Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV

Abstract

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta |<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\mathrm{T}}$, out to $p_{\mathrm{T}}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\mathrm{T}}>8$ GeV/$c$. The small $p_{\mathrm{T}}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\mathrm{T}}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\mathrm{T}}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\mathrm{T}}$.

Comments: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/1860