Magnetic moments of 2^+_1 states in 124,126,128Sn
J. M. Allmond, A. E. Stuchbery, D. C. Radford, A. Galindo-Uribarri, N. J. Stone, C. Baktash, J. C. Batchelder, C. R. Bingham, M. Danchev, C. J. Gross, P. A. Hausladen, K. Lagergren, Y. Larochelle, E. Padilla-Rodal, and C.-H. Yu
Accepted
The $g$~factors of the first-excited states of stable $^{124}$\textrm{Sn} and radioactive $^{126,128}$\textrm{Sn} were measured by the recoil-in-vacuum method with comparatively high precision. The experiments were performed at the Holifield Radioactive Ion Beam Facility by Coulomb exciting $\sim 3$~MeV/u beams in inverse kinematics on carbon and titanium targets. The results for $^{124}$\textrm{Sn} and $^{126}$\textrm{Sn} are in excellent agreement with recent shell model calculations. For $^{128}$\textrm{Sn} the experiment suggests an increase in the magnitude of $g(2^+_1)$, as predicted by some models. The present results provide a sensitive probe of the valence orbitals that contribute to the $2^+_1$ wavefunctions as the double-shell closure at $^{132}$\textrm{Sn} is approached.