The interaction region of high energy protons
  The spatial view of the interaction region of colliding high energy protons (in terms of impact parameter) is considered. It is shown that the region of inelastic collisions has a very peculiar shape. It saturates for central collisions at an energy of 7 TeV. We speculate on the further evolution with energy, which is contrasted to the "black disk" picture. 
I.M. Dremin, S.N. White
hep-ph hep-ex nucl-ex nucl-th