EVIDENCE FOR A NEUTRON SKIN IN N-20

Nuclear interaction and charge-changing cross sections were measured f or 950.A MeV N-20, O-20, F-20, Ne-20, Na-20 and Mg-20 beams incident o n a carbon target. The experimental results are compared to other data , in particular to those obtained for stable nuclei. Root mean square nuclear matter radii and upper limits of root mean square proton radii are derived from the experimental data. Evidence is presented for the existence of a neutron skin in N-20.