1. Suppressed Electric Quadrupole Collectivity in $^{49}$Ti
- Author
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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., Saavedra, E. Lopez, McCann, G. W., Morelock, A., Kelly, B., King, T. T., Rasco, B. C., Sitaraman, V., Tabor, S. L., Temanson, E., Tripathi, V., Wiedenhöver, I., and Yadav, R. B.
- Subjects
Nuclear Experiment ,Nuclear Theory - Abstract
Single-step Coulomb excitation of $^{46,48,49,50}$Ti is presented. A complete set of $E2$ matrix elements for the quintuplet of states in $^{49}$Ti, centered 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. $^{49}_{22}$Ti$_{27}$ shows a $20\%$ quenching in electric quadrupole transition strength as compared to its semi-magic $^{50}_{22}$Ti$_{28}$ 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 $^{49}$Ti-$^{50}$Ti pair (i.e., approximate single-$j$ $0f_{7/2}$ 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., Comment: 8 pages, 5 figures, accepted in Physics Letters B
- Published
- 2024