Search NASA⌕ Search

SEARCH · Search NASA

Results for “elementary school”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

Effective bands and band-like electron transport in amorphous solids

The localization of electrons caused by atomic disorder is a well-known phenomenon. However, under which circumstances electrons remain delocalized and retain band-like characteristics even when the crystal structure is completely absent, as found in certain amorphous solids, is less well understood. Here, in this study, to probe this phenomenon, we develop a fully first-principles description of the electronic structure and charge transport in amorphous materials, which combines a representation of the amorphous state as a composite (ensemble) of local environments and the state-of-the-art many-body electronic structure methods. Using amorphous In 2 O 3 as an example, we demonstrate the accuracy of our approach in reproducing the band-like nature of the conduction electrons as well as their disorder-limited mobility. Our approach reveals the physical origins responsible for the electron delocalization and survival of the band dispersions despite the absence of long-range order.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Demonstration of new MeV-scale capabilities in large neutrino LArTPCs using ambient radiogenic and cosmogenic activity in MicroBooNE

Large neutrino liquid argon time projection chamber (LArTPC) experiments can broaden their physics reach by reconstructing and interpreting MeV-scale energy depositions, or blips, present in their data. We demonstrate new calorimetric and particle discrimination capabilities at the MeV energy scale using reconstructed blips in data from the MicroBooNE LArTPC at Fermilab. We observe a concentration of low-energy (<3 MeV) blips around fiberglass mechanical support struts along the time projection chamber edges with energy spectrum features consistent with the Compton edge of 2.614 MeV 208 Tl decay 𝛾 rays. These features are used to verify proper calibration of electron energy scales in MicroBooNE’s data to few percent precision and to measure the specific activity of 208 Tl in the fiberglass composing these struts, (11.7 ± 0.2⁢(stat) ± 3.1⁢(syst)) Bq/kg. Cosmogenically produced blips above 3 MeV in reconstructed energy are used to showcase the ability of large LArTPCs to distinguish between low-energy proton and electron energy depositions. An enriched sample of low-energy protons selected using this new particle discrimination technique is found to be smaller in data than in dedicated corsika cosmic-ray simulations, suggesting either incorrect corsika modeling of incident cosmic fluxes or particle transport modeling issues in geant4.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Data-driven model validation for neutrino-nucleus cross section measurements

Neutrino-nucleus cross section measurements are needed to improve interaction modeling to meet the precision needs of neutrino experiments in efforts to measure oscillation parameters and search for physics beyond the Standard Model. We review the difficulties associated with modeling neutrino-nucleus interactions that lead to a dependence on event generators in oscillation analyses and cross section measurements alike. We then describe data-driven model validation techniques intended to address this model dependence. The method relies on utilizing various goodness-of-fit tests and the correlations between different observables and channels to probe the model for defects in the phase space relevant for the desired analysis. These techniques shed light on relevant mismodeling, allowing it to be detected before it begins to bias the cross section results. We compare more commonly used model validation methods which directly validate the model against alternative ones to these data-driven techniques and show their efficacy with fake data studies. These studies demonstrate that employing data-driven model validation in cross section measurements represents a reliable strategy to produce robust results that will stimulate the desired improvements to interaction modeling.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Measurement of charged-current muon neutrino-argon interactions without pions in the final state using the MicroBooNE detector

We report a new measurement of flux-integrated differential cross sections for charged-current (CC) muon neutrino interactions with argon nuclei that produce no final-state pions (𝜈 𝜇 ⁢CC⁢0⁢𝜋). These interactions are of particular importance as a topologically defined signal dominated by quasielasticlike interactions. This measurement was performed with the MicroBooNE liquid argon time projection chamber detector located at the Fermilab Booster Neutrino Beam and uses an exposure of 1.3 ×10 21 protons on target collected between 2015 and 2020. The results are presented in terms of single- and double-differential cross sections as a function of the final-state muon momentum and angle. The data are compared with widely used neutrino event generators. We find good agreement with the single-differential measurements, while only a subset of generators are also able to adequately describe the data in double-differential distributions. This work facilitates comparison with Cherenkov detector measurements, including those located at the Booster Neutrino Be

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

QuarkNet Center Summer Internship for High School Students – FY2022

The purpose of this CRADA is to provide the contractual vehicle for Fermilab to receive funds from the College of DuPage in support of high school student research working with the Fermilab/University of Chicago QuarkNet Center, beginning with the effective date of this CRADA and continuing through 2022. Local QuarkNet Centers provide professional development programs to high school teachers and high energy physics research opportunities to high school teachers and students who participate in the local programs. The Office of Education and Public Engagement at Fermi National Accelerator Laboratory (Fermilab) administers a local QuarkNet Center program on behalf of both Fermilab and the University of Chicago.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Low-energy calibration of SuperCDMS HVeV cryogenic silicon calorimeters using Compton steps

