System Size and Energy Dependence of Jet-Induced Hadron Pair Correlation Shapes in Cu+Cu and Au+Au Collisions at sqrt(s_NN) = 200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from {dijets} in Cu+Cu and Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from \Delta\phi=\pi in central and semi-central collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.Comment: 464 authors from 60 institutions, 6 pages, 3 figures, 2 tables. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Measurement of density correlations in pseudorapidity via charged particle multiplicity fluctuations in Au+Au collisions at sNN\sqrt{s_{NN}}=200 GeV

331 authors, 32 pages text, RevTeX4, 7 figures, 27 tables. Submitted to Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htmlLongitudinal density correlations of produced matter in Au+Au collisions at sqrt(s_NN)=200 GeV have been measured from the inclusive charged particle distributions as a function of pseudorapidity window sizes. The extracted \alpha \xi parameter, related to the susceptibility of the density fluctuations in the long wavelength limit, exhibits a non-monotonic behavior as a function of the number of participant nucleons, N_part. A local maximum is seen at N_part ~ 90, with corresponding energy density based on the Bjorken picture of \epsilon_Bj \tau ~ 2.4 GeV/(fm^2 c) with a transverse area size of 60 fm^2. This behavior may suggest a critical phase boundary based on the Ginzburg-Landau framework

Enhancement of the dielectron continuum in sNN\sqrt{s_{NN}} = 200 GeV Au+Au collisions

344 authors from 52 institutions, 7 pages, 4 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htmlThe PHENIX experiment has measured the dielectron continuum in sqrt{s_NN} = 200 GeV Au+Au collisions. In minimum bias collisions the dielectron yield in the mass range between 150 and 750 MeV/c^2 is enhanced by a factor of 3.4 +/- 0.2(stat.) +/- 1.3(syst.) +/- 0.7(model) compared to the expectation from our model of hadron decays. The integrated yield increases faster with the centrality of the collisions than the number of participating nucleons, suggesting emission from scattering processes in the hot and dense medium. The continuum yield between the masses of the phi and the J/psi mesons is consistent with expectations from correlated c-cbar production, though other mechanisms are not ruled out