Pion-Photon Transition Distribution Amplitudes

TL;DR

This paper introduces and analyzes Pion-Photon Transition Distribution Amplitudes (TDAs), exploring their relations, numerical models, and implications for meson pair production cross sections.

Contribution

It presents the first detailed discussion of $$-Photon TDAs, including relations, model comparisons, and extensions of GPD features to TDAs.

Findings

Relations between $$-$$ and $$-$$ TDAs established

Numerical values for TDAs compared across models

Insights into cross section evaluation for meson pair production

Abstract

The newly introduced Transition Distribution Amplitudes (TDAs) are discussed for the $\pi$-$\gamma$ transitions. Relations between $\pi$-$\gamma$ and $\gamma$-$\pi$ TDAs for different cases are given. Numerical values for the $\pi$-$\gamma$ TDAs in different models are compared. GPD's features are extended to TDAs and the role of PCAC highlighted. We give hints for the evaluation of cross sections for meson pair production in our approach.