Measurement of the pseudorapidity and transverse momentum dependence of the elliptic flow of charged particles in lead-lead collisions at sqrt(s_NN) = 2.76 TeV with the ATLAS detector

G. Aad , S. Albrand (1) , M.L. Andrieux (1) , B. Clement (1) , J. Collot (1) , S. Crépé-Renaudin (1) , P. de Saintignon (1) , P.A. Delsart (1) , J. Donini (1) , Daniel Dzahini (1) , J.Y. Hostachy (1) , E. Laisne (1) , F. Ledroit-Guillon (1) , A. Lleres (1) , A. Lucotte (1) , F. Malek (1) , P. Martin (1) , F. Polci (1) , J. Stark (1) , X. Sun (1) , B. Trocmé (1) , C. Weydert (1) , C. Biscarat (2) , E. Cogneras (2) , G. Rahal (2) , H. Bachacou (3) , F. Bauer (3) , N. Besson (3) , N.M. Bolnet (3) , M. Boonekamp (3) , L. Chevalier (3) , J. Ernwein (3) , A.I. Etienvre (3) , A. Formica (3) , L. Gauthier (3) , F. Giraud (3) , C. Guyot (3) , S. Hassani (3) , W. Kozanecki (3) , E. Lancon (3) , J.F. Laporte (3) , E. Le Menedeu (3) , M. Legendre (3) , B. Mansoulie (3) , J.-P. Meyer (3) , N. Morange (3) , E. Mountricha (3) , Thi Hong (3) , R. Nicolaidou (3) , A. Ouraou (3) , D.M. Pomarede (3) , B. Resende (3) , C.R. Royon (3) , Ph. Schune (3) , J. Schwindling (3) , O. Simard (3) , M. Virchaux (3) , C. Xu (3) , J. Yu (3) , Emmanuel Busato (4) , D. Calvet (4) , S. Calvet (4) , Reina Coromoto Camacho Toro (4) , Diane Cinca (4) , R. Febbraro (4) , N. Ghodbane (4) , C. Guicheney (4) , D. Pallin (4) , F. Podlyski (4) , C. Santoni (4) , L. P. Says (4) , F. Vazeille (4) , S. Aoun (5) , C. P. Bee (5) , C. Benchouk (5) , K. Bernardet (5) , N. Bousson (5) , J. C. Clémens (5) , Y. Coadou (5) , P. Delpierre (5) , F. Djama (5) , F. Etienne (5) , L. Feligioni (5) , F. Henry-Couannier (5) , D. Hoffmann (5) , F. Hubaut (5) , E. B. F. G. Knoops (5) , E. Le Guirriec (5) , B. Li (5) , E. Monnier (5) , J. Odier (5) , E. Petit (5) , P. Pralavorio (5) , Z. Qian (5) , A. Rozanov (5) , M. Talby (5) , N. Tannoury (5) , S. Tisserant (5) , J. Toth (5) , F. Touchard (5) , L. Vacavant (5) , T. Beau (6) , S. Bordoni (6) , G. Calderini (6) , A. Camard (6) , P. Cavalleri (6) , E. Chareyre (6) , S. de Cecco (6) , F. Derue (6) , D. Imbault (6) , M.W. Krasny (6) , D. Lacour (6) , B. Laforge (6) , O. Le Dortz (6) , J. Lellouch (6) , G. Marchiori (6) , I. Nikolic-Audit (6) , J. Ocariz (6) , M. Ridel (6) , L. Roos (6) , Ph. Schwemling (6) , Timothée Theveneaux-Pelzer (6) , S. Trincaz-Duvoid (6) , T.N. Trinh (6) , F. Vannucci (7) , L. Aperio Bella (8) , B. Aubert (8) , N. Berger (8) , J. Colas (8) , L. Di Ciaccio (8) , T.K.O. Doan (8) , S. Elles (8) , P. Ghez (8) , M. Gouanère (8) , C. Goy (8) , T. Guillemin (8) , L. Helary (8) , T. Hryn'Ova (8) , G. Ionescu (8) , A. Jérémie (8) , S. Jézéquel (8) , M. Kataoka (8) , J. Labbe (8) , R. Lafaye (8) , J. Leveque (8) , N. Massol (8) , P. Perrodo (8) , H. Przysiezniak (8) , G. Sauvage (8) , E. Sauvan (8) , T. Todorov (8) , D. Tsionou (8) , I. Wingerter-Seez (8) , R. Zitoun (8) , Y. Zolnierowski (8) , H. Abreu (9) , N. Andari (9) , C. Arnault (9) , E. Augé (9) , P. Barrillon (9) , M. Benoit (9) , S. Binet (9) , J.-B. Blanchard (9) , C. Bourdarios (9) , D. Breton (9) , C. Collard (10) , C. de La Taille (9) , J.B. de Vivie de Regie (9) , Sara Diglio (9) , L. Duflot (9) , M. Escalier (9) , A.C. Falou (9) , L. Fayard (9) , D. Fournier (9) , J.-F. Grivaz (9) , M. Heller (9) , S. Henrot-Versillé (9) , J. Hrivnac (9) , L. Iconomidou-Fayard (9) , J. Idarraga (9) , M. Kado (9) , A. Lounis (9) , N. Makovec (9) , P. Matricon (9) , F. Niedercorn (9) , L. Poggioli (9) , P. Puzo (9) , A. Renaud (9) , D. Rousseau (9) , X. Ruan (9, 11) , G. Rybkin (9) , J.B. Sauvan (9) , J. Schaarschmidt (9) , A.C. Schaffer (9) , L. Serin (9) , S. Simion (9) , R. Tanaka (9) , J.J. Veillet (9) , I. Vukotic (9) , F. Wicek (9) , D. Zerwas (9) , Zhiqing Zhang (9)

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
2 CC-IN2P3 - Centre de Calcul de l'IN2P3
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
5 CPPM - Centre de Physique des Particules de Marseille
6 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
7 APC - Neutrinos
8 LAPP - Laboratoire d'Annecy de Physique des Particules
9 LAL - Laboratoire de l'Accélérateur Linéaire
10 IPHC - Institut Pluridisciplinaire Hubert Curien
11 IHEP - Institute of High Energy Physics

This paper describes the measurement of elliptic flow of charged particles in lead-lead collisions at sqrt(s_NN) = 2.76 TeV using the ATLAS detector at the Large Hadron Collider (LHC). The results are based on an integrated luminosity of approximately 7 ub^-1. Elliptic flow is measured over a wide region in pseudorapidity, |eta| < 2.5, and over a broad range in transverse momentum, 0.5 < p_T < 20 GeV. The elliptic flow parameter v_2 is obtained by correlating individual tracks with the event plane measured using energy deposited in the forward calorimeters. As a function of transverse momentum, v_2(p_T) reaches a maximum at p_T of about 3 GeV, then decreases and becomes weakly dependent on p_T above 7 - 8 GeV. Over the measured pseudorapidity region, v_2 is found to be approximately independent of |eta| for all collision centralities and particle transverse momenta, something not observed in lower energy collisions. The results are discussed in the context of previous measurements at lower collision energies, as well as recent results from the LHC.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique Nucléaire Expérimentale [nucl-ex]

G. Aad, S. Albrand, M.L. Andrieux, B. Clement, J. Collot, et al.. Measurement of the pseudorapidity and transverse momentum dependence of the elliptic flow of charged particles in lead-lead collisions at sqrt(s_NN) = 2.76 TeV with the ATLAS detector. Physics Letters B, 2012, 707, pp.330-348. ⟨10.1016/j.physletb.2011.12.056⟩. ⟨in2p3-00617932⟩