1/Nc approximation and universality of vector mesons

In this work, we argue that the observed differences in the value of the vector coupling constant extracted from the decays ρ → π π (gρ = 6.0 ), ρ → l+ l− (gρ = 5.0 ) and ω → l+ l− (gρ = 5.7), where l = e , μ , are an indication of the important role played by the 1/Nc corrections in the description of these processes. We show that an emission of a photon by charged meson loops in the ρ0, ω, ϕ → γ transitions is a key process that allows to describe above vector meson decays into two leptons with a single value gρ = 6.0 . Our result supports the idea of universality of neutral vector mesons and clarifies the role of accounting of 1/Nc corrections to its fulfilment.