Physical Sciences and Mathematics Commons^™

Constraining Of The Minerνa Medium Energy Neutrino Flux Using Neutrino-Electron Scattering, Luis Zazueta

Dissertations, Theses, and Masters Projects

Long baseline neutrino oscillation experiments rely on the flux from accelerator-based neutrino beams. As experimental neutrino physics moves to the next generation of experiments a precise characterization of the neutrino flux on a given experiment becomes crucial to the goals of the experiments: to precisely determine the neutrino oscillation parameters.This work takes advantage of neutrino-electron scattering processes for their precisely predicted cross section. The observed number of scattering events can be used as a benchmark to constrain the neutrino flux. A measurement was made of the energy spectrum of neutrino-electron elastic scattering (νe-→νe-), using data from the antineutrino-enhanced run period …

Experimental Studies Of Neutral Particles And The Isotope Effect In The Edge Of Tokamak Plasmas, Ryan Chaban

Dissertations, Theses, and Masters Projects

The H-mode plasma edge is a region of steep gradients in density and temperature known as the “pedestal” which greatly increases energy confinement. The complex links between neutral-plasma interactions and both diffusive and convective transport in the pedestal must be understood to model, predict, and achieve the high performance required for a fusion power plant. This dissertation explores the effects of different hydrogenic isotope neutral particles and plasma transport from the edge pedestal region into the Scrape-Off Layer. Current experiments typically use deuterium (H with amu=2 or D), however future fusion power plants may startup with hydrogen (H), and eventually …

Investigation Of Stripes, Spin Density Waves And Superconductivity In The Ground State Of The Two-Dimensional Hubbard Model, Hao Xu

Dissertations, Theses, and Masters Projects

The Hubbard model is a "paradigmatic" model in the realm of condensed matter physics. Recently a work with various state-or-art methods established the ground state stripe order near 1/8 doping and strong on-site interaction. Therefore, in this thesis, we determine the spin and charge order of ground state of 2D doped Hubbard model in its simplest form (with only on site repulsion and nearest-neighbor hoping) with various doping and small to medium interaction. At half-filling, the ground state is known to be an antiferromagnetic Mott insulator. Doping Mott insulators is believed to be relevant to the superconductivity observed in cuprates. …

Partial Wave Analysis Of Strange Mesons Decaying To K + Π − Π + In The Reaction Γp → K + Π + Π − Λ(1520) And The Commissioning Of The Gluex Dirc Detector, Andrew Hurley

Dissertations, Theses, and Masters Projects

Hadron spectroscopy is a cornerstone of our understanding of the strong nuclear interac-tions. Studying the hadron spectrum led to the postulation of quarks and gluons, and the development of Quantum Chromodynamics (QCD), the theory of the strong nuclear force. Today hadron spectroscopy provides an important test of QCD, particularly in the non-perturbative energy regime. One such test is the existence of hybrid hadrons that have gluonic degrees of freedom, e.g. qq̄g states, that are allowed by QCD but have remained elusive in experimental searches. The GlueX experiment located at Thomas Jefferson National Accelerator Facility, is designed to map the light …

Exploring The Photophysics Of Brown Carbon Chromophores Using Laser-Based Spectroscopy And Computational Methods, Megan Elizabeth Alfieri

Dissertations, Theses, and Masters Projects

Atmospheric aerosols are made up of suspended liquids and solids in the atmosphere. These aerosols play a very important role in the solar energy exchange in Earth’s atmosphere as well have dramatic impact on human health. Different aerosols have different effects on the atmosphere depending on the physical properties of the aerosols.

The purpose of this research project is to understand how the structure of molecular chromophores impacts the solar absorption properties of aerosols. We propose a series of laboratory studies to investigate the outcomes from solar absorption of brown carbon chromophores: 1-phenylpyrrole, 2-phenyl-1-H-pyrrole, 2-phenylimadazole, as well as water complexes. …

Inclusive And Inelastic Scattering In Neutrino-Nucleus Interactions, Amy Filkins

Dissertations, Theses, and Masters Projects

Neutrino-nucleus cross section measurements can provide both insights into nuclear physics and important data that can be used to improve model predictions used for neutrino oscillation physics. Two measurements of neutrino-nucleus cross sections were performed using data from the MINERvA experiment, each probing different classes of neutrino interactions. Double and single-differential flux-integrated measurements of inclusive charged current neutrino-nucleus cross sections at a peak neutrino energy of 3.5 GeV are presented as a function of the longitudinal and transverse momentum of the muon produced in the interaction. Additionally, an analysis of charged-current deep inelastic scattering (DIS) of muon neutrinos was performed …

