Measurements from the CMS experiment at the LHC of dihadron correlations for charged particles produced in PbPb collisions at a nucleon-nucleon centre-of-mass energy of 2.76 TeV are presented. The results are reported as a function of the particle transverse momenta (p(T)) and collision centrality over a broad range in relative pseudorapidity (Delta eta) and the full range of relative azimuthal angle (Delta phi). The observed two-dimensional correlation structure in Delta eta and Delta phi is characterised by a narrow peak at (Delta eta, Delta phi) approximate to (0, 0) from jet-like correlations and a long-range structure that persists up to at least vertical bar Delta eta vertical bar = 4. An enhancement of the magnitude of the short-range jet peak is observed with increasing centrality, especially for particles of p(T) around 1-2 GeV/c. The long-range azimuthal dihadron correlations are extensively studied using a Fourier decomposition analysis. The extracted Fourier coefficients are found to factorise into a product of single-particle azimuthal anisotropies up to p(T) approximate to 3-3.5 GeV/c for at least one particle from each pair, except for the second-order harmonics in the most central PbPb events. Various orders of the single-particle azimuthal anisotropy harmonics are extracted for associated particle p(T) of 1-3 GeV/c, as a function of the trigger particle p(T) up to 20 GeV/c and over the full centrality range.

Centrality dependence of dihadron correlations and azimuthal anisotropy harmonics in PbPb collisions at root s(NN)=2.76 TeV / S. Chatrchyan, V. Khachatryan, A. M. Sirunyan, A. Tumasyan, W. Adam, T. Bergauer, M. Dragicevic, J. Ero, C. Fabjan, M. Friedl, R. Fruhwirth, V. M. Ghete, J. Hammer, M. Hoch, N. Hormann, J. Hrubec, M. Jeitler, W. Kiesenhofer, A. Knapitsch, M. Krammer, et al.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - ELETTRONICO. - 72:2012:(2012), pp. 1-26. [10.1140/epjc/s10052-012-2012-3]

Centrality dependence of dihadron correlations and azimuthal anisotropy harmonics in PbPb collisions at root s(NN)=2.76 TeV

CIULLI, VITALIANO;D'ALESSANDRO, RAFFAELLO;FOCARDI, ETTORE;FROSALI, SIMONE;GONZI, SANDRO;P. Lenzi;
2012

Abstract

Measurements from the CMS experiment at the LHC of dihadron correlations for charged particles produced in PbPb collisions at a nucleon-nucleon centre-of-mass energy of 2.76 TeV are presented. The results are reported as a function of the particle transverse momenta (p(T)) and collision centrality over a broad range in relative pseudorapidity (Delta eta) and the full range of relative azimuthal angle (Delta phi). The observed two-dimensional correlation structure in Delta eta and Delta phi is characterised by a narrow peak at (Delta eta, Delta phi) approximate to (0, 0) from jet-like correlations and a long-range structure that persists up to at least vertical bar Delta eta vertical bar = 4. An enhancement of the magnitude of the short-range jet peak is observed with increasing centrality, especially for particles of p(T) around 1-2 GeV/c. The long-range azimuthal dihadron correlations are extensively studied using a Fourier decomposition analysis. The extracted Fourier coefficients are found to factorise into a product of single-particle azimuthal anisotropies up to p(T) approximate to 3-3.5 GeV/c for at least one particle from each pair, except for the second-order harmonics in the most central PbPb events. Various orders of the single-particle azimuthal anisotropy harmonics are extracted for associated particle p(T) of 1-3 GeV/c, as a function of the trigger particle p(T) up to 20 GeV/c and over the full centrality range.
2012
72:2012
1
26
S. Chatrchyan;V. Khachatryan;A. M. Sirunyan;A. Tumasyan;W. Adam;T. Bergauer;M. Dragicevic;J. Ero;C. Fabjan;M. Friedl;R. Fruhwirth;V. M. Gh...espandi
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/774690
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