%0 Journal Article
%T Measurement of the azimuthal anisotropy for charged particle production in root s(NN)=2.76 TeV lead-lead collisions with the ATLAS detector
%A ATLAS Collaboration (Aad, G. et al
%A Amoros, G.
%A Cabrera Urban, S.
%A Castillo Gimenez, V.
%A Costa, M. J.
%A Ferrer, A.
%A Fiorini, L.
%A Fuster, J.
%A Garcia, C.
%A Garcia Navarro, J. E.
%A Gonzalez de la Hoz, S.
%A Hernandez Jimenez, Y.
%A Higon-Rodriguez, E.
%A Irles Quiles, A.
%A Kaci, M.
%A Lacasta, C.
%A Lacuesta, V. R.
%A Marti-Garcia, S.
%A Miñano, M.
%A Mitsou, V. A.
%A Moles-Valls, R.
%A Moreno Llacer, M.
%A Oliver Garcia, E.
%A Perez Garcia-Estañ, M. T.
%A Romero Adam, E.
%A Ros, E.
%A Salt, J.
%A Sanchez Martinez, V.
%A Solans, C. A.
%A Soldevila, U.
%A Sanchez, J.
%A Torro Pastor, E.
%A Valladolid Gallego, E.
%A Valls Ferrer, J. A.
%A Villaplana Perez, M.
%A Vos, M.
%A Wildauer, A.
%J Physical Review C
%D 2012
%V 86
%N 1
%I Amer Physical Soc
%@ 0556-2813
%G English
%F ATLASCollaborationAad_etal2012
%O WOS:000306689500001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=1119), last updated on Tue, 04 Sep 2012 11:46:23 +0000
%X Differential measurements of charged particle azimuthal anisotropy are presented for lead-lead collisions at root sNN = 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 v(n) denoting the magnitude of the anisotropy. Significant v(2)-v(6) values are obtained as a function of transverse momentum (0.5 < p(T) < 20 GeV), pseudorapidity (|eta| < 2.5), and centrality using an event plane method. The v(n) values for n >= 3 are found to vary weakly with both eta and centrality, and their p(T) dependencies are found to follow an approximate scaling relation, v(n)(1/n)(p(T)) proportional to v(2)(1/2)(p(T)), except in the top 5% most central collisions. A Fourier analysis of the charged particle pair distribution in relative azimuthal angle (Delta phi = phi(a)-phi(b)) is performed to extract the coefficients v(n,n) = < cos n Delta phi >. For pairs of charged particles with a large pseudorapidity gap (|Delta eta = eta(a) – eta(b)| > 2) and one particle with p(T) < 3 GeV, the v(2,2)-v(6,6) values are found to factorize as v(n,n)(p(T)(a), p(T)(b)) approximate to v(n) (p(T)(a))v(n)(p(T)(b)) in central and midcentral events. Such factorization suggests that these values of v(2,2)-v(6,6) 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 v(1,1)(p(T)(a), p(T)(b)) data are consistent with the combined contributions from a rapidity-even v(1) and global momentum conservation. A two-component fit is used to extract the v(1) contribution. The extracted v(1) isobserved to cross zero at pT approximate to 1.0 GeV, reaches a maximum at 4-5 GeV with a value comparable to that for v(3), and decreases at higher p(T).
%R 10.1103/PhysRevC.86.014907
%U http://arxiv.org/abs/1203.3087
%U https://doi.org/10.1103/PhysRevC.86.014907
%P 014907-41pp