Quark induced excitations of the instanton liquid
  The selfconsistent approach to the quark interactions in the instanton liquid is developed within the tadpole approximation calculating the basic functional integral. The effective Lagrangian obtained includes colourless scalar field interacting with quarks. The origin of this dynamical field as an interaction carrier in soft momentum region is discussed. 
S.V. Molodtsov, A.M. Snigirev, G.M. Zinovjev