Cross Sections in Deuterium at High Energies

Recent measurements at high energies indicate that the total cross sections for collisions of both nucleons and $\ensuremath{\pi}$ mesons with deuterons are noticeably smaller than the sums of the corresponding cross sections for free neutrons and protons. A formalism for calculating the cross sections of the deuteron is developed, based on the assumption that the interactions of the incident particle with the neutron and proton may individually be treated by the general methods of diffraction theory. The nonadditivity of the free-particle cross sections is shown to be due largely to "eclipses" in which either the neutron or the proton lies in the shadow cast by the other, an effect in which quantum mechanical diffraction plays an important role. Simple representations of the high-energy interactions and the ground-state wave function of the deuteron are found to lead to cross-section defects of the magnitude observed.