Physics Commons^™

Investigating The Uncertainties In Ct Non-Small Cell Lung Cancer Radiomics, Gary Ge

Theses and Dissertations--Radiation Medicine

Radiomics is a technique that extracts quantitative features, termed radiomic features, from medical images using data-characterization algorithms. These radiomic features can be used to identify tissue characteristics and radiologic phenotyping that are not observable by clinicians in a non-invasive, low-cost manner, potentially generating image biomarkers for clinical decision. To date, there are still many uncertainties involved in radiomics which limit its clinical implementation. Herein, we propose to explore the impact of each component in the radiomics pipeline on predicting clinical outcomes. In Chapter II, we conduct a thorough review of CT lung cancer radiomics studies to examine the typical feature …

Energy Integrated Ratio Analysis Of The Anomalous Precession Frequency In The Fermilab Muon G-2 Experiment, Ritwika Chakraborty

Theses and Dissertations--Physics and Astronomy

The muon’s anomalous magnetic moment, a_μ, provides a unique way for probing physics beyond the standard model experimentally as it gathers contributions from all the known and unknown forces and particles in nature. The theoretical prediction of a_μ has been in greater than 3 σ tension with the experimental measurement since the results of the Muon g-2 Experiment at the Brookhaven National Laboratory (E-821) were published in the early 2000s with a precision of 540 ppb. To settle this tension, the new Fermilab Muon g - 2 Experiment (E-989) is currently taking data with the aim of …

Magnetization Dynamics In A Modified Square Artificial Spin Ice, Amrit Kaphle

Theses and Dissertations--Physics and Astronomy

Artificial spin ices are magnetic metamaterials consisting of nanomagnet arrays in a 2-D lattice. Typically, these nanomagnet arrays are binary macrospins that can only be in an up or down state similar to the Ising spins. They have been intensively used to study magnetic frustration and ordering phenomena in a controlled environment. The hexagonal artificial spin ice and square artificial spin ice are among the most heavily studied systems. In this dissertation, we designed a modified square artificial spin ice system by an ordered substitution of a double-segment for a nanomagnet array in the unit cell of square artificial spin …

Neutron Spectroscopy Of The Parity-Violating 0.734 Ev Neutron Resonance In Lanthanum-139 In Preparation For The Noptrex Time Reversal Violation Experiment, Danielle Schaper

Theses and Dissertations--Physics and Astronomy

One of the most outstanding questions in physics is the matter-antimatter asymmetry of the Universe, resulting from excess baryogenesis processes during the early moments of the formation of the Universe. At present, the types of processes needed to explain this matter excess, so-called `CP-violating processes' are known to exist within the present framework of the Standard Model of particle physics. However, decades of research has shown that our understanding of the origin of these processes is incomplete, as we do not presently know of enough sources of CP-violating processes to account for the large baryon asymmetry that we observe. The …

An Energy-Integrated Analysis For Measuring The Anomalous Precession Frequency For The Muon G − 2 Experiment At Fermilab, Laura Kelton

Theses and Dissertations--Physics and Astronomy

In the search for physics beyond the Standard Model, the Muon g − 2 Experiment at Fermilab (E989) will make the most precise measurement of the anomalous magnetic moment of the muon, a_μ. Improvements in precision come from both increased statistics and new techniques to significantly reduce previous systematic uncertainties. The muon a_μ is determined by extracting both the anomalous spin precession frequency, ω_a, and the average magnetic field sampled by the muons, B. Traditionally an energy threshold analysis method which requires reconstruction of decay positrons from the muon decay, μ⁺ → e^{+ …}

Enhancements To Uniformity Of Magnetic Fields At The Sns Nedm Experiment, Ahmad Saftah

Theses and Dissertations--Physics and Astronomy

The nEDM experiment at the Spallation Neutron Source (SNS) aims to increase
experimental sensitivity to hadronic CP violation by nearly two orders of magnitude.To do that the nEDMSNS experiment requires an extremely uniform magnetic field to maintain ³He polarization during transit to the measurement cell. The Magnetic Shield Enclosure (MSE) coil provides the required field. However, the superconducting shield distorts the MSE field.

This thesis discusses a magnetic cloak for the nEDM@SNS experiment that can restore the MSE field uniformity and cos theta coils designed to test the magnetic cloak in the first part. The second part of this …

Extraction Of Deep Inelastic Cross Sections Using A 10.4 Gev Electron Beam And A Polarized Helium-3 Target, Murchhana Roy

Theses and Dissertations--Physics and Astronomy

Experiment E12-06-121 at Jefferson Lab aims to do a precision measurement of the neutron spin structure function g₂ using inclusive inelastic scattering of electrons over a large kinematic range of x and Q². The third moment of the linear combination of the spin structure functions g₁ and g₂, d₂, is one of the cleanest higher twist observables and contains information on quark-gluon correlations. It is connected to the "color polarizability" or "color Lorentz force" of the nucleon. The experimental data taking was successfully conducted in Hall C using a longitudinally polarized electron …

Cryogenic Magnetic Field Monitoring System In The Sns Neutron Edm Experiment, Umit Hasan Coskun

