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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.

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At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Right-handed slepton bulk region for dark matter in generalized no-scale F -SU(5) with effective supernatural supersymmetry

We propose generalized no-scale supergravity, the simplest scenario for effective supernatural supersymmetry, naturally solving the supersymmetry electroweak fine-tuning problem and including natural dark matter. A light right-handed slepton bulk region is realized in F -SU(5) and the phenomenological minimal supersymmetric standard model. The bulk may be beyond the LHC reach, although it can be probed at the 1000-day LUX-ZEPLIN, Future Circular Collider at CERN, Circular Electron-Positron Collider, and Hyper-Kamiokande. Published by the American Physical Society 2024

Astronomy & Astrophysics↗
DOE OSTI2024

Search for heavy right-handed Majorana neutrinos in the decay of top quarks produced in proton-proton collisions at s = 13 TeV with the ATLAS detector

A search for heavy right-handed Majorana neutrinos is performed with the ATLAS detector at the CERN Large Hadron Collider, using the 140 fb -1 of proton–proton collision data at $\sqrt{s}$ =13 TeV collected during Run 2. This search targets $t\overline{t}$ production, in which both top quarks decay into a bottom quark and a W boson, where one of the W bosons decays hadronically and the other decays into an electron or muon and a heavy neutral lepton. The heavy neutral lepton is identified through a decay into an electron or muon and another W boson, resulting in a pair of same-charge same-flavor leptons in the final state. This paper presents the first search for heavy neutral leptons in the mass range of 15–75 GeV using $t\overline{t}$ events. No significant excess is observed over the background expectation, and upper limits are placed on the signal cross sections. Assuming a benchmark scenario of the phenomenological type-I seesaw model, these cross section limits are then translated into upper limits on the mixing parameters of the heavy Majorana neutrino with Standard Model neutrinos.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Z -portal right-handed neutrino dark matter in the minimal U ( 1 ) X extended Standard Model

We consider a concise dark matter (DM) scenario in the context of a non-exotic U(1) extension of the Standard Model (SM), where a new U(1) X gauge symmetry is introduced along with three generation of right-handed neutrinos (RHNs) and an SM gauge singlet Higgs field. The model is a generalization of the minimal gauged U(1) B-L (baryon number minus lepton number) extension of the SM, in which the extra U(1) X gauge symmetry is expressed as a linear combination of the SM U(1) Y and U(1) B-L gauge symmetries. We introduce a Z 2 -parity and assign an odd-parity only for one RHN among all particles, so that this Z2-odd RHN plays a role of DM. The so-called minimal seesaw mechanism is implemented in this model with only two Z 2 -even RHNs. In this context, we investigate physics of the RHN DM, focusing on the case that this DM particle communicates with the SM particles through the U(1) X gauge boson (Z' boson). This "Z'-portal RHN DM" scenario is controlled by only three free parameters: the U(1) X gauge coupling (αX), the Z' boson mass (mZ'), and the U(1) X charge of the SM Higgs doublet (x H ). We consider various phenomenological constraints to identify a phenomenologically viable parameter space. The most important constraints are the observed DM relic abundance and the latest LHC Run-2 results on the search for a narrow resonance with the dilepton final state. In conclusion, we find that these are complementary with each other and narrow the allowed parameter region, leading to the lower mass bound of m Z' ≳ 2.7 TeV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Indirect signals from solar dark matter annihilation to long-lived right-handed neutrinos

In this paper, we study indirect detection signals from solar annihilation of dark matter (DM) particles into light right-handed (RH) neutrinos with a mass in a 1–5 GeV range. These RH neutrinos can have a sufficiently long lifetime to allow them to decay outside the Sun, and their delayed decays can result in a signal in gamma rays from the otherwise “dark” solar direction, and also a neutrino signal that is not suppressed by the interactions with solar medium. We find that the latest Fermi-LAT and IceCube results place limits on the gamma ray and neutrino signals, respectively. Combined photon and neutrino bounds can constrain the spin-independent DM-nucleon elastic scattering cross section better than direct detection experiments for DM masses from 200 GeV up to several TeV. Finally, the bounds on spin-dependent scattering are also much tighter than the strongest limits from direct detection experiments.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

