Decay of the 9/2{sup -} isomer in {sup 181}Tl and mass determination of low-lying states in {sup 181}Tl, {sup 177}Au, and {sup 173}Ir

Journal Article · Sat Aug 15 04:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.80.024302· OSTI ID:21293779

Andreyev, A N ^[1]; Antalic, S; Saro, S ^[2]; Ackermann, D; Comas, V F; Heinz, S; Heredia, J A; Hessberger, F P; Khuyagbaatar, J; Kojouharov, I; Kindler, B; Lommel, B; Mann, R ^[3]; Cocolios, T E; Elseviers, J; Huyse, M; Van Duppen, P Van; Venhart, M ^[1]; Franchoo, S ^[4]; Hofmann, S ^[3]

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1. Instituut voor Kern-en Stralingsfysica, K. U. Leuven, University of Leuven, B-3001 Leuven (Belgium)
2. Department of Nuclear Physics and Biophysics, Comenius University, Bratislava, SK-84248 (Slovakia)
3. GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany)
4. IPN Orsay, F-91406 Orsay Cedex (France)

A detailed spectroscopic study of the neutron-deficient isotope {sup 181}Tl and the daughter of its {alpha} decay, {sup 177}Au, has been performed in the complete fusion reaction {sup 40}Ca+{sup 144}Sm{yields}{sup 184}Pb* at the velocity filter SHIP (GSI). The mass excess, excitation energy, and decay scheme of the isomeric 1.40(3) ms, 9/2{sup -} intruder state in {sup 181}Tl have been established for the first time. These results solve a long-standing puzzle of the unrealistically large reduced {alpha}-decay width of this isomer. Based on this, the previously unknown masses of the long-lived isomeric states in {sup 177}Au and {sup 173}Ir have been derived. In turn, it now allows the excitation energies of previously identified bands in {sup 177}Au and {sup 173}Ir to be deduced and compared with theoretical predictions. First measurements of {alpha}-decay branching ratios for {sup 181}Tl{sup m} and {sup 177}Au{sup m,g} are also reported.

• OSTI ID: 21293779
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 80; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
BRANCHING RATIO
CALCIUM 40 TARGET
DAUGHTER PRODUCTS
EXCITATION
FORECASTING
GOLD 177
IRIDIUM 173
ISOMERS
MASS
NEUTRON-DEFICIENT ISOTOPES
THALLIUM 181
VELOCITY