Pion–photon transition distribution amplitudes in the spectral quark model

Abstract: The vector and axial pion–photon transition distribution amplitudes are analyzed in the spectral quark model. We proceed by the evaluation of double distributions through the use of a manifestly covariant calculation based on the α representation of propagators. As a result polynomiality is incorporated and calculations become rather simple. Explicit formulas, holding at the low-energy quark-model scale, are obtained. The corresponding form factors for the anomalous decay and the radiative pion decays are also evaluated and confronted with the data. [Copyright &y& Elsevier]