Centrality and Pseudorapidity of the Transverse Energy Flow in pPb Collisions at Center of Mass Energy 5.02 TeV

Abstract

The almost hermitic coverage of CMS is used to measure the distribution of transverse energy as a function of pseudorapidity for pPb collisions at center of mass energy of 5:02 TeV. For minimum bias collisions (1/N) dET/dη reaches 25 GeV which implies an energy density comparable to that of PbPb collisions at TeV energies. The centrality dependence of transverse energy dependence has been studied using centrality measures defined in three different angular regions. The correlations between which events are selected by are much wider than they were in PbPb collisions and are not reproduced by either the EPOS-LHC or HIJING event generators. Each centrality class was divided by the most central events in order to measure the auto-correlations induced by a centrality definition and reduce the systematic error. This variable is called SPC and the effect of the auto-correlation persists over a much wider pseudo-rapidity range than predicted by either of the event generators.