Charge symmetry breaking via rho-omega mixing from model quark-gluon dynamics

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The quark-loop contribution to the ρ⁰-ω mixing self-energy function is calculated using a phenomenologically successful QCD-based model field theory in which the ρ⁰ and ω mesons are composite qq bound states. In this calculation the dressed quark propagator, obtained from a model Dyson-Schwinger equation, is confining. In contrast to previous studies, the meson-qq vertex functions are characterised by a strength and range determined by the dynamics of the model; and the calculated off-mass-shell behaviour of the mixing amplitude includes the contribution from the calculated diagonal meson self-energies. The mixing amplitude is shown to be very sensitive to the small isovector component of dynamical chiral symmetry breaking. The spacelike quark-loop mixing-amplitude generates an insignificant charge symmetry breaking nuclear force.