Nuclear charge radii of neutron-deficient scandium isotopes

Charge radii of neutron deficient ^40,41Sc (Z=21) isotopes have been determined at the BEam COoler and LAser spectroscopy facility at FRIB to investigate the N=20 shell closure. Particularly, the typical kink structure in the charge radius evolution at N=20 is very weak in Ar, K and Ca while it is strongly pronounced at N=28. With one additional proton in the 1f_7/2 shell in Sc, additional cross-shell interactions occur and affect the behavior at the shell closure. The results will be presented, which promote a global understanding of the structure around ⁴⁰Ca, and the weak shell-closure signature at N=20.