First measurement of the reaction [sup 3]He([rvec [gamma]],[ital p])[ital X] with polarized photons

The first measurement of the reaction [sup 3]He([rvec [gamma]],[ital p])[ital X] using linearly polarized photons is reported. Cross sections and beam-polarization asymmetries for [theta][sub [ital p]][sup lab]=60[degree]--100[degree] and [ital E][sub [gamma]]=195--304 MeV are compared with a microscopic calculation which includes one-, two-, and three-nucleon absorption mechanisms. One- and two-nucleon absorption alone fails to describe the data at low proton momenta. The inclusion of three-nucleon absorption significantly improves the comparison with the measured cross sections. However, some features of the asymmetry distributions are not explained.