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 root s = 0.9 and 7 TeV, using data collected by the CMS experiment at the LHC. The production of charged particles with pseudorapidity vertical bar eta vertical bar < 2 and transverse momentum p(T) > 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 track-jet, 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 centre-of-mass energy increase from 0.9 to 7 TeV. Predictions of several QCD-inspired models as implemented in PYTHIA are compared to the data.

Chatrchyan, S., Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., et al. (2011). Measurement of the underlying event activity at the LHC with root s=7 TeV and comparison with root s=0.9 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2011(9) [10.1007/JHEP09(2011)109].

Measurement of the underlying event activity at the LHC with root s=7 TeV and comparison with root s=0.9 TeV

Guio, F;GHEZZI, ALESSIO;Massironi, A;PAGANONI, MARCO;RAGAZZI, STEFANO;TABARELLI DE FATIS, TOMMASO;Branca, A;Govoni, P;DINARDO, MAURO EMANUELE;
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 root s = 0.9 and 7 TeV, using data collected by the CMS experiment at the LHC. The production of charged particles with pseudorapidity vertical bar eta vertical bar < 2 and transverse momentum p(T) > 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 track-jet, 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 centre-of-mass energy increase from 0.9 to 7 TeV. Predictions of several QCD-inspired models as implemented in PYTHIA are compared to the data.
Articolo in rivista - Articolo scientifico
LHC; PHYSICS; CMS; Underlying event
English
2011
2011
9
109
none
Chatrchyan, S., Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., et al. (2011). Measurement of the underlying event activity at the LHC with root s=7 TeV and comparison with root s=0.9 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2011(9) [10.1007/JHEP09(2011)109].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/46669
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