Quantum Sensing For Low-Light Imaging, Savannah Cuozzo

Dissertations, Theses, and Masters Projects

In high-precision optical measurements, noise due to quantum fluctuations in the amplitude and phase of the probing field becomes the limiting factor in detection sensitivity. While this quantum noise is fundamental and not a result of detection, it is possible to engineer a quantum state that has reduced noise in either amplitude or phase (at the cost of increasing noise in the other) called a quadrature-squeezed state. In this dissertation, we study the use of quadrature-squeezed vacuum states for low-light imaging and develop a quantum detection method to measure the spatial dependence of the quantum noise using a camera instead …

Edge Fueling And Neutral Density Studies Of The Alcator C-Mod Tokamak Using The Solps-Iter Code, Richard M. Reksoatmodjo

Dissertations, Theses, and Masters Projects

Understanding edge neutral dynamics in high-field tokamaks has strong consequencesfor both fueling and plasma profile predictions. We validate the ability of SOLPS-ITER, a 2D fluid plasma/kinetic Monte Carlo neutral code, to accurately model the upstream neutral density profiles of L-mode, I-mode, and H-mode discharges in the Alcator CMod tokamak, for which Lyman-alpha emission measurements were available. We achieve simulated Lyman-alpha emission and neutral density profiles that are within one standard deviation of empirically inferred profiles for all three discharges, via iterative tuning of the perpendicular transport coefficient profiles alone, providing confidence in the conclusion that while further physics (drifts, impurities, …

Electronic Transport In Topological Superconducting Heterostructures, Joseph Jude Cuozzo

Dissertations, Theses, and Masters Projects

In this dissertation, we study Andreev transport and Josephson effects in topological superconducting heterostructures. We study consider two platforms: quantum Hall-superconductor (QH-SC) heterostructures and Josephson junctions. In the first platform, we study QH graphene-SC systems with a focus on the influence symmetry-breaking effects have on Andreev transport. In graphene, valley and spin degeneracy lead to an approximate SU(4) symmetry that is reflected in the approximate 4-fold degeneracy of graphene's Landau levels (LL). We develop an effective low-energy description of Andreev edge states that takes into account the correction to the drift velocity of the QH-SC edge modes due to SU(4) …

Radiative Width Of K*(892) From Lattice Quantum Chromodynamics, Archana Radhakrishnan

Dissertations, Theses, and Masters Projects

In this dissertation, we use lattice quantum chromodynamics to explore the radiative transitions of πK to K, to calculate the radiative width of the resonant K*(892) which appears in the P-wave πK → γK transition amplitude. The matrix elements are extracted from three-point functions calculated in a finite-volume discretized lattice with a pion mass of 284 MeV. The finite-volume amplitudes, which are constrained over a large number of πK energy points and four-momentum transfers, are mapped to the infinite volume transition amplitude by using the Lellouch-Lüscher formalism. The radiative width is determined to be …

Ultrafast Optical Control And Characterization Of Carrier And Spin Dynamics In Novel Magnetic Topological Insulator Systems, Peiwen Liu

Dissertations, Theses, and Masters Projects

Magnetic topological insulators (MTIs) are of considerable interest in developing novel spintronics and quantum computing applications. Under the topological protection by time-reversal Z2 invariant number, magnetic topological insulators are provided with robust electronic and magnetic properties against local perturbations. The quantum anomalous Hall effect (QAHE), which harbors dissipationless chiral edge states in MTIs, provides a competitive platform for future low-power consumption and high-speed spintronic devices. Although the present studies on both bulk and surface magnetic properties in MTIs have made significant progress, the in-depth understanding of the exchange couplings and the interaction between the two magnetization sources is far from …

Excited J-- Resonances In Meson-Meson Scattering From Lattice Qcd, Christopher Johnson

