New isomer in 96Y marking the onset of deformation at N = 57. (28th February 2017)

• Record Type: Journal Article
• Authors: Iskra, Ł. W.; Fornal, B.; Leoni, S.; Bocchi, G.; Petrovici, A.; Porzio, C.; Blanc, A.; De France, G.; Jentschel, M.; Köster, U.; Mutti, P.; Régis, J.-M.; Simpson, G.; Soldner, T.; Ur, C. A.; Urban, W.; Bazzacco, D.; Benzoni, G.; Bottoni, S.; Bruce, A.; Cieplicka-Oryńczak, N.; Crespi, F. C. L.; Fraile, L. M.; Korten, W.; Kröll, T.; Lalkovski, S.; Márginean, N.; Michelagnoli, C.; Melon, B.; Mengoni, D.; Million, B.; Nannini, A.; Napoli, D.; Podolyák, Zs.; Regan, P. H.; Szpak, B.;
• Is Part Of: Europhysics letters. Volume 117:Number 1(2017:Jan.)
• Publication Date: 2017-02-28
• Subjects: 23.20.Lv -- 25.85.Ec -- 21.60.-n; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/117/12001
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: The level scheme of 96 Y was significantly extended and a new 201 ns isomer was located at 1655 keV excitation energy, with spin-parity assignment of 5 ± or 6 − . The isomer decays to spherical low-spin structure by transitions with large hindrance and is fed by a short cascade which resembles the beginning of a rotational band. This is in analogy with the feeding and decay pattern of the 4 − isomer in 98 Y, here confirmed, by lifetime analysis, as a bandhead of a rotational structure with sizable deformation. It is suggested that the new isomer in 96 Y arises from a shape change between deformed and spherical configurations, which indicates the appearance of deformation already at N = 57 in the yttrium chain. The experimental findings for 96 Y are strengthened by theoretical calculations based on the complex Excited Vampir model.