Long-range and short-range dihadron angular correlations in central PbPb collisions at psNN = 2:76 TeV

First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV over a broad range in relative pseudorapidity (Δν) and the full range of relative azimuthal angle (Δø). The data were collected with the C...

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Bibliographic Details
Main Authors: Chatrchyan, S, Khachatryan, V, Sirunyan, A, Tumasyan, A, Adam, W, Bergauer, T, Dragicevic, M, Erö, J, Fabjan, C, Friedl, M, Frühwirth, R, Ghete, V, Hammer, J, Hansel, S, Hoch, M, Hörmann, N, Hrubec, J, Jeitler, M, Kiesenhofer, W, Krammer, M, Liko, D, Mikulec, I, Pernicka, M, Rohringer, H, Schöfbeck, R
Format: Journal article
Language:English
Published: 2011
Description
Summary:First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV over a broad range in relative pseudorapidity (Δν) and the full range of relative azimuthal angle (Δø). The data were collected with the CMS detector, at the LHC. A broadening of the away-side (Δø y≈ π) azimuthal correlation is observed at all Δν, as compared to the measurements in pp collisions. Furthermore, long-range dihadron correlations in Δν are observed for particles with similar ø values. This phenomenon, also known as the \ridge", persists up to at least jΔνj = 4. For particles with transverse momenta (pT) of 2-4 GeV/c, the ridge is found to be most prominent when these particles are correlated with particles of pT = 2-6 GeV/c, and to be much reduced when paired with particles of pT = 10-12 GeV/c. Copyright CERN.