We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76  TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

The p t -differential inclusive production cross sections of the prompt charmed mesons D 0 , D + , and D * + in the rapidity range |y| < 0.5 were measured in proton-proton collisions at √ s = 7 TeV at the LHC using the ALICE detector. Reconstructing the decaysand their charge conjugates, about 8,400 D 0 , 2,900 D + , and 2,600 D * + mesons with 1 < p t < 24 GeV/c were counted, after selection cuts, in a data sample of 3.14×10 8 events collected with a minimum-bias trigger (integrated luminosity L int = 5 nb −1 ). The results are described within uncertainties by predictions based on perturbative QCD.

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The production of the prompt charm mesons D 0 , D + , D * + , and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at the LHC, at a centre-of-mass energy √ s NN = 2.76 TeV per nucleon-nucleon collision. The p t -differential production yields in the range 2 < p t < 16 GeV/c at central rapidity, |y| < 0.5, were used to calculate the nuclear modification factor R AA with respect to a proton-proton reference obtained from the cross section measured at √ s = 7 TeV and scaled to √ s = 2.76 TeV. For the three meson species, R AA shows a suppression by a factor 3-4, for transverse momenta larger than 5 GeV/c in the 20% most central collisions. The suppression is reduced for peripheral collisions. The ALICE Collaboration 29 Keywords: Heavy Ions IntroductionA high-density colour-deconfined state of strongly-interacting matter is expected to be formed in high-energy collisions of heavy nuclei. According to calculations of Quantum Chromodynamics (QCD) on the lattice, under the conditions of high energy density and temperature reached in these collisions, a phase transition to a Quark-Gluon Plasma (QGP) occurs. In such conditions, the confinement of quarks and gluons into hadrons vanishes, and chiral symmetry is restored (see e.g. [1][2][3][4]). Heavy-flavour hadrons, containing charm and beauty, are effective probes of the conditions of the medium formed in nucleus-nucleus collisions at high energy. Hard partons, including gluons, light-flavour quarks, and heavy quarks, are produced at the initial stage of the collision in high-virtuality scattering processes. They interact with the medium, and are expected to be sensitive to its energy density, through the mechanism of parton energy loss. This QCD energy loss is expected to occur via both inelastic (medium-induced gluon radiation, or radiative energy loss) [5,6] and elastic (collisional energy loss) [7][8][9] processes. In QCD, quarks have a smaller colour coupling factor with respect to gluons, so that the energy loss for quarks is expected to be smaller than for gluons. In addition, the 'dead-cone effect' should reduce small-angle gluon radiation for heavy quarks with moderate energy-over-mass values [10][11][12][13][14], thus further attenuating the effect of the medium. Instead, other mechanisms, such as in-medium hadron -1 -

Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.