Right-handed neutrino dark matter in the classically conformal $\mathrm{U(1)'}$ extended standard model

Here we consider the dark matter (DM) scenario in the context of the classically conformal U(1)′ extended standard model (SM), with three right-handed neutrinos (RHNs) and the U(1)′ Higgs field. The model is free from all of the U(1)′ gauge and gravitational anomalies in the presence of the three RHNs. We introduce a Z 2 parity in the model, under which an odd parity is assigned to one RHN, while all of the other particles are assigned to be Z 2 even, and hence the Z 2 -odd RHN serves as a DM candidate. In this model, the U(1)′ gauge symmetry is radiatively broken through the Coleman-Weinberg mechanism, by which the electroweak symmetry breaking is triggered. There are three free parameters in our model—the U(1)′ charge of the SM Higgs doublet (x H ), the new U(1)′ gauge coupling (g X ), and the U(1)′ gauge boson (Z′) mass (m Z′ )—which are severely constrained in order to solve the electroweak vacuum instability problem, and satisfy the LHC Run-2 bounds from the search for the Z′ boson resonance. In addition to these constraints, we investigate the RHN DM physics. Because of the nature of classical conformality, we find that a RHN DM pair mainly annihilates into the SM particles through Z′ boson exchange. This is the so-called Z′-portal DM scenario. Combining the electroweak vacuum stability condition, the LHC Run-2 bounds, and the cosmological constraint from the observed DM relic density, we find that all constraints work together to narrow the allowed parameter regions and, in particular, exclude m Z′ ≲ 3.5 TeV. For the obtained allowed regions, we calculate the spin-independent cross section of the RHN DM with nucleons. We find that the resultant cross section is well below the current experimental upper bounds.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Unified scenario for composite right-handed neutrinos and dark matter

In this study, we entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark SU(3) D interaction with three flavors of massless dark quarks; electroweak symmetry breaking gives masses to the dark quarks. By assigning a Z 2 charge to one flavor, a stable “dark kaon” can provide a good thermal relic DM candidate. We find that “dark neutrons” may be identified as right handed Dirac neutrinos. Some level of “neutron-anti-neutron” oscillation in the dark sector can then result in non-zero Majorana masses for light standard model neutrinos. A simple ultraviolet completion is presented, involving additional heavy SU(3) D -charged particles with electroweak and lepton Yukawa couplings. At our benchmark point, there are “dark pions” that are much lighter than the Higgs and we expect spectacular collider signals arising from the UV framework. This includes the decay of the Higgs boson to ττℓℓ', where ℓ(ℓ ') can be any lepton, with displaced vertices. Finally, we discuss the observational signatures of this UV framework in dark matter searches and primordial gravitational wave experiments; the latter signature is potentially correlated with the H → ττℓℓ' decay.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

The Influence of Visual Provenance Representations on Strategies in a Collaborative Hand-off Data Analysis Scenario

Conducting data analysis tasks rarely occur in isolation. Especially in intelligence analysis scenarios where different experts contribute knowledge to a shared understanding, members must communicate how insights develop to establish common ground among collaborators. The use of provenance to communicate analytic sensemaking carries promise by describing the interactions and summarizing the steps taken to reach insights. Yet, no universal guidelines exist for communicating provenance in different settings. Our work here focuses on the presentation of provenance information and the resulting conclusions reached and strategies used by new analysts. In an open-ended, 30-minute, textual exploration scenario, we qualitatively compare how adding different types of provenance information (specifically data coverage and interaction history) affects analysts' confidence in conclusions developed, propensity to repeat work, filtering of data, identification of relevant information, and typical investigation strategies. We see that data coverage (i.e., what was interacted with) provides provenance information without limiting individual investigation freedom. On the other hand, while interaction history (i.e., when something was interacted with) does not significantly encourage more mimicry, it does take more time to comfortably understand, as represented by less confident conclusions and less relevant information-gathering behaviors. In conclusion, our results contribute empirical data towards understanding how provenance summarizations can influence analysis behaviors.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

TH-E-201-02: Hands-On Physics Teaching of Residents in Diagnostic Radiology

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2025

Introducing Quantum Entanglement and Superposition to Secondary School Students Using Portable, Hands-on Exhibits

Historically, the teaching of quantum mechanics has been reserved for advanced undergraduate physics courses, mostly due to how far removed from classical intuition the subject is. Extensive mathematical background is usually a prerequisite for college-level introductory quantum mechanics courses. However, several ways to introduce quantum mechanics at the secondary school level have been suggested and developed. Unlike most other topics in physics, it is difficult to find intuitive examples of quantum phenomena outside of a specialized laboratory; additionally, straightforward hands-on demonstrations, activities, and experiments are somewhat limited.

