Transition Distribution Amplitudes for gamma* gamma collisions

TL;DR

This paper introduces Transition Distribution Amplitudes (TDAs) to analyze exclusive pi-pi and rho-pi production in gamma* gamma collisions, providing a QCD-based framework with testable predictions at electron-positron colliders.

Contribution

It presents the concept of TDAs for gamma* gamma processes and models their application to exclusive meson production, advancing theoretical understanding in this area.

Findings

Sizable cross sections predicted for rho-pi and pi-pi production

Models for TDAs enable QCD calculations of these reactions

Potential for experimental testing at electron-positron colliders

Abstract

We study the exclusive production of pi-pi and rho-pi in hard gamma* gamma scattering in the forward kinematical region where the virtuality of one photon provides us with a hard scale in the process. The newly introduced concept of Transition Distribution Amplitudes (TDA) is used to perform a QCD calculation of these reactions thanks to two simple models for TDAs. The sizable cross sections for rho-pi and pi-pi production may be tested at intense electron-positron colliders such as CLEO and B factories (Belle and BaBar).