Data are presented on the energy and angle dependence of the charge-symmetry superratio R and simple ratios ${\mathrm{r}}_1^{\prime }$ and ${\mathrm{r}}_2^{\prime }$ for ${\mathrm{\pi }}^{\pm }$ elastic scattering from ${\mathrm{H}}^3$ and ${\mathrm{He}}^3$. ${\mathrm{r}}_1^{\prime }$ and ${\mathrm{r}}_2^{\prime }$ were normalized with respect to ${\mathrm{\pi }}^{+}$ d and ${\mathrm{\pi }}^{\mathrm{-}}$ d elastic scattering, which is assumed to have the ratio 1.0. The beam energies are ${\mathrm{T}}_{\mathrm{\pi }}$=142, 180, and 220 MeV, and the scattering angle, ${\mathrm{\theta }}_{\mathrm{L}}$, ranges from 40° to 110°. In all cases measured it is found that R>1, ${\mathrm{r}}_1^{\prime }$≃1, and ${\mathrm{r}}_2^{\prime }$>1. These results provide substantial evidence for charge-symmetry violation. The angular distributions for ${\mathrm{\pi }}^{\pm }$ ${\mathrm{H}}^3$ and ${\mathrm{\pi }}^{\pm }$ ${\mathrm{He}}^3$ elastic scattering also have been measured and comparisons are made with various model calculations. R≡σ(θ)[${\mathrm{\pi }}^{+}$ ${\mathrm{H}}^3$]σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${\mathrm{H}}^3$]/σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${\mathrm{He}}^3$]σ(θ)[${\mathrm{\pi }}^{+}$ ${\mathrm{He}}^3$], ${\mathrm{r}}_1^{\prime }$=σ(θ)[${\mathrm{\pi }}^{+}$ ${\mathrm{H}}^3$]σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$d]/σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${\mathrm{He}}^3$]σ(θ)[${\mathrm{\pi }}^{+}$d], ${\mathrm{r}}_2^{\prime }$=σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${\mathrm{H}}^3$]σ(θ)[${\mathrm{\pi }}^{+}$d]/σ(θ)[${\mathrm{\pi }}^{+}$ ${\mathrm{He}}^3$]σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$d].

• Received 29 August 1990

DOI:https://doi.org/10.1103/PhysRevC.43.1838