Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “QED”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Searching for a Dark Photon in the HPS Experiment

The Heavy Photon Search (HPS) experiment at Jefferson Lab is designed to search for a hypothesized elementary particle called a dark (heavy) photon. Such a particle would behave as a mediator between dark matter and the Standard Model through a kinetic mixing with the Standard Models photon. The search is performed by scattering GeV-scale electrons off tungsten nuclei in a fixed target and looking for a resonance and/or displaced vertices amidst a background of radiative QED trident events. These background events are kinematically identical to the events in which dark photons are produced and decay into lepton pairs. Several other types of reactions take place in this experiment, such as Bethe-Heitler tridents, Moeller scattering, wide-angle bremsstrahlung and elastic scattering off the nucleus. Each of these types of background reactions are used for calibration of the detector. For one of these calibration studies, we have measured the form factors for electrons scattering elastically and nearly-elastically off a carbon target and compared these to predicted values. A resonance search, performed on 10% of the dataset taken in 2016 with a 2.306 GeV beam, shows no sign of a dark photon in the mass range 45-200 MeV. Preliminary upper limits on the square of the dark-photons kinetic coupling to the Standard Model photon have been set in the 10 6 - 10 5 range at 95% confidence for everymass hypothesis in this mass range.

Source record↗
DOE OSTI2019

Heavy Photon Displaced Vertex Search at 2.3GeV with Prospects for True Muonium Discovery

The Heavy Photon Search (HPS) collaboration at Jefferson Lab is searching for a new massive U(1) gauge boson known as the A', or dark photon, in the sub-GeV regime, which arises from considering an additional symmetry in the Standard Model. Though part of a hidden sector, the A' also kinetically mixes with the photon of electromagnetism, allowing it to have detectable QED decays. The signatures of this new particle in a fixed target experiment include a resonance in the e + e - invariant mass spectrum and a displaced vertex of its decay products, which the HPS detector in Hall B at JLab is equipped to detect. HPS is also sensitive to discover True Muonium (TM), an exotic bound state which has never been observed in experiment. In this dissertation, data taken from the 2016 HPS run at 2.3GeV beam energy is analyzed to search for a displaced decay vertex from an A'. The True Muonium yield is also estimated using Monte Carlo simulations, to determine the feasibility for a True Muonium search in future runs at 6.6GeV.

Yale, Bradley↗
DOE OSTI2018

Measurement of Compton scattering cross section at a few GeV electron energy

Electron Compton scattering is the best known fundamental QED process, however, a precision measurement of its cross section for a beam energy above 1 GeV has been lacking up to now. An updated high precision measurement of the neutral pion lifetime via the Primakoff effect (PrimEx-II) experiment was performed in Hall B of Jefferson Lab in 2010. The experiment used small angle coherent photoproduction of π 0 ’s in the Coulomb field of a nucleus, i:e: the Primakoff effect, to determine the lifetime with a precision of less than 1:5% . It therefore requires thorough understanding of the underlying systematic uncertainties. To facilitate that data for well known electromagnetic processes were taken concurrently with the photoproduction data. This analysis pertains to measuring the Compton scattering cross section, which occurs with similar kinematics to the primary process. The combination of the well established theory for this process with large collected statistics allowed to extract this cross section with high precision in an energy region of 4-5 GeV for 12 C and 28 Si targets. The results of this analysis will be presented.

Ye, Li↗
DOE OSTI2021

Excitation dynamics in galvanically coupled fluxonium circuits

We propose a near-term quantum simulator based on the fluxonium qubits galvanically coupled to form a chain. This system provides long coherence time, large anharmonicity, and strong coupling, making it suitable to study strongly interacting Ising spin models. At half-flux quantum sweet spot, the system is described by the transverse field Ising model (TFIM). We evaluate the propagation of qubit excitations through the system. As disorder increases, the excitations become localized. A single qubit measurement using the circuit QED methods is sufficient to identify localization transition without introducing tunable couplers. We argue that galvanically coupled fluxoniums provide opportunities to study localization and many-body effects in highly coherent quantum systems.