Educational aids↗
DOE OSTI2018

Nonlinear Right-Hand Polarized Wave in Plasma in the Electron Cyclotron Resonance Region

The propagation of a nonlinear right-hand polarized wave along an external magnetic field in subcritical plasma in the electron cyclotron resonance region is studied using numerical simulations. It is shown that a small-amplitude plasma wave excited in low-density plasma is unstable against modulation instability with a modulation period equal to the wavelength of the excited wave. The modulation amplitude in this case increases with decreasing detuning from the resonance frequency. The simulations have shown that, for large-amplitude waves of the laser frequency range propagating in plasma in a superstrong magnetic field, the maximum amplitude of the excited longitudinal electric field increases with the increasing external magnetic field and can reach 30% of the initial amplitude of the electric field in the laser wave. In this case, the energy of plasma electrons begins to substantially increase already at magnetic fields significantly lower than the resonance value. The laser energy transferred to plasma electrons in a strong external magnetic field is found to increase severalfold compared to that in isotropic plasma. It is shown that this mechanism of laser radiation absorption depends only slightly on the electron temperature.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

SMART U(1)$$_X$$: standard model with axion, right handed neutrinos, two Higgs doublets and U(1)$$_X$$ gauge symmetry

Abstract To address five fundamental shortcomings of the Standard Model (SM) of particle physics and cosmology, we propose a phenomenologically viable framework based on a $$U(1)_X \times U(1)_{PQ}$$ U ( 1 ) X × U ( 1 ) PQ extension of the SM, that we call “SMART U(1) $$_X$$ X ”. The $$U(1)_X$$ U ( 1 ) X gauge symmetry is a well-known generalization of the $$U(1)_{B-L}$$ U ( 1 ) B - L symmetry and $$U(1)_{PQ}$$ U ( 1 ) PQ is the global Peccei–Quinn (PQ) symmetry. Three right handed neutrinos are added to cancel $$U(1)_X$$ U ( 1 ) X related anomalies, and they play a crucial role in understanding the observed neutrino oscillations and explaining the observed baryon asymmetry in the universe via leptogenesis. Implementation of PQ symmetry helps resolve the strong CP problem and also provides axion as a compelling dark matter (DM) candidate. The $$U(1)_X$$ U ( 1 ) X gauge symmetry enables us to implement the inflection-point inflation scenario with $$H_{inf} \lesssim 2 \times 10^{7}$$ H inf ≲ 2 × 10 7 GeV, where $$H_{inf}$$ H inf is the value of Hubble parameter during inflation. This is crucial to overcome a potential axion domain wall problem as well as the axion isocurvature problem. The SMART U(1) $$_X$$ X framework can be successfully implemented in the presence of SU (5) grand unification, as we briefly show.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

DAMPE excess from decaying right-handed neutrino dark matter

The flux of high-energy cosmic-ray electrons plus positrons recently measured by the DArk Matter Particle Explorer (DAMPE) exhibits a tentative peak excess at an energy of around 1.4 TeV. In this paper, we consider the minimal gauged U(1)$_{B—L}$ model with a right-handed neutrino (RHN) dark matter (DM) and interpret the DAMPE peak with a late-time decay of the RHN DM into $e^±W^∓$. Here, we find that a DM lifetime $τ_{DM}$~$10^{28}$s can fit the DAMPE peak with a DM mass $m_{DM}$=3TeV. This favored lifetime is close to the current bound on it by Fermi-LAT, our decaying RHN DM can be tested, once the measurement of cosmic gamma ray flux is improved. The RHN DM communicates with the Standard Model particles through the U(1)$_{B—L}$ gauge boson (Z' boson), and its thermal relic abundance is controlled by only three free parameters: $m_{DM}$, the U(1)$_{B—L}$ gauge coupling ($α_{BL}$), and the Z' boson mass ($m_{Z'}$). For $m_{DM}$=3TeV, the rest of the parameters are restricted to be $m_{Z'}$≃6TeV and 0.00807≤$α_{BL}$≤0.0149, in order to reproduce the observed DM relic density and to avoid the Landau pole for running $α_{BL}$ below the Planck scale. This allowed region will be tested by the search for a Z' boson resonance at the future Large Hadron Collider.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

