Off-mass-shell Sudakov-like suppression factor for the fermionic   four-point function in QCD
  We consider a four-point process, associated with a wide-angle elastic scattering of two off-mass-shell spin-1/2 matter particles, in a non-abelian gauge theory. On the basis of a worldline approach, which reverts the functional to a path-integral description of the system, we factorize an eikonal (``soft'') subsector of the full theory and calculate the Sudakov-like suppression factor for the four-point function as a whole, once we have extracted the associated anomalous dimensions and taken into account the renormalization-group controlled evolution. 
A. I. Karanikas, C. N. Ktorides (Athens U.), N. G. Stefanis (Ruhr U.,   Bochum), and S. M. H. Wong (Athens U.)