Underlying event characteristics and their dependence on jet size of charged-particle jet events in pp collisions at √s = 7TeV with the ATLAS detector

Distributions sensitive to the underlying event are studied in events containing one or more charged-particle jets produced in pp collisions at √s=7TeV with the ATLAS detector at the Large Hadron Collider (LHC). These measurements reflect 800μb-1 of data taken during 2010. Jets are reconstructed usi...

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Detalles Bibliográficos
Autores: Anduaga, Xabier Sebastián, Dova, María Teresa, Monticelli, Fernando Gabriel, Tripiana, Martín Fernando, The ATLAS Collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/84609
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84609
Access Level:acceso abierto
Palabra clave:Ciencias Exactas
Física
Jets
ATLAS detector
Large Hadron Collider
Descripción
Sumario:Distributions sensitive to the underlying event are studied in events containing one or more charged-particle jets produced in pp collisions at √s=7TeV with the ATLAS detector at the Large Hadron Collider (LHC). These measurements reflect 800μb-1 of data taken during 2010. Jets are reconstructed using the anti-kt algorithm with radius parameter R varying between 0.2 and 1.0. Distributions of the charged-particle multiplicity, the scalar sum of the transverse momentum of charged particles, and the average charged-particle pT are measured as functions of pTjet in regions transverse to and opposite the leading jet for 4GeV<pTjet<100GeV. In addition, the R dependence of the mean values of these observables is studied. In the transverse region, both the multiplicity and the scalar sum of the transverse momentum at fixed pTjet vary significantly with R, while the average charged-particle transverse momentum has a minimal dependence on R. Predictions from several Monte Carlo tunes have been compared to the data; the predictions from Pythia 6, based on tunes that have been determined using LHC data, show reasonable agreement with the data, including the dependence on R. Comparisons with other generators indicate that additional tuning of soft-QCD parameters is necessary for these generators. The measurements presented here provide a testing ground for further development of the Monte Carlo models.