Home
Scholarly Works
Harmonic decomposition of two particle angular...
Journal article

Harmonic decomposition of two particle angular correlations in Pb–Pb collisions at sNN=2.76 TeV

Abstract

Angular correlations between unidentified charged trigger (t) and associated (a) particles are measured by the ALICE experiment in Pb–Pb collisions at sNN=2.76 TeV for transverse momenta 0.25pTa. The shapes of the pair correlation distributions are studied in a variety of collision centrality classes between 0 and 50% of the total hadronic cross section for particles in the pseudorapidity interval |η|<1.0. Distributions in relative azimuth Δϕ≡ϕt−ϕa are analyzed for |Δη|≡|ηt−ηa|>0.8, and are referred to as “long-range correlations”. Fourier components VnΔ≡〈cos(nΔϕ)〉 are extracted from the long-range azimuthal correlation functions. If particle pairs are correlated to one another through their individual correlation to a common symmetry plane, then the pair anisotropy VnΔ(pTt,pTa) is fully described in terms of single-particle anisotropies vn(pT) as VnΔ(pTt,pTa)=vn(pTt)vn(pTa). This expectation is tested for 1⩽n⩽5 by applying a global fit of all VnΔ(pTt,pTa) to obtain the best values vn{GF}(pT). It is found that for 2⩽n⩽5, the fit agrees well with data up to pTa∼3–4 GeV/c, with a trend of increasing deviation as pTt and pTa are increased or as collisions become more peripheral. This suggests that no pair correlation harmonic can be described over the full 0.25

Authors

Collaboration A; Aamodt K; Abelev B; Quintana AA; Adamová D; Adare AM; Aggarwal MM; Rinella GA; Agocs AG; Agostinelli A

Journal

Physics Letters B, Vol. 708, No. 3-5, pp. 249–264

Publisher

Elsevier

Publication Date

February 28, 2012

DOI

10.1016/j.physletb.2012.01.060

ISSN

0370-2693
View published work (Non-McMaster Users)

Contact the Experts team