Vector meson dominance and the ρ meson

Abstract

We discuss the properties of vector mesons, in particular the 0 , in the context of the hidden local symmetry ͑HLS͒ model. This provides a unified framework to study several aspects of the low energy QCD sector. First, we show that in the HLS model the physical photon is massless, without requiring off field diagonalization. We then demonstrate the equivalence of HLS and the two existing representations of vector meson dominance, VMD1 and VMD2, at both the tree level and one loop order. Finally the S matrix pole position is shown to provide a model and process independent means of specifying the mass and width, in contrast with the real axis prescription currently used in the Particle Data Group tables. ͓S0556-2821͑99͒02807-6͔

The pion form factor within the hidden local symmetry model

“…The ρ mass, as defined by the real part of the propagator M ρ , is highly model dependent [35]. The complex pole, however, is a true invariant, as has been shown for several models [31]. One should also note the difference between M ρ and the "Higgs-Kibble" mass m HK (m [31] resulting from spontaneous symmetry breaking.…”

“…A first such model which illustrates that loop dressing of the γ − ρ transition can accomodate pion form factor data is given in [21] ; quite recently, the same idea was developed up to a more refined comparison with experimental data up to the φ mass [32]. We note that it has been explicitly demonstrated that regular VMD and VMD1 are equivalent [31], as one would expect from corresponding fit results [16].…”

Study of thee+e−→ηγprocess with Spherical Neutral Detector at the VEPP-2Me+e−Ачасов1, Aulchenko2, Beloborodov3 et al. 2006Phys. Rev. D272130View full textAdd to dashboardCite

“…In the energy region below 1 GeV the process e + e − → ηγ, η → 3π 0 is the only process with a significant cross section and multi-photon final state. In the φ-meson region there is a contribution from the process (4). Since this energy region is above the ωπ 0 production threshold, there is also a background from the process (5).…”

“…However, further improvement of accuracy of these branching ratios measurements is still important for development of various phenomenological models -quark models, SU(3) based linear and non-linear sigma models and vector meson dominance models, [2,3,4].…”

Isospin Symmetry Breaking within the HLS Model: A Full (rho, omega, phi) Mixing Scheme

“…Up to inessential coefficients related with vector coupling constants and SU(3) breaking effects, we have [30] :…”