The process p¯↦γπwithin the handbag approach
Fachbereich Physik, Universität Wuppertal, D-42097, Wuppertal, Germany
2 Institut für Theoretische Physik, Universität Regensburg, D-93040, Regensburg, Germany
Accepted: 8 September 2005
Published online: 26 October 2005
We analyse the exclusive channel p¯↦γπ0, assuming handbag dominance. The soft parts are parametrized in terms of CGLN amplitudes for the q¯↦γπ0 transition and form factors for the p¯↦q¯ ones; the latter represent moments of Generalized Distribution Amplitudes. We present a combined fit to Fermilab data from E760 taking simultaneously into account information from other exclusive reactions, especially from p¯↦γγ data. Overall a nicely consistent picture emerges, such that one can hope, that our theoretical analysis will be reliable also for the kinematics of GSI/FAIR, which, hopefully, will provide much more precise and complete data. Consequently, data from this facility should improve our knowledge both on the proton-antiproton distribution amplitudes and the pion production mechanism.
PACS: 12.38.-t Quantum chromodynamics – / 12.38.Bx Perturbative calculations –
© Società Italiana di Fisica and Springer-Verlag, 2005