Nikos Varelas
A5002251964- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Medical Imaging Techniques and Applications
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Distributed and Parallel Computing Systems
- Gamma-ray bursts and supernovae
- International Science and Diplomacy
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Stochastic processes and financial applications
- Algorithms and Data Compression
- Noncommutative and Quantum Gravity Theories
- Radiation Detection and Scintillator Technologies
- Advanced Queuing Theory Analysis
- Nuclear reactor physics and engineering
- Big Data Technologies and Applications
University of Illinois Chicago
2014-2025
University of Chicago
1997-2024
Institute of High Energy Physics
2022-2024
A. Alikhanyan National Laboratory
2022-2024
University of Antwerp
2024
University of Iowa
2023
Universidade Estadual Paulista (Unesp)
2010
Institut National de Physique Nucléaire et de Physique des Particules
2010
Centre National de la Recherche Scientifique
2010
University of Buenos Aires
2010
We report results of an electron-beam-dump search for neutral particles with masses in the range 1 to 15 MeV and lifetimes \ensuremath{\tau} between ${10}^{\mathrm{\ensuremath{-}}14}$ ${10}^{\mathrm{\ensuremath{-}}10}$ s. No evidence was found such object. fule out existence any 1.8-MeV pseudoscalar boson \ensuremath{\tau}>8.2\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$ s absorption cross section matter less than mb per nucleon, exclude...
This report summarizes the work of Energy Frontier New Physics working group 2013 Community Summer Study (Snowmass).
We present results from the initial run of Fermilab experiment E706. The data include incident π− and p beams at 500 GeV/c on Be Cu targets, span kinematic ranges transverse momentum rapidity 3.5≤pT≤10 −0.7≤yc.m.≤0.7, respectively. have measured cross sections for π0 direct-photon production, as well ηπ0 production ratio. From Cu, we extracted nuclear dependence parametrized Aα. are compared with next-to-leading-log QCD predictions different choices scales several sets parton distribution...
We have studied the production of J/\ensuremath{\psi} and \ensuremath{\psi}(2S) charmonium mesons in 515 GeV/c ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$Be collisions Feynman-x range 0.1${\mathit{x}}_{\mathit{F}}$0.8. were detected via their decay into ${\mathrm{\ensuremath{\mu}}}^{+}$${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$, both ${\mathrm{\ensuremath{\mu}}}^{+}$${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$...
We report on ${\ensuremath{\chi}}_{c1}$ and ${\ensuremath{\chi}}_{c2}$ production in the Feynman-x range $0.1<{x}_{F}<0.8$ $515\mathrm{GeV}/c$ ${\ensuremath{\pi}}^{\ensuremath{-}}\mathrm{Be}$ collisions. The ${\ensuremath{\chi}}_{c}$ states are observed via their radiative decays into $J/\ensuremath{\psi}$'s. resulting photons detected either as showers electromagnetic calorimeter or after conversion target ${e}^{+}{e}^{\ensuremath{-}}$ pairs tracking system. fraction of...
We report on a sample of $\frac{J}{\ensuremath{\psi}}$ mesons coming from secondary vertices, characteristic heavyquark decay, detected in the Fermilab Meson West spectrometer. Based eight signal events which emerges vertex occurring an air-gap region, we obtain inclusive $b\overline{b}$ cross section 75 \ifmmode\pm\else\textpm\fi{} 31 26 nb/nucleon. This result is compared to recent QCD predictions. have also observed several exclusive decay modes...
We report new measurements of inclusive direct photon production at high transverse momenta (${\mathit{p}}_{\mathit{T}}$) for ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ and p interactions on Be 500 GeV/c. The yields as a function ${\mathit{p}}_{\mathit{T}}$ rapidity (y) are in good agreement with expectations from next-to-leading-log QCD calculations employing recently extracted quark gluon structure functions.
A study is presented of the sensitivity potential future $pp$ colliders to quark compositeness. The analysis uses normalized dijet angular distributions compared expectations from leading-order contact interaction models.
Abstract We report on the calibration and performance of a large lead liquid-argon electromagnetic calorimeter used by experiment E706 at Fermilab. The reconstructed π 0 mass was to calibrate energy response calorimeter. systematic uncertainty in linearity uniformity mean-energy after found be less than ±0.5% for sample data analyzed. Detector characteristics, including sampling fluctuations position resolution, are discussed.
We present the results of a study hadronic jets produced in association with direct photons and π0's at large transverse momenta π−Be pBe collisions 500 GeV/c. Using primarily charged particles to characterize properties recoiling jets, we compare their fragmentation angular distributions, correlation trigger particle, for both γ π0 event samples. also data QCD calculations that incorporate current parton distribution functions.Received 9 September...
We present new measurements of ${\ensuremath{\pi}}^{0}$ production at high transverse momenta (${p}_{T}$) for ${\ensuremath{\pi}}^{\ensuremath{-}}$ and $p$ interactions on Be Cu targets 500 GeV/c. The observed dependence the yields as a function ${p}_{T}$ rapidity ($y$) is compared with expectations from leading-log QCD over kinematic range in which inclusive cross sections fall by more than 4 order magnitude.
We review the status of searches for Standard Model (SM) Higgs boson from CDF and DØ experiments using a Run II data sample ≈ 400 pb -1 pp collisions at center mass energy 1.96 TeV Fermilab Tevatron.No evidence signal is found updated limits on SM production cross section times branching ratio are presented.Studies W Z bosons produced in association with jets (background processes to production) also discussed.
We present a status report of variety projects related to heavy quark production and parton distributions for the Tevatron Run II.