M. Hildreth
A5046890650- 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
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Distributed and Parallel Computing Systems
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Scientific Computing and Data Management
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Advanced Data Storage Technologies
- Research Data Management Practices
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Evaluation of Teaching Practices
- Parallel Computing and Optimization Techniques
University of Notre Dame
2016-2025
Notre Dame of Dadiangas University
2005-2024
Institute of High Energy Physics
2016-2024
A. Alikhanyan National Laboratory
2022-2024
University of Antwerp
2024
University of Virginia
2017
University of Pittsburgh
2017
University of Kansas
2017
Fermi Research Alliance
2015-2017
University of Wisconsin–Madison
2016
The solutions adopted by the high-energy physics community to foster reproducible research are examples of best practices that could be embraced more widely. This first experience suggests reproducibility requires going beyond openness.
Recent calls for improvement in undergraduate education within STEM (science, technology, engineering, and mathematics) disciplines are hampered by the methods used to evaluate teaching effectiveness. Faculty members at research universities commonly assessed promoted mainly on basis of success. To improve quality across all disciplines, not only fields, requires creating an environment wherein continuous is valued, assessed, rewarded various stages a faculty member’s career. This consistent...
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This has many advantageous properties over previously studied schemes, including being significantly shorter a given energy having better bandwidth. Experimental results from ATF2 accelerator at KEK are presented that validate operating principle such by demonstrating demagnification 1.3 GeV electron beam down to below 65 nm height...
We have searched for events with new-particle topologies in 390 hadronic Z decays the Mark II detector at SLAC Linear Collider. place 95%-confidence-level lower limits of 40.7 GeV/${c}^{2}$ top-quark mass, 42.0 mass a fourth-generation charge -(1/3 quark, and 41.3 an unstable Dirac neutral lepton.
In the absence of a concrete discovery new physics at LHC, global analyses standard model effective field theory (SMEFT) are important to find and describe impact beyond energy reach LHC. Among SMEFT operators that can be constrained via various measurements, dimension six triple gluon operator involves neither Higgs boson nor top quark, yet its variation have measurable effects on production. Without independent constraints impact, sensitivity measurements in sectors is reduced. We show...
We have observed hadronic final states produced in the decays of Z bosons. In order to study parton structure these events, we compare distributions sphericity, thurst, aplanarity, and number jets predictions several QCD-based models data from lower energies. The agree within present statistical precision.
Any future high energy e+e− linear collider aims at precision measurements of Standard Model quantities as well new, not yet discovered phenomena. In order to pursue this physics programme, excellent detectors the interaction region have be complemented by beam diagnostics unprecedented precision. This article gives an overview current plans and issues for polarimeters spectrometers International Linear Collider, which been designed fulfill goals a large range energies from 45.6 GeV Z0 pole...
Over the past several years, CMS experiment has made significant changes to its detector simulation application. The geometry been generalized include modifications being for 2015 operations, as well model improvements of current and implementation a number approved possible future configurations. These both completely new tracker calorimetry systems. We have completed transition Geant4 version 10, we progress in reducing CPU resources required run our simulation. achieved through technical...
The central drift chamber (CDC) of the Stanford Linear Collider Large Detector (SLD) has been recording data since 1992. low mass and use a gas characterized by both velocity diffusion constant help to minimize multiple scattering drift-distance measurement errors. We describe some calibrations corrections applied data, report on resolutions achieved thus far. measure an intrinsic resolution 55–110 μm in region uniform field. Analysis full drift-pulse waveform allows for efficient double-hit...
We have measured the distributions of jet energies in ${e}^{+}$${e}^{\ensuremath{-}}$\ensuremath{\rightarrow}qq\ifmmode\bar\else\textasciimacron\fi{}g events, and three orientation angles event plane, using hadronic ${Z}^{0}$ decays collected SLD experiment at SLAC. find that data are well described by perturbative QCD incorporating vector gluons. also studied models scalar tensor gluon production them to be incompatible with our data.
Using isolated leptons reconstructed in the Mark II detector to tag bb\ifmmode\bar\else\textasciimacron\fi{} events, we measure fraction of events hadronic ${\mathit{Z}}^{0}$ decays be 0.${23}_{\mathrm{\ensuremath{-}}0.09}^{+0.11}$, good agreement with standard-model prediction 0.22. We find \ensuremath{\Gamma}(Z\ensuremath{\rightarrow}bb\ifmmode\bar\else\textasciimacron\fi{})=0.${43}_{\mathrm{\ensuremath{-}}0.17}^{+0.21}$ GeV.
