Event anisotropy of identified π0\pi^{0}, photon and electron compared to charged π\pi, KK, pp and deuteron in sNN\sqrt{s_{NN}} = 200 GeV Au+Au at PHENIX

We report the recent results of event anisotropy analysis focused on $v_2$ in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at PHENIX.Comment: 4 pages, 3 figures, contribution to the proceedings of the 17th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter, Oakland, January 11-17, 2004). To appear in the proceedings (Journal of Physics G

Measurement of Open Heavy Flavor Production with Single Muons in p+p and d+Au Collisions at RHIC

Heavy flavor production in hadronic collisions is dominated by gluonic processes and so is a sensitive probe of the gluon structure function in the nucleon and its modification in nuclei. A study of heavy flavor production in p+p and d+Au collisions in various kinematic regions presents an opportunity to probe cold nuclear medium effects; parton shadowing, color glass condensate, initial state energy loss, and coherent multiple scattering in final state interactions. The PHENIX muon arms cover both forward and backward directions in the rapidity range of $1.2 < |\eta| < 2.4$. We investigate single muon production from open heavy flavor and light mesons decay in p+p and d+Au collisions at forward and backward rapidity.Comment: Strangeness in Quark Matter, 2006, UCL

Excitation functions of baryon anomaly and freeze-out properties at RHIC-PHENIX

The intermediate $p_T$ region (2 - 5 GeV/$c$) in central Au+Au collisions at RHIC has a rich physics content. The (anti)proton to pion ratio at the intermediate $p_T$ gives us a powerful tool to investigate the bulk properties of the hot and dense matter created at RHIC and their hadronization processes. We present the preliminary results of identified charged hadron spectra at the lower beam energies at RHIC. The excitation function of (anti)proton to pion ratios from SPS to RHIC are shown. We also discuss the onset of the baryon enhancement at the high energy heavy ion collisions.Comment: 4 pages, 3 figures, Quark Matter 2006 conference proceeding

Strangeness and heavy flavor at RHIC: Recent results from PHENIX

We report recent results of strangeness and heavy flavor measurements from PHENIX. The topics are: Elliptic flow of strangeness and heavy flavor electron production comparing to the other hadrons, $\phi$ meson production, and an exotic particle search.Comment: 8 pages, 6 figures, 1 table. Submitted to J. Phys. G (Proceedings of the 8th International Conference on Strangeness in Quark Matter, Cape Town, South Africa, September 15-20, 2004

Heavy-Flavor Measurements by the PHENIX Experiment at RHIC

In recent years, PHENIX has studied many important observables related to heavy-flavor physics through their leptonic decay measurements including the invariant yield of electrons from nonphotonic sources, and prompt single muons, both of which are dominated by D and B mesons. Charm and beauty cross-sections were measured and compared through single lepton, and lepton-hadron correlations in p+p collisions at $\sqrt{s}$ = 200 GeV. Observables for quarkonia production such as invariant yield and polarization were also measured in p+p collisions. In Au+Au collisions, preliminary results for the $R_{AA}$ for single electrons and a 90% CL upper limit for the suppression of $\Upsilon$s were produced. And in $d$+Au collisions, a preliminary $R_{CP}$ study for $J/\psi$ production in different centrality ranges was extracted.Comment: 8 pages, 9 figures, International Conference on Strangeness in Quark Matter Conference 2009 Proceeding

High p_T identified particles in PHENIX: data vs. theory

Two of the most interesting experimental results of heavy-ion reactions at RHIC collider energies are in the hard scattering sector where central Au+Au data show a very different behaviour compared to p+p and peripheral Au+Au collisions. The so-called ``high p_T pi^0 suppression'' and the ``anomalous'' baryon/meson ratio observed by PHENIX in central Au+Au collisions at sqrt(s_{NN}) = 200 GeV are reviewed and compared to various theoretical calculations based on different strongly interacting medium scenarios.Comment: To appear in the proceedings of 19th Winter Workshop on Nuclear Dynamics, Breckenridge, Colorado, US, March 8-15, 200

Charge Correlation in Near Side Hadron-Hadron Jets at sqrt(sNN)=200GeV in PHENIX

We analyze the relative azimuthal ($\Delta\phi$) distribution of same-charge and opposite-charge particle pairs. We then remove elliptic flow background using the ZYAM method. Comparisons between near angle $\Delta\phi$ peak widths are presented for various centralities.Comment: Poster Proceedings from 2005 Quark Matter Conference. 4 Pages, 4 Figure

Some thoughts on di-jet correlation in Au + Au collisions from PHENIX

PHENIX has measured the two particle azimuth correlation in Au + Au at $\sqrt{s}$ = 200 GeV. Jet shape and yield at the away side are found to be strongly modified at intermediate and low $p_T$, and the modifications vary dramatically with $p_T$ and centrality. At high $p_T$, away side jet peak reappears but the yield is suppressed. We discuss the possible physics pictures leading to these complicated modifications.Comment: 3 pages, 2 figures. Contributed talk at PANIC '05 conference, Santa Fe, NM, Oct24-28, 200

Direct Photon Measurement at RHIC-PHENIX

Results on direct photon measurements from the PHENIX experiment at RHIC are presented. The direct photon yields for $p_T>$6 GeV/$c$ as a function of centrality in Au-Au collisions at $\sqrt{s_{NN}}$=200 GeV are found to be consistent with NLO pQCD calculation scaled by the number of binary collisions. The results suggest that the photons observed are emitted from the initial stage of hard scattering. Comparisons with several theoretical calculations are also presented.Comment: 8 pages, 13 figures. Proceedings for 21st Winter Workshop on Nuclear Dynamics held in Breckenridge, Colorado, U.S.A., in Feburary, 200