Eur. Phys. J. C (2007) 52: 325-338
https://doi.org/10.1140/epjc/s10052-007-0393-5

Regular Article - Theoretical Physics

Form factors in the radiative pion decay

IFIC, Universitat de València – CSIC, Apt. Correus 22085, 46071, València, Spain

^* e-mail: Jorge.Portoles@ific.uv.es

Received: 13 June 2007
Published online: 5 September 2007

Abstract

We perform an analysis of the form factors that rule the structure-dependent amplitude in radiative pion decay. The resonance contributions to π→eν_eγ decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions 〈VVP〉 and 〈VAP〉, and by demanding the smoothening of the form factors at high transfer of momentum. A comparison between theoretical and experimental determination of the form factors is also carried out. We also consider and evaluate the role played by a non-standard tensor form factor. We conclude that, at present and due to the hadronic uncertainties, the search for new physics in this process is not feasible.