Measurement of the underlying event activity at the LHC with √s = 7 TeV and comparison with √s = 0:9 TeV
Journal
Journal of High Energy Physics
Journal Volume
2011
Journal Issue
9
Date Issued
2011
Abstract
A measurement of the underlying activity in events with a jet of transverse momentum in the several GeV region is performed in proton-proton collisions at s = 0.9 and 7 TeV, using data collected by the CMS experiment at the LHC. The production of charged particles with pseudorapidity
0.5 GeV/c is studied in the azimuthal region transverse to that of the leading set of charged particles forming a track-jet. A significant growth of the average multiplicity and scalar-p T sum of the particles in the transverse region is observed with increasing p T of the leading trackjet, followed by a much slower rise above a few GeV/c. For track-jet p T larger than a few GeV/c, the activity in the transverse region is approximately doubled with a centreof-mass energy increase from 0.9 to 7 TeV. Predictions of several QCD-inspired models as implemented in pythia are compared to the data.
SDGs
Type
journal article