Universal trend of charge radii of even-even Ca–Zn nuclei

Radii of nuclear charge distributions carry information about the strong and electromagnetic forces acting inside atomic nucleus. Whereas global behavior radii is governed by bulk properties matter, their local trends are affected quantum motion proton neutron constituents. The measured differential $\ensuremath{\delta}\ensuremath{\langle}{r}_{c}^{2}\ensuremath{\rangle}$ between numbers $N=28$ $N=40$ exhibit a universal pattern as function $n=N\text{--}28$ that independent number. Here we analyze this remarkable in even-even nuclei from calcium to zinc using two state-of-the-art theories based on quantified interactions: ab initio coupled cluster theory density functional theory. Both reproduce smooth rise weak dependence By considering large set isotopic chains, show trend can be captured just parameters: slope curvature $\ensuremath{\delta}\ensuremath{\langle}{r}_{c}^{2}\ensuremath{\rangle}(n)$. We demonstrate these parameters appreciable model dependence, statistical analysis indicates they not correlated with any single property, i.e., impacted both well shell structure.