1. Fast-timing study of the l-forbidden 1/2(+) -> 3/2(+) M1 transition in Sn-129
- Author
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Lica, R, Mach, H, Fraile, LM, Gargano, A, Borge, MJG, Marginean, N, Sotty, CO, Vedia, V, Andreyev, AN, Benzoni, G, Bomans, P, Borcea, R, Coraggio, L, Costache, C, Flavigny, F, Fynbo, H, Gaffney, Liam, Greenlees, PT, Harkness-Brennan, LJ, Huyse, Mark, Ibanez, P, Judson, DS, Konki, J, Korgul, A, Kroell, T, Kurcewicz, J, Lalkovski, S, Lazarus, I, Lund, MV, Madurga, M, Marginean, R, Marroquin, I, Mihai, C, Mihai, RE, Morales, AI, Nacher, E, Negret, A, Page, RD, Pakarinen, J, Pascu, S, Paziy, V, Perea, A, Perez-Liva, M, Picado, E, Pucknell, V, Rapisarda, E, Rahkila, P, Rotaru, F, Swartz, JA, Tengblad, O, Van Duppen, Piet, Wadsworth, R, Walters, WB, and Warr, N
- Abstract
© 2016 authors. Published by the American Physical Society. The levels in Sn129 populated from the β- decay of In129 isomers were investigated at the ISOLDE facility of CERN using the newly commissioned ISOLDE Decay Station (IDS). The lowest 1/2+ state and the 3/2+ ground state in Sn129 are expected to have configurations dominated by the neutron s1/2 (l=0) and d3/2 (l=2) single-particle states, respectively. Consequently, these states should be connected by a somewhat slow l-forbidden M1 transition. Using fast-timing spectroscopy we have measured the half-life of the 1/2+ 315.3-keV state, T1/2= 19(10) ps, which corresponds to a moderately fast M1 transition. Shell-model calculations using the CD-Bonn effective interaction, with standard effective charges and g factors, predict a 4-ns half-life for this level. We can reconcile the shell-model calculations to the measured T1/2 value by the renormalization of the M1 effective operator for neutron holes. We express our deep appreciation to the late Professor Henryk Mach, who was the initiator of this investigation. He was an inspiring collaborator, mentor, and leader in developing the βγ γ (t) fast-timing technique. His memory and accomplishments will always be with us. This work was partially supported by the Spanish MINECO through Projects No. FPA2012-32443, No. FPA2013-41267-P, and CPAN Consolider (Project No. CSD-2007-00042), and by Romanian IFA Grant CERN/ISOLDE. It was also partly funded by the NuPNET network FATIMA (PRI-PIMNUP-2011-1338), by FWO-Vlaanderen (Belgium), by GOA/2010/010 (BOF KU Leuven), and by the Interuniversity Attraction Poles Programme initiated by the Belgian Science PolicyOffice (BriX network P7/12). Support from Grupo de F´ısica Nuclear (GFN-UCM), Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale (PRIN) Grant No. 2001024324 01302, German BMBF under Contracts No. 05P12PKFNE and No. 05P15PKCIA, the U.K. Science and Technology Facilities Council, and the European Union Seventh Framework through ENSAR (Contract No. 262010) is also acknowledged. Fasttiming electronics were provided by the Fast Timing Collaboration, the ISOLDE Decay Station collaboration, and MASTICON. ispartof: PHYSICAL REVIEW C vol:93 issue:4 status: published
- Published
- 2016