Characteristics of multi-particle production in proton-proton collisions at √s = 7 TeV are studied as a function of the charged-particle multiplicity, N ch. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity {pipe}η{pipe}<2.4 and transverse momentum p T>0.25 GeV/c. Jets are reconstructed from charged-particles only and required to have p T>5 GeV/c. The distributions of jet p T, average p T of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of N ch and compared to the predictions of the pythia and herwig event generators. Predictions without multi-parton interactions fail completely to describe the N ch-dependence observed in the data. For increasing N ch, pythia systematically predicts higher jet rates and harder p T spectra than seen in the data, whereas herwig shows the opposite trends. At the highest multiplicity, the data-model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients. © 2013 CERN for the benefit of the CMS collaboration.

Chatrchyan, S., Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., et al. (2013). Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at √s = 7 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 73(12), 1-26 [10.1140/epjc/s10052-013-2674-5].

Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at √s = 7 TeV

BENAGLIA, ANDREA DAVIDE;DINARDO, MAURO EMANUELE;FIORENDI, SARA;GHEZZI, ALESSIO;GOVONI, PIETRO;LUCCHINI, MARCO TOLIMAN;MANZONI, RICCARDO ANDREA;MARTELLI, ARABELLA;MORONI, LUIGI;PAGANONI, MARCO;RAGAZZI, STEFANO;TABARELLI DE FATIS, TOMMASO;Branca, A;De Guio, F;
2013

Abstract

Characteristics of multi-particle production in proton-proton collisions at √s = 7 TeV are studied as a function of the charged-particle multiplicity, N ch. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity {pipe}η{pipe}<2.4 and transverse momentum p T>0.25 GeV/c. Jets are reconstructed from charged-particles only and required to have p T>5 GeV/c. The distributions of jet p T, average p T of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of N ch and compared to the predictions of the pythia and herwig event generators. Predictions without multi-parton interactions fail completely to describe the N ch-dependence observed in the data. For increasing N ch, pythia systematically predicts higher jet rates and harder p T spectra than seen in the data, whereas herwig shows the opposite trends. At the highest multiplicity, the data-model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients. © 2013 CERN for the benefit of the CMS collaboration.
Articolo in rivista - Articolo scientifico
Physics and Astronomy (miscellaneous); Engineering (miscellaneous); LHC; proton proton collisions; jets
English
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26
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Chatrchyan, S., Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., et al. (2013). Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at √s = 7 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 73(12), 1-26 [10.1140/epjc/s10052-013-2674-5].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/65242
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