Measurement of the azimuthal anisotropy of neutral pions in Pb-Pb collisions at √sNN=2.76 TeV

Abstract

First measurements of the azimuthal anisotropy of neutral pions produced in Pb-Pb collisions at a center-of-mass energy of √sNN=2.76 TeV are presented. The amplitudes of the second Fourier component (v2) of the 0 azimuthal distributions are extracted using an event-plane technique. The values of v2 are studied as a function of the neutral pion transverse momentum (pT) for different classes of collision centrality in the kinematic range 1:6 < pT < 8:0 GeV=c, within the pseudorapidity interval jj < 0:8. The CMS measurements of v2ðpTÞ are similar to previously reported 0 azimuthal anisotropy results from √sNN=200 GeV Au-Au collisions at RHIC, despite a factor of 14 increase in the centerof-mass energy. In the momentum range 2:5 < pT < 5:0 GeV=c, the neutral pion anisotropies are found to be smaller than those observed by CMS for inclusive charged particles.