We have perfromed high-precision measurements of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ charge and magnetic form factors up to ${\mathit{Q}}^2$=1 (GeV/c${)}^2$. These measurements combined with previous data on ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ allow us to separate the three-nucleon isospin charge and magnetic form factors up to ${\mathit{Q}}^2$=1 (GeV/c${)}^2$. A large discrepancy between experiment and theory occurs for the T=1 charge form factor.

• Received 26 March 1992

DOI:https://doi.org/10.1103/PhysRevLett.69.253