Measurement of the Photon Structure Function $F_2^\gamma $ with the L3 Detector at LEP.

The $\mbox{e}^{^+}\mbox{e}^{^-}\to \mbox{e}^{^+}\mbox{e}^{^-}$hadrons reaction, where one of the two electrons is detected in a low polar-angle calorimeter, is analyzed in order to measure the hadronic photon structure function $F_2^\gamma $. The full high-energy and high-luminosity data set, collected with the L3 detector at centre-of-mass energies 189-209 GeV, corresponding to an integrated luminosity of 608 pb$^{-1}$ is used. The Q$^{2}$ range 11-34 GeV$^{2}$ and the x range 0.006-0.556 are considered. The data are compared with recent parton density functions.