Charged-particle multiplicity measurement in proton–proton collisions at √s = 7 TeV with ALICE at LHC
Aamodt, K.; Abel, N.; Abeysekara, U.; Alme, Johan; Bablok, Sebastian Robert; Fehlker, D.; Haaland, Øystein Senneset; Huang, M.; Larsen, Dag Toppe; Nystrand, J.; Ullaland, K.; Øvrebekk, G.
Peer reviewed, Journal article
Published version
Date
2010-08-03Metadata
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Original version
https://doi.org/10.1140/epjc/s10052-010-1350-2Abstract
The pseudorapidity density and multiplicity distribution of charged particles produced in proton–proton collisions at the LHC, at a centre-of-mass energy Ös=7s=7 TeV, were measured in the central pseudorapidity region |η|<1. Comparisons are made with previous measurements at Ös=0.9s=09 TeV and 2.36 TeV. At Ös=7s=7 TeV, for events with at least one charged particle in |η|<1, we obtain dNch/dh = 6.01±0.01(stat.)+0.20-0.12(syst.)dNchd=601001(stat)+020−012(syst). This corresponds to an increase of 57.6%±0.4%(stat.)+3.6-1.8%(syst.)576%04%(stat)+36−18%(syst) relative to collisions at 0.9 TeV, significantly higher than calculations from commonly used models. The multiplicity distribution at 7 TeV is described fairly well by the negative binomial distribution.
Publisher
SpringerJournal
The European Physical Journal CCopyright
CERN for the benefit of the ALICE collaboration 2010Copyright CERN for the benefit of the ALICE collaboration 2010. This article is published with open access at Springerlink.com