125730338
Proposal for an Extension of E151/227 to Study Neutrino Interactions in Deuterium in the 15-Foot Bubble Chamber with Plates
122598679
Measurement of the polarization parameter in K$sup +$p elastic scattering
Full angular distributions of the polarization parameter in elastic ${K}^{+}p$ scattering at 1.37, 1.45, 1.60, 1.71, 1.80, 1.89, 2.11, and 2.31 GeV/c are presented. These data were obtained in an experiment at the Zero Gradient Synchrotron using a polarized proton target with arrays of scintillation and \ifmmode \check{C}\else \v{C}\fi{}erenkov counters to detect the scattered particles.
122557716
Measurement of the polarization parameter in K+p elastic scattering at 1.60, 1.80, 2.11 and 2.31 GeV/c
Abstract The polarization parameter for K+p elastic scattering has been measured at 1.60, 1.80, 2.11 and 3.31 GeV/c incident momenta over the entire angular range with an emphasis on the backward region. The results in the extreme backward region appear to be small and consistent with zero.
119364085
DOUBLE-HYPERFRAGMENT EVENT PRODUCED BY K$sup -$ INTERACTION AT 2.3 Bev/c IN NUCLEAR EMULSION
An event is shown that consists of two hyperfragments and a meson (K/sup +) coming from a single interaction star found in a nuclear emulsion stack exposed to a meson (K/sup -/) beam at 2.3 and 2.5 Bev/c. Unique identification of the hyperfragments is impossible, but the binding energy favors LAMBDA H/sup 4/ or LAMBDA He/sup 4/. The nature of the production mechanism cannot be determined on the basis of the iniormation available in this single event. (C.E.S.)
120716454
Evidence of muonium formation using thin gold foils in vacuum
121317828
MEASUREMENT OF POLARIZATION IN K$sup +$p ELASTIC SCATTERING AT 1.37, 1.45, 1.71, AND 1.89 GeV/c AND PHASE-SHIFT ANALYSIS.
16943370
The Origin of the Difference between Multiplicities in e+e- Annihilation and Heavy Ion Collisions
Multiplicities in e+e- annihilation and relativistic heavy ion collisions show remarkable similarities at high energies. A thermal-statistical model is proposed to explain the differences which occur mainly at low beam energies. Two different calculations are performed, one using an approximate thermodynamic relationship, the other using a full thermal model code. The results are in qualitative agreement, suggesting that the interplay of baryon density and temperature tends to systematically suppress the total multiplicity at lower beam energies.
103715436
Entropy Production at High Energy and mu(B)
The systematics of bulk entropy production in experimental data on Ai-A, p + y and e{sup +}e{sup -} interactions at high energies and large {mu}{sub B} is discussed. It is proposed that scenarios with very early thermalization, such as Landau's hydrodynamical model, capture several essential features of the experimental results. It is also pointed out that the dynamics of systems which reach the hydrodynamic regime give similar multiplicities and angular distributions as those calculated in weak-coupling approximations (e.g. pQCD) over a wide range of beam energies. Finally, it is shown that the dynamics of baryon stopping are relevant to the physics of total entropy production, explaining why A+A and e{sup +}e{sup -} multiplicities are different at low beam energies.
1646349
Heavy ion physics at the LHC with the ATLAS detector
The ATLAS detector at CERN will provide a high-resolution longitudinally segmented calorimeter and precision tracking for the upcoming study of heavy ion collisions at the LHC ( GeV). The calorimeter covers |η| < 5 with both electromagnetic and hadronic sections, while the inner detector spectrometer covers |η| < 2.5. ATLAS will study a full range of observables necessary to characterize the hot and dense matter formed at the LHC. Global measurements (particle multiplicities, collective flow) will provide access into its thermodynamic and hydrodynamic properties. Measuring complete jets out to 100's of GeV will allow detailed studies of energy loss and its effect on jets. Quarkonia will provide a handle on deconfinement mechanisms. ATLAS will also study the structure of the nucleon and nucleus using forward physics probes and ultraperipheral collisions, both enabled by segmented zero degree calorimeters.
122715066
Heavy-ion physics with the ATLAS detector at the LHC
The ATLAS experiment will participate in the Heavy Ion program at the Large Hadron Collider (LHC) and will use its large acceptance, high granularity calorimeters, silicon tracking detectors, and muon spectrometers to study hard scattering processes and jet quenching, quarkonia production and suppression, and global observables in Pb+Pb collisions. The longitudinal and fine transverse segmentation of the ATLAS electromagnetic calorimeter gives ATLAS unique capabilities for measuring complete jets and photons. Brookhaven National Laboratory, Columbia University, Iowa State University, and Stony Brook University propose a focused program to take advantage of ATLAS’s strengths to study the physics of high-energy parton interactions with the quark-gluon plasma (QGP), the physics of Debye screening of Q-Q̄ states in the QGP, and the physics of initial particle production and thermalization to characterize the properties of the QGP created in heavy ion collisions at the LHC. The proposed program can be accomplished for modest cost, will provide substantial physics impact and will have a positive impact on the physics program at the Relativistic Heavy Ion Collider (RHIC) due to the strong involvement of the proposing institutions in the RHIC program. Participation of US groups will strengthen the existing (and growing) ATLAS heavy ion program by bringing physics and analysis expertise developed at RHIC and will allow the US Nuclear Physics program to participate in an experiment that will have subtantial physics impact on the heavy ion community.
209965440
Measurement of high p_T isolated prompt photons in lead-lead collisions at sqrt(s_NN)=2.76 TeV with the ATLAS detector at the LHC
Prompt photons are a powerful tool to study heavy ion collisions. Their production rates provide access to the initial state parton distribution functions and also provide a means to calibrate the expected energy of jets that are produced in the medium. The ATLAS detector measures photons with its hermetic, longitudinally segmented calorimeter, which gives excellent spatial and energy resolutions, and detailed information about the shower shape of each measured photon. This provides significant rejection against the expected background from the decays of neutral pions in jets. Rejection against jet fragmentation products is further enhanced by requiring candidate photons to be isolated. First results on the spectra of isolated prompt photons from a dataset with an integrated luminosity of approximately 0.13 nb^-1 of lead-lead collisions at sqrt(s_NN)=2.76 TeV are shown as a function of transverse momentum and centrality. The measured spectra are compared to expectations from perturbative QCD calculations.