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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 271 records · Page 15
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DOE OSTI2015

Making the most of the relic density for dark matter searches at the LHC 14 TeV Run

As the LHC continues to search for new weakly interacting particles, it is important to remember that the search is strongly motivated by the existence of dark matter. In view of a possible positive signal, it is essential to ask whether the newly discovered weakly interacting particle can be be assigned the label “dark matter”. Within a given set of simplified models and modest working assumptions, we reinterpret the relic abundance bound as a relic abundance range, and compare the parameter space yielding the correct relic abundance with projections of the Run II exclusion regions. Assuming that dark matter is within the reach of the LHC, we also make the comparison with the potential 5σ discovery regions. Reversing the logic, relic density calculations can be used to optimize dark matter searches by motivating choices of parameters where the LHC can probe most deeply into the dark matter parameter space. In the event that DM is seen outside of the region giving the correct relic abundance, we will learn that either thermal relic DM is ruled out in that model, or the DM-quark coupling is suppressed relative to the DM coupling strength to other SM particles.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Review of Particle Physics

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,200 new measurements from 903 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Most of the 118 reviews are updated, including many that are heavily revised.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

A polarized Drell-Yan experiment to probe the dynamics of the nucleon sea

In QCD, nucleon spin comes from the sum of the quark spin, gluon spin, and the quark and gluon orbital angular momentum, but how these different components contribute and the interplay among them is not yet understood. For instance, sea quark orbital contribution remains largely unexplored. Measurements of the Sivers function for the sea quarks will provide a probe of the sea quark orbital contribution. The upcoming E1039 experiment at Fermilab will measure the Sivers asymmetry of the sea quarks via the Drell-Yan process using a 120 GeV unpolarized proton beam directed a transversely polarized ammonia target. We report on the status and plans of the E1039 polarized Drell-Yan experiment.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Search for invisible decays of the Higgs boson produced in association with a hadronically decaying vector boson in pp collisions at √s = 8 with the ATLAS detector

A search for Higgs boson decays to invisible particles is performed using 20.3 fb⁻¹ of pp collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the Large Hadron Collider. The process considered is Higgs boson production in association with a vector boson (V = W or Z) that decays hadronically, resulting in events with two or more jets and large missing transverse momentum. No excess of candidates is observed in the data over the background expectation. The results are used to constrain V H production followed by H decaying to invisible particles for the Higgs boson mass range 115 < m H < 300 GeV. The 95 % confidence-level observed upper limit on σ VH × BR(H → inv.) varies from 1.6 pb at 115 GeV to 0.13 pb at 300 GeV. Assuming Standard Model production and including the gg → H contribution as signal, the results also lead to an observed upper limit of 78% at 95% confidence level on the branching ratio of Higgs bosons decays to invisible particles at a mass of 125 GeV.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Studies of Zγ production in association with a high-mass dijet system in pp collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

The production of a Z boson and a photon in association with a high-mass dijet system is studied using 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV recorded with the ATLAS detector in 2012 at the Large Hadron Collider. Final states with a photon and a Z boson decaying into a pair of either electrons, muons, or neutrinos are analysed. Electroweak and total pp → Zγjj cross-sections are extracted in two fiducial regions with different sensitivities to electroweak production processes. Quartic couplings of vector bosons are studied in regions of phase space with an enhanced contribution from pure electroweak production, sensitive to vector-boson scattering processes VV → Zγ. Finally, no deviations from Standard Model predictions are observed and constraints are placed on anomalous couplings parameterized by higher-dimensional operators using effective field theory.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

A Storage Ring Experiment to Detect a Proton Electric Dipole Moment

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10−29 e ⋅ cm by using polarized “magic” momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Search for gluinos in events with an isolated lepton, jets and missing transverse momentum at $\sqrt{s}$ = 13 Te V with the ATLAS detector

The results of a search for gluinos in final states with an isolated electron or muon, multiple jets and large missing transverse momentum using proton–proton collision data at a centre-of-mass energy of $\sqrt{s}$ = 13 Te V are presented. The dataset used was recorded in 2015 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 3.2 fb -1 . Six signal selections are defined that best exploit the signal characteristics. The data agree with the Standard Model background expectation in all six signal selections, and the largest deviation is a 2.1 standard deviation excess. The results are interpreted in a simplified model where pair-produced gluinos decay via the lightest chargino to the lightest neutralino. In this model, gluinos are excluded up to masses of approximately 1.6 Te V depending on the mass spectrum of the simplified model, thus surpassing the limits of previous searches.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Measurements of electroweak $Wjj$ production and constraints on anomalous gauge couplings with the ATLAS detector

Measurements of the electroweak production of a W boson in association with two jets at high dijet invariant mass are performed using √s = 7 and 8 TeV proton–proton collision data produced by the Large Hadron Collider, corresponding respectively to 4.7 and 20.2 fb -1 of integrated luminosity collected by the ATLAS detector. Lastly, the measurements are sensitive to the production of a W boson via a triple-gauge-boson vertex and include both the fiducial and differential cross sections of the electroweak process.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

Precision Studies of Hadronic and Electro-Weak Interactions for Collider Physics (Final Report)

