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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 1,387 records · Page 77
All sourcesNASA NTRSDOE OSTI
DOE OSTI2010

High-precision Penning trap mass measurements for tests of the Standard Model

With the nowadays achievable accuracy in Penning trap mass spectrometry on short-lived exotic nuclides as well as stable atoms, precision fundamental tests can be performed, among them a test of the Standard Model, in particular with regard to the weak interaction, the CPT symmetry conservation, and the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. In addition, accurate mass values of specific nuclides are important for neutrino physics. The presently best tests of the Standard Model with high-precision Penning trap mass spectrometry will be reviewed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Extended spin symmetry and the standard model

We review unification ideas and explain the spin-extended model in this context. Its consideration is also motivated by the standard-model puzzles. With the aim of constructing a common description of discrete degrees of freedom, as spin and gauge quantum numbers, the model departs from q-bits and generalized Hilbert spaces. Physical requirements reduce the space to one that is represented by matrices. The classification of the representations is performed through Clifford algebras, with its generators associated with Lorentz and scalar symmetries. We study a reduced space with up to two spinor elements within a matrix direct product. At given dimension, the demand that Lorentz symmetry be maintained, determines the scalar symmetries, which connect to vector-and-chiral gauge-interacting fields; we review the standard-model information in each dimension. We obtain fermions and bosons, with matter fields in the fundamental representation, radiation fields in the adjoint, and scalar particles with the Higgs quantum numbers. We relate the fields' representation in such spaces to the quantum-field-theory one, and the Lagrangian. The model provides a coupling-constant definition.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

The neutrino charge radius as a probe of physics beyond the standard model

In this paper, we review the search of possible physics effects beyond the standard model on the electromagnetic charge and anapole form factors, f{sub Q}(q{sup 2}) and f{sub A}(q{sup 2}), for a no massive Dirac neutrino, when these quantities are calculated in the frame of an effective electroweak Yang-Mills theory, which induces the most general SU{sub L}(2)-invariant Lorentz tensor structure of nonrenormalizable type for the WW{gamma} vertex. We found that in this frame, besides the standard model contribution, the additional contribution to f{sub Q}(q{sup 2}) and f{sub A}(q{sup 2}) (f{sub Q}{sup O{sub W}}(q{sup 2}) and f{sub A}{sup O{sub W}}(q{sup 2}), respectively) are gauge independent and finite functions of q{sup 2} after adopting a renormalization scheme. These form factors, f{sub Q}{sup O{sub W}}(q{sup 2}) and f{sub A}{sup O{sub W}}(q{sup 2}), get contribution at the one loop level only from the proper neutrino electromagnetic vertex. Besides, the relation f{sub Q}{sup eff}(q{sup 2}) = q{sup 2}f{sub A}{sup eff}(q{sup 2})(f{sub Q}{sup eff}(q{sup 2}) = f{sub Q}{sup SM}(q{sup 2})+f{sub Q}{sup O{sub W}}(q{sup 2}),f{sub A}{sup eff}(q{sup 2}) = f{sub A}{sup SM}(q{sup 2})+f{sub A}{sup O{sub W}}(q{sup 2})) is still fulfilled and hence the relation a{sub v}{sup eff} = {sup eff}/6(a{sub v}{sup eff} = a{sub v}{sup SM}+a{sub v}{sup O{sub W}}, {sup eff} = {sup SM}+ {sup O{sub W}}) is obtained, just as in the SM. Using the experimental constraint on the anomalous WW{gamma} vertex, a value for the additional contribution to the charge radius of Double-Vertical-Line {sup O{sub W}} Double-Vertical-Line Less-Than-Or-Equivalent-To 10{sup -34} cm{sup 2} is gotten, which is one order of magnitude lower than the SM value.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Radiation thermometry standards at NMIJ from −30 °C to 2800 °C

NMIJ has established a national standard scale in radiation thermometry from −30 °C to 2800 °C. At low temperatures from 160 °C down to −30 °C large aperture fluid-bath blackbodies have been constructed for the calibration of thermal infrared thermometers. In the range from 160 °C to 420 °C, the standard scale has been realized on 1.6 μm thermometers calibrated against In, Sn, and Zn blackbodies. A variable temperature blackbody using an air-bath furnace has recently been developed for direct comparison measurements of a 10 μm thermometer with a 1.6 μm thermometers up to 500 °C. In the higher range of the temperature scale, dissemination consists of three schemes: the range from 400 °C to 1100 °C by Zn, Al, Ag and Cu fixed-point blackbodies: above the Ag point by 0.9 μm and 0.65 μm thermometers: and above the Cu point by metal-carbon high-temperature fixed points.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2014

