Charged-particle multiplicities in pp interactions at root s=900 GeV measured with the ATLAS detector at the LHC ATLAS Collaboration
2010 (English)In: Physics Letters B, ISSN 0370-2693, Vol. 688, no 1, 21-42 p.Article in journal (Refereed) Published
The first measurements from proton–proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity, and the relationship between mean transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range |η|<2.5 and pT>500 MeV. The measurements are compared to Monte Carlo models of proton–proton collisions and to results from other experiments at the same centre-of-mass energy. The charged-particle multiplicity per event and unit of pseudorapidity at η=0 is measured to be 1.333±0.003(stat.)±0.040(syst.), which is 5–15% higher than the Monte Carlo models predict.
Place, publisher, year, edition, pages
2010. Vol. 688, no 1, 21-42 p.
Charged-particle, Multiplicities, 900 GeV, ATLAS, LHC, Minimum bias
IdentifiersURN: urn:nbn:se:uu:diva-148520DOI: 10.1016/j.physletb.2010.03.064ISI: 000286150500001OAI: oai:DiVA.org:uu-148520DiVA: diva2:402294