Examination of the ²²C radius determination with interaction cross sections

A nuclear radius of $^{22}$C is investigated with the total reaction cross sections at medium- to high-incident energies in order to resolve the radius puzzle in which two recent interaction cross section measurements using $^1$H and $^{12}$C targets show the quite different radii. The cross sections of $^{22}$C are calculated consistently for these target nuclei within a reliable microscopic framework, the Glauber theory. To describe appropriately such a reaction involving a spatially extended nucleus, the multiple scattering processes within the Glauber theory are fully taken into account, that is, the multi-dimensional integration in the Glauber amplitude is evaluated using a Monte Carlo technique without recourse to the optical-limit approximation. We discuss the sensitivity of the spatially extended halo tail to the total reaction cross sections. The root-mean-square matter radius obtained in this study is consistent with that extracted from the recent cross section measurement on $^{12}$C target. We show that the simultaneous reproduction of the two recent measured cross sections is not feasible within this framework.