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 vertical bar eta vertical bar < 1.4. In the central region (vertical bar eta vertical bar < 0.5), at 0.9 TeV, we measure charged-particle pseudo-rapidity density dN(ch)/d eta = 3.02 +/- 0.01(stat.)(-0.05)(+0.08)(syst.) for inelastic interactions, and dN(ch)/d eta = 3.58 +/- 0.01 (stat.)(-0.12)(+0.12)(syst.) for non-single-diffractive interactions. At 2.36 TeV, we find dN(ch)/d eta = 3.77 +/- 0.01(stat.)(-0.12)(+0.25)(syst.) for inelastic, and dN(ch)/d eta = 4.43 +/- 0.01(stat.)(-0.12)(+0.17)(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.)(-2.8)(+5.7)%(syst.) for inelastic and 23.7% +/- 0.5%(stat.)(-1.1)(+4.6)%(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. RI Deppman, Airton/F-6332-2010; Pshenichnov, Igor/A-4063-2008; Christensen, Christian/A-4901-2010; ZGURA, Ion Sorin/C-4598-2011; Haiduc, Maria /C-5003-2011; Martinez Hernandez, Mario Ivan/F-4083-2010; Mitu, Ciprian/E-6733-2011; Barnby, Lee/G-2135-2010; Mischke, Andre/D-3614-2011; Petta, Catia/A-7023-2012; Takahashi, Jun/B-2946-2012; Felea, Daniel/C-1885-2012; Sevcenco, Adrian/C-1832-2012; Chinellato, David/D-3092-2012; Christensen, Christian/D-6461-2012; Barbera, Roberto/G-5805-2012; Cortese, Pietro/G-6754-2012; beole', stefania/G-9353-2012; SCAPPARONE, EUGENIO/H-1805-2012; Aglieri Rinella, Gianluca/I-8010-2012

Charged-particle multiplicity measurement in proton-proton collisions at root s=0.9 and 2.36 TeV with ALICE at LHC

Cicalo C;DE FALCO, ALESSANDRO;FIONDA, FIORELLA MARIA CELESTE;PUDDU, GIOVANNA;USAI, GIANLUCA;
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 vertical bar eta vertical bar < 1.4. In the central region (vertical bar eta vertical bar < 0.5), at 0.9 TeV, we measure charged-particle pseudo-rapidity density dN(ch)/d eta = 3.02 +/- 0.01(stat.)(-0.05)(+0.08)(syst.) for inelastic interactions, and dN(ch)/d eta = 3.58 +/- 0.01 (stat.)(-0.12)(+0.12)(syst.) for non-single-diffractive interactions. At 2.36 TeV, we find dN(ch)/d eta = 3.77 +/- 0.01(stat.)(-0.12)(+0.25)(syst.) for inelastic, and dN(ch)/d eta = 4.43 +/- 0.01(stat.)(-0.12)(+0.17)(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.)(-2.8)(+5.7)%(syst.) for inelastic and 23.7% +/- 0.5%(stat.)(-1.1)(+4.6)%(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. RI Deppman, Airton/F-6332-2010; Pshenichnov, Igor/A-4063-2008; Christensen, Christian/A-4901-2010; ZGURA, Ion Sorin/C-4598-2011; Haiduc, Maria /C-5003-2011; Martinez Hernandez, Mario Ivan/F-4083-2010; Mitu, Ciprian/E-6733-2011; Barnby, Lee/G-2135-2010; Mischke, Andre/D-3614-2011; Petta, Catia/A-7023-2012; Takahashi, Jun/B-2946-2012; Felea, Daniel/C-1885-2012; Sevcenco, Adrian/C-1832-2012; Chinellato, David/D-3092-2012; Christensen, Christian/D-6461-2012; Barbera, Roberto/G-5805-2012; Cortese, Pietro/G-6754-2012; beole', stefania/G-9353-2012; SCAPPARONE, EUGENIO/H-1805-2012; Aglieri Rinella, Gianluca/I-8010-2012
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/48466
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