Ozguler, A. Baris↗
DOE OSTI2021

Factorized approach to radiative corrections for inelastic lepton-hadron collisions [Slides]

We propose a new factorized approach to QED radiative corrections (RCs) in inclusive and semi-inclusive lepton-hadron deep-inelastic scattering. The method allows the systematic resummation of the logarithmically enhanced into factorized lepton distribution and fragmentation (or jet) functions that are universal for all final states. The new approach provides a uniform treatment of RCs for the extraction of parton distribution functions, transverse momentum dependent distributions, and other partonic correlation functions from lepton-hadron collision data.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Surface structure studies in 2D and 3D Nb resonators using GI-XRD

Superconductor radio frequency (SRF) Nb-resonators are a key element in the development of new generations of particle accelerators as well as in the fabrication of 3D circuit QED architecture for quantum computing. Nevertheless, Niobium is extremally reactive to light elements such as C, N, O and H, and therefore to the impurities ordering under special conditions, e.g., cryogenic temperatures. Since these resonators are put through a series of metallurgical and chemical processes, the number of impurities in the solid increases in tens of ppm. Upon operational conditions ~1.6 K, Nb become vulnerable to H atoms ordering, which leads to the nucleation of secondary phases such as Nb-hydrides. Thereupon to the energy dissipation and eventually to the superconductivity breakdown known as Q-disease and potentially High-Field Q-slope. In this contribution, we present a detailed structural analysis by high-energy grazing-incidence X-ray diffraction of specimens extracted from 3D Nb resonators to shed light on the kinetic formation of the resulting secondary phases and their crystal phase identification upon cooling and heating cycles. To our knowledge, this is the first study carried out in resonators samples using a light source, shallow angles and temperatures near ~4 K. Consequently, this work opens new routes to understand the chemical and phase composition, crystal and electronic structure of the Nb surface at temperatures near the operating conditions as a strategy to improve the physical and functional properties of Nb superconducting resonators.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Enhancing Entanglement: Non-Markovian and Floquet Reservoir Engineering in Many-Qubit Superconducting Quantum Circuits

This is an experimental and theoretical project to leverage dissipation engineering under non-Markovian settings in order to aid in the preparation and stabilization of large, non-trivial, entangled quantum states. This project is a collaborative effort between the Painter group at Caltech and the Clerk group at the University of Chicago. By utilization of superconducting qubits coupled to the metamaterial waveguide described in the proposal, we tackle this goal via two parallel thrusts: (i) non-Markovian dynamics of a superconducting qubit strongly coupled to a slow-light waveguide reservoir and generation of 2D cluster states and (ii) many-qubit waveguide circuit QED for studying quantum many-body physics. In addition to device development and testing, we are also developing theoretical methods for understanding physics in the deep non-Markovian regime and driven-dissipative protocols for preparing and stabilizing the quantum many-body states.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Quantum Fourier Transform with Leakage Control

In circuit QED (cQED) systems, one can manipulate the cavity Fock states to use quantum processing unit (QPU). Since the coherence times of the Fock states are long, qudit based computation can be possible. One of the most basic gate that can be engineered in this cQED platform is the displacement gate, $D(\alpha)$. However, accessible number of qudit-levels is finite. The truncated displacement gate on the qudit is the source of theoretical error above the logical states and needs to be addressed. In this work, we monitor and minimize the leakage in qudit systems that involves displacement gate by introducing so-called `bumper' states and a modified cost function.

