Charge-radius change and nuclear moments in the heavy tin isotopes from laser spectroscopy: Charge radius of $^{132}$Sn

Abstract

NESTER ACCLaser spectroscopy measurements have been carried out on the neutron-rich tin isotopes with the COMPLIS experimental setup. Using the $5s^25p^2$ $^3P_0 \rightarrow 5s^25_p6s$ $^3P_1$ optical transition, hyperfine spectra of $^{126-132}$Sn and $^{125,127,129-131}Sn^m$ were recorded for the first time. The nuclear moments and the mean square charge radius variation ($\delta) were extracted. From the quadrupole moment values, these nuclei appear to be spherical. The magnetic moments measured are thus compared with those predicted by spherical basis approaches. From the measured$\delta, the absolute charge radii of these isotopes were deduced in particular that of the doubly magic $^{132}$Sn nucleus. The comparison of the results with several mean-field-type calculations have shown that dynamical effects play an important role in the tin isotopes