Theses and Dissertations--Physics and Astronomy

A permanent neutron electric dipole moment (nEDM), d_n, would violate charge-conjugation and parity (CP) symmetry. The neutron electric dipole moment currently has a global limit of d_n < 1.8 x 10^-26 e cm (90% CL). This limit is intended to be improved by two orders of magnitude by the nEDM experiment at the Spallation Neutron Source (SNS nEDM), d_n ~ 10^-28 e cm. The magnetic field non-uniformities within the experimental region must be precisely monitored and managed in order to suppress systematic effects in the experiment caused by magnetic field gradients. The estimation of magnetic field components within …

Elastic And Inelastic Compton Scattering From Deuterium At 61 Mev, Danula Godagama

Theses and Dissertations--Physics and Astronomy

A Compton scattering experiment using deuteron as target nuclei was carried out at the HIγS free electron laser facility at Durham, NC, with the goal of extracting the electromagnetic scalar polarizabilities of the neutron, α_n and β_n. A beam of 61~MeV gamma photons with a narrow energy spread was incident on a liquid deuterium target. The scattered gamma rays were detected at three scattering angles, 55^o, 115^o and 150^o. Backward-scattered gamma rays were detected using two large-volume NaI spectrometers with energy resolution (σ_E/E) better than 2%. The combined effect of …

Angular Distribution Of Electron-Helium Scattering In The Presence Of A 1.17 Ev Laser Field, Brian N. Kim

Theses and Dissertations--Physics and Astronomy

We have measured relative differential cross sections for 350 eV electrons scattered by a helium target in the presence of 1.17 eV photons from an Nd:YAG laser. We report an angular distribution of free-free electrons that were scattered elastically at angles between 15^o and 80^o and of free-free electrons that underwent the process of electron-impact excitation of helium to its unresolved (1s2s)¹S and (1s2p)¹P excited states at angles between 1^o and 80^o. Our experiments test the momentum transfer dependence and the relationship between elastic and inelastic scattering in the Kroll-Watson approximation. …

Thermalization And Quantum Information In Conformal Field Theory, Ashish Kakkar

Theses and Dissertations--Physics and Astronomy

The consequences of the constraints of conformal symmetry are far-reaching within
theoretical physics. In this dissertation we address a series of questions in conformal
field theory: 1) We calculate the spectrum of qKdV charges in a large central charge
expansion. 2) We determine the corrections to bulk information geometry from 1/N
contributions to holographic correlators. 3) We study the higher genus partitions
functions of CFTs associated with classical and quantum error-correcting codes.

Studies Of Time Variations Of The Magnetic Field In The Nedm@Sns Experiment, Mojtaba Behzadipour

Theses and Dissertations--Physics and Astronomy

It is thought that equal quantities of matter and antimatter were generated at the moment of the Big Bang. However, observations of the Universe show that there is a significant excess of matter over antimatter. The matter-antimatter asymmetry in the Universe (baryon to photon ratio) is observed to be of the order of 10^-10 [1]. Baryogenesis is a possible explanation for the matter-antimatter asymmetry of the universe. In 1967, Sakharov proposed three criteria necessary for Baryogenesis. The three conditions are: 1) baryon number violation, 2) C and CP violation and 3) departure from thermal equilibrium. However, the Standard Model's …

High Performance Data Acquisition And Analysis Routines For The Nab Experiment, David Mathews

Theses and Dissertations--Physics and Astronomy

Probes of the Standard Model of particle physics are pushing further and further into the so-called “precision frontier”. In order to reach the precision goals of these experiments, a combination of elegant experimental design and robust data acquisition and analysis is required. Two experiments that embody this philosophy are the Nab and Calcium-45 experiments. These experiments are probing the understanding of the weak interaction by examining the beta decay of the free neutron and Calcium-45 respectively. They both aim to measure correlation parameters in the neutron beta decay alphabet, a and b. The parameter a, the electron-neutrino correlation coefficient, is …

Data Acquisition, Analysis And Simulations For The Fermilab Muon G−2 Experiment, Fang Han

Theses and Dissertations--Physics and Astronomy

The goal of the new Muon g-2 E989 experiment at Fermi National Accelerator Laboratory (FNAL) is a precise measurement of the muon anomalous magnetic moment, a_μ ≡ (g-2)/2. The previous BNL experiment measured the anomaly a_μ(BNL) with an uncertainty of 0.54 parts per million (ppm). The discrepancy between the current standard model calculation of the a_μ(SM) and the previous measurement a_μ(BNL) is over 3σ. The FNAL Muon g-2 experiment aims at increasing the precision to 140 parts per billion (ppb) to resolve the discrepancy between the theoretical …

Understanding The Degradation Mechanism In Methyl Ammonium Lead Halide Perovskite And Black Phosphorene Via Electrical Transport Study, Huda Saleh Aljeailan

Theses and Dissertations--Physics and Astronomy

This work seeks to understand the degradation mechanism of technically important material systems such as black phosphorene (BP), arsenic phosphorene (AsP) and Methyl ammonium lead iodide (CH₃NH₃PbI₃) perovskite. Degradation studies were conducted by studying the in-situ electrical transport properties (resistance and thermoelectric power (TEP)) of these materials in vacuum (under annealed condition) and after exposure to the ambient air.

BP and both exhibited p-type semiconducting (positive TEP) behavior under annealed conditions and the changes in their transport properties upon exposure to ambient air can be explained as due to the charge transfer between the …