Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV

K. Aamodt , Sang Un Ahn (1) , N. Arbor (2) , Laurent Aphecetche (3) , Y.W. Baek (4) , A. Baldisseri (5) , A. Baldit (4) , V. Barret (4) , N. Bastid (4) , Guillaume Batigne (3) , I. Belikov (6) , H. Borel (5) , B. Boyer (7) , M. Bregant (3) , J. Castillo Castellanos (5) , J.L. Charvet (5) , B. Cheynis (8) , J.-P. Coffin (6) , G. Conesa Balbastre (2) , Z. Conesa del Valle (6) , P. Crochet (4) , H. Delagrange (3) , O. Driga (3) , L. Ducroux (8) , P. Dupieux (4) , B. Espagnon (7) , Magali Estienne (3) , J. Faivre (2) , C. Furget (2) , S. Gadrat (2) , Marie Germain (3) , C. Geuna (5) , J.-Y. Grossiord (9) , R. Guernane (2) , Maxime Guilbaud (8) , C. Hadjidakis (7) , B. Hippolyte (6) , I. Hrivnacova (7) , S. Jangal (6) , S. Kox (2) , C. Kuhn (6) , V. Lafage (7) , A. Lardeux (3) , Y. Le Bornec (7) , F. Lefevre (3) , M. Lenhardt (3) , X. Lopez (4) , M. Lopez Noriega (7) , A. Maire (6) , F. Manso (4) , Y. Mao (2) , M. Marchisono (4) , Gines Martinez Garcia (3) , A. Mas (3) , L. Massacrier (8) , Philippe Pillot (3) , A. Rakotozafindrabe (5) , J.S. Real (2) , P. Rosnet (4) , S. Rousseau (7) , C. Roy (6) , P. Saturnini (4) , Diego Stocco (3) , C. Suire (7) , J.D. Tapia Takaki (7) , R. Tieulent (8) , L. Valencia Palomo (7) , R. Vernet (10) , R. Wan (6) , Y. Zoccarato (8)

1 Laboratoire de Physique Corpusculaire
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
3 SUBATECH - Laboratoire SUBATECH Nantes
4 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
5 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
6 IPHC - Institut Pluridisciplinaire Hubert Curien
7 IPNO - Institut de Physique Nucléaire d'Orsay
8 IPNL - Institut de Physique Nucléaire de Lyon
9 ALICE
10 CC-IN2P3 - Centre de Calcul de l'IN2P3

We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

K. Aamodt, Sang Un Ahn, N. Arbor, Laurent Aphecetche, Y.W. Baek, et al.. Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV. Physical Review Letters, 2011, 107, pp.032301. ⟨10.1103/PhysRevLett.107.032301⟩. ⟨in2p3-00595710⟩