The first measurement of exclusive photodisintegration of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ with polarized photons is reported. Cross sections and asymmetries for ${}_{}{}^3{}_{}{}^{}\mathrm{He}(\overrightarrow{\gamma },pn)p$ and ${}_{}{}^3{}_{}{}^{}\mathrm{He}(\overrightarrow{\gamma },pp)n$ at $235\le E_{\gamma }\le 305$ MeV are compared to a theoretical calculation which includes one-, two-, and three-nucleon photon, absorption. Two-nucleon absorption dominates the $\mathrm{pn}$ data, but is suppressed in the $\mathrm{pp}$ data. The $\mathrm{pp}$ data require the inclusion of three-nucleon absorption to describe the cross section and beam asymmetry over all momenta.

• Received 10 February 1994

DOI:https://doi.org/10.1103/PhysRevLett.73.408