Dissertations, Theses, and Masters Projects

Understanding the excited light meson spectrum is vital to our understanding of how quarks and gluons bind to become hadrons. This sector is home to a plethora of states including hadrons laying outside the quark model. Distinguishing the from the rest of the spectrum would be made easier if we first had a handle on the light quark anti-quark spectrum. I present the first determination of excited light JPC=1--,2--,3-- resonances in meson-meson scattering at the SU(3) flavor point from lattice QCD. This system can be described in the context of pseudoscalar-vector elastic scattering and I determine two 1-- resonances; a …

Light-Matter Interactions In Quasi-Two-Dimensional Geometries, David James Lahneman

Dissertations, Theses, and Masters Projects

Emergent phenomena that occur at length scales smaller than approximately half the wavelength of light cannot be resolved by conventional optical techniques due to the Abbe diffraction limit. Scattering-type scanning near-field infrared microscopy (S-SNIM) can circumvent this diffraction limit allowing infrared spectroscopy at nano-scale dimensions independent of the wavelength. Additionally, there is enhanced surface sensitivity resulting from this nanoconfinement of infrared light. S-SNIM is uniquely suitable to study a diverse range of material properties inaccessible by far-field optics in the infrared such as the optical properties of ultrathin films as well as hybrid light matter surface waves called polaritons. Initially, …

Ac & Dc Zeeman Interferometric Sensing With Ultracold Trapped Atoms On A Chip, Shuangli Du

Dissertations, Theses, and Masters Projects

This thesis presents progress in developing a trapped atom interferometer on a chip, based on AC Zeeman potentials. An atom interferometer is a high-precision measuring tool that can detect various types of forces and potentials. The trapped atom interferometer introduced in this thesis targets the shortcomings of traditional ballistic atom interferometers, which are typically meter-scale in height. Notably, a trapped atom interferometer has a localized atomic sample, a potentially longer interferometric phase accumulation time, and the prospect of being the basis for a more compact instrument. This thesis presents multiple projects in the development of a trapped atom interferometer based …

Calculation Of Gluon Pdf In The Nucleon Using Pseudo-Pdf Formalism With Wilson Flow Technique In Lqcd, Md Tanjib Atique Khan

Dissertations, Theses, and Masters Projects

A comprehensive study of the gluonic content in the nucleon from a first principles lattice quantum chromodynamics calculation is presented. The unpolarized gluonic distribution in the nucleon is calculated using the pseudo-PDF framework on the lattice. First, the spectral analyses of the low-lying states in the nucleon, as well as in the delta are performed on the lattice, identifying baryons states with hybrid characteristics, in which the gluons play a manifestly structural role, and determining a set of operators which have significant overlaps onto the ground state of the nucleon. Techniques such as distillation for smearing the quark fields, momentum …

Radiofrequency Ac Zeeman Trapping For Neutral Atoms, Andrew Peter Rotunno

Dissertations, Theses, and Masters Projects

This thesis presents the first experimental demonstration of a two-wire AC Zeeman trap on an atom chip. The AC Zeeman energy is a resonant, bipolar, state-dependent atomic energy shift produced by alternating magnetic fields with frequencies near hyperfine transitions. We demonstrate that high gradients in this energy, as near an atom chip, can produce a spin-state selective force greater than gravity for ultracold rubidium atoms. Our novel trap is generated by a local minimum in AC Zeeman energy. Using less than one watt of power, we demonstrate trap frequency on the order of a few hundred Hz, trap depth about …

Dihadron Beam Spin Asymmetries On An Unpolarized Hydrogen Target With Clas12, Timothy Barton Hayward

Dissertations, Theses, and Masters Projects

The semi-inclusive deep inelastic scattering process, where an electron scatters off a proton target at high enough energy that the process can be described by the scattering off a single constituent particle, offers targeted access to the internal structure of the nucleon. The process can be described in two phases by parton distribution functions (PDFs), which describe the likelihood of finding a quark or gluon in a particular state inside of the nucleon and then by fragmentation functions (FFs) which describe the likelihood of forming a particular final state particle. One way to study these properties is via the measurement …

Proton Spin Structure From Simultaneous Monte Carlo Global Qcd Analysis, Yiyu Zhou

Dissertations, Theses, and Masters Projects

Despite the great effort and achievements made towards understanding proton spin structure in the past few decades, a complete picture is still elusive. Parton distribution functions (PDFs), which in quantum chromodynamics (QCD) encode the momentum and helicity distributions of quarks and gluons inside a proton, provide the means by which to quantify the proton structure information. Being inherently nonperturbative, PDFs have to be extracted from unpolarized and polarized lepton-hadron and hadron-hadron scattering data. In particular, experiments that measure unpolarized and polarized jet observables can provide insight into the momentum and helicity distributions of gluons, which have generally been more difficult …