Cryogenic calorimeters for low-mass dark matter searches have achieved sub-eV energy resolutions, driving advances in both low-energy calibration techniques and our understanding of detector physics. The energy deposition spectrum of gamma rays scattering off target materials exhibits step-like features, known as Compton steps, near the binding energies of atomic electrons. Here, we demonstrate a successful use of Compton steps for sub-keV calibration of cryogenic silicon calorimeters, utilizing four SuperCDMS High-Voltage eV-resolution detectors operated with 0 V bias across the crystal. This new calibration at 0 V is compared with the established high-voltage calibration using optical photons. The comparison indicates that the detector response at 0 V is about 30% weaker than expected, highlighting challenges in detector response modeling for low-mass dark matter searches.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

SUSY 2025 at UC Santa Cruz (Final Technical Report)

The 32nd International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY 2025) took place from August 18--23, 2025. During the week preceding the SUSY 2025 conference, the associated pre-SUSY school took place from August 11--15, 2025. Both events were organized and hosted by the Santa Cruz Institute for Particle Physics at the University of California, Santa Cruz. The SUSY 2025 conference brought together theorists and experimentalists specializing in particle physics, astroparticle physics, cosmology, mathematical physics, and string theory to discuss recent developments in these areas, with a focus on theoretical aspects and experimental searches associated with phenomena that lie beyond the Standard Model of particle physics and the standard mathematical framework of modern cosmology. The pre-SUSY school provided advanced pedagogical lectures for graduate students and early-career postdoctoral researchers on many of the foundational topics that were subsequently addressed in the main SUSY 2025 conference that followed. DOE support helped increase accessibility for early-career scientists by covering conference support costs that enabled free participation in the pre-SUSY school and substantially reduced registration fees for students attending the conference.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

A global significance evaluation method using simulated events

In High-Energy Physics experiments it is often necessary to evaluate the global statistical significance of apparent resonances observed in invariant mass spectra. One approach to determining significance is to use simulated events to find the probability of a random fluctuation in the background mimicking a real signal. As a high school summer project, we demonstrate a method with Monte Carlo simulated events to evaluate the global significance of a potential resonance with some assumptions. This method for determining significance is general and can be applied, with appropriate modification, to other resonances.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Sanford Underground Research Facility’s approach to school education, community activities, and public outreach

The Sanford Underground Research Facility (SURF) is the deepest underground science facility in the United States. SURF hosts world-leading experiments in neutrino, astroparticle and nuclear physics, as well as projects in biology, geology, and engineering, and is home to a major excavation project making space for Fermi National Accelerator Laboratory’s Long-Baseline Neutrino Facility (LBNF), which will power the Deep Underground Neutrino Experiment (DUNE). An emphasis on outreach and education is embedded in SURF’s mission statement: “to advance world-class science and inspire learning across generations.” To achieve this mission, SURF goes beyond established science communication methods, including operating an open-to-the-public visitor center, hosting multiple public outreach events per month, and an annual city-wide science festival. Furthermore, SURF is training K-12 science educators, developing school curriculum units, and providing classroom materials, based on science researched at the laboratory. The strategic approach, specific methods, and successful outcomes of these programs, which are based on SURF’s science, location, and community, may serve as examples for effective science education, public outreach, and community engagement.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

First Measurement of Charged-Current Muon-Neutrino-Induced 𝐾 + Production on Argon Using the MicroBooNE Detector

The MicroBooNE experiment is an 85 tonne active mass liquid argon time projection chamber neutrino detector exposed to the on-axis Booster Neutrino Beam at Fermilab. One of MicroBooNE’s physics goals is the precise measurement of neutrino interactions on argon in the 1 GeV energy regime. Building on the capabilities of the MicroBooNE detector, this analysis identifies 𝐾 + mesons, a key signature for the study of strange particle production in neutrino interactions. This measurement is furthermore valuable for background estimation for future nucleon decay searches and for improved reconstruction and particle identification capabilities in experiments such as the Deep Underground Neutrino Experiment. In this Letter, we present the first-ever measurement of a flux-integrated cross section for charged-current muon neutrino induced 𝐾 + production on argon nuclei, determined to be 7.93 ± 3.22⁢(stat) ± 2.83⁢(syst)×10 −42 cm 2 /nucleon based on an analysis of 6.88 × 10 20 protons on target. This result was found to be consistent with model predictions from different neutrino event generators within the reported uncertainties.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Search for an Anomalous Production of Charged-Current 𝜈 𝑒 Interactions without Visible Pions across Multiple Kinematic Observables in MicroBooNE

