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

TL;DR

This paper investigates the $\gamma\gamma ightarrow M^{+}M^{-}$ processes including twist-3 corrections in QCD, showing significant contributions from twist-3 and matching experimental data for energies above 2.8 GeV.

Contribution

It introduces the calculation of twist-3 contributions in the two-photon meson production processes within the standard hard-scattering approach, highlighting their importance.

Findings

Twist-3 contributions are comparable to twist-2 in these processes.

Cross sections agree with experimental data for energies above 2.8 GeV.

Predicted cross section ratio matches experimental observations.

Abstract

We study the $\gamma\gamma\rightarrow M^{+}M^{-}(M=\pi, K)$ 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 comparing with the leading-twist contributions and the cross sections agree well with the experimental data in the two-photon center-of-mass energy $W>2.8$ GeV. We also predict the cross section ratio $\sigma_{0}(\pi^{+}\pi^{-})/\sigma_{0}(K^{+}K^{-})$, which is compatible with the experimental data from TPC and Belle.