Dynamical gluon mass in the instanton vacuum model

Abstract

We are considering the modifications of gluon properties in Instanton Liquid Model (ILM) for the QCD vacuum. Re-scattering of a gluons on an instantons leads to the dynamical momentum-dependent gluon mass $M_g(q).$ First, we considered scalar "gluon", since there are no zero-modes problem and found its dynamical mass $M_s(q)$. At the typical phenomenological values of the average instanton size $\rho =1/3fm$ and average inter-instanton distance $R=1fm$ we got $M_s(0)=256MeV$. Further, we extended this approach to the real vector gluon with careful consideration of zero-modes and got $M_g^2(q)=2M_s^2(q).$ This modification of the gluon in the instanton media might be important for the heavy quarkonium physics at least.