Reactionπ−p→π0n below theΔresonance

The reaction ${\pi }^{\mathrm{-}}$p→${\pi }^0$n has been studied using a large NaI crystal to detect the decay γ rays of the ${\pi }^0$, at pion beam energies of 45.6, 62.2, 76.4, 91.7, 106.8, and 121.9 MeV. The NaI was set at nine different laboratory angles, but at almost every angle the angular distribution of the ${\pi }^0$ can be derived from the energy spectrum of the γ rays. The results are compared with recent phase-shift analyses and with various calculations. New values of the charge exchange scattering length are derived.