K-mixing in the doubly mid-shell nuclide 170Dy and the role of vibrational degeneracy

Autor: P.-A. Söderström, P.M. Walker, J. Wu, H.L. Liu, P.H. Regan, H. Watanabe, P. Doornenbal, Z. Korkulu, P. Lee, J.J. Liu, G. Lorusso, S. Nishimura, V.H. Phong, T. Sumikama, F.R. Xu, A. Yagi, G.X. Zhang, D.S. Ahn, T. Alharbi, H. Baba, F. Browne, A.M. Bruce, R.J. Carroll, K.Y. Chae, Zs. Dombradi, A. Estrade, N. Fukuda, C.J. Griffin, E. Ideguchi, N. Inabe, T. Isobe, H. Kanaoka, S. Kanaya, I. Kojouharov, F.G. Kondev, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, G.J. Lane, E.J. Lee, C.S. Lee, G. Lotay, C.-B. Moon, I. Nishizuka, C.R. Niţă, A. Odahara, Z. Patel, Zs. Podolyák, O.J. Roberts, H. Sakurai, H. Schaffner, C.M. Shand, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J.J. Valiente-Dòbon, Z.Y. Xu
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Physics Letters B, Vol 762, Iss , Pp 404-408 (2016)
Druh dokumentu: article
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2016.09.058
Popis: A detailed study of the structure of the doubly mid-shell nucleus Dy104166170 has been carried out, following isomeric and β decay. We have measured the yrast band up to the spin-parity Jπ=6+ state, the K=2 γ-vibration band up to the 5+ state, a low-lying negative-parity band based on a 2− state that could be a candidate for the lowest energy octupole vibration state within this nucleus, and a candidate for the Kπ=6+ two quasi-particle isomer. This state was determined to have an excitation energy of 1643.91(23) keV and a half life of 0.99(4) μs, with a reduced hindrance for its decay to the ground-state band an order of magnitude lower than predicted by NpNn systematics. This is interpreted as being due to γ-vibrational mixing from a near degeneracy of the isomer and the 6+ state of the γ band. Furthermore, the parent nucleus 170Tb has been determined to have a half-life of 0.91(−13+18) s with a possible spin-parity of 2−. Keywords: K isomer, Dysprosium, Mid-shell, γ-Ray spectroscopy
Databáze: Directory of Open Access Journals
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