K-Mixing and fast decay of a seven-quasiparticle isomer in179Ta.

Authors :: Kondev, F.
Dracoulis, G.
Lane, G.
Ahmad, I.
Byrne, A.
Carpenter, M.
Chowdhury, P.
Freeman, S.
Hammond, N.
Janssens, R.
Kibédi, T.
Lauritsen, T.
Lister, C. J.
Mukherjee, G.
Seweryniak, D.
Tandel, S. K.
Source :: European Physical Journal A -- Hadrons & Nuclei; Oct2004, Vol. 22 Issue 1, p23-27, 5p
Publication Year :: 2004
Abstract: A seven-quasiparticle isomer withandT<subscript>1/2</subscript> = 53 (<superscript> + 3</superscript><subscript>-7</subscript>) ns has been identified in<superscript>179</superscript>Ta. By comparing its excitation energy with results from multi-quasiparticle calculations that include the effects of blocking and residual nucleon-nucleon interactions, the isomer is assigned the(5/2<superscript> +</superscript>[402], 7/2<superscript> +</superscript>[404],(5/2<superscript>-</superscript>[512], 7/2<superscript>-</superscript>[514], 7/2<superscript>-</superscript>[503], 9/2<superscript> +</superscript>[624]) configuration. The decay of this isomer is found to be unusually fast, a feature that is attributed to a mixing with a specific collective level. The interaction strength is found to be orders of magnitude lower than that observed between interacting collective levels. [ABSTRACT FROM AUTHOR]