Measurement of the photon structure function with the L3 detector at LEP

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