Digital Commons Network^™

Lepton Flavor Violation And Effective Field Theories, Renae Conlin

Wayne State University Dissertations

The Standard Model is believed to be a low energy effective theory of some completetheory at higher energies. This is already evidenced in the observation of neutrino oscillations. Standard Model processes conserve the lepton flavor quantum numbers. Adding massive neutrinos to the Standard Model, the branching ratios of lepton flavor violating processes are found to be incredibly small. For example, a process μ → eγ has a branching ratio order ∼ 10^−54. These tiny branching ratios of lepton flavor violating processes indicate that they are especially clean areas to look for beyond the Standard Model physics. Any observed flavor violation …

Correlations And Dynamic Fluctuations In High Energy Collisions, Zoulfekar Mazloum

Wayne State University Dissertations

Is thermalization necessary for hydrodynamic flow in nuclear collisions? The discovery of flow-like azimuthal correlations in pA and high-multiplicity pp collisions raises profound questions about the onset of collective flow and its relation to hydrodynamics. We seek independent experimental information on the degree of thermalization in order to identify those hydrodynamic collision systems in which flow is sensitive to equilibrium QCD properties. We aim to develop a protocol for identifying the degree of thermalization using a combination of momentum and multiplicity correlation. To study the effect ofthermalization on these correlations, we use Boltzmann equation in the relaxation time approximation with …

Photophysics Of Metalloporphyrins Strongly Coupled To Cavity Photons, Aleksandr Avramenko

Wayne State University Dissertations

This dissertation will discuss the photophysics of metalloporphyrins, mainly CuTPP, ZnTPP, and H2TPP under strong light-matter coupling conditions. Strong light-matter coupling was achieved by embedding the previously mentioned chromophores into a spun coated PMMA polymer coating which is then incorporated as a spacer layer in a FabryPérot nano-cavity. The cavity thickness is chosen so that the cavity photon is of similar energy as the B, or Soret transition (2nd excited state) of the porphyrin molecule. The exchange of energy between the cavity photon and the molecular mode leads to the formation of polariton states.

Increasing the concentration of the molecules …

Jet Substructure Measurements In Proton-Proton And Proton-Gold Collisions, Isaac Arthur Mooney

Wayne State University Dissertations

Observing a modification of high-energy probes in the hot nuclear environment created by ultrarelativistic heavy-ion collisions is critical for understanding the microscopic structure of the QCD medium. However, before a modification can be observed, the probes must be calibrated. For this reason, measurements of jet observables in vacuum (pp collisions) and in the presence of cold nuclear matter (pAu collisions) are presented, which will allow for future comparison of jet substructure measurements in AuAu to these baseline measurements. \parData from the STAR detector on the Relativistic Heavy Ion Collider at Brookhaven National Laboratory are used for both analyses. The pp …

Non-Perturbative Processes In Standard Model \& New Physics: From Standard Calculations To Machine Learning, Cody Michael Grant

Wayne State University Dissertations

I calculated non-perturbative processes to study the Standard Model and probe areas of new physics. I found that invisible decays of heavy mesons are not dominated by the leading order contribution in the Standard Model. I argue that this affects neutrino mass constraints and avenues for discovering new physics, such as dark photons. In addition to this, I used a novel approach to approximate a semileptonic form factor with an artificial neural network (ANN). Comparing the results from the ANN to common phenomenological parameterizations, and using it to set a lower bound constraint on the CKM matrix element, $V_{cd}$. Finally, …

Study Of Zyomogen Granule Movement Along Actin Filaments Using A Single Beam Optical Trap, Justin James Raupp

Wayne State University Dissertations

Zymogen granules are enzymatic vesicles in the pancreas. The surface of these zymogen granules (ZGs) has several different kinds of myosin molecules, such as myosin 1c, 6, 5c, and 7b. These molecular motors may contribute to ZG transportation in cells. To understand the molecular motors involved in the vesicle trafficking, we observed the in vitro motility of purified ZGs from rat pancreas and examined the stepping behavior and force that is generated using a single beam optical trap. To be involved in trafficking, molecular motors have certain characteristics, a high duty ratio and the ability to move continuously along actin …

