G. Øvrebekk

Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at root S-NN=2.76 TeV

Article history: Received 28 May 2012 Received in revised form 28 November 2012 Accepted 28 December 2012 Available online 4 January 2013 Editor: V. Metag The elliptic, v2, triangular, v3, and quadrangular, v4, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions, and (anti-)protons in Pb–Pb collisions at √ sNN = 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 |η| < 0.8 at different collision centralities and as a function of transverse momentum, pT, out to pT = 20 GeV/c. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for pT > 8 GeV/c. The small pT dependence of the difference between elliptic flow results obtained from the event plane and fourparticle cumulant methods suggests a common origin of flow fluctuations up to pT = 8 GeV/c. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least pT = 8 GeV/c indicating that the particle type dependence persists out to high pT.

Particle-Yield Modification in Jetlike Azimuthal Dihadron Correlations in Pb-Pb Collisions at root S-NN=2.76 TeV

The yield of charged particles associated with high-p(t) trigger particles (8<p(t)<15 GeV/c) is measured with the ALICE detector in Pb-Pb collisions at √s(NN)=2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jetlike correlation peaks in azimuthal dihadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta p(t)>3 GeV/c on the away side drops to about 60% of that observed in pp collisions, while on the near side a moderate enhancement of 20%-30% is found.

Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV

A bstractThe ALICE experiment at the LHC has studied J/ψ production at mid-rapidity in pp collisions at

Measurement of electrons from beauty hadron decays in pp collisions at root s=7 TeV

\sqrt{s}=7

ALICE HLT High Speed Tracking on GPU

TeV through its electron pair decay on a data sample corresponding to an integrated luminosity Lint = 5.6 nb−1. The fraction of J/ψ from the decay of long-lived beauty hadrons was determined for J/ψ candidates with transverse momentum pt> 1.3 GeV/c and rapidity |y| < 0.9. The cross section for prompt J/ψ mesons, i.e. directly produced J/ψ and prompt decays of heavier charmonium states such as the ψ(2S) and χc resonances, is σprompt J/ψ (pt> 1.3 GeV/c, |y| < 0.9) = 8.3 ± 0.8 (stat.) ± 1.1 (syst.)

Two- and three-pion quantum statistics correlations in Pb-Pb collisions at root S-NN=2.76 TeV at the CERN Large Hadron Collider

_{-1.4}^{+1.5 }

High Level Trigger Applications for the ALICE Experiment

(syst. pol.) μb. The cross section for the production of b-hadrons decaying to J/ψ with pt> 1.3 GeV/c and |y| < 0.9 is

ALICE HLT high speed tracking and vertexing

{\sigma_{{{J \left/ {{\psi \leftarrow {{\mathrm{h}}_{\mathrm{B}}}}} \right.}}}}

Event Reconstruction Performance of the ALICE High Level Trigger for

(pt > 1.3 GeV/c, |y| < 0.9) = 1.46 ± 0.38 (stat.)

{\rm p} + {\rm p}

_{-0.32}^{+0.26 }