Charged-particle production was studied in proton-proton collisions collected at the LHC with the ALICE detector at centre-of-mass energies 0.9 TeV and 2.36 TeV in the pseudorapidity range |eta| < 1.4. In the central region (|eta| < 0.5), at 0.9 TeV, we measure charged-particle pseudorapidity density dNch/deta = 3.02 +- 0.01 (stat.) +0.08 -0.05 (syst.) for inelastic interactions, and dNch/deta = 3.58 +- 0.01 (stat.) +0.12 -0.12 (syst.) for non-single-diffractive interactions. At 2.36 TeV, we find dNch/deta = 3.77 +- 0.01 (stat.) +0.25 -0.12 (syst.) for inelastic, and dNch/deta = 4.43 +- 0.01 (stat.) +0.17 -0.12 (syst.) for non-single-diffractive collisions. The relative increase in charged-particle multiplicity from the lower to higher energy is 24.7% +- 0.5% (stat.) +5.7% -2.8% (syst.) for inelastic and 23.7% +- 0.5% (stat.) +4.6% - 1.1% (syst.) for non-single-diffractive interactions. This increase is consistent with that reported by the CMS collaboration for non-single-diffractive events and larger than that found by a number of commonly used models. The multiplicity distribution was measured in different pseudorapidity intervals and studied in terms of KNO variables at both energies. The results are compared to proton-antiproton data and to model predictions.

Charged-particle multiplicity measurement in proton-proton collisions at sqrt(s) = 7 TeV with ALICE at LHC

DE CARO, ANNALISA;DE GRUTTOLA, DANIELE;DE PASQUALE, Salvatore;FUSCO GIRARD, Mario;PAGANO, PAOLA;VIRGILI, Tiziano;
2010-01-01

Abstract

Charged-particle production was studied in proton-proton collisions collected at the LHC with the ALICE detector at centre-of-mass energies 0.9 TeV and 2.36 TeV in the pseudorapidity range |eta| < 1.4. In the central region (|eta| < 0.5), at 0.9 TeV, we measure charged-particle pseudorapidity density dNch/deta = 3.02 +- 0.01 (stat.) +0.08 -0.05 (syst.) for inelastic interactions, and dNch/deta = 3.58 +- 0.01 (stat.) +0.12 -0.12 (syst.) for non-single-diffractive interactions. At 2.36 TeV, we find dNch/deta = 3.77 +- 0.01 (stat.) +0.25 -0.12 (syst.) for inelastic, and dNch/deta = 4.43 +- 0.01 (stat.) +0.17 -0.12 (syst.) for non-single-diffractive collisions. The relative increase in charged-particle multiplicity from the lower to higher energy is 24.7% +- 0.5% (stat.) +5.7% -2.8% (syst.) for inelastic and 23.7% +- 0.5% (stat.) +4.6% - 1.1% (syst.) for non-single-diffractive interactions. This increase is consistent with that reported by the CMS collaboration for non-single-diffractive events and larger than that found by a number of commonly used models. The multiplicity distribution was measured in different pseudorapidity intervals and studied in terms of KNO variables at both energies. The results are compared to proton-antiproton data and to model predictions.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/3016211
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