P. Chung

Quadrupole anisotropy in dihadron azimuthal correlations in central d+Au collisions at √sNN=200 GeV

The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC) reports measurements of azimuthal dihadron correlations near midrapidity in d+Au collisions at √(s(NN))=200 GeV. These measurements complement recent analyses by experiments at the Large Hadron Collider (LHC) involving central p+Pb collisions at √(s(NN))=5.02 TeV, which have indicated strong anisotropic long-range correlations in angular distributions of hadron pairs. The origin of these anisotropies is currently unknown. Various competing explanations include parton saturation and hydrodynamic flow. We observe qualitatively similar, but larger, anisotropies in d+Au collisions at RHIC compared to those seen in p+Pb collisions at the LHC. The larger extracted v2 values in d+Au are consistent with expectations from hydrodynamic calculations owing to the larger expected initial-state eccentricity compared with that from p+Pb collisions. When both are divided by an estimate of the initial-state eccentricity the scaled anisotropies follow a common trend with multiplicity that may extend to heavy ion data at RHIC and the LHC, where the anisotropies are widely thought to arise from hydrodynamic flow.

Measurement of High-p(T) single electrons from heavy-flavor decays in p+p collisions at root s=200 GeV

The momentum distribution of electrons from decays of heavy flavor (charm and bottom) for midrapidity absolute value of y < 0.35 in p + p collisions at square root of s = 200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.3 < pT < 9 GeV/c. Two independent methods have been used to determine the heavy-flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.71+/-0.02stat+/-0.18sys for 0.3 < pT < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma cc = 567+/-57stat+/-193sys microb.

Has the QCD critical point been signaled by observations at the BNL relativistic heavy ion collider

The shear viscosity to entropy ratio (

J/psi suppression at forward rapidity in Au plus Au collisions at root s(NN)=200 GeV

\eta/s

Elliptic flow: Transition from out-of-plane to in-plane emission in Au + Au collisions

) is estimated for the hot and dense QCD matter created in Au+Au collisions at RHIC (

Disappearance of elliptic flow: A new probe for the nuclear equation of state

\sqrt{s_{NN}}=200

Charged pion production in 2A to 8A GeV central Au plus Au collisions

GeV). A very low value is found

Neutral pion production with respect to centrality and reaction plane in Au plus Au collisions at root S-NN=200 GeV

\eta/s \sim 0.1

Decomposition of harmonic and jet contributions to particle-pair correlations at ultrarelativistic energies

, which is close to the conjectured lower bound (

Longitudinal flow of protons from (2-8)A GeV central Au+Au collisions.

1/4\pi