Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry
| Autor: | Budinčević, I., Billowes, J., Bissell, M. L., Cocolios, T. E., de Groote, R. P., De Schepper, S., Fedosseev, V. N., Flanagan, K. T., Franchoo, S., Ruiz, R. F. Garcia, Heylen, H., Lynch, K. M., Marsh, B. A., Neyens, G., Procter, T. J., Rossel, R. E., Rothe, S., Strashnov, I., Stroke, H. H., Wendt, K. D. A. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevC.90.014317 |
| Popis: | The magnetic dipole moments and changes in mean-square charge radii of the neutron-rich $^{218m,219,229,231}\text{Fr}$ isotopes were measured with the newly-installed Collinear Resonance Ionization Spectroscopy (CRIS) beam line at ISOLDE, CERN, probing the $7s~^{2}S_{1/2}$ to $8p~^{2}P_{3/2}$ atomic transition. The $\delta\langle r^{2}\rangle^{A,221}$ values for $^{218m,219}\text{Fr}$ and $^{229,231}\text{Fr}$ follow the observed increasing slope of the charge radii beyond $N~=~126$. The charge radii odd-even staggering in this neutron-rich region is discussed, showing that $^{220}\text{Fr}$ has a weakly inverted odd-even staggering while $^{228}\text{Fr}$ has normal staggering. This suggests that both isotopes reside at the borders of a region of inverted staggering, which has been associated with reflection-asymmetric shapes. The $g(^{219}\text{Fr}) = +0.69(1)$ value supports a $\pi 1h_{9/2}$ shell model configuration for the ground state. The $g(^{229,231}\text{Fr})$ values support the tentative $I^{\pi}(^{229,231}\text{Fr}) = (1/2^{+})$ spin, and point to a $\pi s_{1/2}^{-1}$ intruder ground state configuration. Comment: Accepted for publication with Physical Review C |
| Databáze: | arXiv |
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