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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 1,333 records · Page 74
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Revealing the short-range structure of the mirror nuclei 3 H and 3 He

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements. Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. In this work we obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Measurement of simplified template cross sections of the Higgs boson produced in association with W or Z bosons in the H → b b ¯ decay channel in proton-proton collisions at s = 13 TeV

Differential cross sections are measured for the standard model Higgs boson produced in association with vector bosons (W, Z) and decaying to a pair of b quarks. Measurements are performed within the framework of the simplified template cross sections. The analysis relies on the leptonic decays of the W and Z bosons, resulting in final states with 0, 1, or 2 electrons or muons. The Higgs boson candidates are either reconstructed from pairs of resolved b-tagged jets, or from single large-radius jets containing the particles arising from two b quarks. Proton-proton collision data at $\sqrt{s}$ =13 TeV, collected by the CMS experiment in 2016–2018 and corresponding to a total integrated luminosity of 138 fb -1 , are analyzed. The inclusive signal strength, defined as the product of the observed production cross section and branching fraction relative to the standard model expectation, combining all analysis categories, is found to be μ = $1.15^{+0.22}_{-0.20}$. This corresponds to an observed (expected) significance of 6.3 (5.6) standard deviations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Search for charged Higgs bosons produced in top-quark decays or in association with top quarks and decaying via H±→τ±ντ in 13 TeV pp collisions with the ATLAS detector

Charged Higgs bosons produced either in top-quark decays or in association with a top quark, subsequently decaying via , are searched for in of proton-proton collision data at recorded with the ATLAS detector. Depending on whether the top quark is produced together with the decays hadronically or semileptonically, the search targets or final states, in both cases with a -lepton decaying into a neutrino and hadrons. No significant excess over the Standard Model background expectation is observed. For the mass range of , upper limits at 95% confidence level are set on the production cross section of the charged Higgs boson times the branching fraction in the range 4.5 pb–0.4 fb. In the mass range 80–160 GeV, assuming the Standard Model cross section for production, this corresponds to upper limits between 0.27% and 0.02% on .

Aad, G↗
DOE OSTI2021

Measurements of WH and ZH production in the $$H \rightarrow b\bar{b}$$ decay channel in pp collisions at $$13\,\text {Te}\text {V}$$ with the ATLAS detector

Measurements of the Standard Model Higgs boson decaying into a $$b\bar{b}$$ b b ¯ pair and produced in association with a W or Z boson decaying into leptons, using proton–proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centre-of-mass energy of $$\sqrt{s} = 13\,\text {Te}\text {V}$$ s = 13 Te , corresponding to an integrated luminosity of $$139\,\mathrm {fb}^{-1}$$ 139 fb - 1 . The production of a Higgs boson in association with a W or Z boson is established with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Cross-sections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, W or Z , decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The cross-section measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions. Limits are subsequently set on the parameters of an effective Lagrangian sensitive to modifications of the WH and ZH processes as well as the Higgs boson decay into $$b\bar{b}$$ b b ¯ .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Observation of W W γ Production and Search for H γ Production in Proton-Proton Collisions at s = 13 TeV

The observation of W W γ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138 fb − 1 is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for W W γ is 5.9 ± 0.8 ( stat ) ± 0.8 ( syst ) ± 0.7 ( modeling ) fb , in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks. © 2024 CERN, for the CMS Collaboration 2024 CERN

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Materials Data on H(WO3)2 by Materials Project

(WO3)4H2 is High-temperature superconductor-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional and consists of four hydrogen molecules and one WO3 framework. In the WO3 framework, W+5.50+ is bonded to six equivalent O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All W–O bond lengths are 1.93 Å. O2- is bonded in a linear geometry to two equivalent W+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H(WO3)2 by Materials Project

(WO3)4H2 is High-temperature superconductor-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional and consists of one hydrogen molecule and one WO3 framework. In the WO3 framework, there are two inequivalent W+5.50+ sites. In the first W+5.50+ site, W+5.50+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of W–O bond distances ranging from 1.87–2.02 Å. In the second W+5.50+ site, W+5.50+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of W–O bond distances ranging from 1.87–2.02 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two W+5.50+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two W+5.50+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two W+5.50+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two W+5.50+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two W+5.50+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two W+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H(C3N2)4 by Materials Project

(C3N2)8H2 is alpha carbon monoxide-like structured and crystallizes in the tetragonal P4mm space group. The structure is zero-dimensional and consists of one hydrogen molecule and one C3N2 cluster. In the C3N2 cluster, C+1.92+ is bonded in a bent 120 degrees geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.44 Å. N3- is bonded in a trigonal planar geometry to three equivalent C+1.92+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H(WO3)4 by Materials Project

(WO3)8H2 is High-temperature superconductor-derived structured and crystallizes in the tetragonal I-42m space group. The structure is three-dimensional and consists of two dihydrogen molecules and one WO3 framework. In the WO3 framework, W+5.75+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of W–O bond distances ranging from 1.83–2.08 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent W+5.75+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.75+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Analysis of H-Canyon 6.4D Dissolver Solid

During reconfiguration of the 6.4D dissolver for the dissolution of High Flux Isotope Reactor (HFIR) fuel, solid material was observed on the bottom of the dissolver pot. Samples of the solids were taken from the north and south side of the 6.4D pot and were transported to the Savannah River National Laboratory (SRNL) for characterization. The samples were initially dried, and then a small portion of each sample set was removed, and rinsed with either 1 M HNO 3 or 6 M HNO 3 . A portion of each unrinsed and rinsed sample was dissolved and analyzed for elemental and radiochemical concentrations. Results from the analyses indicated that the solids were primarily Si, Fe, Al, and Cr. The U content in the initial dried, unrinsed solids was 0.380 wt %, but was reduced to 0.057 wt % in the rinsed solids, indicating the majority of the U was mostly soluble in HNO 3 . Small amounts of Pu were measured at 0.010 wt % in both the rinsed and unrinsed solids.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