Chiral Effective Field Theory Calculations Of Weak Transitions In Light Nuclei,
2020
Old Dominion University
Chiral Effective Field Theory Calculations Of Weak Transitions In Light Nuclei, G.B. King, L. Andreoli, S. Pastore, M. Piarulli, R. Schiavilla, R.B. Wiringa, J. Carlson, S. Gandolfi
Physics Faculty Publications
We report quantum Monte Carlo calculations of weak transitions in A 10 nuclei, based on the Norfolk two-and three-nucleon chiral interactions, and associated one-and two-body axial currents. We find that the contribution from two-body currents is at the 2-3% level, with the exception of matrix elements entering the rates of Li-8, B-8, and He-8 beta decay. These matrix elements are suppressed in impulse approximation based on the (leading order) Gamow Teller transition operator alone; two-body currents provide a 20-30% correction, which is, however, insufficient to bring theory in agreement with experimental data. For the other transitions, the agreement with the …
Novel Observation Of Isospin Structure Of Short-Range Correlations In Calcium Isotopes,
2020
Old Dominion University
Novel Observation Of Isospin Structure Of Short-Range Correlations In Calcium Isotopes, D. Nguyen, Z. Ye, Lawrence Weinstein, X. Zheng, P. Zhu, R. Zielinski, Et Al., Jefferson Lab Hall A Collaboration
Physics Faculty Publications
Short-range correlations (SRCs) have been identified as being responsible for the high-momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of nucleon pairs generate the high-momentum tail and imprint a universal character on n(k) for all nuclei at large momentum. Triple coincidence experiments have shown a strong dominance of np pairs, but these measurements involve large final-state interactions. This paper presents the results from Jefferson Lab experiment E08014 which measured inclusive electron scattering cross section from Ca isotopes. By comparing the inclusive cross section from 48Ca to 40Ca in a kinematic region dominated by SRCs …
Photoproduction Of Η Mesons Off The Proton For 1.2 < EΓ < 4.7 Gev Using Clas At Jefferson Laboratory,
2020
Old Dominion University
Photoproduction Of Η Mesons Off The Proton For 1.2 < EΓ < 4.7 Gev Using Clas At Jefferson Laboratory, K. P. Adhikari, M. J. Amaryan, G. Gavalian, M. Hattawy, M. Khachatryan, J. Poudel, Y. Prok, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration
Physics Faculty Publications
Photoproduction cross sections are reported for the reaction γp→pη using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The η mesons are detected in their dominant charged decay mode, η→π+π−π0, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new η photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are also compared with the experimental results from several other experiments, and with predictions of η-MAID 2018 and the latest solution of the …
Magnetic Structure And Radiative Captures Of Few-Nucleon Systems: Status And Prospects,
2020
Old Dominion University
Magnetic Structure And Radiative Captures Of Few-Nucleon Systems: Status And Prospects, Laura Elisa Marcucci, Rocco Schiavilla, Alex Gnech, Michele Viviani
Physics Faculty Publications
We review the main ingredients for an ab-initio study of few-nucleon reactions of astrophysical interest within the chiral effective field theory approach, with particular attention to radiative captures relevant for Big Bang Nucleosynthesis and stellar evolution. We conclude with an outlook for ongoing and future work.
