High p<inf>T</inf> hadron production in photon-photon collisions

We have studied the properties of hadron production in photon-photon scattering with tagged photons at the e+e- storage ring PETRA. A tail in the pT distribution of particles consistent with pT-4 has been observed. We show that this tail cannot be due to the hadronic part of the photon. Selected events with high pT particles are found to be consistent with a two-jet structure as expected from a point-like coupling of the photons to quarks. The lowest-order cross section predicted for γγ → qq, σ = 3 Σ eq4 · σγγ → μμ, is approached from above by the data at large transverse momenta. © 1981