Pion form factor in large $N_c$ QCD

Abstract

The electromagnetic form factor of the pion is obtained using a particular realization of QCD in the large $N_c$ limit, which sums up the infinite number of zero-width resonances to yield an Euler's Beta function of the Veneziano type. This form factor agrees with space-like data much better than single rho-meson dominance. A simple unitarization ansatz is illustrated, and the resulting vector spectral function in the time-like region is shown to be in reasonable agreement with the ALEPH data from threshold up to about 1.3 ${GeV}^2$.

Plain Latex, 9 pages, 2 figures

Cited by in corpus (30)

• Precision Tau Physics
• Modeling the Pion and Kaon Form Factors in the Timelike Region
• The VV'P form factors in resonance chiral theory and the pi-eta-eta' light-by-light contribution to the muon g-2
• Dispersive representation of the pion vector form factor in $\tau \to \pi \pi {\nu }_{\tau }$ decays
• Meson dominance of hadron form factors and large-Nc phenomenology
• $B\to \pi \pi$ Form Factors from Light-Cone Sum Rules with $B$-meson Distribution Amplitudes
• Narrow resonances studies with the radiative return method
• The pion light-cone distribution amplitude from the pion electromagnetic form factor
• Scalar-isoscalar states in the large-Nc Regge approach
• Pion transition form factor and distribution amplitudes in large-Nc Regge models
• Pion transverse charge density from timelike form factor data
• On meson dominance in the `second class' tau \to eta pi nu_tau decay
• On the branching ratio of the "second class" tau --> eta' pi nu_tau decay
• Pion electromagnetic form factor, perturbative QCD, and large-Nc Regge models
• Hadronic contribution to the muon g-2: a theoretical determination
• Contributions for the kaon pair from $\rho (770)$, $\omega (782)$ and their excited states in the $B\to K\bar{K}h$ decays
• Pion form factor in the Kroll-Lee-Zumino model
• Hadronic decays of the tau lepton: Theoretical outlook
• Hadronic decays of the tau lepton: Theoretical overview
• Electromagnetic proton form factors in large $N_c$ QCD
• Hadronic currents for ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ and other decays of interest in TAUOLA
• Transverse charge and current densities in the nucleon from dispersively improved chiral effective field theory
• FASTERD: a Monte Carlo event generator for the study of final state radiation in the process $e^{+}{e}^{-}\to \pi \pi \gamma$ at DA$\Phi$NE
• Determination of pion distribution amplitudes from the electromagnetic form factor with the data-driven dispersion relation
• Kaon transverse charge density from space- and timelike data
• Electromagnetic form factors of the Delta(1232) in Dual-Large N_c QCD
• PHOKHARA 7.0 Monte Carlo generator: the narrow resonances implementation and new pion and kaon form factors
• A new $G$-parity violating amplitude in the $J/\psi$ decay?
• Dispersive analysis of the $J/\psi \to {\pi }^0{\gamma }^{\ast }$ transition form factor with $\rho$-$\omega$ mixing effects
• Electromagnetic proton form factors in dual large-$N_c$ QCD: an update