A correlated-cluster model and the ridge phenomenon in hadron-hadron   collisions
  A study of the near-side ridge phenomenon in hadron-hadron collisions based on a cluster picture of multiparticle production is presented. The near-side ridge effect is shown to have a natural explanation in this context provided that clusters are produced in a correlated manner in the collision transverse plane. 
Miguel-Angel Sanchis-Lozano, Edward Sarkisyan-Grinbaum
hep-ph hep-ex