English

The process p + pbar --> gamma + pi^0 within the handbag approch

High Energy Physics - Phenomenology 2025-01-22 v1

Abstract

We analyse the exclusive channel p\pbγπ0p\pb\to\gamma \pi^0, assuming handbag dominance. The soft parts are parametrized in terms of CGLN amplitudes for the q\qbγπ0q\qb\to\gamma \pi^0 transition and form factors for the p\pbq\qbp\pb\to q\qb 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\pbγγp\pb\to \gamma\gamma 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.

Cite

@article{arxiv.hep-ph/0505258,
  title  = {The process p + pbar --> gamma + pi^0 within the handbag approch},
  author = {P. Kroll and A. Schafer},
  journal= {arXiv preprint arXiv:hep-ph/0505258},
  year   = {2025}
}