2006/05/31 by Anatoly Radyushkin, A. V. Radyushkin · 1 citation
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Feynman diagram #Form factor (electronics) #Geometry #Hadron #Mathematical physics #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Quark #Regularization (linguistics) #Scalar (mathematics) #hep-ph
paper · pdf · doi:10.1016/j.physletb.2006.10.008
published as Phys.Lett.B642:459-468,2006 · Final version published in Physics Letters B
openalex publication_date 2006/10/20 · arxiv created 2007/05/24 · arxiv updated 2014/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the large-Q2 behavior of the meson form factor FM (Q2) constructed using the holographic light-front wave functions proposed recently by Brodsky and de Teramond. We show that this model can be also obtained within the Migdal's regularization approach (``meromorphization''), if one applies it to 3-point function for scalar currents made of scalar quarks. We found that the asymptotic 1/Q2 behavior of FM (Q2) is generated by soft Feynman mechanism rather than by short distance dynamics, which causes very late onset of the 1/Q2 asymptotic behavior. Using meromorphization for spin-1/2 quarks, we demonstrated that resulting form factor FspinorM (Q2) has 1/Q4 asymptotic behavior. Now, owing to the late onset of this asymptotic pattern, FspinorM (Q2) imitates the 1/Q2 behavior in the few GeV2 region. We discuss analogy between meromorphization and local quark-hadron duality model for the pion form factor, and show that adding the O(αs) correction to the spectral function brings in the hard pQCD contribution that has the dimensional counting 1/Q2 behavior at large Q2. At accessible Q2, the O(αs) term is a rather small fraction of the total result. We conclude that the ``observed'' quark counting rules for hadronic form factors is an approximate phenomenon resulting from Feynman mechanism in its preasymptotic regime.