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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 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Search for Heavy Neutral Leptons in Electron-Positron and Neutral-Pion Final States with the MicroBooNE Detector

We present the first search for heavy neutral leptons (HNLs) decaying into ν e + e − or ν π 0 final states in a liquid-argon time projection chamber using data collected with the MicroBooNE detector. The data were recorded synchronously with the NuMI neutrino beam from Fermilab’s main injector corresponding to a total exposure of 7.01 × 10 20 protons on target. We set upper limits at the 90% confidence level on the mixing parameter | U μ 4 | 2 in the mass ranges 10 ≤ m HNL ≤ 150 MeV for the ν e + e − channel and 150 ≤ m HNL ≤ 245 MeV for the ν π 0 channel, assuming | U e 4 | 2 = | U τ 4 | 2 = 0 . These limits represent the most stringent constraints in the mass range 35 < m HNL < 175 MeV and the first constraints from a direct search for ν π 0 decays. Published by the American Physical Society 2024

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Cross sections of hadronic reactions e{sup +} e{sup −} → K{sup +} K{sup −} nπ (n =1,2,3) measured with the CMD3 detector at the VEPP-2000 electron-positron collider

We analyze the data on e{sup +} e{sup −} collisions at c.m.s. energies between 0.32 and 2 GeV collected in 2011–2013 with the CMD3 detector operating at the VEPP-3 e{sup +} e{sup −} collider of the Budker Institute of Nuclear Physics. The data correspond to an integrated luminosity of nearly 60 pb{sup -1}. Preliminary results e{sup +} e{sup −} → K{sup +} K{sup −} nπ (n = 1, 2, 3) on the reactions with two charged kaons in the final state are presented, and the procedure for estimating the integrated luminosity for each energy setting is described.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Higgs physics at the CLIC electron–positron linear collider

The Compact Linear Collider (CLIC) is an option for a future \({\mathrm{e}^{+}}{\mathrm{e}^{-}} \) collider operating at centre-of-mass energies up to \(3\,\text {TeV} \) , providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: \(\sqrt{s} = 350\,\text {GeV} \) , 1.4 and \(3\,\text {TeV} \) . The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung ( \({\mathrm{e}^{+}}{\mathrm{e}^{-}} \rightarrow {\mathrm{Z}} {\mathrm{H}} \) ) and \({\mathrm{W}} {\mathrm{W}} \) -fusion ( \({\mathrm{e}^{+}}{\mathrm{e}^{-}} \rightarrow {\mathrm{H}} {{\nu }}_{\!\mathrm{e}} {\bar{{\nu }}}_{\!\mathrm{e}} \) ), resulting in precise measurements of the production cross sections, the Higgs total decay width \(\varGamma _{{\mathrm{H}}}\) , and model-independent determinations of the Higgs couplings. Operation at \(\sqrt{s} > 1\,\text {TeV} \) provides high-statistics samples of Higgs bosons produced through \({\mathrm{W}} {\mathrm{W}} \) -fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes \({\mathrm{e}^{+}}{\mathrm{e}^{-}} \rightarrow \mathrm{t} {\bar{\mathrm{t}}} {\mathrm{H}} \) and \({\mathrm{e}^{+}}{\mathrm{e}^{-}} \rightarrow {\mathrm{H}} {\mathrm{H}} {{\nu }}_{\!\mathrm{e}} {\bar{{\nu }}}_{\!\mathrm{e}} \) allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Production of Positron Emitting Radiometals: Cu-64, Y-86, Zr-89. Final report

This proposal seeks support to increase our production of the radionuclides yttrium-86 and zirconium-89 while continuing to produce copper-64. We have the advantage that we already ship out copper-64 to some 20-25 institutions per week (over 60 different institutions total including 4 Canadian sites) and thus our group already has significant experience with producing, purifying and shipping radioactive materials. A significant portion of the funds requested supported the purchase of a new hotcell for the production of zirconium-89 and yttrium-86.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2018

Relativistic electron-positron plasma jets and interactions using LFEX lasers

Relativistic pair plasmas and jets are believed to exist in many astrophysical objects [Wardle 1998, Weidenspointner 2008] and are invoked to explain energetic phenomena related to Gamma Ray Bursts, Black Holes and the heating of intergalactic medium (IGM) [Mirabel & Rodriguez 1999, Meszaros 2002].

42 ENGINEERING↗