Study Of The Decay B^± → K^0_S Π^± Π^0 At The Belle Experiment, Suravinda Janaka Kumara Kospalage

Wayne State University Dissertations

Belle is a particle physics experiment based at the KEK laboratory in Tsukuba Japanwhich ran from 1999 to 2010 and collected 1ab−1 of data. The Belle experiment is focused on studying the properties of particles called B mesons which are produced by accelerating and colliding electron and positron beams. These B mesons show the biggest differences between the properties of matter and anti-matter of any known particles. One of the main goals of the Belle experiments is to understand the differences between matter and anti-matter, specifically violations of charge-parity symmetry (CP violation) and how anti-matter vanished and we come to …

Optical Signal Processing With Discrete-Space Metamaterials, Mohammad Moein Moeini

Wayne State University Dissertations

As digital circuits are approaching the limits of Moore’s law, a great deal of efforthas been directed to alternative computing approaches. Among them, the old concept of optical signal processing (OSP) has attracted attention, revisited in the light of metamaterials and nano-photonics. This approach has been successful in realizing basic mathematical operations, such as derivatives and integrals, but it is difficult to be applied to more complex ones. Inspired by digital filters, we propose a radically new OSP approach, able to realize arbitrary mathematical operations over a nano-photonic platform. We demonstrate this concept for the case of spatial differentiation, image …

Accumulation-Type Ohmic Van Der Waals Contacts To Nearly Intrinsic Wse2, Upendra Rijal

Wayne State University Dissertations

We report the fabrication of ohmic van der Waals (vdW) contacts to WSe2 using degenerately p-doped MoS2 (p+-MoS2) as a contact-metal. We demonstrate in WSe2 field-effect transistors (FETs) that accumulation-type ohmic contacts and high device performance are achieved without electrostatically gating the drain/source contact regions despite the nearly intrinsic nature of WSe2. Back-gated WSe2 FETs with p+-MoS2 bottom-contacts (which screen the back-gate electric field in the drain/source regions) exhibit linear output characteristics, a high on/off ratio of 108, and a high two-terminal field-effect mobility up to ~200 cm2V-1s-1 at room temperature. Our theoretical modeling reveals that the p+-MoS2/WSe2 vdW contact …

High Mobility N-Type Field Effect Transistors Enabled By Wse2/Pdse2 Heterojunctions, Arthur Bowman Iii

Wayne State University Dissertations

Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDs) have emerged as a promising candidate for post-silicon electronics. Few-layer tungsten diselenide (WSe2), a well-studied TMD, has sown high hole mobility and ON/OFF ratio in field effect transistor (FET) devices. But the n-type performance of WSe2 is still quite limited by the presence of a substantial Schottky Barrier. Palladium diselenide, (PdSe2) is a newly discovered TMD that is of interest because of its high electron mobility, and moderate ON/OFF ratios. However, despite its relatively small bandgap, the n-type performance of few-layer PdSe2 FETs has also been limited by a Schottky barrier, …

An Investigation Of Uncertainties In Intensity Modulated Radiation Therapy, Cory Knill

Wayne State University Dissertations

Introduction: The treatment of cancer using intensity modulated radiation therapy (IMRT) is complex, involving many sub-processes to commission a treatment platform and treat patients. Uncertainties within the individual sub-process can lead to inaccurate treatments and sub-optimal patient outcomes. This research focused on minimizing uncertainties throughout IMRT commissioning and treatments. Methods: Five sub-processes were selected for uncertainty reduction: 1) optimizing radiation-imaging coincidence of the treatment machine, 2) improving the statistical model used to analyze IMRT commissioning data, 3) reducing the effect of ion recombination in IMRT quality assurance measurements, 4) improving the correlation between IMRT quality assurance results and patient-specific delivery …

Measurement Of The Cross Section Of Top Quark Pairs Produced In Association With A Photon In Lepton + Jets Events At √S = 13 Tev With Full Runii Cms Data, Nabin Poudyal

