The pseudorapidity distributions of the produced charged particles in   p-p collisions at center-of-mass energies from 23.6 to 900 GeV
  In p-p collisions, there are two leading particles. One is in projectile fragmentation region. The other is in target fragmentation region. The investigations of present paper show that, just like in nucleus-nucleus collisions, the revised Landau hydrodynamic model alone is not enough to have a good description to the measured pseudorapidity distributions of the produced charged particles in p-p collisions. Only after the leading particles are taken into account as well, can the experimental data be matched up properly. The theoretical model works well in p-p collisions in the whole available energy region from sqrt(s_NN) =23.6 to 900 GeV. 
Z. J. Jiang and H. L. Zhang
nucl-th hep-ph