D. Broemmelsiek
A5028349185- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Gyrotron and Vacuum Electronics Research
- Neutrino Physics Research
- Nuclear physics research studies
- Muon and positron interactions and applications
- Advanced Data Storage Technologies
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Photocathodes and Microchannel Plates
- Quantum, superfluid, helium dynamics
- Magnetic confinement fusion research
- X-ray Spectroscopy and Fluorescence Analysis
- Astrophysics and Cosmic Phenomena
- Terahertz technology and applications
- Advanced NMR Techniques and Applications
- Advanced Multi-Objective Optimization Algorithms
Fermi National Accelerator Laboratory
2013-2024
Indiana University South Bend
2011
Syracuse University
2007
University of Virginia
2007
Brookhaven National Laboratory
2007
University of California, Berkeley
2007
University of Illinois Urbana-Champaign
2007
Institute for Nuclear Research
2007
University of Massachusetts Amherst
2007
University of California, Riverside
2007
New data are reported from the operation of a 4.0 kg CF$_{3}$I bubble chamber in 6800-foot-deep SNOLAB underground laboratory. The effectiveness ultrasound analysis discriminating alpha-decay background events single nuclear recoils has been confirmed, with lower bound $>$99.3% rejection events. Twenty recoil event candidates and three multiple were observed during total exposure 553 kg-days distributed over different nucleation thresholds. effective for recoil-like was 437.4 kg-days. A...
New data are reported from the operation of a 2 liter ${\mathrm{C}}_{3}{\mathrm{F}}_{8}$ bubble chamber in SNOLAB underground laboratory, with total exposure 211.5 kg days at four different energy thresholds below 10 keV. These show that provides excellent electron-recoil and alpha rejection capabilities very low thresholds. The exhibits an sensitivity $<3.5\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}10}$ factor $>98.2%$. also include first observation dependence acoustic signal on...
We report results from the first search for νμ→νe transitions by NOvA experiment. In an exposure equivalent to 2.74×1020 protons on target in upgraded NuMI beam at Fermilab, we observe 6 events Far Detector, compared a background expectation of 0.99±0.11(syst) based Near Detector measurement. A secondary analysis observes 11 with 1.07±0.14(syst). The 3.3σ excess observed primary disfavors 0.1π<δCP<0.5π inverted mass hierarchy 90% C.L.Received 19 January...
The PICO collaboration reports results obtained by PICO-2L Run-2 after carefully controlling for particulate contamination. data clearly indicates that previously observed anomalies were due to contamination in the bubble chamber fluid. These observations set new bounds on spin-dependent scattering of dark matter, and help pave way larger scale experiments.
Data from the operation of a bubble chamber filled with 3.5 kg CF3I in shallow underground site are reported. An analysis ultrasound signals accompanying nucleations confirms that alpha decays generate significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during effective exposure 28.1 day, consistent neutron background. This observation provides strong direct detection...
New data are reported from the operation of PICO-60 dark matter detector, a bubble chamber filled with 36.8 kg CF$_3$I and located in SNOLAB underground laboratory. is largest to search for date. With an analyzed exposure 92.8 livedays, exhibits same excellent background rejection observed smaller chambers. Alpha decays exhibit frequency-dependent acoustic calorimetry, similar but not identical that recently C$_3$F$_8$ chamber. also observes large population unknown events, exhibiting...
This paper reports the first measurement using NOvA detectors of ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ disappearance in a beam. The analysis uses 14 kton-equivalent exposure $2.74\ifmmode\times\else\texttimes\fi{}{10}^{20}$ protons-on-target from Fermilab NuMI Assuming normal neutrino mass hierarchy, we measure $\mathrm{\ensuremath{\Delta}}{m}_{32}^{2}=({2.52}_{\ensuremath{-}0.18}^{+0.20})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{eV}}^{2}$ and...
The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons electrons using injectors momenta of 70 150 MeV/c, respectively. program includes the study nonlinear focusing integrable optical lattices based on special magnets electron lenses, dynamics space-charge effects their compensation, stochastic cooling, several other experiments. In this article, we present design...
We have performed a search for the 1P1 state of charmonium resonantly formed in p¯p annihilations, close to center gravity 3PJ states. report results from study J/ψ+π0 and J/ψ+2π final observed statistically significant enhancement p¯+p→J/ψ+π0 cross section at √s ≃3526.2 MeV. This has characteristics narrow resonance mass, total width, production consistent with what is expected state. In our we found no candidates reactions p¯+p→J/ψ+π0+π0 p¯+p→J/ψ+π++π−.Received 10 July...
Cross sections for the reaction pp¯→e+e− have been measured at s=8.9,12.4, and 13.0 GeV2. The cross analyzed to obtain proton electromagnetic form factors in timelike region. We find that GM(q2)∝q−4α2s(q2) q2≥5 (GeV/c)2.Received 30 September 1992DOI:https://doi.org/10.1103/PhysRevLett.70.1212©1993 American Physical Society
We report on an experimental demonstration of electron cooling high-energy antiprotons circulating in a storage ring. In our experiments, cooling, well-established method at low energies ($<500\text{ }\text{ }\mathrm{MeV}/\mathrm{\text{nucleon}}$), was carried out new region beam parameters, requiring multi-MeV dc and unusual transport line. this Letter, we present the results longitudinal force measurements compare them with theoretical predictions.
We report new measurements for the mass, width, and branching ratios $\frac{J}{\ensuremath{\psi}}$ ${\ensuremath{\psi}}^{\ensuremath{'}}$. These charmonium states are formed exclusively in $\overline{p}p$ annihilations at Fermilab Antiproton Accumulator ring, where stochastically cooled antiprotons brought into collision with protons of an internal hydrogen gas jet target. The antiproton energy is precisely controlled measured allowing accurate measurement resonance parameters. From shape...
We have directly measured the energy threshold and efficiency for bubble nucleation from iodine recoils in a CF3I chamber range of interest dark matter search. These interactions cannot be probed by standard neutron calibration methods, so we develop new technique observing elastic scattering 12 GeV/c negative pions. The pions are tracked with silicon pixel telescope reconstructed angle provides measure nuclear recoil kinetic energy. was operated nominal (13.6+-0.6) keV. Interpretation...
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The E760 Collaboration has studied the reaction p\ifmmode\bar\else\textasciimacron\fi{}p\ensuremath{\rightarrow}${\mathrm{\ensuremath{\chi}}}_{2}$\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma} using a hydrogen gas jet target in Fermilab antiproton acumulator ring. following values are obtained for branching ratio and partial width to two photons;...
The E760 Collaboration performed an experiment in the Antiproton Accumulator at Fermilab to study two photon decay of ηc(1 1S0) charmonium state formed p¯p annihilations. This resulted a new measurement mass Mηc=2988.3+3.3−3.1 MeV/c2 and product B(ηc→p¯p)×Γ(ηc→γγ) =(8.1+2.9−2.0) eV. We search for process p¯p→η′c(2 1S0)→γγ over limited range center-of-mass energies. Since no signal was observed, we derived upper limits on branching ratios B(η′c→p¯p)×B(η′c→γγ) energy 3584≤ √s ≤3624 MeV....
Fermilab experiment E-760 studies the resonant formation of charmonium states in proton-antiproton interactions using a hydrogen gas-jet target Antiproton Accumulator ring at Fermilab. Precision measurements mass and width χc1,χc2, direct measurement ψ’ width, new precision J/ψ are presented.Received 3 February 1992DOI:https://doi.org/10.1103/PhysRevLett.68.1468©1992 American Physical Society