RT Journal Article T1 Fast-timing study of the l-forbidden 1/2(+) -> 3/2(+) M1 transition in Sn-129 A1 Fraile Prieto, Luis Mario A1 Vedia Fernández, María Victoria A1 Ibáñez García, Paula Beatriz A1 Paziy, Vadym A1 Pérez Liva, Mailyn A1 Picado, E. A1 Vidal, M. AB The levels in Sn-129 populated from the beta(-) decay of In-129 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 129Sn are expected to have configurations dominated by the neutron s(1/2) (l = 0) and d(3/2) (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 havemeasured the half-life of the 1/2(+) 315.3-keV state, T-1/2 = 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 T-1/2 value by the renormalization of the M1 effective operator for neutron holes. PB Amer Physical Soc SN 0556-2813 YR 2016 FD 2016-04-04 LK https://hdl.handle.net/20.500.14352/24506 UL https://hdl.handle.net/20.500.14352/24506 LA eng NO © 2016 Amer Physical Soc.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 beta gamma gamma (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 Fisica 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. Fast-timing electronics were provided by the Fast Timing Collaboration, the ISOLDE Decay Station collaboration, and MASTICON. NO Spanish MINECO NO CPAN Consolider NO Romanian IFA Grant CERN/ISOLDE NO NuPNET network FATIMA NO FWO-Vlaanderen (Belgium) NO BOF KU Leuven NO Grupo de Fisica Nuclear (GFN-UCM) NO Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale (PRIN) NO German BMBF NO U.K. Science and Technology Facilities Council NO European Union Seventh Framework NO Interuniversity Attraction Poles Programme NO Belgian Science PolicyOffice (BriX network) DS Docta Complutense RD 7 abr 2025