Abstract
Low-energy isomeric states of 86Y were populated in the reaction 73Ge + 16O at 57MeV and were investigated by means of delayed n\( \gamma\) and \( \gamma\) \( \gamma\) coincidences. A half-life of 70(7)ns was measured for the 5- state at 208keV, yielding an exceptionally small B(M1) value of 2.0(7)×10-5 W.u. and a B(E2) value of 0.34(+24 -13) W.u. For the other three known isomeric states at 218, 243, and 302keV, the half-lives extracted from the present experimental data are in very good agreement with previous measurements. Given the newly observed isomeric character of the 5- 208keV state, the re-analysis of earlier experimental data on the 302keV isomer led to a new spin-parity assignment, 6+, for this state. In addition, this re-evaluation provided two g -factors, -0.083(3) and +0.63(2) , for the 208 and 302keV states, respectively. The results are discussed in terms of spherical-shell model calculations performed with a truncated space of configurations built on the f 5/2 , p 3/2 , p 1/2 , and g 9/2 valence orbitals. Effective spin, orbital, and “tensor” g -factors were determined empirically for protons and neutrons in the considered configuration space.
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C. Rusu, C.A. Ur, D. Bucurescu, A. Iordăchescu, N. Mărginean, G. Căta-Danil, I. Căta-Danil, M. Ionescu-Bujor, M. Ivaşcu, D. Bazzacco, T. Kröll, S. Lenzi, S. Lunardi, R. Menegazzo, C. Rossi Alvarez, G. de Angelis, A. Gadea, D. Napoli, Nucl. Phys. A 818, 1 (2009)
D. Bucurescu, G. Constantinescu, D. Cutoiu, M. Ivaşcu, N.V. Zamfir, A. Abdel Haliem, J. Phys. G 10, 1189 (1984)
M. Ionescu-Bujor, A. Iordăchescu, D. Bucurescu, Phys. Rev. C 62, 014306 (2000)
E.K. Hyde, W.J. Treytl, A. Siivola, D.H. Sisson, D.K. Horen, Phys. Rev. 142, 657 (1966)
W.J. Treytl, E. Matthias, in Proceedings of the International Conference on Hyperfine Structure and Nuclear Radiations, Asilomar, Pacific Grove, CA, 1967, edited by E. Matthias, D.A. Shirley (North-Holland, Amsterdam, 1968) p. 145
ENSDF at NNDC (database version of July 10, 2009) http://www.nndc.bnl.gov/ensdf
B. Singh, Nucl. Data Sheets 94, 1 (2001)
M. Davidson, J. Davidson, A.J. Kreiner, C. Pomar, Phys. Rev. C 29, 1717 (1984)
M. Ionescu-Bujor, E.A. Ivanov, A. Iordăchescu, D. Ploştinaru, G. Pascovici, Nucl. Phys. A 272, 1 (1976)
A. Etchegoyen, W.D.M. Rae, N.S. Godwin, OXBASH code (MSU version by B.A. Brown, 1986)
I.P. Johnstone, L.D. Skouras, Eur. Phys. J. A 11, 125 (2001)
J.P. Schiffer, W.W. True, Rev. Mod. Phys. 48, 191 (1976)
G. Mukherjee, A.A. Sonzogni, Nucl. Data Sheets 105, 419 (2005)
N.J. Stone, At. Data Nucl. Data Tables 90, 75 (2005)
I.S. Towner, Phys. Rep. 155, 263 (1987)
B. Castel, I.S. Towner, Modern Theories of Nuclear Moments (Clarendon, Oxford, 1990)
A. Bohr, B.R. Mottelson, Nuclear Structure (World Scientific, Singapore, 1998)
I.P. Johnstone, I.S. Towner, Eur. Phys. J. A 3, 237 (1998)
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Communicated by A.A. Korsheninnikov
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Rusu, C., Bucurescu, D., Mărginean, N. et al. Isomerism of low-lying states in 86Y. Eur. Phys. J. A 44, 31–41 (2010). https://doi.org/10.1140/epja/i2010-10928-8
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DOI: https://doi.org/10.1140/epja/i2010-10928-8