Wayne State University Dissertations

The inclusive production cross section of top quark pairs in association with a photon is measured in proton-proton collisions at the LHC with 13 TeV energy using the full RunII data collected by CMS in 2016, 2017, and 2018 with a total corresponding integrated luminosity of 137 fb −1 . The relative fraction of ttγ events normalized to inclusive tt production is measured. The cross section measurement provides important information about the electromagnetic coupling of the standard model top quark and is sensitive to physics beyond the standard model. The analysis is carried out in the in semileptonic decay channel …

Improved Contacts And Device Performance In Mos2 Transistors Using 2d Semiconductor Interlayers, Kraig Andrews

Wayne State University Dissertations

The rapid growth of modern electronics industry over the past half-century has been sustained by the continued miniaturization of silicon-based electronics. However, as fundamental limits approach, there is a need to search for viable alternative materials for next-generation electronics in the post-silicon era. Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDs) have attracted much attention due to their atomic thickness, absence of dangling bonds and moderately high carrier mobility. However, achieving low-resistance contacts has been major impediment in developing high-performance field-effect transistors (FETs) based on 2D semiconductors. A substantial Schottky barrier (SB) is often present at the metal/2D-semicondcutor interface, …

Reflection And Reverberation In Neutron Star Low-Mass X-Ray Binaries, Benjamin Coughenour

Wayne State University Dissertations

Neutron star low-mass X-ray binaries (NS LMXBs) are systems which consist of a NS and a low-mass companion star. They are naturally variable on a variety of timescales, and are even classified by their X-ray spectral variability on the timescales of hours to days. The most luminous NS LMXB sources are known as ‘Z’ sources, because they trace out a characteristic ‘Z’ shape when plotted on a color-color or hardness-intensity diagram. The physical mechanisms causing this variability are not well understood. To try to address this, we model spectra taken from different positions on a hardness-intensity diagram of two Z …

Effective Field Theory And Machine Learning Approaches To Controlling Nonperturbative Uncertainties In Flavor Physics, Ayesh Gunawardana

Wayne State University Dissertations

The radiative decay $\bar{B}\to X_s\gamma$ and semileptonic heavy meson decay $D\to \pi l \nu$ are important flavor physics probes of new physics. However, these decays are plagued with nonperturbative uncertainties that are needed to be controlled to obtain a theoretically clean description. In this dissertation, we provide effective field theory and machine learning approaches to controlling these uncertainties.\par

In $\bar B\to X_s\gamma$, the largest uncertainty on the total rate and the CP asymmetry arises from resolved photon contributions. These appear first at order $1/m_b$ and are related to operators other than $Q_{7\gamma}$ in the effective weak Hamiltonian. One of the …

Exploring Jet Transport Coefficients In The Quark-Gluon Plasma, Amit Kumar

Wayne State University Dissertations

The modifications of hard jets play an essential role as multi-scale probes of the properties of the Quark-Gluon Plasma (QGP) produced in high-energy heavy-ion collisions. In this thesis, we explore the interplay between the soft and hard scales involved in the modification of jet partons as they propagate through the QGP. First, we focus on a regime where the exchanged momenta between the hard parton and the medium are at a high enough scale that QCD perturbation theory can be applied. Based on the assumption that the multiple scatterings inside the plasma are incoherent in the high-energy and high-virtuality phase …

Data Analysis Of Large Angle Beamstrahlung Monitor, Samuel Doeg Izaguirre Gamez

Wayne State University Dissertations

The first experimental evidence of large angle beamstrahlung at SuperKEKB is discussed in this Thesis. Beamstrahlung is the tn radiation emitted by particles belonging to one beam when they are accelerated transversely by the electro-magnetic field of the other beam. The properties of the radiation are related to the beam interaction topologyand can be used to optimize the beam-beam collision. This, in turn, makes the machine’s luminosity, and therefore the number of produced events, higher. A device entirely built at WSU, the Large Angle Beamstrahlung Monitor, or LABM, has been deployed in the SuperKEKB accelerator since 2015. A five Institutions …

Incorporating Cardiac Substructures Into Radiation Therapy For Improved Cardiac Sparing, Eric Daniel Morris

Wayne State University Dissertations

Growing evidence suggests that radiation therapy (RT) doses to the heart and cardiac substructures (CS) are strongly linked to cardiac toxicities, though only the heart is considered clinically. This work aimed to utilize the superior soft-tissue contrast of magnetic resonance (MR) to segment CS, quantify uncertainties in their position, assess their effect on treatment planning and an MR-guided environment.

