English

Pion-Photon Transition Form Factor and Pion Distribution Amplitude in QCD: Facing the Enigmatic Behavior of the BaBar Data

High Energy Physics - Phenomenology 2013-01-03 v2 High Energy Physics - Experiment High Energy Physics - Lattice

Abstract

We present an extended analysis of the data for the pion-photon transition form factor from different experiments, CELLO, CLEO, and BaBar, and discuss various theoretical approaches which try to reason from them. We focus on the divergent behavior of the BaBar data for the pion and those for the η(η)\eta(\eta') pseudoscalar mesons and comment on recently proposed explanations for this discrepancy. We argue that it is not possible at present to accommodate these data within the standard QCD framework self-consistently.

Keywords

Cite

@article{arxiv.1111.7137,
  title  = {Pion-Photon Transition Form Factor and Pion Distribution Amplitude in QCD: Facing the Enigmatic Behavior of the BaBar Data},
  author = {N. G. Stefanis and Alexander P. Bakulev and S. V. Mikhailov and A. V. Pimikov},
  journal= {arXiv preprint arXiv:1111.7137},
  year   = {2013}
}

Comments

5 pages, 2 figures, talk presented by the second author at the International Workshop on e^+e^- collisions from phi to psi (PHIPSI11), Novosibirsk (Russia), Sept. 19--22, 2011