A measurement of the underlying activity in scattering processes with p (T) scale in the GeV region is performed in proton-proton collisions at root s = 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 |eta|< 2, p (T) > 0.5 GeV/c, and azimuthal direction transverse to that of the leading object.
First measurement of the underlying event activity at the LHC with root s=0.9 TeV
BELLAN, PAOLO;BISELLO, DARIO;CARLIN, ROBERTO;DE MATTIA, MARCO;GASPARINI, FABRIZIO;GIUBILATO, PIERO;MARGONI, MARTINO;MENEGUZZO, ANNA TERESA;POZZOBON, NICOLA;RONCHESE, PAOLO;SIMONETTO, FRANCO;TOSI, MIA;A. Triossi;VANINI, SARA;ZOTTO, PIERLUIGI;M. Grassi;ROSSIN, ROBERTO;
2010
Abstract
A measurement of the underlying activity in scattering processes with p (T) scale in the GeV region is performed in proton-proton collisions at root s = 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 |eta|< 2, p (T) > 0.5 GeV/c, and azimuthal direction transverse to that of the leading object.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.