Automatic substructure segmentation of 12 CS was completed using a novel hybrid MR/computed tomography (CT) atlas method and was improved upon using a 3-dimensional neural network (U-Net) from deep learning. Intra-fraction motion due to respiration was then quantified. The inter-fraction setup …

Diffusion Of Gold Nanoparticles Within Polymer Solutions And Gels, Kavindya Kumari Senanayake R W H

Wayne State University Dissertations

Soft matter is a subfield of condensed matter physics including systems, such as polymers, colloidal dispersions, liquid crystals, surfactants. Understanding their interaction and dynamics is essential for many interdisciplinary fields of study as well as important for technological advancements. We used gold nanoparticles (AuNPs) to investigate the length-scale dependent dynamics in dilute, semidilute, entangled polymer solutions and gels. Two-photon fluctuation correlation spectroscopy (FCS) technique was used to investigate the translation diffusion coefficient of AuNPs. For polymer solutions, we found that existing hydrodynamic and obstruction models are inadequate to describe the size dependence of the particle diffusion coefficient. Within entangled Poly …

High Frequency Percussive Ventilation For Tumor Motion Immobilization, Ina Marina Sala

Wayne State University Dissertations

This work investigates the use of High Frequency Percussive Ventilation as a technique for respiratory motion mitigation in radiotherapy. This technique was extensively investigated in several prospective and retrospective studies.

In an initial prospective study, we evaluated the feasibility of HFPV and chest-wall motion reduction, by recruiting 15 healthy volunteers to undergo HFPV with three commercially available interfaces. For direct tumor motion immobilization, a second prospective study was performed in which with ten lung cancer patients underwent HFPV while imaged with high frame rate fluoroscopy. Diaphragm motion and image artifacts were quantified in a prospective study of a healthy volunteer …

Colloidal Dynamics Within Polymer Solutions And Complex Fluids, Namita Shokeen

Wayne State University Dissertations

Soft matter is a subfield of condensed matter physics that includes the study of colloidal dynamics. This is important in multidisciplinary fields for technological and medical advancements. My research focused on quantifying the dynamics of nano and micron-sized particles within various media using two-photon fluorescence correlation spectroscopy (FCS) and differential dynamic microscopy (DDM). FCS is a single photon sensitive technique that detects spontaneous fluctuations in fluorescence during dynamical processes over time while DDM used optical microscopy to analyze the colloidal motion in Fourier space. The diffusion coefficient (D) of 25 nm radii particles within aqueous entangled solutions of polyethylene oxide …

Balance Functions Of Charged Hadron Pairs $(\Pi,K,P)\Otimes (\Pi,K,P)$ In Pb--Pb Collisions At $\Sqrt{S_{_{\Rm Nn}}} =$2.76 Tev, Jinjin Pan

Wayne State University Dissertations

We present the first balance function (BF) measurement of charged hadron pairs $(\pi,K,p)\otimes (\pi,K,p)$ in Pb--Pb collisions at $\sqrt{s_{_{\rm NN}}} =$2.76 TeV.

The BF measurements are carried out as two-dimensional (2D) differential correlators vs. the relative rapidity ($\Delta y$) and azimuthal angle ($\Delta\varphi$) of hadron pairs, and studied as a function of collision centrality. While the BF azimuthal widths of all pairs substantially decrease from peripheral to central collisions, the longitudinal widths exhibit mixed behaviors: BF of $\pi\pi$ and cross-species pairs narrow in more central collisions whereas those of $KK$ and $pp$ are found invariant with collision centrality. This dichotomy …

Jet Geometry Engineering Via Di-Jet Imbalance Measurements At Rhic In Star, Nicholas Elsey

