Harmonic decomposition of two-particle angular correlations in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV

0388792 - ÚJF 2013 RIV NL eng J - Článek v odborném periodiku
Aamodt, K. - Abelev, B. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Čepila, J. - Krus, M. - Kushpil, Svetlana - Kushpil, Vasilij - Mareš, Jiří A. - Pachr, M. - Petráček, V. - Petráň, M. - Pospíšil, V. - Šmakal, R. - Šumbera, Michal - Tlustý, D. - Vajzer, Michal - Wagner, V. - Zach, Č. - Závada, Petr … celkem 938 autorů
Harmonic decomposition of two-particle angular correlations in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV.
Physics Letters. B. Roč. 708, 3-5 (2012), s. 249-264. ISSN 0370-2693. E-ISSN 1873-2445
Grant CEP: GA MŠMT LA08015
Institucionální podpora: RVO:61389005 ; RVO:68378271
Klíčová slova: quark-gluon plasma * ALICE
Kód oboru RIV: BG - Jaderná, atomová a mol. fyzika, urychlovače
Impakt faktor: 4.569, rok: 2012

Angular correlations between unidentified charged trigger (t) and associated (a) particles are measured by the ALICE experiment in Pb–Pb collisions at √ sNN = 2.76 TeV for transverse momenta 0.25 < p t,a T < 15 GeV/c, where p t T > p a T . The shapes of the pair correlation distributions are studied in a variety of collision centrality classes between 0 and 50% of the total hadronic cross section for particles in the pseudorapidity interval |η| < 1.0. Distributions in relative azimuth φ ≡ φ t − φ a are analyzed for | η| ≡ |η t − η a | > 0.8, and are referred to as “long-range correlations”. Fourier components Vn ≡ cos(n φ) are extracted from the long-range azimuthal correlation functions. If particle pairs are correlated to one another through their individual correlation to a common symmetry plane, then the pair anisotropy Vn (p t T , p a T ) is fully described in terms of single-particle anisotropies vn(pT ) as Vn (p t T , p a T ) = vn(p t T )vn(p a T ). This expectation is tested for 1 n 5 by applying a global fit of all Vn (p t T , p a T ) to obtain the best values vn{GF}(pT ). It is found that for 2 n 5, the fit agrees well with data up to p a T = 3–4 GeV/c, with a trend of increasing deviation as p t T and p a T are increased or as collisions become more peripheral. This suggests that no pair correlation harmonic can be described over the full 0.25 < pT < 15 GeV/c range using a single vn(pT ) curve; such a description is however approximately possible for 2 n 5 when p a T < 4 GeV/c. For the n = 1 harmonic, however, a single v1(pT ) curve is not obtained even within the reduced range p a T < 4 GeV/c.
Trvalý link: http://hdl.handle.net/11104/0217703