578 research outputs found

    ALICE probes of local parity violation with charge dependent azimuthal correlations in Pb-Pb collisions

    Full text link
    We report on the measurement of two and three particle azimuthal correlations in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV recorded with ALICE at the LHC. While two particle azimuthal correlations mainly provide an important information on possible background correlations, the three particle correlator probes the charge separation of hadrons with respect to the collision reaction plane which is expected for local parity violation in strong interactions. The two and three particle correlations are presented as a function of collision centrality and differentially vs. pseudorapidity and transverse momentum, and provide strong constraints on the possible mechanism of background (parity conserving) and signal (parity odd) effects in heavy-ion collisions.Comment: Talk given at the 7th Workshop on Particle Correlations and Femtoscopy (WPCF 2011), 20-24 September 2011, Tokyo, Japan; 6 pages, 3 figure

    Photon-jet coincidence measurements in polarized pp collisions at sqrt{s}=200 GeV with the STAR Endcap Calorimeter

    Full text link
    Recent inclusive measurements with polarized proton-proton collisions at RHIC provide significant constraints on the polarized gluon distribution, Delta g(x), integrated over the gluon momentum range 0.02 < x < 0.3. Di-jet and photon-jet coincidence measurements will allow to study the x-dependence of Delta g(x). In this report we present the status of photon-jet coincidence studies for photons detected at forward pseudorapidity, 1.08<eta<2, using the STAR Endcap Calorimeter.Comment: Talk given at the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), 26-31 May 2009, San Diego CA, USA; 4 pages, 3 figure

    Anisotropic flow and other collective phenomena measured in Pb-Pb collisions with ALICE at the LHC

    Full text link
    Recent results of the anisotropic flow measurements by the ALICE Collaboration at the LHC are reviewed. Directed, elliptic, triangular, and quadrangular flow are presented differentially vs. transverse momentum, pseudo-rapidity, and the collision centrality for charged and identified particles. Experimental probes of local parity violation using the charge dependent azimuthal correlations with respect to the reaction plane are also discussed.Comment: Talk given at the International Symposium on Multiparticle Dynamics (ISMD 2011), 26-30 September 2011, AHiroshima (Miyajima Island), Japan; 6 pages, 5 figure

    Global polarization measurement in Au+Au collisions

    Full text link
    The system created in non central relativistic nucleus-nucleus collisions carries large angular orbital momentum. Due to spin-orbital coupling, produced particles could be globally polarized along the direction of the system angular momentum. We present results of a measurement of Lambda hyperon global polarization in Au+Au collisions at the center of mass energies 62 and 200 GeV with the STAR detector at RHIC. The observed global polarization of Lambda hyperons in the STAR acceptance is consistent with zero within the precision of the measurement. The obtained upper limit, |P_Lambda| < 0.01, is significantly below the theoretical values discussed recently in the literature.Comment: Talk given at SQM 2006, International Conference on Strangeness in Quark Matter, March 26-31, 2006, Los Angeles CA; 4 pages, 2 figure

    Charged particle directed flow in Pb-Pb collisions at sqrt{s_NN} = 2.76 TeV measured with ALICE at the LHC

    Full text link
    Charged particle directed flow at midrapidity, |eta|<0.8, and forward rapidity, 1.7 < |eta|<5.1, is measured in Pb-Pb collisions at sqrt{s_NN} = 2.76 TeV with ALICE at the LHC. Directed flow is reported as a function of collision centrality, charged particle transverse momentum, and pseudo-rapidity. Results are compared to measurements at RHIC and recent model calculations for LHC energies.Comment: Talk given at the XXII International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2011), 23-28 May 2011, Annecy, France; 4 pages, 3 figure
    • …
    corecore