LEPTON AND PHOTON PHYSICS AT RHIC.

Results on physics at RHIC using outgoing leptons and photons will be presented from Au+Au collisions at nucleon-nucleon c.m. energies {radical}(sNN) = 130 GeV and 200 GeV, and from p-p collisions at {radical}(sNN) = 200 GeV. Introduction and motivation will be presented both from the theoretical and experimental perspectives. Topics include open charm production via single e{sup {+-}}, J/{Psi} {yields} e{sup +} + e{sup -}, {mu}{sup +} + {mu}{sup -} and inclusive photon production

From Bjorken Scaling to pQCD--Experimental techniques from p-p collisions of the 1970's with application to Au+Au collisions at RHIC

Hard scattering in p-p collisions was discovered at the CERN ISR in 1972, by the method of leading particles, which proved that the partons of Deeply Inelastic Scattering strongly interacted with each other. Further ISR measurements utilizing inclusive single or pairs of hadrons established that high pT particles are produced from states with two roughly back-to-back jets which are the result of scattering of constituents of the nucleons as described by Quantum Chromodynamics. These techniques, which are the only practical method to study hard-scattering and jet phenomena in Au+Au collisions at RHIC, will be reviewed.Comment: 10 pages, 6 figures, Proceedings of the 18th International Nuclear Physics Divisional Conference of the European Physical Society (NPDC18) Prague, Czech Republic, August 22-28, 2004, to appear in NP

Systematics of mid-rapidity E{sub T} and multiplicity distributions in nucleus and nucleon collisions at AGS energies

In the period 1986--1992, the E802 Collaboration at the BNL-AGS made systematic measurements of transverse energy (E{sub T}) emission in an electromagnetic calorimeter (PbGl) which covered the pseudorapidity interval 1.25 {le} {eta} {le} 2.50 and half the azimuth (where mid-rapidity for these energies is y{sub cm}{sup N N} {approx_equal} 1.6 - 1.7 depending the species). The other half of the azimuth was occupied by a 25 msr magnetic spectrometer with full particle identification. Runs were also taken with two different full-azimuth configurations of the PbGl, covering 1.25 {le} {eta} {le} 2.44, and also 1.3 {le} {eta} {le} 2.4. It was noticed that the shapes of the upper edges of the E{sub T} distributions, as represented for example by the p parameter in a gamma distribution fit, seemed to vary with the solid angle of the configuration. To systematically investigate this effect, the A-dependence and pseudorapidity-interval ({delta}{eta}) dependence of E{sub T} distributions in the half-azimuth electromagnetic calorimeter were measured for p+Be, p+Au, O+Cu, Si+Au and Au+Au collisions

Measurements of fluctuations in H.E. scattering using mid-rapidity E{sub T} and multiplicity distributions in nucleus and nucleon collisions

Measurements by the E802 Collaboration of the A-dependence and pseudorapidity-interval ({delta}{eta}) dependence of E{sub T} distributions in a half-azimuth electromagnetic calorimeter are presented for p+Be, p+Au, O+Cu, Si+Au and Au+Au collisions at the BNL-AGS. The issues addressed are whether the shapes of the upper edges of the E{sub T} distributions vary similarly to the variation in shape with {delta}{eta} of mid-rapidity charged particle multiplicity distributions and how small a {delta}{eta} interval would still give a meaningful characterization of the nuclear geometry of a reaction

Measurements of Hard-Scattering by PHENIX at RHIC

Hard-scattering in p-p collisions was discovered in 1972 at the CERN-ISR, the first hadron collider. Techniques were developed and several hard-processes were discovered which form the basis for many of the measurements made in p-p and Au+Au collisions at RHIC. Recent measurements of hard-scattering and related reactions by the PHENIX experiment at RHIC are presented in this context.Comment: 6 pages, 12 figures, Proceedings of Hadron Collider Physics Symposium 2007, La Biodola, Isola d'Elba (Italy), May 20-26, 200

Short range rapidity correlations from the Bose-Einstein effect and intermittency: A quantitative demonstration

A measurement of the two-particle correlation of identified pions was performed in the E802/E859 magnetic spectrometer on the interval 1.5 {le} y {le} 2.0, {delta}{phi} = 0.4 rad, for central {sup 28}Si + Au collisions. It is demonstrated that the two-pion correlation in rapidity is entirely due to Bose-Einstein interference. The directly measured exponential correlation length is {zeta}{sub y} = 0.20 {+-} 0.03 for two {pi}{sup {minus}}, with strength R(0,0) {approximately} 1%, in agreement with previous E802 indirect measurements derived from an analysis of intermittency using Negative Binomial Distributions

Critical current measurements of ISABELLE superconducting cables

Short sample critical measurements on ISABELLE superconducting cables are described. The purpose is to provide a basis for assessing magnet performance and to provide Quality Assurance data on materials purchases. The measurements are made on 1 m samples in a dipole magnet. Voltages on the V-I curve are determined to a precision of several tenths of a microvolt. The critical current is defined as that at which rho = 1 x 10/sup -12/..cap omega..cm/sup 1/ and is determined to a precision of 1 to 2%. Similar techniques are employed in determining the critical currents of the wires of which the cables are made. The relation between cable and wire critical currents will be discussed. It is found that well insulated, slowly ramped cables of the ISABELLE design are stable for currents up to approximately rho = 2 x 10/sup -12/..cap omega..cm. The value of current corresponding to the resistivity determines the limit of magnet performance. Additional properties of the cabled conductors such as the normal state resistance and the longitudinal quench propagation velocity are also measured

Deciphering the properties of the medium produced in heavy ion collisions at RHIC by a pQCD analysis of quenched large p⊥p_{\perp} π0\pi^0 spectra

We discuss the question of the relevance of perturbative QCD calculations for analyzing the properties of the dense medium produced in heavy ion collisions. Up to now leading order perturbative estimates have been worked out and confronted with data for quenched large $p_{\perp}$ hadron spectra. Some of them are giving paradoxical results, contradicting the perturbative framework and leading to speculations such as the formation of a strongly interacting quark-gluon plasma. Trying to bypass some drawbacks of these leading order analysis and without performing detailed numerical investigations, we collect evidence in favour of a consistent description of quenching and of the characteristics of the produced medium within the pQCD framework.Comment: 10 pages, 3 figure

Debye screening in strongly coupled N=4 supersymmetric Yang-Mills plasma

Using the AdS/CFT correspondence, we examine the behavior of correlators of Polyakov loops and other operators in N=4 supersymmetric Yang-Mills theory at non-zero temperature. The implications for Debye screening in this strongly coupled non-Abelian plasma, and comparisons with available results for thermal QCD, are discussed.Comment: 21 pages, 5 figures, significantly expanded discussion of Polyakov loop correlator and static quark-antiquark potentia

A Dual Geometry of the Hadron in Dense Matter

We identify the dual geometry of the hadron phase of dense nuclear matter and investigate the confinement/deconfinement phase transition. We suggest that the low temperature phase of the RN black hole with the full backreaction of the bulk gauge field is described by the zero mass limit of the RN black hole with hard wall. We calculated the density dependence of critical temperature and found that the phase diagram closes. We also study the density dependence of the rho meson mass.Comment: 16 pages, 4 figures, typos corrected, references adde