2001/07/19 by Tsung-Wen Yeh, Tsung-Wen yeh
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.65.074016
published as Phys.Rev.D65:074016,2002 · 8 pages, 4 figures, a typo corrected, 2 references added
arxiv created 2001/07/19 · openalex publication_date 2002/03/19 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
As is well recognized, the asymptotic of the perturbative QCD prediction for the pion form factor is much smaller than the upper end of the data. We investigate this problem. We first evaluate the next-to-leading-order (NLO) power correction for the pion form factor. The corrected form factor contains nonperturbative parameters which are determined from a \ensuremathχ2 fit to the data. Interpreting these parameters leads to the fact that the involved strong interaction coupling constant should be identified as an effective coupling constant under a nonperturbative QCD vacuum. If the scale associated with the effective coupling constant is identified as 〈x〉2Q2, then Q2, the momentum transfer square for the pion form factor to be measured, can have a value about 1 GeV2, and 〈x〉, the averaged momentum fraction variable, can locate around 0.5. This circumstance is consistent with the asymptotic model for the pion wave function.