title: Scaling of charge-changing interaction cross sections and point-proton radii of neutron-rich carbon isotopes.
abstract: Charge-changing cross sections σ(cc) of stable and unstable nuclei ((9-11)Be, (14-16)C, and (16-18)O) on a carbon target were investigated at 300  MeV/nucleon. A phenomenological analysis based on the Glauber theory indicates an approximate, but universal, scaling of σ(cc) over a wide range of A/Z. This allows the determination of the density distributions of protons tightly bound in the nuclei. An application to (16)C, which is considered to be an anomalously deformed nucleus, indicates a systematic evolution of proton root-mean-square radii and has revealed for the first time a neutron skin effect in carbon isotopes. Being complementary to isotope-shift and electron-scattering experiments, the present method can open up a new approach to explore the structure of exotic nuclei.
authors.affiliation: Department of Physics, Saitama University, Saitama 338-8570, Japan. yamaguti@phy.saitama-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: I
authors.initials: I
authors.lastname: Hachiuma
authors.forename: A
authors.initials: A
authors.lastname: Kitagawa
authors.forename: K
authors.initials: K
authors.lastname: Namihira
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: I
authors.initials: I
authors.lastname: Tanihata
authors.forename: M
authors.initials: M
authors.lastname: Fukuda