1. Isomers and high-spin structures in the N=81 isotones Xe 135 and Ba 137
- Author
-
Vogt, A, Birkenbach, B, Reiter, P, Blazhev, A, Siciliano, M, Hadyńska-Klȩk, K, Valiente-Dobón, JJ, Wheldon, C, Teruya, E, Yoshinaga, N, Arnswald, K, Bazzacco, D, Bowry, M, Bracco, A, Bruyneel, B, Chakrawarthy, RS, Chapman, R, Cline, D, Corradi, L, Crespi, FCL, Cromaz, M, De Angelis, G, Eberth, J, Fallon, P, Farnea, E, Fioretto, E, Freeman, SJ, Fu, B, Gadea, A, Geibel, K, Gelletly, W, Gengelbach, A, Giaz, A, Görgen, A, Gottardo, A, Hayes, AB, Hess, H, Hirsch, R, Hua, H, John, PR, Jolie, J, Jungclaus, A, Kaya, L, Korten, W, Lee, IY, Leoni, S, Lewandowski, L, Liang, X, Lunardi, S, Macchiavelli, AO, Menegazzo, R, Mengoni, D, Michelagnoli, C, Mijatović, T, Montagnoli, G, Montanari, D, Müller-Gatermann, C, Napoli, D, Pearson, CJ, Pellegri, L, Podolyák, Z, Pollarolo, G, Pullia, A, Queiser, M, Radeck, F, Recchia, F, Regan, PH, Rosiak, D, Saed-Samii, N, Şahin, E, Scarlassara, F, Schneiders, D, Seidlitz, M, Siebeck, B, Sletten, G, Smith, JF, Söderström, PA, Stefanini, AM, Steinbach, T, Stezowski, O, Szilner, S, Szpak, B, Teng, R, Ur, C, Vandone, V, Warner, DD, Wiens, A, Wu, CY, and Zell, KO
- Abstract
The high-spin structures and isomers of the N=81 isotones Xe135 and Ba137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in Xe136+U238 and (ii) Xe136+Pb208 MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii) in the Xe136+Pt198 MNT reaction employing the γ-ray array GAMMASPHERE in combination with the gas-detector array CHICO, and (iv) via a B11+Te130 fusion-evaporation reaction with the HORUS γ-ray array at the University of Cologne. The high-spin level schemesof Xe135 and Ba137 are considerably extended to higher energies. The 2058-keV (19/2-) state in Xe135 is identified as an isomer, closing a gap in the systematics along the N=81 isotones. Its half-life is measured to be 9.0(9) ns, corresponding to a reduced transition probability of B(E2,19/2-→15/2-)=0.52(6) W.u. The experimentally deduced reduced transition probabilities of the isomeric states are compared to shell-model predictions. Latest shell-model calculations reproduce the experimental findings generally well and provide guidance to the interpretation of the new levels.
- Published
- 2017