J. Freeman
A5071099739- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Distributed and Parallel Computing Systems
- Radiation Therapy and Dosimetry
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- International Science and Diplomacy
- CCD and CMOS Imaging Sensors
- Planetary Science and Exploration
- Parallel Computing and Optimization Techniques
Fermi National Accelerator Laboratory
2016-2025
University of Antwerp
2024
Institute of High Energy Physics
2015-2024
A. Alikhanyan National Laboratory
2022-2024
University at Buffalo, State University of New York
2022
Northwestern University
2021
University of Stuttgart
2020
University of Auckland
2020
Lanzhou University
2020
University of Florida
1998-2014
We present measurements of the pseudorapidity (η) distribution charged particles (dNchdη) produced within |η|≤3.5 in proton-antiproton collisions at √s 630 and 1800 GeV. measure dNchdη η=0 to be 3.18±0.06(stat)±0.10(syst) GeV, 3.95±0.03 (stat)±0.13(syst) Many systematic errors ratio two energies cancel, we 1.26±0.01±0.04 for GeV that |η|≤3. Comparing lower-energy data, observe an increase faster than ln(s) η=0.Received 2 October 1989DOI:https://doi.org/10.1103/PhysRevD.41.2330©1990 American...
We report a measurement of the proton-antiproton total cross section ${\mathrm{\ensuremath{\sigma}}}_{\mathit{T}}$ at c.m.s. energies \ensuremath{\surd}s =546 and 1800 GeV. Using luminosity-independent method, we find ${\mathrm{\ensuremath{\sigma}}}_{\mathit{T}}$=61.26\ifmmode\pm\else\textpm\fi{}0.93 mb GeV 80.03\ifmmode\pm\else\textpm\fi{}2.24 =1800 In this energy range, ratio ${\mathrm{\ensuremath{\sigma}}}_{\mathrm{el}}$/${\mathrm{\ensuremath{\sigma}}}_{\mathit{T}}$ increases from...
Measurements of inclusive transverse-momentum spectra for charged particles produced in proton-antiproton collisions at √2 630 and 1800 GeV are presented compared with data taken lower energies.Received 8 June 1988DOI:https://doi.org/10.1103/PhysRevLett.61.1819©1988 American Physical Society
Kinematic properties of four-jet events produced in $p\overline{p}$ collisions at $\sqrt{s}=1.8$ TeV have been studied using data with an integrated luminosity 325 ${\mathrm{nb}}^{\ensuremath{-}1}$ collected the Collider Detector Fermilab during 1988-1989 run. The individual jet ${p}_{T}$ spectra and angles between each pair are compared to predictions leading-order quantum chromodynamics for double gluon bremsstrahlung process good agreement is observed. In addition, a search parton...
A trigger track processor, called the eXtremely Fast Tracker (XFT), has been designed for Collider Detector at Fermilab (CDF) upgrade. This processor identifies high-transverse-momentum (> 1.5 GeV/c) charged particles in new central outer tracking chamber CDF II. The XFT design is highly parallel to handle input rate of 183 Gb/s and output 44 Gb/s. pipelined reports result a event every 132 ns. uses three stages: hit classification, segment finding, linking. pattern recognition algorithms...
Antiproton-proton elastic scattering was measured at c.m.s. energies √s =546 and 1800 GeV in the range of four-momentum transfer squared 0.025<-t<0.29 GeV2. The data are well described by exponential form ebt with a slope b=15.28±0.58 (16.98±0.25) GeV−2 (1800) GeV. cross sections are, respectively, σel=12.87±0.30 19.70±0.85 mb.Received 5 August 1993DOI:https://doi.org/10.1103/PhysRevD.50.5518©1994 American Physical Society
We have determined mW=79.91±0.39 GeV/c2 from an analysis of W→eν and W→μν data the Collider Detector at Fermilab in p¯p collisions a c.m. energy √s =1.8 TeV. This result, together with world-average Z mass, determines weak mixing angle to be sin2θW=0.232±0.008. Bounds on top-quark mass are discussed.Received 13 August 1990DOI:https://doi.org/10.1103/PhysRevLett.65.2243©1990 American Physical Society
An analysis of pp\ifmmode\bar\else\textasciimacron\fi{} collision events at \ensuremath{\surd}s =1.8 TeV with jets and large missing transverse energy finds no event >40 GeV. This result yields a 90%-C.L. limit on the cross section for one-jet-event production <0.1 nb jet in pseudorapidity range \ensuremath{\Vert}\ensuremath{\eta}\ensuremath{\Vert}<1.0 ${E}_{T}$>52 Limits masses squarks gluinos minimal supersymmetry model are also set. At 90% C.L., ${m}_{q\ifmmode \tilde{}\else...
