L. Spiegel
A5104170270- 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
- Medical Imaging Techniques and Applications
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Black Holes and Theoretical Physics
- Nuclear physics research studies
- Distributed and Parallel Computing Systems
- Muon and positron interactions and applications
- Gamma-ray bursts and supernovae
- CCD and CMOS Imaging Sensors
- Radiation Therapy and Dosimetry
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- International Science and Diplomacy
- Nuclear reactor physics and engineering
- X-ray Spectroscopy and Fluorescence Analysis
Fermi National Accelerator Laboratory
2016-2025
Institute of High Energy Physics
2013-2024
University of Antwerp
2024
A. Alikhanyan National Laboratory
2022-2024
Rockefeller University
2018
Purdue University West Lafayette
2017
University of Rochester
2017
Rice University
2017
European Organization for Nuclear Research
2014
Fermi Research Alliance
2002
The production of the χ1 and χ2 states charmonium has been observed in 300 GeV/c π±N pN interactions. fraction total inclusive J/ψ due to radiative χ decay determined be 0.40±0.04, 0.37±0.03, 0.30±0.04 for π+, π−, proton data, respectively. Total cross sections have obtained 131±18±14 188±30±21 nb/nucleon π−N interactions production. By measuring contributions both ψ’ decay, direct 97±14, 102±14, 89±12 protons, respectively.Received 21 October...
In particle physics, it is needed to evaluate the possibility that excesses of events in mass spectra are due statistical fluctuations as quantified by standards local and global significances. Without prior knowledge a particle’s mass, especially critical estimate its significance. The usual approach count number times significance limit exceeded collection simulated Monte Carlo (MC) “toy experiments”. To demonstrate this conventional method for significance, we performed simulation studies...
We present the xF and pT differential cross sections of J/ψ ψ′, respectively, in ranges −0.05<xF<0.25 pT<3.5GeV/c. The data samples are constituted by about 12 000 200 ψ′ produced proton-silicon interactions at 800 GeV/c decaying into opposite sign muons. distributions compared with recent results from experiments E789 same energy to leading order QCD predictions using MRS D0 parametrization for parton structure function. measured shapes sections, except dσ/dxF small xF, agree very well...
A search has been made in 300 GeV/c π±- and proton-Li interactions for production of states that decay into J/ψ or ψ' plus one two pions. 2.5σ enhancement the π0 spectrum, possibly recently reported 1P1 state charmonium, is observed at a mass 3.527 GeV/c2. In pion we report, together with expected ψ'→J/ψ π+π−, tentative observation structure 3.836 No enhancements are seen π±π±, π±π0, π±, π± spectra.Received 9 February 1994DOI:https://doi.org/10.1103/PhysRevD.50.4258©1994 American Physical Society
The cross section for bb¯ production in 800GeV/c pN interactions has been measured Fermilab experiment E771 to be 43−17+27(stat)−7+7(syst)nb per nucleon from the observation of events which both b and b¯ decay semimuonically or a B decays into J/ψ followed by J/ψ→μ+μ−.Received 7 July 1997DOI:https://doi.org/10.1103/PhysRevLett.82.41©1999 American Physical Society
The radiation damage experience of the silicon vertex detector used in CDF experiment during 1993–1995 collider run is described. single sided, AC coupled, FOXFET biased, and uses hard readout chips. detector's noise seen to increase anomalously with dose.
The planned luminosity upgrade of the CERN LHC to super (sLHC) requires investigation new radiation hard tracking detectors. Compared LHC, detectors must withstand a 5–10 times higher fluence. Promising options are planar silicon with n-side readout and in 3D technology, where columnar electrodes etched into substrate. This article presents beam test measurements performed n-in-p strip were irradiated different fluences, maximum fluence was <formula formulatype="inline"...
The cross sections for the hadroproduction of Chi1 and Chi2 states charmonium in proton-silicon collisions at sqrt{s}=38.8 GeV have been measured Fermilab fixed target Experiment 771. Chi were observed via their radiative decay to J/psi+gamma, where photon converted e+e- material spectrometer. values x_F>0 are 263+-69(stat)+-32(syst) 498+-143(stat)+-67(syst) nb per nucleon respectively. resulting sigma(Chi1}/sigma(Chi2) ratio 0.53+-0.20(stat)+-0.07(syst), although somewhat larger than most...
