ASYMMETRIC ELECTRON PAIR PRODUCTION ON CARBON"t

The cross section for the reaction 7 + C -+e+ + e+ C has been measured for a series of kinematic points giving nuclear momentum transfers in the region 0.2 0.7 F -2 , with incident -photon energies in the region for photoproduction of the first two pi-nucleon resonances. Measurements were made, using asymmetric detection geome-try, of e3.ectron and positron cross sections for each point. The charge independent yields are shown to be in agreement with predictions of qu::ntum electrodynamics for coherent and quasi-elastic production on carbon. The charge asymmetric result:: are shown to be consistent with recent estim:t-tes of the interference between Rethe-HeitLer and Compton pair productioli :tmplit;udc:; with excitation of' an iutcrmediate n-N state in the Compton diagram.