Production and characterization of a nitrogen-implanted Fe standard to calibrate PIGE measurements

Three calibration standard was produced by ion implantation of nitrogen in samples of Armco iron (99.7% iron). The samples was irradiated with nitrogen ion beams at several different energies (between 4 keV and 40 keV), and the ion doses were adjusted to obtain an uniform depth profile, using simulations with SRIM code. Two standards, one thick and other a foil (1.62mg/cm{sup 2}), was irradiated at same time with total nominal dose of 6.6×10{sup −16} atoms/cm{sup 2} distributed in a region of 100 nm in depth, with an average concentration of 9.0% nitrogen in iron. The third sample uses the same profile, but with a small dose, 1.1×10{sup −16} atoms/cm{sup 2} and average concentration of 1.5% nitrogen. The characterization of the implanted samples was done using RBS and NRA techniques to quantification of nitrogen.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Penguin-like diagrams from the standard model

The Standard Model is highly successful in describing the interactions of leptons and quarks. There are, however, rare processes that involve higher order effects in electroweak interactions. One specific class of processes is the penguin-like diagram. Such class of diagrams involves the neutral change of quark flavours accompanied by the emission of a gluon (gluon penguin), a photon (photon penguin), a gluon and a photon (gluon-photon penguin), a Z-boson (Z penguin), or a Higgs-boson (Higgs penguin). Such diagrams do not arise at the tree level in the Standard Model. They are, however, induced by one-loop effects. In this paper, we present an exact calculation of the penguin diagram vertices in the ‘tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex functions for the penguin diagram vertices are obtained. The various penguin diagram vertex functions are related to one another via Ward-Takahashi identity. From these, a set of relations is obtained connecting the vertex form factors of various penguin diagrams. Explicit expressions for the gluon-photon penguin vertex form factors are obtained, and their contributions to the flavor changing processes estimated.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Validation of galvanomagnetic and thermomagnetic transport measurements using Standard Reference Material 3451

In the “method of four coefficients,” electrical resistivity (ρ), Seebeck coefficient (S), Hall coefficient (RH), and Nernst coefficient (Q) of a material are measured and typically fit or modeled with theoretical expressions based on Boltzmann transport theory to glean experimental insights into features of electronic structure and/or charge carrier scattering mechanisms in materials. Although well-defined and readily available reference materials exist for validating measurements of ρ and S, none currently exists for R H or Q. We show that measurements of all four transport coefficients—ρ, S, R H , and Q—can be validated using a single reference sample, namely, the low-temperature Seebeck coefficient Standard Reference Material® (SRM) 3451 (composition Bi 2 Te 3+x ) available from the National Institute for Standards and Technology (NIST) without the need for inter-laboratory sample exchange. Here, R H and Q data for NIST SRM 3451 reported here for the temperature range 80–400 K complement the data already available for ρ and S and will therefore be of interest to researchers desiring to validate new or existing galvanomagnetic and thermomagnetic transport properties measurement systems.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

A Review of Remote Welding and Nondestructive Examination Technologies for the DOE Standard Canister

The U.S. Department of Energy (DOE) manages a wide variety of spent nuclear fuel (SNF) that poses a unique management challenge. To help address this challenge, the DOE Standard Canister (DOESC), designed to remain sealed during handling, storage, transportation, and disposal, was conceptualized as a standardized containment vessel to accommodate DOE-managed SNF. Since 1999, several welding and examination processes have been independently developed for the DOESC’s closure welds. However, neither the DOESC nor these processes have been realized in an operational capacity. This review paper seeks to present and compare previously developed DOESC closure weld, nondestructive examination, and repair processes and technologies. Specific processes developed for the Idaho Spent Fuel Facility, in preparation for the Yucca Mountain geological repository, and the recent Road-Ready Demonstration Project are discussed. Further, specific focus is given to how different operating constraints and the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (BPVC) have driven certain welding and nondestructive examination requirements. Historical DOESC welding and examination strategies are assessed against current regulatory and BPVC requirements. The comparison of welding processes, technologies, and DOESC designs presented in this review paper will inform further construction efforts for other commercial and DOE-managed SNF containments, including the DOESC.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Electric currents in flare ribbons: Observations and three-dimensional standard model