We describe technologies which can be developed to produce large area, low cost pixelated tracking detec- tors. These utilize wafer-scale 3D electronics and sensor currently being in industry. This result fully active sensor/readout chip tiles assembled into area arrays with good yield minimal dead area. The ability connect though the bulk of device also provide better electrical performance lower mass.
We present a measurement and comparison of the ${\ensuremath{\chi}}_{c1}$ ${\ensuremath{\chi}}_{c2}$ production cross sections determined from interactions 300-GeV/c ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ $p$ with Li target. find $\frac{{\ensuremath{\chi}}_{c1}}{{\ensuremath{\chi}}_{c2}}$ ratios $0.52_{\ensuremath{-}0.27}^{}{}_{}{}^{+0.57}$ $0.08_{\ensuremath{-}0.15}^{}{}_{}{}^{+0.25}$ reactions induced by $p$, respectively.
In particle physics, it is needed to evaluate the possibility that excesses of events in mass spectra are due statistical fluctuations as quantified by standards local and global significances. Without prior knowledge a particle's mass, especially critical estimate its significance. The usual approach count number times significance limit exceeded collection simulated Monte Carlo (MC) 'toy experiments.' To demonstrate this conventional method for significance, we performed simulation studies...
We have searched for the flavor changing neutral current decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ in dimuon data obtained by E771 experiment conducted at Fermilab. No evidence is found. A 90% confidence level upper limit of $4.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ branching ratio. This new about two times lower than best published result.
Three dimensional integrated circuit technologies offer the possibility of fabricating large area arrays sensors with complex electronics minimal dead area, which makes them ideally suited for applications at LHC upgraded detectors and other future detectors. We describe ongoing R&D efforts to demonstrate functionality components such This includes study 3D active edge produce "active tiles" can be tested assembled into arbitrary size high yield.
Details of the construction high-rate, mid-sized (1-m*2-m) pad chambers, intended for use in Fermi National Accelerator Laboratory (FNAL) experiment E-771, are described. Each gas volume module represents a chamber doublet: two identical anode wire planes, transverse strip and planes. Wire signals, from 8-mm square cells, recorded via TDCs; corresponding stripe image signals latched. Pad sizes range 0.8 cm*3.6 cm to 3.2 cm*35 cm. In addition facilitating pattern recognition, also used as...
The design and performance of a 4.2-radiation-length, lead-sandwich, gas tube hodoscope are discussed. device, measuring 1*2 m/sup 2/ in area 12 cm depth, was used Fermi National Accelerator Laboratory experiment 705. Multiple samplings anode wires situated within three-walled aluminum tubes were to generate an X coordinate; similarly, capacitively coupled copper-clad strips ganged together yield Y coordinate. results reviewed analysis electron calibration data taken during recent six-month...
A fine-grain hodoscope to measure the position of showers in outer (>52 cm) region E-705 electromagnetic calorimeter is described. The constructed with two layers vertical conducting plastic tubes for X measurement showers. Y was accomplished by cathode-induced horizontal strips. 50/50-ethane mixture bubbled through isopropyl alcohol at 0 degrees C circulated parallel. were operated +1.925 kV on wire (below saturated avalanche) limited proportionality mode. described, and results are...
We describe a project to demonstrate fully active sensor/readout chip tiles which can be assembled into large area arrays with good yield and minimal dead area. Such used as building blocks for next generation trackers, such the tracking trigger system CMS in LHC, or precise, low mass pixelated sensors.
A 544-channel low-noise, high-rate precision charge-amplification and ADC (analog/digital converter) system was constructed for the Fermilab Experiment 705 electromagnetic calorimeter, which uses SCG1-C scintillating glass SF5 lead instrumented with photomultiplier tubes. general discussion of is given, charge amplification, fast-trigger-pulse generation, analog/digital conversion aspects are presented in more detail. Performance evaluated using data from offline tests. Short- long-term...
The CMS detector at the CERN Large Hadron Collider features as its innermost component a silicon pixel detector. original was completely replaced during 2016-2017 winter technical stop. One of goals this Phase-1 Upgrade to replace sensors in forward with new, unirradiated sensors. new must survive an integrated luminosity 300 fb$^{-1}$ before being again prior High-Luminosity LHC era. Just construction, were made n$^{+}$-in-n Diffusion Oxygenated Float Zone silicon. This note documents...