Forward & Off-Forward Parton Distributions From Lattice Qcd, Colin Paul Egerer

Dissertations, Theses, and Masters Projects

The interpretation of (semi-)inclusive and certain exclusive scattering processes relies on the factorization of hard parton level cross sections from long-range and non-perturbative parton correlations. The familiar Parton Distribution Functions (PDFs) and Generalized Parton Distributions quantify the non-perturbative dynamics in these situations and address a number of key questions surrounding the structure of hadrons. A certain class of matrix elements accessible in lattice QCD, so called Lattice Cross Sections, have been shown to factorize into these collinear distributions in a manner akin to the factorization of hadronic cross sections. In the short-distance regime, matrix elements of space-like separated two-current operators …

Quantitative Analysis Of Ekg And Blood Pressure Waveforms, Denise Erin Mckaig

Dissertations, Theses, and Masters Projects

In the intensive care unit (ICU) of a hospital, patients are monitored continuously and the data on those patients provide powerful diagnostic tools for the medical community. However, the patient data creates incredibly large data sets with instruments measuring multiple signals simultaneously. This work seeks to improve monitoring techniques through analysis of large data sets from former ICU patients. By knowing the outcomes of patients in the past, can we detect patterns to diagnose future patients while also reducing the amount of recorded information? This thesis first seeks to improve methods of storing infant electrocardiograms (EKGs) by reducing the full …

Competing And Cooperating Orders In The Three-Band Hubbard Model: A Comprehensive Quantum Monte Carlo And Generalized Hartree-Fock Study, Adam Chiciak

Dissertations, Theses, and Masters Projects

Significant progress has been made in studying strongly correlated electronic systems with major focus on understanding high-temperature superconductivity. At the center of these studies are the so-called cuprates, which are characterized by a quasi-2D Copper-Oxide plane in which superconductivity is believed to arise. From the theoretical point of view, the complex electronic structure of these materials makes a fully ab initio many-body computation a formidable task, so we are forced to focus on minimal models that can reproduce the physics, the most well known of which is known as the Hubbard Model, which relies on the Zhang-Rice singet notion to …

Study Of Scalar Extensions For Physics Beyond The Standard Model, Marco Antonio Merchand Medina

Dissertations, Theses, and Masters Projects

In this thesis we investigate the phenomenology of beyond the Standard Model scenarios with extra scalar fields. A review and motivation of extended electroweak symmetry breaking is presented. Then we address observational evidence of new physics such as possible lepton flavor violating processes and the relic abundance of dark matter by implementing models with three Higgs doublets. The complementarity between theoretical restrictions and experimental bounds on some of the predicted signals is leveraged to sharpen the allowed parameter space. After that we study embeddings of two-Higgs doublets into the Randall-Sundrum model with emphasis on the scalar fluctuations of the metric …

Experiments And Theory On Dynamical Hamiltononian Monodromy, Matthew Perry Nerem

Dissertations, Theses, and Masters Projects

In classical mechanics, one of the advanced topics is the study of action and angle variables. These variables are quite abstract, but very powerful tools for describing classical motion. If a system has a full set of conservation laws, and if the motion of the system is bounded, then the motion can be described as flow on a torus. Action variables are functions of the conservation laws that identify the torus on which the motion lies, while angle variables tell the location of the system on that torus. In certain cases, the functional relationship between the conservation laws and the …

A First-Principles Study Of The Nature Of The Insulating Gap In Vo2, Christopher Hendriks

Dissertations, Theses, and Masters Projects

Upon cooling past a critical temperature Tc = 340 K Vanadium dioxide (VO2) exhibits a metal-insulator transition (MIT) from a metallic rutile R to an insulating monoclinic M1 phase. Other insulating phases, a monoclinic M2 and triclinic T, have been identifed and are accessible via strain or doping. Despite decades of research, the nature of the VO2 MIT is still not fully understood. In this work we present ab-initio hybrid density functional theory (DFT) calculations on the insulating phases, compare the results to experimental measurements and discuss their implications on our understanding of the VO2 MIT. Recent measurements on M1 …

Insulator To Metal Transition Dynamics Of Vanadium Dioxide Thin Films, Scott Madaras

