ar X iv : h ep - p h / 96 12 23 8 v 2 7 M ar 1 99 7 hep - ph / 9612238 ( revised

The mechanism where flavour symmetry of is broken spontaneously is demonstated for a model involving nonets of pseudoscalar and vector mesons. Degenerate bare nonets of vector pseudoscalar mesons coupling sufficiently strongly to each others lead to unstable self-consistency equations, such that the SU3f symmetric spectrum breaks down into a stable isospin symmetric mass spectrum similar to the physical spectrum. Pacs numbers:12.39.Ki, 11.30.Hv, 11.30.Qc, 12.15.Ff Conventionally [1] one breaks flavour symmetry by adding effective non-degenerate quark masses to the QCD Lagrangian, whereby the pseudoscalars obtain (small) masses and the degeneracy of all flavour multiplets is split. Most of the chiral quark masses are assumed to come from a short distance regime, where weak interactions, and the Higgs mechanism are relevant. Here I shall discuss an alternative way of breaking flavour symmetry, which is a generalisation of the arguments given in a recent paper [2] to the physical case of three light flavours. In that paper I discussed a mechanism where a meson mass spectrum, obeying exact flavour symmetry, the Okubo-Zweig-Iizuka (OZI) rule and general constraints of analyticity and unitarity, is unstable with respect to quantum loops involving quark pair creation. The instability followed from the nonlinear self-consistency equations for inverse