C-12((gamma)over-right-arrow,pn) photon asymmetry for E-gamma=180-340MeV

The photon asymmetry (Sigma) of the C-12((gamma)over-right-arrow,pn) reacti on has been measured using linearly polarised tagged photons at the Mainz m icrotron MAMI for E-gamma = 180-340 MeV. The data have been analysed in sep arate missing energy (E-m) regions corresponding to the ejection of nucleon s from (lp)(2) and (lp)(ls) shells. The measured Sigma values for both E-m regions are smaller in magnitude than corresponding H-2 data, but the (lp)( 2) results have a similar E-gamma dependence. Calculations of direct two-nu cleon emission overestimate the magnitude of Sigma at all photon energies. (C) 1999 Elsevier Science B.V. All rights reserved.