H. P. Mumm
A5002157386- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Neutrino Physics Research
- Quantum, superfluid, helium dynamics
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Advanced MRI Techniques and Applications
- Radioactive Decay and Measurement Techniques
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- NMR spectroscopy and applications
- Nuclear physics research studies
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced NMR Techniques and Applications
- Cold Fusion and Nuclear Reactions
- Radiation Therapy and Dosimetry
- Advanced Semiconductor Detectors and Materials
- Particle accelerators and beam dynamics
- Medical Imaging Techniques and Applications
- Radioactive contamination and transfer
- Quantum Chromodynamics and Particle Interactions
- Risk Perception and Management
- Advanced Frequency and Time Standards
National Institute of Standards and Technology
2016-2025
National Institute of Standards
2006-2025
Physical Measurement Laboratory
2017
University of Wisconsin–Madison
2013
University of Washington
2000-2011
University of Michigan–Ann Arbor
2010
North Carolina State University
2005-2008
Yale University
2008
Harvard University
2008
Indiana University
2005
The PROSPECT Collaboration presents their improved results with new limits on the oscillation of electron antineutrinos to light sterile neutrinos and energy spectrum measurements several short baselines.
This Letter reports the first scientific results from observation of antineutrinos emitted by fission products $^{235}\mathrm{U}$ at High Flux Isotope Reactor. PROSPECT, Precision Reactor Oscillation and Spectrum Experiment, consists a segmented 4 ton $^{6}\mathrm{Li}$-doped liquid scintillator detector covering baseline range 7--9 m reactor operating under less than 1 water equivalent overburden. Data collected during 33 live days operation nominal power 85 MW yield detection $25\text{...
The violation of Baryon Number, $\mathcal{B}$, is an essential ingredient for the preferential creation matter over antimatter needed to account observed baryon asymmetry in universe. However, such a process has yet be experimentally observed. HIBEAM/NNBAR %experiment program proposed two-stage experiment at European Spallation Source (ESS) search number violation. will include high-sensitivity searches processes that violate by one or two units: free neutron-antineutron oscillation...
The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make a precise measurement of the antineutrino spectrum from highly-enriched uranium reactor probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long distances. PROSPECT conceived as 2-phase experiment utilizing segmented $^6$Li-doped liquid scintillator detectors both efficient detection antineutrinos through inverse beta decay reaction excellent background discrimination....
If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if is upscattered high by collisions with cosmic rays, may be both experiments and neutrino We report the results of a dedicated search for boosted rays using PROSPECT reactor antineutrino experiment. show that such flux would display characteristic diurnal sidereal modulation, use this set new experimental constraints on sub-GeV...
This Letter reports the first measurement of $^{235}$U $\overline{\nu_{e}}$ energy spectrum by PROSPECT, Precision Reactor Oscillation and Spectrum experiment, operating 7.9m from 85MW$_{\mathrm{th}}$ highly-enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678$\pm$304 (stat.) $\overline{\nu_{e}}$-induced inverse beta decays (IBD), largest sample HEU fission to date, 99% which are attributed $^{235}$U. Despite broad agreement,...
This Letter reports one of the most precise measurements to date antineutrino spectrum from a purely 235U-fueled reactor, made with final dataset PROSPECT-I detector at High Flux Isotope Reactor. By extracting information previously unused segments, this analysis effectively doubles statistics previous PROSPECT measurement. The reconstructed energy is unfolded into and compared both Huber-Mueller model commercial reactor burning multiple fuel isotopes. A local excess over observed in 5–7 MeV...
We report the results of an improved determination triple correlation $D P \cdot(p_{e}\times p_{\nu})$ that can be used to limit possible time-reversal invariance in beta decay polarized neutrons and constrain extensions Standard Model. Our result is $D=(-0.96\pm 1.89 (stat)\pm 1.01 (sys))\times 10^{-4}$. The corresponding phase between g_A g_V $\phi_{AV} = 180.013^\circ\pm0.028^\circ$ (68 % confidence level). This represents most sensitive measurement D decay.
The standard model predicts that, in addition to a proton, an electron, and antineutrino, continuous spectrum of photons is emitted the β decay free neutron. We report on RDK II experiment which measured photon using two different detector arrays. An annular array bismuth germanium oxide scintillators detected from 14 782 keV. spectral shape was consistent with theory, we determined branching ratio 0.00335±0.00005[stat]±0.00015[syst]. A second large area avalanche photodiodes directly 0.4...
