Resonant Production in Two Photon Collisions.

Using 220 picobarn^{-1} of data collected by the Mark II detector at PEP, we have measured the width of the eta^ ' for quasi real photons. The width is separately measured in three reactions e^+e ^- to e^+e^- eta^0 pi^+ pi^-; eta ^0 to gammagamma, e^+e^ - to e^+e^- eta^0pi ^+pi^-; eta^0 to pi^+pi-(pi^0, gamma) and e^+e^- to e^+e^-rho^0 gamma, giving a statistically weighted average two-photon width of Gamma_{eta^' to gammagamma} = 5.21 +/- 0.28 keV. As a by-product of the measurement of Gamma_{eta^' to gammagamma} using the decay mode eta^' to rhogamma, we also measured a two-photon decay width for for the a_2(1320) of Gamma_{a_{2}(1320) to gammagamma} = 1.17 +/- 0.15 +/- 0.25 keV.