English

On the large-Q^2 behavior of the pion transition form factor

High Energy Physics - Phenomenology 2017-11-22 v3 High Energy Physics - Lattice Nuclear Theory

Abstract

We study the transition of non-perturbative to perturbative QCD in situations with possible violations of scaling limits. To this end we consider the singly- and doubly-virtual pion transition form factor π0γγ\pi^0\to\gamma\gamma at all momentum scales of symmetric and asymmetric photon momenta within the Dyson-Schwinger/Bethe-Salpeter approach. For the doubly virtual form factor we find good agreement with perturbative asymptotic scaling laws. For the singly-virtual form factor our results agree with the Belle data. At very large off-shell photon momenta we identify a mechanism that introduces quantitative modifications to Efremov-Radyushkin-Brodsky-Lepage scaling.

Keywords

Cite

@article{arxiv.1704.05774,
  title  = {On the large-Q^2 behavior of the pion transition form factor},
  author = {Gernot Eichmann and Christian S. Fischer and Esther Weil and Richard Williams},
  journal= {arXiv preprint arXiv:1704.05774},
  year   = {2017}
}

Comments

5 pages, 7 figures, v3:contents revised, version published in PLB