R. G. Kellogg
- 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
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Distributed and Parallel Computing Systems
- Muon and positron interactions and applications
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Radiation Therapy and Dosimetry
- Advanced NMR Techniques and Applications
- Radioactivity and Radon Measurements
- International Science and Diplomacy
University of Maryland, College Park
2016-2025
A. Alikhanyan National Laboratory
2022-2024
Institute of High Energy Physics
2014-2024
University of Antwerp
2024
Massachusetts Institute of Technology
2014-2023
University of Puerto Rico-Mayaguez
2019
University at Buffalo, State University of New York
2016-2017
The Ohio State University
2016-2017
Rutgers, The State University of New Jersey
2015-2016
Lawrence Livermore National Laboratory
2015
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...
Hadronic event shape distributions from e+e− annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 are used to determine strong coupling α S. The results based on QCD predictions complete next-to-next-to-leading order (NNLO), NNLO calculations matched resummed next-to-leading-log-approximation terms (NNLO + NLLA). combined result all variables is while NLLA completeness of with respect missing higher contributions, studied varying renormalization...
A pair of small angle silicon-tungsten (Si-W) calorimeters has been built to measure the luminosity a precision better than 0.1% in OPAL experiment at Large Electron Positron (LEP) collider CERN near Geneva. Each calorimeter contains 19 layers tungsten (W) plates and silicon (Si) detectors, corresponding total 22 radiation lengths, sampled by about 1 m/sup 2/ detectors divided into 304/spl times/64 independently read out channels. complete electronics system developed, from preamplifier up...
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.
Anomalous quartic couplings between the electroweak gauge bosons may contribute to $\ensuremath{\nu}\overline{\ensuremath{\nu}}\ensuremath{\gamma}\ensuremath{\gamma}$ and $q\overline{q}\ensuremath{\gamma}\ensuremath{\gamma}$ final states produced in ${e}^{+}{e}^{\ensuremath{-}}$ collisions. This analysis uses LEP2 OPAL data sample at center-of-mass energies up 209 GeV. Event selections identify events which two photons are reconstructed within detector acceptance. The cross section for...
Abstract A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected OPAL experiment at $\sqrt{s}=189\mbox{--}209\ \mbox{GeV}$ , corresponding to an integrated luminosity approximately 600 pb −1 . Charged are assumed be pair-produced and decay into $\mathrm{q} \bar{\mathrm{q}}$ τν τ or AW ± No signal observed. Model-independent limits on Higgs-boson production cross section derived combining...
This letter describes a direct search for pair produced magnetic monopoles in e+e- collisions. The analysis is based on 62.7 pb^-1 of data collected with the OPAL detector at an average centre-of-mass energy sqrt(s)= 206.3GeV. monopole signal was assumed to be characterized by two back-to-back particles anomalously high ionization loss de/dx tracking chambers. No evidence production observed. Upper limits were obtained pair-production cross-section (sigma) mass range 45 GeV/c^2