During the High Luminosity LHC, CMS detector will need charged particle tracking at hardware trigger level to maintain a manageable rate and achieve its physics goals. The tracklet approach is track-finding algorithm based on road-search that has been implemented commercially available FPGA technology. achieved high performance in completes within 3.4 μs Xilinx Virtex-7 FPGA. An overview of implementation an given, results are shown from demonstrator test stand system studies presented.
We report the current status of full simulation application developed by CMS experiment. For LHC run-II, is using Geant4 10.0p02 built in sequential mode. About 16 billion events were produced for run-II analysis during 2015-2016. A new method to handle pileup has been and now used regular processing events. plan use 10.2p02 2017 production. In this work, we present CPU memory performance different configurations versions considered our testing. also discuss technical aspects migration 10.2...
The high instantaneous luminosities expected following the upgrade of Large Hadron Collider (LHC) to High-Luminosity LHC (HL-LHC) pose major experimental challenges for CMS experiment.A central component allow efficient operation under these conditions is reconstruction charged particle trajectories and their inclusion in hardwarebased trigger system.There are many involved achieving this: a large input data rate about 20-40 Tb/s; processing new batch every 25 ns, each consisting 15,000...
The lifetimes of B+ and B0 mesons are measured using a sample 150 000 hadronic Z0 decays collected by the SLD experiment at SLAC Linear Collider between 1993 1995. Two analyses presented in which decay length charge B meson reconstructed. first method uses novel topological vertexing technique while second semi-inclusively reconstructed semileptonic decays. analysis yields 6033 (3665) charged (neutral) vertices with good purity, whereas smaller 634 (584) excellent purity. Combining results...
During LHC shutdown between run-1 and run-2 intensive developments were carried out to improve performance of CMS simulation. For physics improvements migration from Geant4 9.4p03 10.0p02 has been performed. CPU improved by introduction the Russian roulette method inside calorimeters, optimization simulation sub-libraries, usage statics build executable. As a result these efforts, speeded up about factor two. In this work we provide description updates for different software components...
We report for the first time on performance of Central Drift Chamber (CDC) Stanford Linear Collider Large Detector (SLD), which has been recording data since 1992. The low mass chamber and use a gas characterized by both drift velocity diffusion constant help to minimize drift-distance measurement errors. describe some calibrations corrections applied data, resolutions achieved thus far. measure an intrinsic resolution 55-110 /spl mu/m in region uniform field. Analysis full drift-pulse...
We have determined the strong coupling ${\mathrm{\ensuremath{\alpha}}}_{\mathit{s}}$ from measurements of jet rates in hadronic decays ${\mathit{Z}}^{0}$ bosons collected by SLD experiment at SLAC. Using six collinear and infrared safe algorithms we compared our data with predictions QCD calculated up to second order perturbation theory, also resummed calculations. find...
REANA is a reusable and reproducible data analysis platform allowing researchers to structure their pipelines run them on remote containerised compute clouds. supports several different workflows systems (CWL, Serial, Yadage) uses Kubernetes' job execution backend. We have designed an abstract component that extends the capabilities support multiple backends. tested with HTCondor verified scalability of solution. The results show would be able hybrid scientific where parts can executed computing
We determine the strong coupling αs from a comprehensive study of energy-energy correlations (EEC's) and their asymmetry (AEEC's) in hadronic decays Z0 bosons collected by SLD experiment at SLAC. The data are compared with all four available predictions QCD calculated up to O(α2s) perturbation theory, also resummed calculation matched these calculations. find large discrepancies between values extracted different renormalization scale ambiguity determined EEC's using calculations; this is...
We describe methods that can be employed at a $\sqrt{s}=500$ GeV ${e}^{+}{e}^{\ensuremath{-}}$ linear collider to measure the branching fractions of Higgs boson. These select one Higgs-boson decay mode above all others with high purity, leaving measurable standard model backgrounds as only source contamination. Integrated luminosities 50 ${\mathrm{fb}}^{\ensuremath{-}1}$ are required obtain statistical errors 10-20% on $b\overline{b}$,...
We have measured the fraction of bb\ifmmode\bar\else\textasciimacron\fi{} events in hadronic ${\mathit{Z}}^{0}$ decays, ${\mathit{R}}_{\mathit{b}\mathit{b}\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}$, using vertex detector system Mark II at SLAC Linear Collider. tag by requiring coincidence three or more tracks with significant impact parameters. This is 50% efficient and results a sample 85% purity. find...