Kurkcuoglu, D. [Fermilab] (ORCID:0000000311097074)↗
DOE OSTI2020

Positronium: an illustration of nonperturbative renormalization in a basis light-front approach

We calculate the mass spectrum and the structure of the positronium system at a strong coupling in a basis light-front approach. We start from the light-front QED Hamiltonian and retain one dynamical photon in our basis. We perform the fermion mass renormalization associated with the nonperturbative fermion self-energy correction. We present the resulting mass spectrum and wave functions for the selected low-lying states. Next, we apply this approach to QCD and calculate the heavy meson system with one dynamical gluon retained. We illustrate the obtained mass spectrum and wave functions for the selected low-lying states.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

A Multi-Qubit Quantum Gate Using the Zeno Effect

The Zeno effect, in which repeated observation freezes the dynamics of a quantum system, stands as an iconic oddity of quantum mechanics. When a measurement is unable to distinguish between states in a subspace, the dynamics within that subspace can be profoundly altered, leading to non-trivial behavior. Here we show that such a measurement can turn a non-interacting system with only single-qubit control into a two- or multi-qubit entangling gate, which we call a Zeno gate. The gate works by imparting a geometric phase on the system, conditioned on it lying within a particular nonlocal subspace. We derive simple closed-form expressions for the gate fidelity under a number of non-idealities and show that the gate is viable for implementation in circuit and cavity QED systems. More specifically, we illustrate the functioning of the gate via dispersive readout in both the Markovian and non-Markovian readout regimes, and derive conditions for longitudinal readout to ideally realize the gate.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2025

The Principle of Maximum Conformality Correctly Resolves the Renormalization-Scheme-Dependence Problem

In this paper, we clarify a serious misinterpretation and consequent misuse of the Principle of Maximum Conformality (PMC), which also can serve as a mini-review of PMC. In a recently published article, P. M. Stevenson has claimed that “the PMC is ineffective and does nothing to resolve the renormalization-scheme-dependence problem”, concluding incorrectly that the success of PMC predictions is due to the PMC being a “laborious, ad hoc, and back-door” version of the Principle of Minimal Sensitivity (PMS). We show that such conclusions are incorrect, deriving from a misinterpretation of the PMC and an overestimation of the applicability of the PMS. The purpose of the PMC is to achieve precise fixed-order pQCD predictions, free from conventional renormalization schemes and scale ambiguities. We demonstrate that the PMC predictions satisfy all the self-consistency conditions of the renormalization group and standard renormalization-group invariance; the PMC predictions are thus independent of any initial choice of renormalization scheme and scale. The scheme independence of the PMC is also ensured by commensurate scale relations, which relate different observables to each other. Moreover, in the Abelian limit, the PMC dovetails into the well-known Gell-Mann–Low framework, a method universally revered for its precision in QED calculations. Due to the elimination of factorially divergent renormalon terms, the PMC series not only attains a convergence behavior far superior to that of its conventional counterparts but also deftly curtails any residual scale dependence caused by the unknown higher-order terms. This refined convergence, coupled with its robust suppression of residual uncertainties, furnishes a sound and reliable foundation for estimating the contributions from unknown higher-order terms. Anchored in the bedrock of standard renormalization-group invariance, the PMC simultaneously eradicates the factorial divergences and eliminates superfluous systematic errors, which inversely provides a good foundation for achieving high-precision pQCD predictions. Consequently, owing to its rigorous theoretical underpinnings, the PMC is eminently applicable to virtually all high-energy hadronic processes.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Proton Electric Charge Radius from Lepton Scattering

A proton is a bound state of a strong interaction, governed by Quantum Chromodynamics (QCD). The electric charge radius of a proton, denoted by $r^{p}_{E}$, characterizes the spatial distribution of its electric charge carried by the quarks. It is an important input for bound-state Quantum Electrodynamic (QED) calculations of the hydrogen atomic energy levels. However, physicists have been puzzled by the large discrepancy between $r^{p}_{E}$ measurements from muonic hydrogen spectroscopy and those from ep elastic scattering and ordinary hydrogen spectroscopy for over a decade. Tremendous efforts, both theoretical and experimental, have been dedicated to providing various insights into this puzzle, but certain issues still remain unresolved, particularly in the field of lepton scatterings. This review will focus on lepton-scattering measurements of $r^{p}_{E}$, recent theoretical and experimental developments in this field, as well as future experiments using this technique.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

