Number of Collisions in the Glauber Model and Beyond
  The so called number of hadron-nucleus collisions n_coll(b) at impact parameter b, and its integral value N_coll, which are used to normalize the measured fractional cross section of a hard process, are calculated within the Glauber-Gribov theory including the effects of nucleon short-range correlations. The Gribov inelastic shadowing corrections are summed to all orders by employing the dipole representation. Numerical calculations are performed at the energies of the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC). We found that whereas the Gribov corrections generally increase the value of N_coll, the inclusion of nucleon correlations, acting in the opposite directions, decreases it by a comparable amount. The interplay of the two effects varies with the value of the impact parameter. 
C. Ciofi degli Atti, B. Z. Kopeliovich, C. B. Mezzetti, I. K.   Potashnikova, I. Schmidt
nucl-th hep-ph nucl-ex