1998/02/28 by B. Melic, Blaženka Melić, B. Nizic +3 · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.60.074004
published as Phys.Rev.D60:074004,1999 · 39 pages, RevTex, 17 figures included; revised version (an error in the analytical expression for T_H corrected, numerical results correspondigly modified; presentation of the results modified to some extent and some points discussed in more detail after referees reports)
arxiv created 1999/03/21 · openalex publication_date 1999/08/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present the results of a complete leading-twist next-to-leading order (NLO) QCD analysis of the spacelike pion electromagnetic form factor at large momentum transfer Q. We have studied their dependence on the form of the pion distribution amplitude. For a given distribution amplitude, we have examined the sensitivity of the predictions to the choice of the renormalization and factorization scales. Compared to the renormalization scale, the factorization scale turns out to be of secondary importance. The renormalization scale dependence of the leading-order (LO) results has been significantly reduced by including the NLO corrections. Adopting the criteria according to which a NLO prediction is considered reliable if both the ratio of the NLO to LO contributions and the strong coupling constant are reasonably small, we find that reliable perturbative predictions for the pion electromagnetic form factor with all distribution amplitudes considered can already be made at a momentum transfer Q of the order 5\ensuremath-10 GeV, with corrections to the LO results being up to \ensuremath∼30%. The theoretical uncertainty related to the renormalization scale ambiguity has been estimated to be less than 10%. To check our predictions and to discriminate between the distribution amplitudes, it is necessary to obtain experimental data extending to higher values of Q.