Ab Initio Study Of (𝜈ℓ, ℓ⁻) And (𝜈ℓ, ℓ⁺) Inclusive Scattering In 12C: Confronting The Miniboone And T2k Ccqe Data,
2020
Argonne National Laboratory
Ab Initio Study Of (𝜈ℓ, ℓ⁻) And (𝜈ℓ, ℓ⁺) Inclusive Scattering In 12C: Confronting The Miniboone And T2k Ccqe Data, A. Lovato, J. Carlson, S. Gandolfi, N. Rocco, R. Schiavilla
Physics Faculty Publications
We carry out an ab initio calculation of the neutrino flux-folded inclusive cross sections measured on ¹²C by the MiniBooNE and T2K Collaborations in the charged-current quasielastic regime. The calculation is based on realistic two- and three-nucleon interactions, and on a realistic nuclear electroweak current with one- and two-nucleon terms that are constructed consistently with these interactions and reproduce low-energy electroweak transitions. Numerically exact quantum Monte Carlo methods are utilized to compute the nuclear weak response functions, by fully retaining many-body correlations in the initial and final states and interference effects between one- and two-body current contributions. We employ a …
Evaluation Of The Activity Of Zn-65 Isotope And Radiation Dose Delivered To Drosophila Melanogaster,
2020
Minnesota State University, Mankato
Evaluation Of The Activity Of Zn-65 Isotope And Radiation Dose Delivered To Drosophila Melanogaster, Wasiu Ajani Erinoso
All Graduate Theses, Dissertations, and Other Capstone Projects
Radioactivity is a natural part of our environment. Ionizing radiation from radioactive materials can affect the life cycle of organisms; sometimes increase the rate of transition between cycle leading to the proliferation of cells as seen in some cancer cells or delay the rate of transition between cell cycle. A NaI detector is essential to determine the activity of a radioactive material. To determine the resolution of NaI detector and the efficiency of the geometry used for this experiment, quality control was done for NaI detector using 22Na reference source. The efficiency of the detector was used to verify the …
Neutron Valence Structure From Nuclear Deep Inelastic Scattering,
2020
Old Dominion University
Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen
Physics Faculty Publications
Mechanisms of spin-flavor SU(6) symmetry breaking in quantum chromodynamics (QCD) are studied via an extraction of the free neutron structure function from a global analysis of deep inelastic scattering (DIS) data on the proton and on nuclei from A = 2 (deuterium) to 208 (lead). Modification of the structure function of nucleons bound in atomic nuclei (known as the EMC effect) are consistently accounted for within the framework of a universal modification of nucleons in short-range correlated (SRC) pairs. Our extracted neutron-to-proton structure function ratio Fn2/Fp2 becomes constant for xB ≥ 0.6, equaling 0.47 …
First Measurement Of Direct Photoproduction Of The A2(1320)⁰ Meson On The Proton,
2020
Old Dominion University
First Measurement Of Direct Photoproduction Of The A2(1320)⁰ Meson On The Proton, K.P. Adhikari, M. J. Amaryan, D. Bullumulla, F. Hauenstein, M. Khachatryan, Y. Prok, Et Al., Clas Collaboration
Physics Faculty Publications
We present the first measurement of the reaction 𝛾p -> a₂(1320)⁰ p in the photon energy range 3.5-5.5 GeV and four-momentum transfer squared 0.2 < -t < 2.0 GeV2. Data were collected with the CEBAF Large Acceptance Spectrometer detector at the Thomas Jefferson National Accelerator Facility. The a2resonance was detected by measuring the reaction 𝛾p → π0ηp and reconstructing the π0η invariant mass. The most prominent feature of the differential cross section is a dip at -t ≈ 0.55 GeV2. This can be described in the framework of Regge phenomenology, where the exchange degeneracy hypothesis …
Distribution And Evolution Of Fukushima Dai-Ichi Derived 137cs, 90sr, And 129i In Surface Seawater Off The Coast Of Japan,
2020
Edith Cowan University
Distribution And Evolution Of Fukushima Dai-Ichi Derived 137cs, 90sr, And 129i In Surface Seawater Off The Coast Of Japan, Jennifer A. Kenyon, Ken O. Buesseler, Núria Casacuberta, Maxi Castrillejo, Shigeyoshi Otosaka, Pere Masqué, Jessica A. Drysdale, Steven M. Pike, Virginie Sanial
Research outputs 2014 to 2021
© 2020 American Chemical Society. The Fukushima Dai-ichi Nuclear Power Plants (FDNPPs) accident in 2011 led to an unprecedented release of radionuclides into the environment. Particularly important are 90Sr and 137Cs due to their known health detriments and long half-lives (T1/2 ≈ 30 y) relative to ecological systems. These radionuclides can be combined with the longer-lived 129I (T1/2 = 15.7 My) to trace hydrologic, atmospheric, oceanic, and geochemical processes. This study seeks to evaluate 137Cs, 90Sr, and 129I concentrations in seawater off the coast of Japan, reconcile the sources of contaminated waters, and assess the application of 137Cs/90Sr, 129I/137Cs, and …
