Forward-central two-particle correlations in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV

J. Adam , G. Conesa Balbastre (1) , J. Faivre (1) , C. Furget (1) , R. Guernane (1) , J.S. Real (1) , C. Silvestre (1) , A. Vauthier (1) , R. Vernet (2) , I. Belikov (3) , B. Hippolyte (3) , C. Kuhn (3) , A. Maire (3) , L. Molnar (3) , F. Rami (3) , C. Roy (3) , X. Sanchez Castro (3) , Laurent Aphecetche (4) , G. Batigne (4) , A. Baldisseri (5) , H. Borel (5) , J. Castillo Castellanos (5) , J.L. Charvet (5) , C. Cheshkov (6) , B. Cheynis (6) , L. Ducroux (6) , Marie Germain (4) , J.-Y. Grossiord , A. Lardeux (5) , J. Martin Blanco (4) , Gines Martinez Garcia (4) , L. Massacrier (4) , H. Pereira Da Costa (5) , Philippe Pillot (4) , L. Ronflette (4) , Y. Schutz (4) , Alexandre Shabetai (4) , B. Teyssier (6) , R. Tieulent (6) , A. Uras (6) , M. Wang (4) , V. Barret (7) , N. Bastid (7) , A. Batista Camejo (7) , P. Crochet (7) , P. Dupieux (7) , V.J.G. Feuillard (5, 7) , S. Li (7) , X. Lopez (7) , F. Manso (7) , S. Porteboeuf-Houssais (7) , P. Rosnet (7) , B. Vulpescu (7) , Z. Conesa Del Valle (8) , I. Das (8) , B. Espagnon (8) , C. Hadjidakis (8) , I. Lakomov (8) , Diego Stocco (4) , C. Suire (8) , J. D. Tapia Takaki (8) , M. Tarhini (8) , L. Valencia Palomo (8)

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

Two-particle angular correlations between trigger particles in the forward pseudorapidity range ($2.5 < |\eta| < 4.0$) and associated particles in the central range ($|\eta| < 1.0$) are measured with the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The trigger particles are reconstructed using the muon spectrometer, and the associated particles by the central barrel tracking detectors. In high-multiplicity events, the double-ridge structure, previously discovered in two-particle angular correlations at midrapidity, is found to persist to the pseudorapidity ranges studied in this Letter. The second-order Fourier coefficients for muons in high-multiplicity events are extracted after jet-like correlations from low-multiplicity events have been subtracted. The coefficients are found to have a similar transverse momentum ($p_{\rm T}$) dependence in p-going (p-Pb) and Pb-going (Pb-p) configurations, with the Pb-going coefficients larger by about $16\pm6$%, rather independent of $p_{\rm T}$ within the uncertainties of the measurement. The data are compared with calculations using the AMPT model, which predicts a different $p_{\rm T}$ and $\eta$ dependence than observed in the data. The results are sensitive to the parent particle $v_2$ and composition of reconstructed muon tracks, where the contribution from heavy flavour decays are expected to dominate at $p_{\rm T}>2$ GeV/$c$.

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

J. Adam, G. Conesa Balbastre, J. Faivre, C. Furget, R. Guernane, et al.. Forward-central two-particle correlations in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. Physics Letters B, 2016, 753, pp.126-139. ⟨10.1016/j.physletb.2015.12.010⟩. ⟨in2p3-01172182⟩