Hadronic correlation functions in the interacting instanton liquid

In this paper we study hadronic correlation functions in the interacting instanton liquid model, both at zero and nonzero temperature $T$. At zero $T$ we investigate the dependence of the correlators on the instanton ensemble, in particular, the effect of the fermionic determinant. We demonstrate that quark-induced correlations between instantons are important, especially in the repulsive ${\eta }^{\prime }$ and $\delta$-meson channels. We also calculate a large number of mesonic and baryonic correlation functions as a function of temperature. We find three different types of behavior as $T\to T_c$. The vector channels $\rho$, $a_1$, $\Delta$ show a gradual melting of the resonance contribution and approach free quark behavior near the chiral phase transition. The light pseudoscalars and scalars $\pi$, $\sigma$ as well as the nucleon show stable resonance contributions, probably even surviving above $T_c$. Correlation functions in the heavy scalar channels ${\eta }^{\prime }$, $\delta$ are enhanced as $T\to T_c$.