This Letter presents an investigation of low-energy electron-neutrino interactions in the Fermilab Booster Neutrino Beam by the MicroBooNE experiment, motivated by the excess of electron-neutrino-like events observed by the MiniBooNE experiment. This is the first measurement to use data from all five years of operation of the MicroBooNE experiment, corresponding to an exposure of 1.11 × 10 21 protons on target, a 70% increase on past results. Two samples of electron neutrino interactions without visible pions are used, one with visible protons and one without any visible protons. The MicroBooNE data show reasonable agreement with the nominal prediction, with 𝑝 values ≥26.7% when the two 𝜈 𝑒 samples are combined, though the prediction exceeds the data in limited regions of phase space. The data are further compared to two empirical models that modify the predicted rate of electron-neutrino interactions in different variables in the simulation to match the unfolded MiniBooNE low energy excess. In the first model, this unfolding is performed as a function of electron neutrino energy, while the second model aims to match the observed shower energy and angle distributions of the MiniBooNE excess. This measurement excludes an electronlike interpretation of the MiniBooNE excess based on these models at >99% CLs in all kinematic variables.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Enhanced search for neutral current Δ radiative single-photon production in MicroBooNE

We report results from an updated search for neutral current (NC) resonant Δ⁡(1232) baryon production and subsequent Δ radiative decay (NC Δ → 𝑁⁢𝛾). We consider events with and without final state protons; events with a proton can be compared with the kinematics of a Δ⁡(1232) baryon decay, while events without a visible proton represent a more generic phase space. In order to maximize sensitivity to each topology, we simultaneously make use of two different reconstruction paradigms, Pandora and Wire-Cell, which have complementary strengths, and select mostly orthogonal sets of events. Considering an overall scaling of the NC Δ → 𝑁⁢𝛾 rate as an explanation of the MiniBooNE anomaly, our data exclude this hypothesis at 94.4% CL. When we decouple the expected correlations between NC Δ → 𝑁⁢𝛾 events with and without final state protons, our data exclude an interpretation in which all excess events have associated protons at 2.0⁢𝜎, and are consistent with an interpretation in which all excess events have no associated protons at 0.63⁢𝜎.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Search for the production of Higgs-portal scalar bosons in the NuMI beam using the MicroBooNE detector

We present the strongest experimental limits to date on the mixing angle, 𝜃, with which a new scalar particle, 𝑆, mixes with the Higgs field in the mass range 110 MeV < 𝑚 𝑆 <155 MeV. This result uses the MicroBooNE liquid argon time projection chamber to search for decays of these Higgs-portal scalar particles through the 𝑆 → 𝑒 + ⁢𝑒 − channel with the decays of kaons in the NuMI neutrino beam acting as the source of the scalar particles. The analysis uses an exposure of 2.01 × 10 21 protons on target of NuMI beam data including periods when the beam focusing system was configured to focus positively charged hadrons and separate periods when negatively charged hadrons were focused. The analysis searches for scalar particles produced from kaons decaying in flight in the beam’s decay volume and at rest in the target and absorber. At 𝑚 𝑆 =125 MeV (𝑚 𝑆 =150 MeV) we set a limit of 𝜃 < 3.19 ×10 −4 (𝜃 < 2.79 ×10 −4 ) at the 95% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Direct experimental constraints on the spatial extent of a neutrino wavepacket

Despite their high relative abundance in our Universe, neutrinos are the least understood fundamental particles of nature. In fact, the quantum properties of neutrinos emitted in experimentally relevant sources are theoretically contested and the spatial extent of the neutrino wavepacket is only loosely constrained by reactor neutrino oscillation data with a spread of 13 orders of magnitude. Here we present a method to directly access this quantity by precisely measuring the energy width of the recoil daughter nucleus emitted in the radioactive decay of beryllium-7. The final state in the decay process contains a recoiling lithium-7 nucleus, which is entangled with an electron neutrino at creation. The lithium-7 energy spectrum is measured to high precision by directly embedding beryllium-7 radioisotopes into a high-resolution superconducting tunnel junction that is operated as a cryogenic sensor. Under this approach, we set a lower limit on the Heisenberg spatial uncertainty of the recoil daughter of 6.2 pm, which implies that the final-state system is localized at a scale more than a thousand times larger than the nucleus itself. From this measurement, the first, to our knowledge, direct lower limit on the spatial extent of a neutrino wavepacket is extracted. These results may have implications in several areas including the theoretical understanding of neutrino properties, the nature of localization in weak nuclear decays and the interpretation of neutrino physics data.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