A Hands-on Course on Intensified Membrane Processes for Sustainable Water Purification

The lack in process intensification (PI) training may be limiting processes to achieve sustainability goals. Furthermore, this project developed a hands-on course on intensified membrane processes to address knowledge gaps in PI. Bench-scale activities introduced concepts of membrane separation, operating engineering-scale modules provided a near-industrial experience, and simulation software allowed modeling and optimization of a process. Student evaluations showed that the combination of modeling, experimental, and peer-instruction work helped them understand the application of theoretical concepts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Validation of ANSI N42.34 – American National Standard Performance Criteria for Hand-Held Instruments for the Detection and Identification of Radionuclides

SRNL’s validation of ANSI N42.34-D6 for the Domestic Nuclear Detection Office (DNDO) was performed utilizing one hand-held instrument (or RID) – the FLIR identiFINDER 2. Each section of the standard was evaluated via a walk-through or test. NOTE: In Table 1, W = walk-through and T = test, as directed by the Domestic Nuclear Detection Office (DNDO). For a walk-through, the experiment was either setup or reviewed for setup; for a test, the N42.34-D6 procedures were followed with some exceptions and comments noted. SRNL is not fully able to evaluate a RID against Sections 7 (Environmental), 8 (Electromagnetic), and 9 (Mechanical) of N42.34, so those portions of this validation were done in collaboration with Qualtest, Inc. in Orlando, Florida. The walk-throughs and tests of Sections 7, 8, and 9 were performed in Qualtest, Inc. facilities with SRNL providing radiological sources as necessary. Where applicable, assessment results and findings of the walk-throughs and tests were recorded on datasheets and a validation summary is provided. A general comment pertained to test requirements found in another standard and referenced in N42.34-D6. For example, step 1 of the test method in section 8.1.2 states “RF test set up information can be found in IEC 61000-4-3.” It is recommended that any information from other standards necessary for conducting the tests within N42.34 should be posted in N42.34 for simplicity and to prevent the user from having to peruse other documents. Another general comment, as noted by Qualtest, is that a tolerance reference is not listed for each test in sections 7-9. Overall, the N42.34-D6 was proven to be practicable, but areas for improvement and recommendations were identified for consideration prior to final ballot submittal.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

US-ROK Action Sheet 34: Safeguards Application of a Hand-held Mechanically Cooled Germanium Spectrometer

This report summarizes results of Action Sheet 34 - for the cooperative efforts on the field testing and evaluation of a high-resolution, hand-held, gamma-ray spectrometer, known as SPG (Spectroscopic Planar Germanium), for safeguards application such as short notice inspections, UF6 analysis, enrichment determination, and other potential applications. The Spectroscopic Planar Germanium (SPG) has been demonstrated IAEA Physical Inventory Verification (PIV) in South Korea. This field test was a success and the feedback provided by KINAC, IAEA, and national laboratory staff was used to direct efforts to improve the instrument this year. Key points in this report include measurement results from PIV, analysis of spectra with commercially available Ortec U235 and PC-FRAM, and completion of tripod and tungsten collimator and integration of user feedback.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

ISR All Hands

This presentation provides highlights from LANL's Intelligence and Space Research all hands meeting.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Designing Hands-on Exercises for the Nuclear Detection and Sensor Test Center [Poster]

The Nuclear Detection and Sensor Testing Center (NDSTC) provides a test bed for researchers to test both their instrumentation systems and analytical techniques using nuclear material from Y-12. Students and professionals from outside of Y-12 visit Site 2 of the NDSTC as a part of Nonproliferation Workshops and other Y-12-hosted events. Site 2 of the NDSTC holds Category IV quantities of uranium-bearing materials and radiological sources. The goal of this project is to design engaging, hands-on activities which will be implemented during these visits in order to give the participants a more informative experience in nuclear detection.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