Extended Longitudinal Scaling: direct evidence of saturation

Multiparticle production of charged particles at high energies exhibit the phenomenon of Limiting Fragmentation. Furthermore, the region in rapidity over which the production of particles appears to be independent of energy, increases with energy. It is argued that this phenomenon, known as Extended Longitudinal Scaling, is a direct manifestation of some kind of saturation, akin to that in the Color Glass Condensate picture of particle production.Comment: 10 pages, 10 figures, Invited paper presented at The Glasma Workshop, BNL, May 201

(Di)lepton physics with ALICE

Physics perspectives with(di)lepton measurements with the ALICE detector at the LHC are reviewed. Special emphasis is placed on heavy flavor physics.Comment: 4 pages, 1 figure, 18th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions : Quark Matter 2005, Budapest, Hongrie, Ao\^{u}t 2005, submitted to Nuclear Physic

Identified Particle Jet Correlations from PHENIX

Two-particle azimuthal correlations have been shown to be a powerful probe for extracting novel features of the interaction between hard scattered partons and the medium produced in Au+Au collisions at RHIC. At intermediate $p_T$, 2-5GeV/c, jets have been shown to be significantly modified in both particle composition and angular distribution compared to p+pcollisions. We present recent PHENIX results from Au+Au collisions for a variety of $p_T$ and particle combinations.Comment: Parallel talk given at Quark Matter 2006, Shanghai Chin

PHENIX measurement of jet properties and their modification in heavy-ion collisions

The properties of jets produced in p+p, d+Au and Au+Au collisions at sqrt{s_NN}=200 GeV are studied using the method of two particle correlations. The trigger particle is assumed to be a leading particle from a high p_T jet while the associated particle is assumed to come from either the same jet or the away jet. From the angular width and yield of the same and away side correlation peaks, the parameters characterizing the jet properties are extracted.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

Neutral Pion Distributions in PHENIX at RHIC

Transverse momentum spectra for identified $\pi^0$'s in the range 1 GeV/c $< p_T <$ 4 GeV/c have been measured by the PHENIX experiment in Au-Au collisions at $\sqrt{s}=130$ GeV. The spectra from peripheral nuclear collisions are consistent with the simple expectation of scaling the spectra from p+p collisions by the average number of nucleon-nucleon binary collisions. The spectra from central collisions and the ratio of central/peripheral spectra are significantly suppressed when compared to point-like scaling.Comment: 6 pages, 3 figure

Two Particle Azimuthal Correlation Measurements in PHENIX

Two particle azimuthal correlation functions are presented for charged hadrons produced in Au-Au collisions at RHIC sqrt(s_NN)=200 GeV.The correlation functions indicate sizeable asymmetries and anisotropies. The trend of the asymmetries is compatible with the presence of emission patterns associated with mini-jets. The magnitude and the trend of the differential anisotropies v_2(p_T) and v_2(N_Part), provide important model constraints.Comment: 4 pages 3 fig

Hadron production in the forward and backward rapidities in dAu collisions at RHIC

We have developed new techniques to detect hadrons with the PHENIX muon spectrometers. This allows us to study the centrality dependent nuclear modification factor $R_{CP}$ with high $p_{T}$ hadrons in both forward (d direction) and backward (Au direction) rapidities, $1 < |\eta| < 2$, in dAu collisions at $\sqrt{s_{NN}} = 200 GeV$. Preliminary results show a suppression (enhancement) of high $p_{T}$ hadron production in central $0-20$ dAu collisions relative to the peripheral one ($60-88$ in centrality) at forward (backward) rapidity.Comment: 4 pages, 4 figures, Quark Matter 2004 tal

Results on Photon Production in Au+Au Collisions at RHIC

The status of the search for direct photons in Au+Au collisions at sqrt{s_NN} = 130 GeV and sqrt{s_NN} = 200 GeV with the PHENIX experiment is presented. Within errors, no excess of direct photons was found in a first analysis pass done on a limited data set. Significantly reduced systematic and statistical uncertainties are expected in future analyses.Comment: 4 pages, 3 figures. Talk presented at the Quark Matter 2002 conference, Nantes, France, July 18-24, 2002. To appear in the proceedings (Nucl. Phys. A

Strange Particle Abundance in QGP Formed in 200 GeV A Nuclear Collisions

We investigate here the relative abundance of strange particles produced in nuclear collisions at the SPS energies (9 GeV A in CM frame) assuming that the central reaction fireball consists of quark-gluon plasma. We show that the total strangeness yield in S-S, S-Ag and S-W reactions is compatible with this picture.Comment: 11 pages, LaTeX, 3 postscript figures, Phys. Lett. B 323 (1994) 39

Extracting Nuclear Transparency from p-A Cross sections

We study nuclear structure effects on the transparency in high transverse momentum $(p,2p)$ and $(e,e'p)$ reactions. We show that in the DWIA-eikonal approximation, even when correlations are included, one can get a factorized expression for the transparency. This depends only on the average nucleon density $\rho(r)$ and a correlation function. We develop a technique to include correlations in a Monte-Carlo Glauber type calculation. We compare calculations of $T$ using the eikonal formalism and a continuous density, with a Monte Carlo method based on discrete nucleons.Comment: 22 pages, 9 postscript figures. LaTeX with epsf styl