Inclusive production of charged hadrons in photon-photon collisions

The inclusive production of charged hadrons in the collisions of quasi-real photons (e+e−→e+e−+X) has been measured using the OPAL detector at LEP. The data were taken at e+e− centre-of-mass energies from 183 to 209GeV. The differential cross-sections as a function of the transverse momentum and the pseudorapidity of the hadrons are compared to theoretical calculations of up to next-to-leading order (NLO) in the strong coupling constant αs. The data are also compared to a measurement by the L3 Collaboration, in which a large deviation from the NLO predictions is observed.