학술논문
Suppressed Electric Quadrupole Collectivity in $^{49}$Ti
Document Type
Working Paper
Author
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.; Yadav, R. B.
Source
Subject
Language
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
Comment: 8 pages, 5 figures, accepted in Physics Letters B