We report a measurement of the diffraction dissociation differential cross section ${\mathit{d}}^{2}$${\mathrm{\ensuremath{\sigma}}}_{\mathrm{SD}}$/${\mathit{dM}}^{2}$dt for p\ifmmode\bar\else\textasciimacron\fi{}p\ensuremath{\rightarrow}p\ifmmode\bar\else\textasciimacron\fi{}X at \ensuremath{\surd}s =546 and 1800 GeV, ${\mathit{M}}^{2}$/s0.2 0\ensuremath{\le}-t\ensuremath{\le}0.4 ${\mathrm{GeV}}^{2}$. Our results are compared to theoretical predictions extrapolations from experimental lower...
An analysis of ${Z}^{0}$\ensuremath{\rightarrow}${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ and ${Z}^{0}$\ensuremath{\rightarrow}${\ensuremath{\mu}}^{+}$${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$ data from the Collider Detector at Fermilab in p\ifmmode\bar\else\textasciimacron\fi{}p collisions \ensuremath{\surd}s =1.8 TeV yields a mass ${Z}^{0}$ boson ${M}_{Z}$=90.9\ifmmode\pm\else\textpm\fi{}0.3 (stat+syst)\ifmmode\pm\else\textpm\fi{}0.2 (scale) GeV/${c}^{2}$ width...
We report on the test beam results and calibration methods using high energy electrons, pions muons with CMS forward calorimeter (HF). The HF covers a large pseudorapidity region ( $3\leq|\eta|\leq5$ ), is essential for number of physics channels missing transverse energy. It also expected to play prominent role in measurement tagging jets weak boson fusion Higgs production. based steel absorber embedded fused-silica-core optical fibers where Cherenkov radiation forms basis signal...
We present a measurement of the inclusive jet cross section in p¯p collisions at √s =1.8 TeV Fermilab Tevatron using Collider Detector Fermilab. Good agreement is seen with predictions recent next-to-leading-order [O(α3s)] QCD predictions. The dependence on clustering cone size reported for first time. An improved limit Λc, term characterizing possible quark substructure, set 1.4 (95% C.L.).Received 7 August 1991DOI:https://doi.org/10.1103/PhysRevLett.68.1104©1992 American Physical Society
Inclusive jet production at √s=1.8 TeV has been measured in the CDF detector Fermilab Tevatron ¯pp Collider. Jets with transverse energies (Et) up to 250 GeV have observed. The Et dependence of inclusive cross section is consistent leading-order quantum-chromodynamic calculations, and comparison lower-energy data shows deviations from scaling QCD. A lower limit 700 (95% confidence level) placed on quark compositeness scale parameter Λc associated an effective contact interaction.Received 3...
We present results of searches for the top quark in $p\overline{p}$ collisions at $\sqrt{s}=1.8$ TeV. The data sample was collected during 1988-1989 Fermilab Tevatron Collider and has an integrated luminosity 4.1 ${\mathrm{pb}}^{\ensuremath{-}1}$. have extended our previous search $e\ensuremath{\mu}$ final states to include $\mathrm{ee}$ $\ensuremath{\mu}\ensuremath{\mu}$ channels. In addition, we searched a low-transverse-momentum muon as tag bottom decay events with lepton least two jets....
In $p\overline{p}$ collisions at $\sqrt{s}=1.8$ TeV we find jet events with a rapidity gap topology. The number of hadrons in the interval $\ensuremath{\Delta}{\ensuremath{\eta}}_{D}$ between leading-jet cones was sampled by charged tracks ${P}_{T}>400$ MeV/c. We excess trackless beyond that expected smooth multiplicity distribution. control region outside see no excess. For $\ensuremath{\Delta}{\ensuremath{\eta}}_{D}>0.8$, fraction events, consistent estimates based on exchange...
Extensive measurements have been made with pions, electrons and muons on four production wedges of the compact muon solenoid (CMS) hadron barrel (HB) calorimeter in H2 beam line at CERN particle momenta varying from 20 to 300 GeV/c. The time structure events was measured full chain preproduction front-end electronics running 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers HB. energy dependent slewing effect tuned optimal performance.
Color coherence effects in pp¯ collisions are observed and studied with CDF, the Collider Detector at Fermilab Tevatron collider. We demonstrate these by measuring spatial correlations between soft leading jets multijet events. Variables sensitive to interference identified comparing data predictions of various shower Monte Carlo programs that substantially different respect implementation coherence.Received 24 March 1994DOI:https://doi.org/10.1103/PhysRevD.50.5562©1994 American Physical Society