Study Of Cell Charging Effects For The Neutron Electric Dipole Moment Experiment At Oak Ridge National Laboratory,
2020
University of Kentucky
Study Of Cell Charging Effects For The Neutron Electric Dipole Moment Experiment At Oak Ridge National Laboratory, Mark Broering
Theses and Dissertations--Physics and Astronomy
The neutron electric dipole moment (nEDM) collaboration at the Spallation Neutron Source plans to use ultra-cold neutrons in superfluid helium to improve the nEDM limit by about two orders of magnitude. In this apparatus, neutrons are stored in poly(methyl methacrylate), PMMA, cells located in a strong, stable electric field. This electric field is produced by high voltage electrodes located outside of the neutron cells. Several sources generate charged particles inside the neutron cells. The electric field pulls these charges farther apart, attracting each to the oppositely charged electrode. As the charges build up on the cells walls, they create an …
The Pion Form Factor And Momentum And Angular Momentum Fractions Of The Proton In Lattice Qcd,
2020
University of Kentucky
The Pion Form Factor And Momentum And Angular Momentum Fractions Of The Proton In Lattice Qcd, Gen Wang
Theses and Dissertations--Physics and Astronomy
Lattice Quantum Chromodynamics (QCD) provides a way to have a precise calculation and a new way of understanding the hadrons from first principles. From this perspective, this dissertation focuses first on a precise calculation of the pion form factor using overlap fermions on six ensembles of 2+1-flavor domain-wall configurations generated by the RBC/UKQCD collaboration with pion masses varying from 137 to 339 MeV. Taking advantage of the fast Fourier transform, low-mode substitution (LMS) and the multi-mass algorithm to access many combinations of source and sink momenta, we have done a simulation with various valence quark masses and with a range …
Sensitivity Of Electron-Proton Coincidence Asymmetries In Neutron Beta-Decay To Scalar And Tensor Interactions,
2020
University of Kentucky
Sensitivity Of Electron-Proton Coincidence Asymmetries In Neutron Beta-Decay To Scalar And Tensor Interactions, Subash C. Nepal
Theses and Dissertations--Physics and Astronomy
We study the combined sensitivity of measurements of electron-proton coincidence asymmetries in polarized neutron beta-decay together with a measurement of the electron energy spectrum in unpolarized neutron beta-decay to beyond Standard Model (BSM) scalar and tensor interactions, via the appearance of such BSM physics in the Fierz interference terms b and bv. Whereas measurements of the electron energy spectrum directly probe b, both the proton and neutrino asymmetries for which experimental results exist are not sensitive to bv, but effectively to b - bv. This results in reduced sensitivity to BSM scalar and …
Verification Of The Vertical Bubble Flow Experiments,
2020
Virginia Commonwealth University
Verification Of The Vertical Bubble Flow Experiments, Reginald Jones Ii
Theses and Dissertations
Detailed experimental design to support basic pedagogy of flow regimes – single phase liquid, bubbly, slug, annular, dispersed droplet, and single phase vapor – occurring in flow channels of nuclear reactors has been developed for EGMN 203 - Nuclear Engineering Practicum offering at Virginia Commonwealth University’s Department of Mechanical and Nuclear Engineering. The laboratory instruction will be used to help students forming ideas and understanding flow regimes occurring in nuclear engineering applications. We designed and constructed four water columns to act as surrogates for water channels in a nuclear reactor. Each column was used for a different experiment: salted versus …
Parton Distribution Functions From Loffe Time Pseudo-Distributions,
2019
Old Dominion University
Parton Distribution Functions From Loffe Time Pseudo-Distributions, Bálint Joó, Joseph Karpie, Kostas Orginos, Anatoly V. Radyushkin, David Richards, Savvas Zafeiropoulos
Physics Faculty Publications
In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing the approach of parton pseudo-distribution functions. We perform a systematic analysis using three lattice ensembles at two volumes, with lattice spacings a = 0.127 fm and a = 0.094 fm, for a pion mass of roughly 400 MeV. With two lattice spacings and two volumes, both continuum limit and infinite volume extrapolation systematic errors of the PDF are considered. In addition to the x dependence of the PDF, we compute their first two moments and compare them with the pertinent phenomenological determinations.
Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev,
2019
Old Dominion University
Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev, S. Adhikari, A. Ali, M. J. Amaryan, A. Austregesilo, F. Barbosa, J. Barlow, A. Barnes, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, N. Wickramaarachchi, B. Zihlmann, The Gluex Collaboration
Physics Faculty Publications
We report on the measurement of the beam asymmetry Σ for the reactions →γp→pη and →γp→pη′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer −t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η′ in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of Ση to Ση′ to these models as …
Generalized Parton Distributions And Pseudodistributions,
2019
Old Dominion University
Generalized Parton Distributions And Pseudodistributions, Anatoly V. Radyushkin
Physics Faculty Publications
We derive one-loop matching relations for the Ioffe-time distributions (ITDs) related to the pion distribution amplitude (DA) and generalized parton distributions (GPDs). They are obtained from a universal expression for the one-loop correction in an operator form, and will be used in the ongoing lattice calculations of the pion DA and GPDs within the parton pseudodistributions approach.
Gamma-Ray Radiation Effects In Graphene-Based Transistors With H-Bn Nanometer Film Substrates,
2019
University of Utah
Gamma-Ray Radiation Effects In Graphene-Based Transistors With H-Bn Nanometer Film Substrates, E. J. Cazalas, Michael R. Hogsed, S. R. Vangala, Michael R. Snure, John W. Mcclory
Faculty Publications
Radiation effects on graphene field effect transistors (GFETs) with hexagonal boron nitride (h-BN) thin film substrates are investigated using 60Co gamma-ray radiation. This study examines the radiation response using many samples with varying h-BN film thicknesses (1.6 and 20 nm thickness) and graphene channel lengths (5 and 10 μm). These samples were exposed to a total ionizing dose of approximately 1 Mrad(Si). I-V measurements were taken at fixed time intervals between irradiations and postirradiation. Dirac point voltage and current are extracted from the I-V measurements, as well as mobility, Dirac voltage hysteresis, and the total number of GFETs that remain …
Measurements Of The 16c + 12c And 16c + 13c Fusion Cross Sections With Implications For Astrophysics,
2019
Texas A & M University - College Station
Measurements Of The 16c + 12c And 16c + 13c Fusion Cross Sections With Implications For Astrophysics, Ashley Ann Hood
LSU Doctoral Dissertations
The fusion of neutron-rich nuclei is of interest to nuclear astrophysics and nuclear structure. X-ray superbursts are powered by runaway thermonuclear burning deep inside of a neutron star, where heating from the pycnonuclear fusion of neutron-rich isotopes is an important heat source. Experimental measurements of fusion cross sections of neutron-rich isotopes have provided insights regarding nucleon transfer and nuclear structure properties affecting fusion. Recently, the 15C + 12C total fusion cross section was measured using a 15C beam produced by the in-flight beam production facility, which is part of the Argonne Tandem LINAC Accelerator System (ATLAS) at …
Alpha Capture Reaction Rates For Nucleosynthesis Within An Ab Initio Framework,
2019
Louisiana State University and Agricultural and Mechanical College
Alpha Capture Reaction Rates For Nucleosynthesis Within An Ab Initio Framework, Alison Constance Dreyfuss
LSU Doctoral Dissertations
Clustering in nuclear systems has broad impacts on all phases of stellar burning, and plays a significant role in our understanding of nucleosynthesis, or how and where nuclei are produced in the universe. The role of alpha particles in particular is extremely important for nuclear astrophysics: 4He was one of the earliest elements produced in the Big Bang, it is one of the most abundant elements in the universe, and helium burning -- in particular, the triple-alpha process -- is one of the most important ``engines'' in stars. To better understand nucleosynthesis and stellar burning, then, it is important …
Weaponizing Radioactive Medical Waste - The Looming Threat,
2019
Yenepoya University
Weaponizing Radioactive Medical Waste - The Looming Threat, Shreekumar Menon, Vagish Kumar L.S.
International Journal of Nuclear Security
Across the globe, use of radioactive substances for medical treatment, by hospitals has resulted in generation of toxic wastes on a large scale. Disposal of these wastes are being entrusted to waste disposal vendors. Environmental concerns, pressures, restrictions and high labor costs, compel these vendors to dump these wastes in third world countries, where enforcement and awareness are substantially low. Unrestricted access to these waste dumps is an open invitation to terror organizations to extract toxic substances and fabricate crude dirty bombs to threaten public safety, and cause low-level contamination of sensitive installations. It is therefore imperative to create an …
