Gluon Regge Trajectory in the two-loop Approximation
  Evaluating two-loop integrals in the transverse momentum space we obtain the trajectory of the Reggeized gluon in QCD in an explicit form in the two-loop approximation. It is presented as an expansion in powers of $(D-4)$ for the space-time dimension $D$ tending to the physical value $D=4$. As the result of a remarkable cancellation the third order pole in$D-4$ disappears in the trajectory and the expansion starts with $(D-4)^{-2}$. 
V.S. Fadin, R. Fiore, M.I. Kotsky