We present for the first time the evolution of the photospheric electric currents during an eruptive X-class flare, accurately predicted by the standard three-dimensional (3D) flare model. We analyze this evolution for the 2011 February 15 flare using Helioseismic and Magnetic Imager/Solar Dynamics Observatory magnetic observations and find that localized currents in J-shaped ribbons increase to double their pre-flare intensity. Our 3D flare model, developed with the OHM code, suggests that these current ribbons, which develop at the location of extreme ultraviolet brightenings seen with Atmospheric Imaging Assembly imagery, are driven by the collapse of the flare's coronal current layer. These findings of increased currents restricted in localized ribbons are consistent with the overall free energy decrease during a flare, and the shapes of these ribbons also give an indication of how twisted the erupting flux rope is. Finally, this study further enhances the close correspondence obtained between the theoretical predictions of the standard 3D model and flare observations, indicating that the main key physical elements are incorporated in the model.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider

Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these long-lived particles (LLPs) can decay far from the interaction vertex of the primary proton–proton collision. Such LLP signatures are distinct from those of promptly decaying particles that are targeted by the majority of searches for new physics at the LHC, often requiring customized techniques to identify, for example, significantly displaced decay vertices, tracks with atypical properties, and short track segments. Given their non-standard nature, a comprehensive overview of LLP signatures at the LHC is beneficial to ensure that possible avenues of the discovery of new physics are not overlooked. Here we report on the joint work of a community of theorists and experimentalists with the ATLAS, CMS, and LHCb experiments—as well as those working on dedicated experiments such as MoEDAL, milliQan, MATHUSLA, CODEX-b, and FASER—to survey the current state of LLP searches at the LHC, and to chart a path for the development of LLP searches into the future, both in the upcoming Run 3 and at the high-luminosity LHC. The work is organized around the current and future potential capabilities of LHC experiments to generally discover new LLPs, and takes a signature-based approach to surveying classes of models that give rise to LLPs rather than emphasizing any particular theory motivation. We develop a set of simplified models; assess the coverage of current searches; document known, often unexpected backgrounds; explore the capabilities of proposed detector upgrades; provide recommendations for the presentation of search results; and look towards the newest frontiers, namely high-multiplicity 'dark showers', highlighting opportunities for expanding the LHC reach for these signals.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Non-Gaussianities from the Standard Model Higgs

We have recently proposed that the Standard Model Higgs might be responsible for generating the cosmological perturbations of the universe by acting as an isocurvature mode during a de Sitter inflationary stage. In this paper we study the level of non-Gaussianity in the cosmological perturbations which are inevitably generated due to the non-linearities of the Standard Model Higgs potential. In particular, for the current central value of the top mass, we find that a future detection of non-Gaussianity would exclude the detection of tensor modes by the PLANCK satellite.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

Domain walls and gravitational waves in the Standard Model

We study domain walls which can be created in the Standard Model under the assumption that it is valid up to very high energy scales. We focus on domain walls interpolating between the physical electroweak vacuum and the global minimum appearing at very high field strengths. The creation of the network which ends up in the electroweak vacuum percolating through the Universe is not as difficult to obtain as one may expect, although it requires certain tuning of initial conditions. Our numerical simulations confirm that such domain walls would swiftly decay and thus cannot dominate the Universe. We discuss the possibility of detection of gravitational waves produced in this scenario. We have found that for the standard cosmology the energy density of these gravitational waves is too small to be observed in present and planned detectors.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

Standard Model–axion–seesaw–Higgs portal inflation. Five problems of particle physics and cosmology solved in one stroke

