Rho - Omega Splitting and Mixing in Nuclear Matter

Abstract

We investigate the splitting and mixing of $ρ$ and $ω$ mesons in nuclear matter. The calculations were performed on the basis of QCD sum rules and include all operators up to mass dimension-6 twist-4 and up to first order in the coupling constants. Special attention is devoted to the impact of the scalar 4-quark condensates on both effects. In nuclear matter the Landau damping governs the $ρ- ω$ mass splitting while the scalar 4-quark condensates govern the strenght of individual mass shifts. A strong in-medium mass splitting causes the disappearance of the $ρ- ω$ mixing.