17 de julho de 2023 | Publicações
D A Fagundes, E G S Luna, A A Natale, M Peláez
Journal of Physics G: Nuclear and Particle Physics
26/02/2020
Abstract
Considering, as a limit case, an approximately flat pion distribution amplitude, which is determined from the hardest, in momentum space, solution of the Bethe–Salpeter equation for the pion wave function, we compute the pion transition form factor ${F}_{\pi \gamma {\gamma }^{* }}({Q}^{2})$ and the pion form factor Fπ(Q2), taking into account the LO as well as NLO form of the hard coefficient function entering the leading-twist factorization formula. We also compute the exclusive photoproduction of pions pairs at high energies, $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$, where perturbative QCD can be used to compute the hard scattering matrix elements. We verify that the existent data for exclusive pion production can be reasonably described as a function of such a flat distribution amplitude.