Dependence of the C12(γ→,pd) reaction on photon linear polarisation

The sensitivity of the C12(γ→,pd) reaction to photon linear polarisation has been determined at MAMI, giving the first measurement of the reaction for a nucleus heavier than 3He. Photon asymmetries and cross sections were measured for Eγ=170 to 350 MeV. For Eγ below the Δ resonance, reactions leaving the residual 9Be near its ground state show a positive asymmetry of up to 0.3, similar to that observed for 3He suggesting a similar reaction mechanism for the two nuclei.