Dissertations, Theses, and Masters Projects

Vanadium Dioxide (VO2) is a strongly correlated material which has been studied for many decades. VO2 has been proposed for uses in technologies such as optical modulators, IR modulators, optical switches and Mott memory devices. These technologies are taking advantage of VO2’s insulator to metal transition (IMT) and the corresponding changes to the optical and material properties. The insulator to metal transition in VO2 can be accessed by thermal heating, applied electric field, or ultra-fast photo induced processes. Recently, thin films of VO2 grown on Titanium Dioxide doped with Niobium (TiO2:Nb), have shown promise as a possible UV photo detector …

Development Of Quantum Information Tools Based On Multi-Photon Raman Processes In Rb Vapor, Nikunjkumar Prajapati

Dissertations, Theses, and Masters Projects

Multi-photon nonlinear processes in atoms have served as important tools for quantum metrology, quantum communications, and quantum sensing. In this thesis, we experimentally address the interplay of various multi-photon Raman processes in hot Rb vapor, with the four-wave mixing (FWM) process being a central theme. FWM is the nonlinear response of a medium to a strong optical pump field inelastically scattering off atomic resonances and resulting in the generation of additional photons in different modes. FWM is a detrimental, but inherent part of electromagnetically induced transparency (EIT) and Raman based quantum memories. However, we were able to weaken the four-photon …

Growth Engineering And Characterization Of Vanadium Dioxide Films For Ultraviolet Detection, Jason Andrew Creeden

Dissertations, Theses, and Masters Projects

There is a need for efficient ultraviolet (UV) detectors in many fields, such as aerospace, automotive manufacturing, biology, environmental science, and defense, due to photomultiplier tubes (the currently available technology) often not meeting application constraints in weight, robustness, and power consumption. In my thesis, I demonstrate that high quality vanadium dioxide (VO2) thin films, epitaxially grown on niobium doped titanium dioxide substrates (TiO2:Nb), display a strong photoconductive response in the UV spectral range, making them promising candidates for photomultiplier-free UV photodetection. By adjusting the characteristics of the substrate and VO2 film, the samples achieve external quantum efficiency exceeding 100% (reaching …

Interfacial Forces Of 2d Materials At The Oil–Water Interface, William Winsor Dickinson

Dissertations, Theses, and Masters Projects

Two-dimensional (2D) materials, including graphene and graphene oxide (GO), are a subject of interest for many researchers due to their exceptional properties (strength, conductivity, etc.). These materials, comprised of atomically-thin sheets, may naturally occur stacked together like sheets of paper, but their most interesting properties emerge when separated into individual layers. However, scaling up the processes used to isolate single sheets of some of these materials, particularly graphene, has proven problematic. They can be fiercely resistant to exfoliation, difficult to disperse, and have a worrying propensity to restack. All these problems contribute to the great difficulty these fascinating materials have …

Global Shipping Container Monitoring Using Machine Learning With Multi-Sensor Hubs And Catadioptric Imaging, Victor Esteban Trujillo

Dissertations, Theses, and Masters Projects

We describe a framework for global shipping container monitoring using machine learning with multi-sensor hubs and infrared catadioptric imaging. A wireless mesh radio satellite tag architecture provides connectivity anywhere in the world which is a significant improvement to legacy methods. We discuss the design and testing of a low-cost long-wave infrared catadioptric imaging device and multi-sensor hub combination as an intelligent edge computing system that, when equipped with physics-based machine learning algorithms, can interpret the scene inside a shipping container to make efficient use of expensive communications bandwidth. The histogram of oriented gradients and T-channel (HOG+) feature as introduced for …

Extraction And Parametrization Of Isobaric Trinucleon Elastic Cross Sections And Form Factors, Scott Kevin Barcus

Dissertations, Theses, and Masters Projects

By mining data from Jefferson Lab Hall A experiment E08-014 a new measurement of the 3He elastic cross section at Q^2 ≈ 34 fm^−2 was extracted from a large quasielastic background. This new data point falls approximately halfway between the first and second diffractive minima of the 3He form factors. When combined with recent high Q^2 3He elastic cross section measurements from JLab this new point improves our knowledge of the cross section and form factors at large momentum transfers. The new high Q^2 data motivate a reanalysis of the 3He elastic cross section world data and promise an improved …