The forward-angle differential cross sections of pion single charge exchange on $^{7}\mathrm{Li}$ and $^{13}\mathrm{C}$ were measured at 70, 100, 150, 165, and 180 MeV. The cross sections rise steeply up to 150 MeV and remain almost constant between 150 and 180 MeV. Comparisons with theoretical calculations and with the free charge-exchange cross sections are presented. There is poor agreement with the data. Only phenomenological calculations can fit the resonance region. The isobaric analog excitation functions rise more steeply than the continuum single-charge-exchange cross sections.

A spectrometer for the detection of neutral pions in nuclear physics research was designed, constructed, and tested at the Los Alamos Meson Physics Facility. It is capable of detecting neutral pions with high efficiency, and with a fwhm energy resolution of 2 MeV with a typical acceptance of 1 msr. In the first experiment in which the spectrometer was used, its performance was evaluated, and nuclear physics research, based on the detection of neutral pions, was performed.

High precision data have been obtained for the polarization analyzing power $A(\ensuremath{\theta})$ in $\mathrm{pp}$ elastic scattering from 12 to 43\ifmmode^\circ\else\textdegree\fi{} c.m. at 796 MeV. These data extend the angular range of data previously published by this group. Data at 428 MeV have also been obtained and are in agreement with recent double scattering data.NUCLEAR REACTIONS $^{1}\mathrm{H}(p,p)^{1}\mathrm{H}$, $E=428, 796$ MeV; measured $A(\ensuremath{\theta})$; $\ensuremath{\theta}=12 \mathrm{to} 43\ifmmode^\circ\else\textdegree\fi{}$ c.m.

Isobaric-analog-state transitions have been observed throughout the periodic table in the (${\ensuremath{\pi}}^{+}$,${\ensuremath{\pi}}^{0}$) reaction. The forward-angle differential cross sections at ${T}_{\ensuremath{\pi}}=98$ MeV on targets of C${\mathrm{H}}_{2}$, $^{7}\mathrm{Li}$, $^{13}\mathrm{C}$, $^{27}\mathrm{Al}$, $^{58}\mathrm{Ni}$, $^{90}\mathrm{Zr}$, $^{120}\mathrm{Sn}$, and $^{208}\mathrm{Pb}$ are reported. The $A$ dependence follows $(N\ensuremath{-}Z){A}^{\ensuremath{-}\frac{4}{3}}$, which is qualitatively understood in terms of a strong-absorption model. Optical-potential calculations which demonstrate the sensitivity to neutron density distributions and to the isospin dependence of higher-order dynamical effects are discussed.

Data have been obtained for the polarization analyzing power ${A}_{y}(\ensuremath{\theta})$ in $\mathrm{pp}$ elastic scattering from near 30\ifmmode^\circ\else\textdegree\fi{} to 90\ifmmode^\circ\else\textdegree\fi{} (c.m.) at 643, 787, and 796 MeV. Relative uncertainties are typically \ifmmode\pm\else\textpm\fi{} 0.003 with an overall normalization uncertainty of $\left({+1}{\ensuremath{-}0.5}\right)%$. Data are not consistent with existing phase-shift analyses.