Spin dependence of k-mixing, strong configuration mixing and electromagnetic properties of {sup 178}Hf.

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Phys. Rev. C

DOI:https://doi.org/10.1103/PhysRevC.75.034308· OSTI ID:940692

Hayes, A B; Cline, D; Wu, C Y; Ai, H; Amro, H; Beausang, C; Casten, R F; Gerl, J; Hecht, A A; Heinz, A; Hua, H; Hughes, R; Janssens, R V F; Lister, C J; Macchiavelli, A O; Meyer, D A; Moore, E F; Napiorkowski, P; Pardo, R C; Schlegel, Ch ; Seweryniak, D; Simon, W M; Srebrny, J; Teng, R; Vetter, K; LLNL,; GSI,

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 -} (t 1/2 = 4s) 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{pi} = 16{sup +} {parallel} E2 {parallel} K{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.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NSF; Air Force Office of Scientific Research; Polish State Committee for Scientific Research
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 940692
• Report Number(s): ANL/PHY/JA-57737
• Journal Information: Phys. Rev. C, Journal Name: Phys. Rev. C Journal Issue: 2007 Vol. 75; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BREAKDOWN
CONFIGURATION MIXING
COULOMB EXCITATION
FORBIDDEN TRANSITIONS
GYROMAGNETIC RATIO
HAFNIUM 178
ISOMERS
ROTATIONAL STATES