A5110397868- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Particle Accelerators and Free-Electron Lasers
- Parallel Computing and Optimization Techniques
- Superconducting Materials and Applications
- Computational Physics and Python Applications
- Nuclear physics research studies
- Nuclear Physics and Applications
- Scientific Computing and Data Management
- Scientific Research and Discoveries
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- Quantum, superfluid, helium dynamics
- Radiation Therapy and Dosimetry
- Muon and positron interactions and applications
- Astronomy and Astrophysical Research
Fermi National Accelerator Laboratory
2016-2025
European Organization for Nuclear Research
2021
Princeton University
2015
Fermi Research Alliance
2007-2012
United States Department of Energy
2007
McGill University
1993-2003
Institute of Particle Physics
1994-1999
University of Toronto
1993-1999
Children's Defense Fund
1998-1999
Duke University
1998-1999
We establish the existence of top quark using a 67 pb^-1 data sample Pbar-P collisions at Sqrt(s) = 1.8 TeV collected with Collider Detector Fermilab (CDF). Employing techniques similar to those we previously published, observe signal consistent t-tbar decay WW b-bbar, but inconsistent background prediction by 4.8 sigma. Additional evidence for is provided peak in reconstructed mass distribution. measure be 176 +/-8(stat) +/- 10(sys.) GeV/c^2, and production cross section 6.8 +3.6 -2.4 pb.
We present the results of a search for top quark in 19.3 pb−1 p¯p collisions at √s =1.8 TeV. The data were collected Fermilab Tevatron collider using Collider Detector (CDF). includes standard model tt¯ decays to final states eeνν¯, eμνν¯, and μμνν¯ as well e+ν+jets or μ+ν+jets. In (e,μ)+ν+jets channel we b quarks from t via secondary vertex identification semileptonic cascade c quarks. dilepton find two events with background 0.56+0.25−0.13 events. e,μ+ν+jets identified vertex, six 2.3±0.3....
We present the results of a search for dark matter WIMPs in mass range below 20 GeV/c^2 using target low-radioactivity argon. The data were obtained DarkSide-50 apparatus at Laboratori Nazionali del Gran Sasso (LNGS). analysis is based on ionization signal, which time projection chamber fully efficient 0.1 keVee. observed rate detector 0.5 keVee about 1.5 events/keVee/kg/day and almost entirely accounted by known background sources. obtain 90% C.L. exclusion limit above 1.8 spin-independent...
We summarize a search for the top quark with Collider Detector at Fermilab (CDF) in sample of p¯p collisions √s =1.8 TeV an integrated luminosity 19.3 pb−1. find 12 events consistent either two W bosons, or boson and least one b jet. The probability that measured yield is background 0.26%. Though statistics are too limited to establish firmly existence quark, natural interpretation excess it due tt¯ production. Under this assumption, constrained fits individual mass 174±10+13−12 GeV/c2....
This paper describes the design and construction of MicroBooNE liquid argon time projection chamber associated systems. is first phase Short Baseline Neutrino program, located at Fermilab, will utilize capabilities detectors to examine a rich assortment physics topics. In this document details specifications, assembly procedures, acceptance tests are reported.
We report the first results of DarkSide-50, a direct search for dark matter operating in underground Laboratori Nazionali del Gran Sasso (LNGS) and searching rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The detector is Liquid Argon Time Projection Chamber with (46.4+-0.7) kg active mass, operated inside 30 t organic liquid scintillator neutron veto, which turn installed at center 1 kt water Cherenkov veto residual flux cosmic rays. here null...
We report results from the first search for νμ→νe transitions by NOvA experiment. In an exposure equivalent to 2.74×1020 protons on target in upgraded NuMI beam at Fermilab, we observe 6 events Far Detector, compared a background expectation of 0.99±0.11(syst) based Near Detector measurement. A secondary analysis observes 11 with 1.07±0.14(syst). The 3.3σ excess observed primary disfavors 0.1π<δCP<0.5π inverted mass hierarchy 90% C.L.Received 19 January...
The DarkSide-50 direct-detection dark matter experiment is a dual-phase argon time projection chamber operating at Laboratori Nazionali del Gran Sasso. This paper reports on the blind analysis of (16,660+-270) kg d exposure using target low-radioactivity extracted from underground sources. We find no events in selection box and set 90% C.L. upper limit matter-nucleon spin-independent cross section 1.14E-44 cm^2 (3.78E-44 cm^2, 3.43E-43 cm^2) for WIMP mass 100 GeV/c^2 (1 TeV/c^2, 10 TeV/c^2).
We present new constraints on sub-GeV dark matter particles scattering off electrons in argon based an analysis of ionization signal data from the DarkSide-50 detector.
The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection far detector simulation parameterized analysis near detector. Detailed uncertainties due flux prediction, interaction model, effects are included. DUNE will resolve mass ordering precision 5$\sigma$, for all $\delta_{\mathrm{CP}}$ values, after 2 years running with nominal design beam configuration. It has potential observe...
The preponderance of matter over antimatter in the early universe, dynamics supernovae that produced heavy elements necessary for life, and whether protons eventually decay—these mysteries at forefront particle physics astrophysics are key to understanding evolution our its current state, eventual fate. DUNE is an international world-class experiment dedicated addressing these questions as it searches leptonic charge-parity symmetry violation, stands ready capture supernova neutrino bursts,...
