/ hep-ex CERN-PH-EP-2014-065

Measurement of the centrality and pseudorapidity dependence of the integrated elliptic flow in lead-lead collisions at $\sqrt{s_{NN}}$=2.76 TeV with the ATLAS detector

Pages: 21

Abstract: The integrated elliptic flow of charged particles produced in Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV has been measured with the ATLAS detector using data collected at the Large Hadron Collider. The anisotropy parameter, $v_2$, was measured in the pseudorapidity range $|\eta|\leq$ 2.5 with the event-plane method. In order to include tracks with very low transverse momentum $p_T$, thus reducing the uncertainty in $v_2$ integrated over $p_T$, a $1 \mu b^{-1}$ data sample recorded without a magnetic field in the tracking detectors is used. The centrality dependence of the integrated $v_2$ is compared to other measurements obtained with higher $p_T$ thresholds. A weak pseudorapidity dependence of the integrated elliptic flow is observed for central collisions, and a small decrease when moving away from mid-rapidity is observed only in peripheral collisions. The integrated $v_2$ transformed to the rest frame of one of the colliding nuclei is compared to the lower-energy RHIC data.

Note: 21 pages (30 including author list), 24 figures, submitted to EPJC, all figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2012-06

Total numbers of views: 919
Numbers of unique views: 457