Instantons, chiral dynamics, and hadronic resonances

We use the interacting instanton liquid model (IILM) as a tool to study the role played by the chiral interactions in the lowest-lying vector and axial-vector meson resonances. We find that narrow a1 and ρ meson resonances can be generated by instanton-induced chiral forces, even in the absence of confinement. In the IILM, these hadrons are found to have masses only about 30% larger than the experimental value and small width ≲10–50MeV. This result suggests that chiral interactions are very important in these systems and provide most of their mass. We explore the decaying patterns of the ρ meson, in the absence of confinement. We argue that, in our model where only chiral forces are switched on, this meson decays dissociating into its quark-antiquark constituents.