Charge-changing interactions probing point-proton radii of nuclei

The question of whether charge-changing interactions can be used to probe point-proton radii of nuclei remains unanswered. Charge-changing cross sections, cc, were systematically investigated using stable and unstable nuclear beams of intermediate- energy. The ratios of the experimental cc values to the calculated ones obtained from a phenomenological Glauber-type model analysis are found to be nearly constant in a broad range of Z=N for light neutron-rich nuclei. This enables the determination of den- sity distributions, i.e., the radii of protons tightly bound in nuclei. To test the applicability of the present method to all nuclei in the nuclear chart, extensive measurements were per- formed for medium-mass nuclei ranging from Z = 18 to 32. The present study suggests the potential capability of a new experimental approach for exploring exotic nuclei.