A5054182550- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Distributed and Parallel Computing Systems
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Advanced Data Storage Technologies
- Superconducting Materials and Applications
- Muon and positron interactions and applications
- advanced mathematical theories
- CCD and CMOS Imaging Sensors
- Atomic and Subatomic Physics Research
- Big Data Technologies and Applications
- Pulsars and Gravitational Waves Research
- International Science and Diplomacy
- X-ray Spectroscopy and Fluorescence Analysis
- Scientific Computing and Data Management
Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Udine
2016-2025
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2016-2025
University of Udine
2016-2025
Northern Illinois University
2020-2024
Institute for High Energy Physics
1997-2024
Institute of Science and Technology
2023-2024
Atlas Scientific (United States)
2024
SR Research (Canada)
2024
Federación Española de Enfermedades Raras
2024
A. Alikhanyan National Laboratory
2024
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.
The silicon pixel tracking system for the ATLAS experiment at Large Hadron Collider is described and performance requirements are summarized. Detailed descriptions of detector electronics sensors given. design, fabrication, assembly modules presented. Data obtained from test beams as well studies using cosmic rays also discussed.
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 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....
The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying dielectron or dimuon final states. Results are presented from an analysis of proton-proton (pp) collisions a center-of-mass energy 8 TeV corresponding integrated luminosity 20.3 fb-1 in channel and 20.5 channel. A narrow resonance with Standard Model Z couplings fermions excluded 95% confidence level masses less than 2.79 channel, 2.53 2.90 two channels combined. Limits on other model...
During the shutdown of CERN Large Hadron Collider in 2013-2014, an additional pixel layer was installed between existing Pixel detector ATLAS experiment and a new, smaller radius beam pipe. The motivation for this new layer, Insertable B-Layer (IBL), to maintain or improve robustness performance tracking system, given higher instantaneous integrated luminosities realised following shutdown. Because extreme radiation collision rate environment, several radiation-tolerant sensor electronic...
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...
The ATLAS collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing and vacuum pipe of Large Hadron Collider. extreme operating conditions at this location have necessitated development radiation hard sensor technologies front-end readout chip, called FE-I4. Planar sensors 3D been investigated to equip layer, prototype modules using FE-I4A fabricated characterized 120 GeV pions CERN SPS 4 positrons DESY, before after module...
Measurements of charged-particle fragmentation functions jets produced in ultra-relativistic nuclear collisions can provide insight into the modification parton showers hot, dense medium created collisions. ATLAS has measured $\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb at LHC using a data set recorded 2011 with an integrated luminosity 0.14 nb$^{-1}$. Jets were reconstructed anti-$k_{t}$ algorithm distance parameter values $R$ 0.2, 0.3, and 0.4. Distributions transverse momentum longitudinal fraction...
We have analyzed events with jets and large missing transverse energy produced in p¯p colisions at √s =1.8 TeV. The observed event rate is consistent standard model predictions. In a version of the supersymmetry (SUSY) light photino (mγ̃<15 GeV/c2) no cascade decays, we exclude 90% confidence level existence squarks gluinos masses less than 126 141 GeV/c2, respectively. mass limits are lower other choices SUSY parameters. An example presented.Received 17 August...
We have searched for heavy neutral gauge bosons (Z′) in dielectron and dimuon decay modes using 110pb−1 of ¯pp collisions at √s=1.8TeV collected with the Collider Detector Fermilab. present a limit on production cross section times branching ratio Z′ boson decaying into dileptons as function mass. For mass MZ′>600GeV/c2, upper is 40 fb 95% confidence level. set lower limits 690, 590, 620, 595, 565, 630, 600GeV/c2 Z′SM, Zψ, Zη, Zχ, ZI, ZLR, ZALRM, respectively.Received 6 May...
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
The transverse momentum and total cross section of e^+e^- pairs in the Z-boson region 66<M_{ee}<116 GeV$/c^2$ from $p\bar{p}$ collisions at $\sqrt{s}=1.8$ TeV are measured using 110 pb^{-1} taken by Collider Detector Fermilab during 1992-1995. is to be $248 \pm 11$ pb. differential compared with calculations that match quantum chromodynamics perturbation theory high gluon resummation formalism low momentum.
We report test beam studies of 11% the production ATLAS Tile Calorimeter modules. The modules were equipped with front-end electronics and all calibration systems planned for final detector. used muon, electron hadron beams ranging in energy from 3 to 350 GeV. Two independent showed that light yield calorimeter was ∼70pe/GeV, exceeding design goal by 40%. Electron provided a at electromagnetic scale. Over 200 cells variation response 2.4%. linearity also measured. Muon an intercalibration...
This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag remove background contaminated events data. Trigger-rate based monitoring beam-related is presented. The correlations with machine conditions, such as residual pressure beam-pipe, are discussed. Results from dedicated beam-background simulations shown, their qualitative agreement data evaluated. Data taken during passage unpaired, i.e. non-colliding, proton bunches used...