isomer bands were evaluated, showing that the gyromagnetic ratios of the 6{sup +} isomer band are consistent with a pure {pi}(7/2){sup +}[404],{pi}(5/2){sup +}[402] structure. The 8{sup -} isomer band at 1147 keV and the second 8{sup -} band at 1479 keV, thought to be predominantly {nu}(7/2){sup -}[514],{nu}(9/2){sup +}[624] and {pi}(9/2){sup -}[514],{pi}(7/2){sup +}[404], respectively, are mixed to a degree approaching the strong-mixing limit. Based on measured <K{sup {pi}}=16{sup +} parallel E 2 parallel K{sup {pi}}=0{sup +}> matrix elements, it was shown that heavy-ion bombardment could depopulate the 16{sup +} isomer at the {approx}1% level, although no states were found that would mediate photodeexcitation of the isomer via low-energy x-ray absorption.},
doi = {10.1103/PHYSREVC.75.034308},
journal = {Physical Review. C, Nuclear Physics},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
-
The combined data of two Coulomb excitation experiments has verified the purely electromagnetic population of the K{pi} = 4{sup +}, 6{sup +}, 8{sup -}, and 16{sup +} rotational bands in {sup 178}Hf via 2 {le} {nu} {le} 14 K-forbidden transitions, quantifying the breakdown of the K-selection rule with increasing spin in the low-K bands. The {gamma}{sup -}, 4{sup +}, and 6{sup +} bands were extended, and four new states in a rotational band were tentatively assigned to a previously known K{pi} = 0{sup +} band. The quasiparticle structure of the 6{sup +} (t 1/2 = 77 ns) and 8{sup -}more »
-
Decays of 2.45-h $sup 178$Ta/sup m/ and 23.8-min $sup 178$Lu/sup m/ to the K/sup $pi$/ = 8$sup -$ levels in $sup 178$Hf
The decays of the high-spin isomers of $sup 178$Ta (2.45 h) and $sup 178$Lu (23.8 min) to the two strongly admixed K/sup $pi$/ = 8$sup -$ states in $sup 178$Hf were reinvestigated. The main features of the previously reported decay schemes are confirmed and several long-standing ambiguities are resolved. The results of this investigation indicate that the 1147-keV level is largely the two-neutron state and the 1479-keV level is largely the two-proton state in $sup 178$Hf. They are found to be 34% admixed with one another. This mixing value is in good agreement with the value deduced from the M1/E2more »