A geometrical model is proposed for the distribution of matter in the ${}_{}{}^3{}_{}{}^{}\mathrm{-}_{}^3{}_{}{}^{}$He system, incorporating a short-range three-nucleon correlation. Charge symmetry violation is introduced through a distortion of this correlation in going from ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ to ${}_{}{}^3{}_{}{}^{}\mathrm{He}$. The model is able to describe the charge-symmetry violating effects observed in ${\pi }^{\pm }$ scattering from these nuclei. When adjusted to fit the high $q^2$ behavior of the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ charge form factor, the model yields a prediction for the corresponding structure in ${}_{}{}^3{}_{}{}^{}\mathrm{H}$.

• Received 20 February 1985

DOI:https://doi.org/10.1103/PhysRevC.31.2133