We present a minimal extension of the Standard Model (SM) providing a consistent picture of particle physics from the electroweak scale to the Planck scale and of cosmology from inflation until today. Three right-handed neutrinos N {sub i} , a new color triplet Q and a complex SM-singlet scalar σ, whose vacuum expectation value v {sub σ} ∼ 10{sup 11} GeV breaks lepton number and a Peccei-Quinn symmetry simultaneously, are added to the SM. At low energies, the model reduces to the SM, augmented by seesaw generated neutrino masses and mixing, plus the axion. The latter solves the strong CP problem and accounts for the cold dark matter in the Universe. The inflaton is comprised by a mixture of σ and the SM Higgs, and reheating of the Universe after inflation proceeds via the Higgs portal. Baryogenesis occurs via thermal leptogenesis. Thus, five fundamental problems of particle physics and cosmology are solved at one stroke in this unified Standard Model—axion—seesaw—Higgs portal inflation (SMASH) model. It can be probed decisively by upcoming cosmic microwave background and axion dark matter experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Searches for physics beyond the standard model

Jefferson Lab has now demonstrated ablility to test the fundamental symmetries of nature, and thereby probe for new physics beyond the Standard Model. Here we review the tremendous advances in precision parity-violation measurements with CEBAF that enable searches for new physics. This has been demonstrated with a determination of the weak charge of the proton, which is found to be in agreement with the prediction of the standard electroweak theory, and at a precision that rules out relevant new physics to the TeV scale. We also review the planned future experiments which aim to further test the electroweak theory at Jefferson Lab, including a further improvement on the proton weak charge, an ultra-precise Møller measurement, and a probe of the axial quark charges in PVDIS.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Evaluation of the systematic shifts of a single-{sup 40}Ca{sup +}-ion frequency standard

Progress on the evaluation of systematic frequency shifts is described in the development of the optical frequency standard based on single-trapped {sup 40}Ca{sup +} with a ''clock'' transition at 729 nm. The overall systematic uncertainty of the 4s {sup 2} S{sub 1/2}-3d {sup 2} D{sub 5/2} clock resonance has been characterized to be 7.8 x 10{sup -16}. This uncertainty is at a level similar to the Cs fountain primary standard, while the potential stability for the {sup 40}Ca{sup +} clock exceeds that of Cs.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2010

Dark matter in natural supersymmetric extensions of the standard model

We explore the dark matter sector in extensions of the minimal supersymmetric standard model that can provide a good fit to the PAMELA cosmic-ray positron excess, while at the same time addressing the little-hierarchy problem of the minimal supersymmetric standard model. Adding a singlet Higgs superfield S can account for the observed positron excess, as recently discussed in the literature, but we point out that it requires a fine-tuned choice for the parameters of the model. We find that including an additional singlet {Psi} in a model with gauge-mediated supersymmetry breaking is a minimal extension which allows both a reduction of the weak-scale fine-tuning and an interpretation of the cosmic-ray observations in terms of dark matter annihilations in the galactic halo. Our setup contains a light axion but does not require light CP-even scalars in the spectrum.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Dark matter direct detection constraints on the minimal supersymmetric standard model and implications for LHC Higgs boson searches

Assuming the lightest neutralino solely composes the cosmic dark matter, we examine the constraints of the CDMS-II and XENON100 dark matter direct searches on the parameter space of the minimal supersymmetric standard model (MSSM) Higgs sector. We find that the current CDMS-II/XENON100 limits can exclude some of the parameter space which survive the constraints from the dark matter relic density and various collider experiments. We also find that in the currently allowed parameter space, the charged Higgs boson is hardly accessible at the LHC for an integrated luminosity of 30 fb{sup -1}, while the neutral non-SM (standard model) Higgs bosons (H,A) may be accessible in some allowed region characterized by a large {mu}. The future XENON100 (6000 kg-days exposure) will significantly tighten the parameter space in case of nonobservation of dark matter.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

e{sup +}e{sup -{yields}{mu}+{mu}-} scattering in the noncommutative standard model

We study muon pair production e{sup +}e{sup -{yields}{mu}+{mu}-} in the noncommutative (NC) extension of the standard model using the Seiberg-Witten maps of this to the second order of the noncommutative parameter {Theta}{sub {mu}{nu}}. Using O({Theta}{sup 2}) Feynman rules, we find the O({Theta}{sup 4}) cross section (with all other lower order contributions simply cancelled) for the pair production. The momentum dependent O({Theta}{sup 2}) NC interaction significantly modifies the cross section and angular distributions which are different from the commuting standard model. We study the collider signatures of the space-time noncommutativity at the International Linear Collider (ILC) and find that the process e{sup +}e{sup -{yields}{mu}+{mu}-} can probe the NC scale {Lambda} in the range 0.8-1.0 TeV for typical ILC energy ranges.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