Multiplicity and Pt Correlations in Relativistic Nuclear Collisions
  The theoretical description of the correlations between observables in two separated rapidity intervals for AA-interactions at high energies is presented. In the case with the realistic nucleon distribution density of colliding nuclei the MC calculations of the long-range correlation functions at different values of impact parameter are done.   For n-n and pt-n correlations it is shown that the impact parameter fluctuations at a level of a few fermi, unavoidable in any experiment, significantly change the magnitude of correlation coefficients. The rise of pt-n and especially pt-pt correlation coefficients is found when one passes from SPS to RHIC and LHC energies. 
R. S. Kolevatov, V. V. Vechernin