Show simple item record

dc.contributor.authorAad, G.en_US
dc.contributor.authorAbbott, B.en_US
dc.contributor.authorAbdallah, J.en_US
dc.contributor.authorAbdel Khalek, S.en_US
dc.contributor.authorAbdelalim, A. A.en_US
dc.contributor.authorAbdesselam, A.en_US
dc.contributor.authorAbdinov, O.en_US
dc.contributor.authorAhsan, Mahsanaen_US
dc.contributor.authorIzen, Joseph M.en_US
dc.contributor.authorLou, Xinchouen_US
dc.contributor.authorReeves, Kendallen_US
dc.description.abstractDifferential measurements of charged particle azimuthal anisotropy are presented for lead-lead collisions at √{S_{NN}} = 2.76 TeV with the ATLAS detector at the LHC, based on an integrated luminosity of approximately 8 μb⁻¹. This anisotropy is characterized via a Fourier expansion of the distribution of charged particles in azimuthal angle relative to the reaction plane, with the coefficients vn denoting the magnitude of the anisotropy. Significant v₂–v₆ values are obtained as a function of transverse momentum (0.5 < p_T < 20 GeV), pseudorapidity (|η| < 2.5), and centrality using an event plane method. The ν_n values for n ≥ 3 are found to vary weakly with both η and centrality, and their p_T dependencies are found to follow an approximate scaling relation, v_{1/n / n} (p_T) ∝ v{1/2 / 2} (p_T), except in the top 5% most central collisions. A Fourier analysis of the charged particle pair distribution in relative azimuthal angle (Δφ = φ_a − φ_b) is performed to extract the coefficients v_{n,n} = (cos nΔφ). For pairs of charged particles with a large pseudorapidity gap (|Δη = η_a−η_b| > 2) and one particle with pT < 3 GeV, the v₂,₂ – v₆,₆ values are found to factorize as v_{n,n}(p_T^a, pp_T^b) ≈ v_n(p_T^a) ν_n (p_T^b) in central and midcentral events. Such factorization suggests that these values of v₂,₂ – v₆,₆ are primarily attributable to the response of the created matter to the fluctuations in the geometry of the initial state. A detailed study shows that the v₁,₁ (p_T^a,p_T^b) data are consistent with the combined contributions from a rapidity-even v₁ and global momentum conservation. A two-component fit is used to extract the v₁ contribution. The extracted v₁ is observed to cross zero at p_T ≈ 1.0 GeV, reaches a maximum at 4–5 GeV with a value comparable to that for v₃, and decreases at higher p_T.en_US
dc.publisherAmerican Physical Societyen_US
dc.rightsCC BY 3.0 (Attribution)en_US
dc.rights©2014 CERN for the ATLAS collaborationen_US
dc.sourcePhysical Review C - Nuclear Physics
dc.subjectAzimuthal anisotropyen_US
dc.subjectLead-lead interactionsen_US
dc.subjectFourier seriesen_US
dc.titleMeasurement of the Azimuthal Anisotropy for Charged Particle Production in √{S_{NN}} = 2.76 TeV Lead-Lead Collisions with the ATLAS Detectoren_US
dc.identifier.bibliographicCitationAad, G., B. Abbott, J. Abdallah, S. Abdel Khalek, et al. 2014. "Measurement of the azimuthal anisotropy for charged particle production in √{S_{NN}} = 2.76 TeV lead-lead collisions with the ATLAS detector." Physical Review C - Nuclear Physics 86(1), doi:10.1103/PhysRevC.86.014907en_US
dc.contributor.utdAuthorLou, Xinchouen_US
dc.contributor.utdAuthorIzen, Joseph M.en_US
dc.contributor.VIAF250674117 (Izen, JM)en_US
dc.contributor.VIAF250674117 (Izen, JM)
dc.contributor.ORCID0000-0003-0867-2189 (Lou, X)

Files in this item


This item appears in the following Collection(s)

Show simple item record

CC BY 3.0 (Attribution)
Except where otherwise noted, this item's license is described as CC BY 3.0 (Attribution)