The Deep Underground Neutrino Experiment (DUNE), a 40-kton underground liquid argon time projection chamber experiment, will be sensitive to the electron-neutrino flavor component of burst neutrinos expected from next Galactic core-collapse supernova. Such an observation bring unique insight into astrophysics core collapse as well properties neutrinos. general capabilities DUNE for neutrino detection in relevant few- few-tens-of-MeV energy range described. As example, DUNE's ability...
We report on the search for dark matter weakly interacting massive particles (WIMPs) in mass range below $10\text{ }\text{ }\mathrm{GeV}/{\mathrm{c}}^{2}$, from analysis of entire dataset acquired with a low-radioactivity argon target by DarkSide-50 experiment at Laboratori Nazionali del Gran Sasso. The new benefits more accurate calibration detector response, improved background model, and better determination systematic uncertainties, allowing us to accurately model rate spectra down...
We present a search for dark matter particles with sub-GeV/c^{2} masses whose interactions have final state electrons using the DarkSide-50 experiment's (12 306±184) kg d low-radioactivity liquid argon exposure. By analyzing ionization signals, we exclude new parameter space matter-electron cross section σ[over ¯]_{e}, axioelectric coupling constant g_{Ae}, and photon kinetic mixing κ. also set first direct-detection constraints on angle |U_{e4}|^{2} keV/c^{2} sterile neutrinos.
Dark matter elastic scattering off nuclei can result in the excitation and ionization of recoiling atom through so-called Migdal effect. The energy deposition from electron adds to deposited by nuclear system allows for detection interactions sub-GeV/c^{2} mass dark matter. We present new constraints using dual-phase liquid argon time projection chamber DarkSide-50 experiment with an exposure (12 306±184) kg d. analysis is based on signal alone significantly enhances sensitivity DarkSide-50,...
We have observed bottom-charm mesons B_c via the decay mode Bc -> J/psi lepton neutrino in 1.8 TeV p-bar p collisions using CDF detector at Fermilab Tevatron. A fit of background and signal contributions to + mass distribution yielded 20.4 +6.2 -5.5 events from mesons. same with alone was rejected level 4.8 standard deviations. measured be 6.40 +- 0.39 0.13 GeVc^2 lifetime tau(B_c) = 0.46 +0.18 -0.16 0.03 ps. production cross section times branching ratio for relative that B+ K 0.132 +0.041...
We present a study of $J/\ensuremath{\psi}$ and $\ensuremath{\psi}(2S)$ production in $p\overline{p}$ collisions, at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\mathrm{TeV}$ with the CDF detector Fermilab. The mesons are reconstructed using their ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decay modes. have measured inclusive cross section for both as function transverse momentum central region, $|\ensuremath{\eta}|<0.6$. also measure fraction these events...
A strong signal for double parton (DP) scattering is observed in a $16{\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$ sample of $\overline{p}p\ensuremath{\rightarrow}\ensuremath{\gamma}/{\ensuremath{\pi}}^{0}+3\mathrm{jets}+X$ data from the CDF experiment at Fermilab Tevatron. In DP events, two separate hard scatterings take place single $\overline{p}p$ collision. We isolate large $(\ensuremath{\sim}14000\mathrm{events})$ which 53% are found to be DP. The process-independent parameter scattering,...
We have measured the fraction of $J/\ensuremath{\psi}$ mesons originating from ${\ensuremath{\chi}}_{c}$ meson decays in $p\overline{p}$ collisions at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\mathrm{TeV}$. The fraction, for ${P}_{T}^{J/\ensuremath{\psi}}>4.0\mathrm{GeV}/c$ and $|{\ensuremath{\eta}}^{J/\ensuremath{\psi}}|<0.6$, not including contributions $b$ flavored hadrons, is...
Inclusive J/\ensuremath{\psi} and \ensuremath{\psi}(2S) production has been studied in p\ifmmode\bar\else\textasciimacron\fi{}p collisions at \ensuremath{\surd}s =1.8 TeV using 2.6\ifmmode\pm\else\textpm\fi{}0.2 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$ of data taken with the Collider Detector Fermilab. The products cross section times branching fraction were measured as functions ${\mathit{P}}_{\mathit{T}}$ for...
We report the observation of bottom-charmed mesons ${B}_{c}$ in 1.8 TeV $p\overline{p}$ collisions using CDF detector at Fermilab Tevatron. The were found through their semileptonic decays, ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{l}^{\ifmmode\pm\else\textpm\fi{}}X.$ A fit to $J/\ensuremath{\psi}l$ mass distribution yielded ${20.4}_{\ensuremath{-}5.5}^{+6.2}$ events from mesons. test null hypothesis, i.e., an attempt data with background alone, was...
The inclusive jet differential cross section has been measured for transverse energies, ET, from 15 to 440 GeV, in the pseudorapidity region 0.1≤|η|≤0.7. results are based on 19.5pb−1 of data collected by CDF Collaboration at Fermilab Tevatron collider. compared with QCD predictions various sets parton distribution functions. jets ET>200GeV is significantly higher than current O(αs3) perturbative calculations. Various possible explanations high- ET excess discussed.Received 25 January...
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...
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...