Spin dependence of K mixing, strong configuration mixing, and electromagnetic properties of {sup 178}Hf

Journal Article · Thu Mar 15 04:00:00 EDT 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.75.034308· OSTI ID:20995121

Hayes, A B; Cline, D; Hua, H; Simon, M W; Teng, R ^[1]; Wu, C Y ^[1]; Ai, H; Amro, H; Casten, R F; Hecht, A A; Heinz, A; Hughes, R; Meyer, D A ^[2]; Beausang, C ^[3]; Gerl, J; Schlegel, Ch; Wollersheim, H J ^[4]; Janssens, R V. F.; Lister, C J; Moore, E F ^[5]

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1. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)
2. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)
3. Physics Department, University of Richmond, Richmond, Virginia 23173 (United States)
4. GSI, Gesellschaft fuer Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt (Germany)
5. Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

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.

• OSTI ID: 20995121
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 3 Vol. 75; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

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