Information on the nuclear periphery from antiprotonic atoms

Abstract

In the PS209 experiments at CERN two kinds of measurements were performed: the in-beam measurement of X-rays from antiprotonic atoms and the radiochemical, off-line determination of the yield of annihilation products with mass number At — 1 (less by 1 than the target mass). Both methods give observables which allows to study the peripheral matter density composition and distribution. A comparisons of the PS209 results with the theoretical and semiempirical predictions for neutron and proton densities and with the differences Arnp of the rms radii of neutrons and protons obtained in other experiments are also presented.