First study of neutrino angle reconstruction using quasielasticlike interactions in MicroBooNE

We investigate the expected precision of the reconstructed neutrino direction using a 𝜈 𝜇 -argon quasielasticlike event topology with one muon and one proton in the final state and the reconstruction capabilities of the MicroBooNE liquid argon time projection chamber. This direction is of importance in the context of DUNE sub-GeV atmospheric oscillation studies. MicroBooNE allows for a data-driven quantification of this resolution by investigating the deviation of the reconstructed muon-proton system orientation with respect to the well-known direction of neutrinos originating from the Booster Neutrino Beam with an exposure of 1.3 ×10 21 protons on target. Using simulation studies, we derive the expected sub-GeV DUNE atmospheric-neutrino reconstructed simulated spectrum by developing a reweighting scheme as a function of the true neutrino energy. We further report flux-integrated single- and double-differential cross section measurements of charged-current 𝜈 𝜇 quasielasticlike scattering on argon as a function of the muon-proton system angle using the full MicroBooNE data sets. We also demonstrate the sensitivity of these results to nuclear effects and final state hadronic reinteraction modeling.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

First Search for Dark Sector 𝑒 + ⁢𝑒 − Explanations of the MiniBooNE Anomaly at MicroBooNE

We present MicroBooNE’s first search for dark sector 𝑒 + ⁢𝑒 − explanations of the long-standing MiniBooNE anomaly. The MiniBooNE anomaly has garnered significant attention over the past 20 years including previous MicroBooNE investigations into both anomalous electron and photon excesses, but its origin still remains unclear. In this Letter, we provide the first direct test of dark sector models in which dark neutrinos, produced through neutrino-induced scattering, decay into missing energy and visible 𝑒 + ⁢𝑒 − pairs comprising the MiniBooNE anomaly. Many such models have recently gained traction as a viable solution to the anomaly while evading past bounds. Using an exposure of 6.87 × 10 20 protons-on-target in the Booster Neutrino Beam, we implement a selection targeting forward-going, coherently produced 𝑒 + ⁢𝑒 − events. After unblinding, we observe 95 events, which we compare with the constrained background-only prediction of 69.7 ±17.3. This analysis sets the world’s first direct limits on these dark sector models and, at the 95% confidence level, excludes the entirety of the single dark neutrino and majority of the dual dark neutrino, parameter space that is viable as a solution to the MiniBooNE anomaly.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Nm-scale electrical resistance imaging on CdTe by scanning spreading resistance microscopy

Local resistance imaging can provide information on nm-scale carrier distribution in semiconductor devices. Scanning spreading resistance microscopy (SSRM), an atomic force microscopy-based nm-scale resistance mapping technique, has been developed for carrier delineation in Si microdevices. We report on the development and validation of SSRM on CdTe materials, by testing on molecular beam epitaxy (MBE) grown CdTe films. The probe/CdTe contact resistance was suppressed sufficiently below sample's spreading resistance by pressing the probe into the sample with ∼mN contact force and applying a large sample/probe forward bias voltage (V s ), which was understood by analyzing current-voltage (I-V) involving a serially connected insulating top layer with underlying spreading resistance. The carrier concentration as deduced from the resistance measurement, using a single mobility value, is consistent with Hall measurement with a standard deviation of 14% based on a set of MBE films with carrier concentrations in the range of 10 15 –10 16 /cm 3 . The doping polarity was readily identified by flipping V s polarity, where the resistance with reverse V s is orders of magnitude larger than forward V s . While focusing on the SSRM technique validation, we also show an example on an As-doped Cd(Se,Te) polycrystalline thin film of a high-performance CdTe solar cell, which illustrates the local resistance nonuniformity with up to two orders of magnitude differences, indicating if local mobility is roughly constant, local carrier concentration can have significant nonuniformity.

14 SOLAR ENERGY↗

High Energy Theory and Cosmology Workshops at the Leinweber Center for Theoretical Physics at the University of Michigan

This award partially supported a workshop and a summer school held at the Leinweber Center for Theoretical Physics at the University of Michigan in Ann Arbor. Funds were primarily used to support the travel of external participants. The programs were substantially delayed owing to the pandemic. The symposium was initially slated for Spring 2020. The 2023 Michigan Cosmology Summer School was held June 5-9 2023 in Ann Arbor Michigan. There were about 150 in-person international participants (of whom about 35Nine external lecturers listed below delivered a series of lectures ranging on topics from “Measuring and Mapping Cosmic Shear” to “Dark Dark Energy and Modified Gravity.” Many archived version of the slides and videos of the lectures may be found at https://johannesulf.github.io/cosmology-school-2023/program.html

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