Pion-Photon Transition Distribution Amplitudes

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.