Photodisintegration of a Proton Pair in $^3$He

Hard photodisintegration of the deuteron has been studied extensively in order to understand the dynamics of the transition from hadronic to quark-gluon descriptions of the strong interaction. Recently Brodsky {\it et al.} [1] have discussed an extension of this program to hard photodisintegration of a proton pair in the $^3$He nucleus. The $\gamma + ^3$He$ \to ppn$ reaction was studied in a comprehensive experiment at Jefferson Lab Hall B for photon energies up to 1.55 GeV [2]. The observed cross section for the photodisintegration of a proton pair in $^3$He is much smaller than for deuteron photodisintegration even at the highest photon energy. Results will be discussed and compared with model calculations. Jefferson Lab experiment E03-101 [3] will be a dedicated experiment to study the photodisintegration of a proton pair in $^3$He for photon energies up to 5 GeV.\\ \hspace{0mm}[1] S.J. Brodsky {\it et al.}, Phys. Lett. B {\bf 578}, 69 (2004)\\ \hspace{0mm}{}[2] S. Niccolai {\it et al.}, Phys. Rev. C {\bf 70}, 064003 (2004)\\ \hspace{0mm}[3] Jefferson Lab Experiment E03-101, R. Gilman and E. Piasetzky (spokespersons)