2001/05/31 by M. Diehl, P. Kroll, C. Vogt
Physics and Astronomy · #hep-ph
published as eConf C010430 (2001) T21 · 4 pages, 5 figures. Talk delivered by C. Vogt at the workshop "e+ e- Physics at Intermediate Energies", SLAC, April 30 - May 2, 2001. v2: Some clarifications in the text
arxiv created 2001/11/13 · arxiv updated 2009/11/30
We discuss the photon to meson transition form factor for virtual photons, which can be measured in e+ e- collisions. We demonstrate that this form factor is independent of the shape of the meson distribution amplitude over a wide kinematical range. This leads to a parameter-free prediction of perturbative QCD to leading twist accuracy, which has a status comparable to the famous leading-twist prediction of the cross section ratio R.