Next-to-Leading-Order Perturbative-QCD Predictions forγγ→M+M−(M=π,K)

Abstract

We report the first complete leading-twist next-to-leading-order perturbative-QCD predictions for the two-photon exclusive channels gammagamma-->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.