J. Crittenden
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Gyrotron and Vacuum Electronics Research
- Electron and X-Ray Spectroscopy Techniques
- Photocathodes and Microchannel Plates
- Dark Matter and Cosmic Phenomena
- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Advanced X-ray Imaging Techniques
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Crystallography and Radiation Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Therapy and Dosimetry
- Astrophysics and Cosmic Phenomena
- Atomic and Molecular Physics
- Muon and positron interactions and applications
- Spacecraft and Cryogenic Technologies
- Reliability and Maintenance Optimization
Cornell University
2012-2021
Brookhaven National Laboratory
2018
University of Amsterdam
1995-2003
Netherlands Institute for Social Research
1996-2003
University of Bonn
1993-2002
Zeus Consulting (Greece)
2002
Argonne National Laboratory
1993-2002
Deutsches Elektronen-Synchrotron DESY
1994-2002
Universität Hamburg
2002
Forschungszentrum Jülich
1994
Experimental results on the production of dimuons by 800-GeV protons incident a copper target are presented. The include measurements both continuum and dimuon decays three lowest-mass ϒ S states. A description apparatus, data acquisition, analysis techniques is included. comparison with taken at lower energies indicates scaling behavior yields.Received 29 October 1990DOI:https://doi.org/10.1103/PhysRevD.43.2815©1991 American Physical Society
Next-to-leading-order QCD analyses of the ZEUS data on deep inelastic scattering together with fixed-target have been performed, from which gluon and quark densities proton value strong coupling constant αs(MZ) were extracted. The study includes a full treatment experimental systematic uncertainties including point-to-point correlations. resulting in parton density functions are presented. A combined fit for yields agreement world average. derived alone indicate importance HERA determining...
A small electromagnetic sampling calorimeter, installed in the ZEUS experiment 1995, significantly enhanced acceptance for very low x and Q^2 inelastic neutral current scattering, e^{+}p \to e^{+}X, at HERA. measurement of proton structure function F_2 total virtual photon-proton (\gamma^*p) cross-section is presented 0.11 \le Q^{2} 0.65 GeV^2 2 \times 10^{-6} 6 10^{-5}, corresponding to a range \gamma^{*}p c.m. energy 100 W 230 GeV. Comparisons with various models are also presented.
The photoproduction reaction gamma p -> mu+ mu- has been studied in ep interactions using the ZEUS detector at HERA. data sample corresponds to an integrated luminosity of 43.2 pb^{-1}. Upsilon meson observed for first time. sum products elastic Upsilon(1S), Upsilon(2S), Upsilon(3S) cross sections with their respective branching ratios is determined be 13.3 +- 6.0(stat.)^{+2.7}_{-2.3}(syst.) pb a mean photon-proton centre mass energy 120 GeV. section above prediction perturbative QCD model.
This paper presents measurements of D∗± production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 protons. The data have been taken with the ZEUS detector at HERA. decay channel D∗+ → (D0 K−π+)π+ (+c.c) has used study. e+p cross section for inclusive 5 < Q2 100 GeV2> y 0.7 is 5.3 ± 1.0 0.8 nb kinematic region 1.3 pT(D∗±) 9.0 |η(D∗±)| 1.5. Differential sections as functions pT(D∗±), η(D∗±), W are compared next-to-leading order QCD calculations based on...
Energy recovery has been achieved in a multipass linear accelerator, demonstrating technology for more compact particle accelerators operating at higher currents and reduced energy consumption. delivered to the beam during first four passes through accelerating structure was recovered subsequent decelerating passes. High-energy efficiency by use of superconducting cavities permanent magnets. The fixed-field alternating-gradient optical system used return loop successfully transported...
Inclusive jet differential cross sections have been measured in neutral current deep inelastic e+p scattering for boson virtualities Q2>125 GeV2. The data were taken using the ZEUS detector at HERA and correspond to an integrated luminosity of 38.6 pb−1. Jets identified Breit frame longitudinally invariant kT cluster algorithm. Measurements inclusive are presented as functions transverse energy (EBT,jet), pseudorapidity Q2, jets with EBT,jet>8 GeV. Next-to-leading-order QCD calculations...
This paper reports the cross section measurements for process ep → e J/ψ p Q2 < 4 GeV2 at s = 296 GeV, based on an integrated luminosity of about 0.5 pb−1, using ZEUS detector. The was detected in its e+e− and μ+μ− decay modes. photoproduction measured to be 52−12+7 ± 10 nb average γp centre mass energy 67 GeV 71−20+13±12 114 GeV. significant rise compared lower is not agreement with VDM models, but can described by QCD inspired models if a gluon momentum density low x proton assumed.
We present a high-statistics, species-identified measurement of the W-to-Be per-nucleon cross-section ratio, ${\mathit{R}}_{\mathrm{W}/\mathrm{B}\mathrm{e}}$, for high-${\mathit{x}}_{\mathit{t}}$ hadrons and high-\ensuremath{\tau} ${\mathit{h}}^{+}$${\mathit{h}}^{\mathrm{\ensuremath{-}}}$ pairs produced in p-A collisions at \ensuremath{\surd}s =38.8 GeV. The data extend to 0.62 ${\mathit{x}}_{\mathit{t}}$ 0.39 \ensuremath{\surd}\ensuremath{\tau} . For single hadrons,...
The gluon momentum density xg(x, Q2) of the proton was extracted at Q2 = 20 GeV2 for small values x between 4 × 10−4 and 10−2 from scaling violations structure function F2 measured recently by ZEUS in deep inelastic neutral current ep scattering HERA. extraction performed two ways. Firstly, using a global NLO fit to data on low constrained measurementsfrom NMC larger x; secondly published approximate methods solution GLAP QCD evolution equations. Consistent results are obtained. A...