J. Ellison
A5105673175- 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
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Distributed and Parallel Computing Systems
- Particle accelerators and beam dynamics
- CCD and CMOS Imaging Sensors
- Scientific Research and Discoveries
- Astronomical Observations and Instrumentation
- Algorithms and Data Compression
- Gamma-ray bursts and supernovae
- Radiation Effects in Electronics
- International Science and Diplomacy
Institute of High Energy Physics
2010-2019
University of California, Riverside
2010-2019
Universidad de Cantabria
2017
Centro Brasileiro de Pesquisas Físicas
2010-2016
University of California, Los Angeles
2015
University of California, San Diego
2014
European Organization for Nuclear Research
2012-2014
Fermi National Accelerator Laboratory
1994-2013
University of Arizona
1997-2012
University of Washington
2010-2012
The D0 Collaboration reports on a search for the standard model top quark in pp¯ collisions at s=1.8TeV Fermilab Tevatron with an integrated luminosity of approximately 50pb−1. We have searched tt¯ production dilepton and single-lepton decay channels without tagging b-quark jets. observed 17 events expected background 3.8±0.6 events. probability upward fluctuation to produce signal is 2×10−6 (equivalent 4.6 deviations). kinematic properties excess are consistent decay. conclude that we...
We investigate the decay ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}{K}^{+}$ in a search for $X(4140)$ state, narrow threshold resonance $J/\ensuremath{\psi}\ensuremath{\phi}$ system. The data sample corresponds to an integrated luminosity of $10.4\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\mathrm{TeV}$ collected by D0 experiment Fermilab Tevatron collider. observe mass peak with statistical significance 3.1...
We present a measurement of the forward–backward asymmetry in top quark–antiquark production using full Tevatron Run II data set collected by D0 experiment at Fermilab. The is performed lepton+jets final states new kinematic fitting algorithm for events with four or more jets and partial reconstruction only three jets. Corrected detector acceptance resolution effects, evaluated to be AFB=(10.6±3.0)%. Results are consistent standard model predictions which range from 5.0% 8.8%. also...
We present the observation of doubly-produced $J/\psi$ mesons with D0 detector at Fermilab in $p\bar{p}$ collisions $\sqrt{s}=1.96$ TeV. The production cross section for both singly and is measured using a sample an integrated luminosity 8.1fb$^{-1}$. For first time, double separated into contributions due to single parton scatterings. Using these measurements, we determine effective $\sigma_{eff}$, parameter characterizing spatial area parton-parton interactions related density inside nucleon.
The D0 Collaboration has performed a measurement of the top quark mass mt based on six candidate events for process tt¯→bW+b¯W−, where W bosons decay to eν or μν. This sample was collected during an exposure detector integrated luminosity 125pb−1 s=1.8TeVpp¯ collisions. We obtain mt=168.4±12.3(stat)±3.6(syst)GeV/c2, consistent with obtained using single-lepton events. Combination and dilepton results yields mt=172.0±7.5GeV/c2.Received 16 June...
We present a search for events consistent with the production and decay of squarks gluinos minimal supersymmetric standard model (MSSM) in D0 detector at Fermilab Tevatron $p\overline{p}$ collider. examined data containing large missing transverse energy three or more jets. observed no excess above expected yield from processes. For choice MSSM parameter values, we set lower limit 95% confidence level on mass gluino 144 GeV ${/c}^{2}$ all squark masses 212 equal masses.
We present a measurement of the electron charge asymmetry in $p\overline{p}\ensuremath{\rightarrow}W+X\ensuremath{\rightarrow}e\ensuremath{\nu}+X$ events at center-of-mass energy 1.96 TeV, using data corresponding to $9.7\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity collected with D0 detector Fermilab Tevatron Collider. The is measured as function pseudorapidity and presented five kinematic bins based on transverse missing event. compared next-to-leading-order...
The Core Cosmology Library (CCL) provides routines to compute basic cosmological observables a high degree of accuracy, which have been verified with an extensive suite validation tests. Predictions are provided for many quantities, including distances, angular power spectra, correlation functions, halo bias and the mass function through state-of-the-art modeling prescriptions available in literature. Fiducial specifications expected galaxy distributions Large Synoptic Survey Telescope...
We report evidence for the simultaneous production of $J/\psi$ and $\Upsilon$ mesons in 8.1 fb$^{-1}$ data collected at $\sqrt{s}=$1.96 TeV by D0 experiment Fermilab $p \bar p$ Tevatron Collider. Events with these characteristics are expected to be produced predominantly gluon-gluon interactions. In this analysis, we extract effective cross section characterizing initial parton spatial distribution, $\sigma_{eff}=2.2\pm 0.7\mbox{(stat)} \pm 0.9 \mbox{(syst)} ~\mbox{mb}$.
Inflation may provide unique insight into the physics at highest available energy scales that cannot be replicated in any realistic terrestrial experiment. Features primordial power spectrum are generically predicted a wide class of models inflation and its alternatives, observationally one most overlooked channels for finding evidence non-minimal inflationary models. Constraints from observations cosmic microwave background cover widest range feature frequencies, but sensitive constraints...
