$$\gamma \gamma \rightarrow M^{+}M^{-}(M=\pi , K)$$ γ γ → M + M - ( M = π , K ) processes with twist-3 corrections in QCD

Abstract

Abstract We study the $$\gamma \gamma \rightarrow M^{+}M^{-}(M=\pi , K)$$ γ γ → M + M - ( M = π , K ) processes with the contributions from the two-particle twist-2 and twist-3 distribution amplitudes of pion and kaon mesons on BHL prescription in the standard hard-scattering approach. The results show that the contributions from twist-3 parts are actually not power suppressed compared with the leading-twist contributions in the low energy region. The cross sections with twist-3 corrections agree well with the experimental data in the two-photon center-of-mass energy $$W>2.8$$ W > 2.8 GeV and we also predict the cross section ratio $$\sigma _{0}(K^{+}K^{-})/\sigma _{0}(\pi ^{+}\pi ^{-})$$ σ 0 ( K + K - ) / σ 0 ( π + π - ) , which is compatible with the experimental data from TPC and Belle.