NLO perturbative QCD predictions for gamma gamma -> M+ M- (M=pi,K)
  We report the first complete leading-twist next-to-leading-order perturbative QCD predictions for the two-photon exclusive channels gamma gamma -> M+ M- (M=pi,K) at large momentum transfer. The asymptotic distribution amplitude is utilized as a candidate form for the nonperturbative dynamical input. Comparison of the obtained results with the existing experimental data does not provide sufficiently clear evidence to support the applicability of the hard-scattering approach at currently accessible energies. 
Goran Duplancic, Bene Nizic