Wilson Coefficients in the Operator Product Expansion of Scalar Currents   at Finite Temperature
  In this paper, we investigate operator product expansion for thermal correlation function of the two scalar currents. Due to breakdown of Lorentz invariance at finite temperature, more operators of the same dimension appear in the operator product expansion than at zero temperature. We calculated Wilson coefficients in the short distance expansion and obtain operator product expansion for thermal correlation function in terms of quark condensate, gluon condensate, quark energy density and gluon energy density. 
Elsen Veli Veliev and Takhmassib M. Aliev