Probing the nuclear medium by antiprotons

We propose to use anti-protons to investigate the sizes of stable and neutron-rich exotic nuclei by measurements of the pA absorption cross section along isotopic chains in inverse kinematics. The expected effects are studied theoretically in a microscopic model. The pU optical potentials are obtained by folding free space pN scattering amplitudes with HFB ground state densities and solving the scattering equations by direct integration. The mass dependence of the absorption cross sections and of the nuclear radii are found to be directly related by a scaling law. (author)