13 TeV pp collisions, SM type, PYTHIA8 generator: tev13pp_qcd_pythia8_weighted

Inclusive dijet events for pT>50 GeV. (PhaseSpace:pTHatMin=50 GeV). 20,000 events per file. PDF: LHAPDF6:NNPDF23_lo_as_0130_qed. The sample was created using the Pythia8 tune Tune:pp = 14, similar to ATLAS. How to use: This is weighted events to obtain good statistics up to very large pT. This feature is set via PhaseSpace:bias2Selection and PhaseSpace:bias2SelectionPow = 5.0 (thanks to Caterina Doglioni). Use event weights to obtain correct pT distribution. Slimmed as: Particle records are slimmed (all stable with pT>0.3 GeV) and (PID=5 || PID=6) or PID>22 && PID<38) or PID>10 && PID<17).

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

14 TeV e+e- collisions, SM type, PYTHIA8 generator: tev14pp_pythia8_ttbar_tunes

Top production (ttbar) using LHAPDF6:NNPDF23_lo_as_0130_qed. The processes are Top:gg2ttbar and Top:qqbar2ttbar. All top decays are enabled. The sample contains a tune pp Nr=14 as explained in Pythia8 manual. File description: Each file has the string "_tuneN", where "N" is an integer value that specifies Pythia8 tune.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

380 GeV e+e- collisions, SM type, PYTHIA8 generator: gev380ee_pythia8_qcdjets_tunes_qedof

Standard model productions for jets in e+e- . Full interference between Z and gamma. QED radiation off leptons is OFF. The sample contains 7 sub-samples with seven different e+e- tunes explained in Pythia8 manual. File description: Each file has the string "_tuneN", where "N" is an integer value that specifies Pythia8 tune. There are 20 files per each tune.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

3 TeV e+e- collisions, SM type, PYTHIA8 generator: tev3ee_pythia8_qcdjets_tunes_qedoff

Standard model productions for jets in e+e-. Full interference between Z and gamma. QED radiation off electrons is OFF. The sample contains 7 sub-samples with seven different e+e- tunes explained in Pythia8 manual. File description: Each file has the string "_tuneN", where "N" is an integer value that specifies Pythia8 tune. There are 20 files per each tune.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

14 TeV pp collisions, SM type, PYTHIA8 generator: tev14pp_qcd_pythia8_weighted

Inclusive dijet events for pT>40 GeV. (PhaseSpace:pTHatMin=40 GeV). PDF: LHAPDF6:NNPDF23_lo_as_0130_qed and Tune:pp = 14 (Monash 2013 Tune). 5,000 events per file. How to use: The events are weighted to obtain good statistics up to large pT. This feature is set via PhaseSpace:bias2Selection and PhaseSpace:bias2SelectionPow = 5.0. Use the event weights to obtain the correct pT distribution.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

27 TeV pp collisions, SM type, PYTHIA8 generator: tev27pp_qcd_pythia8_weighted

Inclusive dijet events for pT>50 GeV. (PhaseSpace:pTHatMin=50 GeV). PDF: LHAPDF6:NNPDF23_lo_as_0130_qed. Pythia8 tune Tune:pp = 14 similar to ATLAS. Created for studies by Frank Taylor. How to use: This is weighted events to obtain good statistics up to very large pT. This feature is set via PhaseSpace:bias2Selection and PhaseSpace:bias2SelectionPow = 5.0. Use event weights to obtain correct pT distribution. Slimmed as: Particle records are slimmed (all stable with pT>0.3 GeV) and (PID=5 || PID=6) or PID>22 && PID<38) or PID>10 && PID<17).

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