We determine the top quark mass m_t using t-tbar pairs produced in D0 detector by \sqrt{s} = 1.8 TeV p-pbar collisions a 125 pb^-1 exposure at Fermilab Tevatron. make two constraint fit to -> b W^+bbar W^- final states with one W boson decaying q-qbar and other e-nu or mu-nu. Likelihood fits data yield m_t(l+jets) 173.3 +- 5.6 (stat) 5.5 (syst) GeV/c^2. When this result is combined an analysis of events which both bosons decay into leptons, we obtain 172.1 5.2 4.9 An alternate analysis,...
We present new results on the search for top quark in p¯p collisions at √s=1.8 TeV with an integrated luminosity of 13.5±1.6 pb–1. have considered t¯t production standard model using electron and muon dilepton decay channels ( t¯t→eμ+ jets, ee+ μμ+ jets) single-lepton t¯t→e+ jets μ+ without tagging b jets. From all we nine events expected background 3.8±0.9. If assume that excess is due to production, a mass 180 GeV/ c2, obtain cross section 8.2±5.1 pb.Received 7 November...
We report on measurements inclusive cross sections times branching fractions into electrons for W and Z bosons produced in pp¯ collisions at s=1.8TeV. From an integrated luminosity of 84.5 pb−1 recorded 1994–1995 using the DØ detector Fermilab Tevatron, we determine σ(pp¯→W+X)×B(W→eν)=2310±10(stat)±50(syst)±100(lum)pb σ(pp¯→Z+X)×B(Z→ee)=221±3(stat)±4(syst)±10(lum)pb. these, derive σ(pp¯→W+X)×B(W→eν)/σ(pp¯→Z+X)×B(Z→ee)=10.43±0.15(stat)±0.20(syst)±0.10(NLO),...
We report a measurement of the inclusive muon and b-quark production cross sections in pp¯ collisions at s=1.8 TeV using D0 detector Fermilab Tevatron collider. The spectrum extends over kinematic range |yμ|<0.8 3.5<pTμ<60GeV/c, is well described by expected contributions from various known sources. section for |yb|<1.0 pTb>6GeV/c extracted, agrees with next-to-leading order QCD predictions within experimental theoretical uncertainties.Received 12 December...
We measure the top quark mass mt using tt¯ pairs produced in D0 detector by s=1.8TeVpp¯ collisions a 125pb−1 exposure at Fermilab Tevatron. make two constraint fit to tt¯→bW+b¯W− final states with one W decaying qq¯ and other eν or μν. Events are binned versus of probability for events be signal rather than background. Likelihood fits data yield mt=173.3±5.6(stat)±6.2(syst)GeV/c2.Received 11 March 1997DOI:https://doi.org/10.1103/PhysRevLett.79.1197©1997 American Physical Society
We measure the inclusive single muon charge asymmetry and like-sign dimuon in $p \bar{p}$ collisions using full data set of 10.4 fb$^{-1}$ collected with D0 detector at Fermilab Tevatron. The standard model predictions asymmetries induced by CP violation are small magnitude compared to current experimental precision, so non-zero measurements could indicate new sources violation. differ from these a significance 3.6 deviations. These results interpreted framework $B$ meson mixing within CKM...
We measure the mass of top quark in lepton+jets final states using full sample pp collision data collected by D0 experiment Run II Fermilab Tevatron Collider at sqrt[s] = 1.96 TeV, corresponding to 9.7 fb(-1) integrated luminosity. use a matrix element technique that calculates probabilities for each event result from tt production or background. The overall jet energy scale is constrained situ W boson. m(t) 174.98 ± 0.76 GeV. This constitutes most precise single measurement top-quark mass.
We determine the fraction of events with double parton (DP) scattering in a single $p\overline{p}$ collision at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ samples $\ensuremath{\gamma}+3$ jet and $\ensuremath{\gamma}+b/c\text{ }\text{jet}+2$ collected D0 detector corresponding to an integrated luminosity about $8.7\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. The DP fractions effective cross sections (${\ensuremath{\sigma}}_{\text{eff}}$) are measured for both event using same kinematic...
The hot dense environment of the early universe is known to have produced large numbers baryons, photons, and neutrinos. These extreme conditions may also other long-lived species, including new light particles (such as axions or sterile neutrinos) gravitational waves. effects any such relics can be observed through their unique imprint in cosmic microwave background (CMB), large-scale structure, primordial element abundances, are important determining initial universe. We argue that future...
We report a measurement of the top quark mass using six candidate events for process $p\overline{p}\ensuremath{\rightarrow}t\overline{t}+\stackrel{\ensuremath{\rightarrow}}{X}{l}^{+}\ensuremath{\nu}{\mathrm{bl}}^{\ensuremath{-}}\overline{\ensuremath{\nu}}\overline{b}+X$, observed in D0 experiment at Fermilab $p\overline{p}$ collider. Using maximum likelihood fits to dynamics decays, we measure...