Pi-/Pi+ ratio from deuterium in photoproduction at 500-1000 Mev

The ratio of charged pions photoproduced from deuterium has been studied using the brems-strahlung photon beam from the electron synchrotron at the California Institute of Technology. The ratio yields of negative and positive pions gives directly the ratio of the cross sections of the two processes, γ+p=n+π+, and γ+n=p+ π-, assuming deuteron structure effects to be negligible.