Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

Abstract

In this paper experiments are reported on annihilation and scattering of antiprotons in ${\mathrm{H}}_2$O, ${\mathrm{D}}_2$O, and ${\mathrm{O}}_2$. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the $\overline{p}-p$ and $\overline{p}-n$ cross sections as 104 mb for the $\overline{p}-p$ reaction cross section and 113 mb for the $\overline{p}-n$ reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the $\overline{p}-d$ to the $\overline{p}-n$ cross section by subtraction of the $\overline{p}-p$ cross section is unfortunately large and somewhat uncertain. The data are compared with the $p-p$ and $p-n$ cross sections and with other results on $\overline{p}-p$ collisions.