First Measurement of the Underlying Event Activity at the LHC with $\\sqrt{s} = 0.9$ TeV
Journal
European Physical Journal
Journal Volume
C70
Pages
555-572
Date Issued
2010
Author(s)
Khachatryan V. et al.
Abstract
A measurement of the underlying activity in scattering processes with pT scale in the GeV region is performed in proton-proton collisions at √ = 0.9 TeV, using data collected by the CMS experiment at the LHC. Charged particle production is studied with reference to the direction of a leading object, either a charged particle or a set of charged particles forming a jet. Predictions of several QCD-inspired models as implemented in PYTHIA are compared, after full detector simulation, to the data. The models generally predict too little production of charged particles with pseudorapidity {pipe}η{pipe} < 2, pT > 0.5 GeV/c, and azimuthal direction transverse to that of the leading object. © 2010 CERN for benefit of the CMS collaboration.
Type
journal article