Nuclear sizes derived from high-energy reaction cross sections

An analysis has been made of reaction cross sections for negative pions on a range of nuclei in the momentum region from 20 to 60 GeV/c. Data for C, Al, Sn and Pb are analysed in terms of nuclear sizes. Assuming the neutron and proton distributions in C are identical it is found that for Pb the best agreement with experiment is obtained using neutron density distributions which have similar geometrical parameters to that of the proton distribution. The accuracy with which the neutron distribution can be determined by these experiments is considered. The analysis is also extended to similar measurements for K^- mesons and antiprotons.