Vector meson dominance and the pi^0 transition form factor

Abstract

It is shown that the pi^0 transition form factor F(Q_1^2,Q_2^2) differs substantially from its one-real-photon limit F(Q_1^2,0) even for rather small values of Q_2^2 (approx 0.1 GeV^2), which cannot be excluded in experiments with one "untagged" electron. It indicates that the comparison of data with theoretical calculations, which usually assume Q_2^2=0, may be untrustworthy. Our phenomenological model of the pi^0 transition form factor is based on the vector-meson-dominance hypothesis and all its parameters are fixed by using the experimental data on the decays of vector mesons. The model soundness is checked in the two-real-photon limit, where it provides a good parameter-free description of the pi^0 -> 2 gamma decay rate, and in the pi^0 Dalitz decay. The dependence of F(Q_1^2,Q_2^2) on Q_1^2 at several fixed values of Q_2^2 is presented and the comparison with existing data performed.

A slightly abbreviated version has been published as a Brief Report in Physical Review D

References in corpus (8)

• Measurements of the Meson-Photon Transition Form Factors of Light Pseudoscalar Mesons at Large Momentum Transfer
• Measurement of the gamma gamma* --> pi0 transition form factor
• The $e^{+}{e}^{-}\to 2({\pi }^{+}{\pi }^{-}){\pi }^0$, 2(π^+π^-)η$,$K^+ K^-π^+π^-π^0$and$K^+ K^-π^+π^-η$ Cross Sections Measured with Initial-State Radiation
• Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR
• Pion transition form factor in the Regge approach and incomplete vector-meson dominance
• Running mass of the rho0 meson's implication for the dilepton mass spectrum and the mu+mu-/e+e- branching ratio in the K+ --> pi+l+l- decays
• Joint description of the e+e- annihilation into both four-pion channels
• Pseudoscalar meson transition form factors

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• Measurement of the ${\pi }^0$ electromagnetic transition form factor slope
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• ${\pi }^0\to {\gamma }^{\ast }\gamma$ transition form factor within Light Front Quark Model
• Influence of confining gluon configurations on the $P\to {\gamma }^{\ast }\gamma$ transition form factors
• Inferring the nature of active neutrinos: Dirac or Majorana?
• gamma^* gamma^* -> pi^0 Form Factor from AdS/QCD
• The omega rho pi coupling in the VMD model revisited
• Study of pesudoscalar transition form factors within light front quark model
• QCD analysis of electromagnetic Dalitz decays $J/\psi \to {\eta }^{(\prime )}{\ell }^{+}{\ell }^{-}$
• Role of the $\rho (1450)$ in low-energy observables from an analysis in the meson dominance approach
• EKHARA - new gamma gamma generator