Gray, T. J.Allmond, J. M.Benetti, C.Wibisono, C.Baby, L.Gargano, A.Miyagi, T.Macchiavelli, A. O.Stuchbery, A. E.Wood, J. L.Ajayi, S.Aragon, J.Asher, B. W.Barber, P.Bhattacharya, S.Boisseau, R.Christie, J. M.Conley, A. L.De Rosa, P.Dowling, D. T.Esparza, C.Gibbons, J.Hanselman, K.Holt, J. D.Lopez-Caceres, S.Lopez Saavedra, E.McCann, G. W.Morelock, A.Kelly, B.King, T. T.Rasco, B. C.Sitaraman, V.Tabor, S. L.Temanson, E.Tripathi, V.Wiedenhöver, I.Yadav, R. B.2025-05-302025-05-300370-2693WOS:001278285100001ORCID:/0000-0002-0198-9901/work/165894360http://www.scopus.com/inward/record.url?scp=85198512878&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733755409Single-step Coulomb excitation of Ti-46,Ti-48,Ti-49,Ti-50 is presented. A complete set of E2 matrix elements for the quintuplet of states in Ti-49, centred on the 2+ core excitation, was measured for the first time. A total of nine E2 matrix elements are reported, four of which were previously unknown. Ti-49(22)27 shows a 20% quenching in electric quadrupole transition strength as compared to its semi-magic Ti-50(22)28 neighbour. This 20% quenching, while empirically unprecedented, can be explained with a remarkably simple two-state mixing model, which is also consistent with other ground-state properties such as the magnetic dipole moment and electric quadrupole moment. A connection to nucleon transfer data and the quenching of single-particle strength is also demonstrated. The simplicity of the Ti-49-Ti-50 pair (i.e., approximate single-j 0f7/2 valence space and isolation of yrast states from non-yrast states) provides a unique opportunity to disentangle otherwise competing effects in the ground-state properties of atomic nuclei, the emergence of collectivity, and the role of proton-neutron interactions.We would like to acknowledge the Center for Accelerator Target Science (CATS) and Matt Gott for making the C and Al foils used in this study and Alfredo Poves for useful discussions on the shell-model calculations. This material is based upon work supported in part by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract No. DE-AC05-00OR22725 (ORNL) . This work was also supported by the U.S. National Science Foundation under Grant No. PHY-2012522 (FSU) and the Australian Research Council un-der grant No. DP210101201. In addition, this work was supported in part by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project-ID 279384907 - SFB 1245, and the European Research Council (ERC) under the European Union's Horizon 2020 re-search and innovation programme (Grant Agreement No. 101020842) . The VS-IMSRG calculations were supported by NSERC under grants SAPIN-2018-00027 and RGPAS-2018-522453 and the Arthur B. McDon-ald Canadian Astroparticle Physics Research Institute. Calculations were performed with an allocation of computing resources at the Julich Su-percomputing Center and Cedar at WestGrid with The Digital Research Alliance of Canada. The publisher acknowledges the US government li-cense to provide public access under the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan) .6enPublisher Copyright: © 2024 The Author(s)Core excitationsCoulomb-excitationEven titaniumGeneralized seniorityNpnn schemeNucleiShell-model descriptionSpectroscopy202410.1016/j.physletb.2024.13885685198512878