This project was directed toward developing precision computational tools for proton collisions at the Large Hadron Collider, focusing primarily on electroweak boson production and electroweak radiative corrections. The programs developed under this project carried the name HERWIRI, for High Energy Radiation With Infra-Red Improvements, and are the first steps in an ongoing program to develop a set of hadronic event generators based on combined QCD and QED exponentiation. HERWIRI1 applied these improvements to the hadronic shower, while HERWIRI2 will apply the electroweak corrections from the program KKMC developed for electron-positron scattering to a hadronic event generator, including exponentiated initial and final state radiation together with first-order electroweak corrections to the hard process. Some progress was also made on developing differential reduction techniques for hypergeometric functions, for application to the computation of Feynman diagrams.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Electromagnetic soliton-particle with spin and magnetic moment

Electromagnetic soliton-particle with both quasi-static and quick-oscillating wave parts is considered. Its mass, spin, charge, and magnetic moment appear naturally when the interaction with distant solitons is considered. The substantiation of Dirac equation for the wave part of the interacting soliton-particle is given.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Proca Particle in Riemannian Spacetimes

Relativistic quantum-mechanical description of electromagnetic, inertial, and gravitational interactions of a Proca (spin-1) particle is presented. Covariant equations defining electromagnetic interactions of a Proca particle with the anomalous magnetic and electric dipole moments in Riemannian spacetimes are formulated. The relativistic Foldy-Wouthuysen transformation with allowance for only terms proportional to the zero power of the Planck constant is performed as an example. The Hamiltonian obtained agrees with the corresponding Hamiltonians derived for scalar and Dirac particles and with their classical counterpart.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Future long-baseline neutrino oscillations: View from North America

In late 2012 the US Department of Energy gave approval for the first phase of the Long-Baseline Neutrino Experiment (LBNE) that will conduct a broad scientific program including neutrino oscillations, neutrino scattering physics, search for baryon violation, supernova burst neutrinos and other related astrophysical phenomena. The project is now being reformulated as an international facility hosted by the United States. The facility will consist of an intense neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), a highly capable set of neutrino detectors on the Fermilab campus, and a large underground liquid argon time projection chamber at Sanford Underground Research Facility (SURF) in South Dakota 1300 km from Fermilab. With an intense beam and massive far detector, the experimental program at the facility will make detailed studies of neutrino oscillations, including measurements of the neutrino mass hierarchy and Charge-Parity symmetry violation, by measuring neutrino and anti-neutrino mixing separately. At the near site, the high-statistics neutrino scattering data will allow for many cross section measurements and precision tests of the Standard Model. This presentation will describe the configuration developed by the LBNE collaboration, the broad physics program, and the status of the formation of the international facility.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Design and simulation of a muon detector to characterize geological overburden

This study presents the design, construction, and simulation of a mobile muon detector tailored for geological overburden characterization. The detector employs plastic scintillator paddles with silicon photomultipliers (SiPMs) and a QuarkNet data acquisition system, offering a portable solution suitable for remote field deployment. The simulator’s modular aluminum frame allows for adjustable geometry and directional sensitivity, while its battery system supports over a week of autonomous operation. Preliminary experimental tests confirmed that its muon flux measurements were consistent with theoretical expectations. A comprehensive simulation framework using Geant4 and CORSIKA was developed to model detector response and overburden effects. Analytical and Monte Carlo methods were used to assess quadrant resolution and infer muon directionality. This work lays the foundation for future overburden mapping and supports the development of reconstruction algorithms for geological applications.

72 - PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Search for Axion Dark Matter from 1.1 to 1.3 GHz with ADMX

Axion dark matter can satisfy the conditions needed to account for all of the dark matter and solve the strong 𝐶⁢𝑃 problem. The Axion Dark Matter eXperiment (ADMX) is a direct dark matter search using a haloscope to convert axions to photons in an external magnetic field. Key to this conversion is the use of a microwave resonator that enhances the sensitivity at the frequency of interest. The ADMX experiment boosts its sensitivity using a dilution refrigerator and near quantum-limited amplifier to reduce the noise level in the experimental apparatus. In the most recent run, ADMX searched for axions between 1.10 and 1.31 GHz to extended Kim-Shifman-Vainshtein-Zakharov sensitivity. This Letter reports on the results of that run, as well as unique aspects of this experimental setup.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Nucleon axial-vector form factor and radius from radiatively corrected antineutrino scattering data

The nucleon axial-vector form factor, 𝐺 𝐴 , is critical to determine the electroweak interactions of leptons with nucleons. Important examples of processes influenced by 𝐺 𝐴 are elastic (anti)neutrino-nucleon scattering and muon capture by the proton. Sparse experimental data results in a large uncertainty on the momentum dependence of 𝐺 𝐴 and has motivated the consideration of new experimental probes and first-principles lattice quantum chromodynamics (QCD) evaluations. The comparison of new and precise theoretical predictions for 𝐺 𝐴 with future experimental data necessitates the application of radiative corrections to experimentally observable processes. We apply these corrections in the extraction of 𝐺 𝐴 and the associated axial-vector radius from the recent MINERvA antineutrino-hydrogen data, compare the effects from radiative corrections to other uncertainties in neutrino scattering experiments, and discuss the comparison of lattice QCD evaluations to experimental measurements.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