ψ′Photoproduction at a Mean Energy of 150 GeV

Abstract

A measurement of the diffractive ${\ensuremath{\psi}}^{\ensuremath{'}}$ photoproduction cross section is presented. The ratio of the ${\ensuremath{\psi}}^{\ensuremath{'}}$ photoproduction cross section to the $\ensuremath{\psi}$ photoproduction cross section is found to be 0.20 \ifmmode\pm\else\textpm\fi{} 0.05 at an average energy of 150 GeV. With vector-meson dominance, the ratio of ${\ensuremath{\psi}}^{\ensuremath{'}}$-nucleon to $\ensuremath{\psi}$-nucleon cross sections is 0.75 \ifmmode\pm\else\textpm\fi{} 0.12.