High-Energy Deuteron Cross Sections: Charge-Exchange Effects

Abstract

The effects of charge exchange in collisions of high-energy particles of isotopic spin \textonehalf{} with deuterons are investigated. The diffraction approximation is used to express the deuteron charge-exchange cross section in terms of the elastic-scattering amplitudes of the neutron and proton and the deuteron ground-state wave function. Examinations are also made of the influence of the charge-exchange mechanism on the total cross section of the deuteron, the elastic differential cross section, and the summed angular distribution of scattering (elastic plus inelastic scattering with initial charges preserved). The important role played by double-scattering processes in shaping the differential cross sections of the deuteron is illustrated in a discussion of proton-deuteron elastic scattering at 2 BeV. Double scattering is shown to be the dominant collision mechanism at scattering angles which are not too close to the forward direction. The effect of the double charge-exchange process on the elastic differential cross section is shown to be small but of some significance in the angular range which is dominated by double scattering. The theory developed for charge-exchange reactions is applied to the ${K}^{0}$ angular distribution which has been observed from ${K}^{+}$-deuteron collisions at 2.27 $\frac{\mathrm{BeV}}{c}$. Estimates are found for the differential and integrated ${K}^{+}$-neutron charge-exchange cross sections, and for some related parameters. The effects of double collisions on these cross sections are relatively small and easily evaluated. The effect of the charge-exchange mechanism on the values of the $\mathrm{pn}$, $\overline{p}n$, and ${K}^{\ifmmode\pm\else\textpm\fi{}}n$ total cross sections which are reached indirectly via measurements on the deuteron is shown to be exceedingly small for momenta above \ensuremath{\sim}2 $\frac{\mathrm{BeV}}{c}$.