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

2010/04/20 by ALICE Collaboration · 1 voice
Physics and Astronomy · #hep-ex

paper · pdf · doi:10.1140/epjc/s10052-010-1350-2

published as Eur. Phys. J. C 68 (2010) 345-354 · 12 pages, 3 captioned figures, 1 table, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/3904

arxiv published 2010/04/20 · arxiv created 2017/09/28 · arxiv updated 2017/09/28

Abstract

The pseudorapidity density and multiplicity distribution of charged particles produced in proton-proton collisions at the LHC, at a centre-of-mass energy √(s) = 7 TeV, were measured in the central pseudorapidity region |η| < 1. Comparisons are made with previous measurements at √(s) = 0.9 TeV and 2.36 TeV. At √(s) = 7 TeV, for events with at least one charged particle in |η| < 1, we obtain dNch/deta = 6.01 ± 0.01 (stat.) ^+0.20_-0.12 (syst.). This corresponds to an increase of 57.6% ± 0.4% (stat.) ^+3.6_-1.8% (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.

Discussions

• First results at 7 TeV from ALICE: http://arxiv.org/abs/1004.3514 - and something not quite expected is seen [bsky, 0 points, 0 comments]

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