A measurement of the underlying activity in scattering processes with a hard scale in the several-GeV region is performed in proton-proton collisions at Energies of 0.9 and 7 TeV, using data collected by the CMS experiment at the LHC. The production of charged particles with pseudorapidity |eta| < 2 and transverse momentum pT > 0.5 GeV/c is studied in the azimuthal region transverse to that of the leading set of charged particles forming a track-jet. Various comparisons are made between the two different energies and also beteen two sets of cuts on pT for leading track jet pT-leading > 3 GeV and pT-leading > 20 GeV. The activity is studied using 5 types of plots. 2 profile plots for the multiplcity of charged particles and the scalar sum of pT. and 3 distributions for the two previous quantities as well we pT for all the particles in the transverse region.
Generated at Wednesday, 28. August 2013 10:54AM
