Pion-induced single charge exchange in deuterium

We report the measurement of the differential cross section for ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(${\mathrm{\pi }}^{\mathrm{-}}$,${\mathrm{\pi }}^0$) for laboratory angles 0°–145°, at incident pion energies of 164, 263, and 371 MeV. A Faddeev calculation at 164 MeV incorporating Pauli-blocking and multiple-scattering effects describes those data well. At the two higher energies the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(${\mathrm{\pi }}^{\mathrm{-}}$,${\mathrm{\pi }}^0$) cross section is essentially identical to the ${}_{}{}^1{}_{}{}^{}\mathrm{H}$(${\mathrm{\pi }}^{\mathrm{-}}$,${\mathrm{\pi }}^0$) cross section, except at forward angles where the former is suppressed by the Pauli principle. This experiment was the first to make use of a major component of the Neutral Meson Spectrometer at the Los Alamos National Laboratory.