The PROSPECT and STEREO collaborations present a combined measurement of the pure ^{235}U antineutrino spectrum, without site specific corrections or detector-dependent effects. spectral measurements two highest precision experiments at research reactors are found to be compatible with χ^{2}/ndf=24.1/21, allowing joint unfolding prompt energy into energy. This ν[over ¯]_{e} spectrum is provided community, an excess events relative Huber model in 5-6 MeV region. When Gaussian bump fitted...
We report an upper bound on parity-violating neutron spin rotation in $^{4}\mathrm{He}$. This experiment is the most sensitive search for neutron-weak optical activity yet performed and represents a significant advance precision comparison to past measurements heavy nuclei. The was at NG-6 slow-neutron beamline National Institute of Standards Technology (NIST) Center Neutron Research. Our result angle per unit length $^{4}\mathrm{He}$...
Background: Time-reversal-invariance violation, or equivalently CP may explain the observed cosmological baryon asymmetry as well signal physics beyond Standard Model. In decay of polarized neutrons, triple correlation D<J_{n}>\cdot(p_{e}\timesp_{\nu}) is a parity-even, time-reversal- odd observable that uniquely sensitive to relative phase axial-vector amplitude with respect vector amplitude. The also possible contributions from scalar and tensor amplitudes. Final-state effects contribute D...
This paper describes the design and performance of a 50 liter, two-segment $^{6}$Li-loaded liquid scintillator detector that was designed operated as prototype for PROSPECT (Precision Reactor Oscillation Spectrum) Experiment. The constructed according to specifications experiment. It features low-mass optical separators, an integrated source calibration system, materials are compatible with $^{6}$Li-doped developed by PROSPECT. We demonstrate high light collection 850$\pm$20 PE/MeV, energy...
We describe a new detector, called NuLat, to study electron anti-neutrinos few meters from nuclear reactor, and search for anomalous neutrino oscillations. Such oscillations could be caused by sterile neutrinos, might explain the "Reactor Antineutrino Anomaly". is made possible natural synergy between miniTimeCube mini-LENS programs described in this paper. It features "Raghavan Optical Lattice" (ROL) consisting of 3375 boron or $^6$Li loaded plastic scintillator cubical cells 6.3\,cm...
We describe an experiment that has set new limits on the time reversal invariance violating D coefficient in neutron beta-decay. The emiT measured angular correlation J . p_e x p_p using octagonal symmetry optimizes electron-proton coincidence rates. result is D=[-0.6+/-1.2(stat)+/-0.5(syst)]x10^(-3). This improves constraints phase of g_A/g_V and contributions to T violation due leptoquarks. paper presents details experiment, data analysis, investigation systematic effects.
The theory of quantum electrodynamics predicts that the $\ensuremath{\beta}$ decay neutron into a proton, electron, and antineutrino is accompanied by continuous spectrum emitted photons described as inner bremsstrahlung. While this phenomenon has been observed in nuclear electron-capture for many years, it only recently free-neutron decay. We present detailed discussion an experiment which radiative mode free was observed. In experiment, branching ratio rare determined recording were...
Current models of antineutrino production in nuclear reactors predict detection rates and spectra at odds with the existing body direct reactor measurements. High-resolution detectors operated close to compact research cores can produce new precision measurements useful testing explanations for these observed discrepancies involving underlying or physics. Absolute measurement 235U-produced spectrum provide additional constraints evaluating accuracy current future models, while relative...
This work reports the production and characterization of lithium-loaded liquid scintillator (LiLS) for Precision Reactor Oscillation Spectrum Experiment (PROSPECT) . Fifty-nine 90 liter batches LiLS (6Li mass fraction 0.082%±0.001%) were produced samples from all characterized by measuring their optical absorbance relative to air, light yield a pure reference, pulse shape discrimination capability. Fifty-seven passed quality assurance criteria used PROSPECT experiment.
Abstract The precision reactor oscillation and spectrum experiment, PROSPECT, has made world-leading measurements of antineutrinos at short baselines. In its first phase, conducted the high flux isotope (HFIR) Oak Ridge National Laboratory, PROSPECT produced some strongest limits on eV-scale sterile neutrinos, a measurement antineutrino from 235 U, demonstrated observation in an aboveground detector with good energy resolution well-controlled backgrounds. collaboration is now preparing...
Reactor antineutrinos are used to study neutrino oscillation, search for signatures of non-standard interactions, and monitor reactor operation safeguard applications. The flux energy spectrum can be predicted from the decays nuclear fission products. A comparison recent calculations with past measurements at baselines 10-100m suggests a 5.7% deficit. Precision very short O(1-10 m) probe this anomaly possible oscillations into sterile species. This paper studies experimental requirements new...