Instanton propagator in scalar model: exact expression and contribution   to instanton induced processes
  The propagator in the instanton background in the -lambda phi^4 scalar model in four dimensions is studied. Leading and sub-leading terms of its asymptotics for large momenta and its on-shell double residue are calculated. These results are applied to the analysis of the initial state and initial-final state corrections and the calculation of the next-to-leading (propagator) correction to the exponent of the cross section of multiparticle scattering processes. 
Yu.A. Kubyshin (INP, Moscow State University, Moscow) and P.G.   Tinyakov (INR, Moscow)