Wayne State University Dissertations

Ultra-relativistic heavy ion collisions produced at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) produce a new state of matter of deconfined quarks and gluons (partons) called the quark-gluon plasma (QGP). This plasma of deconfined but strongly coupled partons is believed to have been the primary state of matter in the universe up to a few milliseconds after the Big Bang. High energy partons produced in hard scatterings early in the collision can be used to probe the entire lifetime of the QGP. These partons propagate through and interact with the QGP before fragmenting into collimated …

Kilovoltage Intensity Modulated Radiotherapy, Brian Loughery

Wayne State University Dissertations

Contrast enhanced kilovoltage radiotherapy could be a significant improvement over the standard of care in glioblastoma multiforme, but its potential benefit has been hindered by fears of insufficient dose falloff, high skin and skull dose, contrast delivery concerns, and high cost. This dissertation aims to address the validity of these fears.

Contrast delivery concerns are examined by assuming that sufficient dose can be safely delivered to the tumor. Iodine, gadolinium, and gold nanoparticle biological effect and delivery research is examined and the ideal contrast delivery methods are reported. Dose falloff and skull dose are then investigated through treatment planning and …

Doped And Chemically Transformed Transition Metal Dichalcogenides (Tmdcs) For Two-Dimensional (2d) Electronics, Sagar Prasad Paudel

Wayne State University Dissertations

Transition metal dichalcogenides (TMDCs) as the semiconductor counterparts of gra-phene have emerged as promising channel materials for flexible electronic and optoelectronic devices. The 2D layer structure of TMDCs enables the ultimate scaling of TMDC-based devices down to atomic thickness. Furthermore, the absence of dangling bonds in these materials helps to form high quality heterostructures with ultra-clean interfaces. The main objective of this work is to develop novel approaches to fabricating TMDC-based 2D electronic devices such as diodes and transistors. In the first part, we have fabricated 2D p-n junction diodes through van der Waals assembly of heavily p-doped MoS2 (WSe2) …

Magnetic Moment And Susceptibility Quantification In Mri: Additional Frequency Shifts From Materials And Background Phase Removal Using A Reference Phantom, He Xie

Wayne State University Dissertations

The first part of this thesis was to utilize existing methods to remove the unwanted background phase from phantom studies. Magnetic moments of straws filled by three different materials (gadolinium, ferritin, and nanoparticles) with four different concentrations of each material were subsequently quantified at 10 different echo times, with straws perpendicular to the main magnetic field. As the radius of each straw was known, susceptibility was calculated from each measured magnetic moment. Results from different echo times agreed within uncertainties. In addition, near perfect linear relation between quantified susceptibility and concentration was obtained for each material. However, phase values inside …

Addressing The Proton Radius Puzzle Using Qed-Nrqed Effective Field Theory, Steven Patrick Dye

Wayne State University Dissertations

In 2010 the first extraction of the proton charge radius from muonic hydrogen was found to be five standard deviations away from the regular hydrogen value. Seven years later, this proton radius puzzle still persists, and challenges our understanding of the structure of the proton. An effective field theory analysis using Non-Relativistic Quantum Electrody- namics (NRQED) indicates that the muonic hydrogen result can be interpreted as a large, compared to some model estimates, muon-proton spin-independent contact interaction. The muonic hydrogen result can be tested by a muon-proton scattering experiment, MUSE, that is planned at the Paul Scherrer Institute in Switzerland. …

Polarized Localization Microscopy (Plm) Detects Nanoscale Membrane Curvature And Induced Budding By Cholera Toxin Subunit B (Ctxb), Abir Kabbani

Wayne State University Dissertations

The curvature of biological membranes at the nanometer scale is critically important for vesicle trafficking, organelle morphology, and disease propagation. Many proteins and lipids interact with diverse curvature sensing and curvature generating mechanisms. Deciphering the molecular mechanisms of toxin-membrane interactions has been limited by the resolution and drawbacks of conventional experimental techniques. This study reveals the inherent membrane bending capability of cholera toxin subunit B (CTxB) through the development and implementation of Polarized Localization Microscopy (PLM). PLM is a pointillist optical imaging technique for the detection of nanoscale membrane curvature in correlation with single-molecule dynamics and molecular sorting.

PLM combines …

Identification Of Streptococcus Pyogenes Using Raman Spectroscopy, Ehsan Majidi

Wayne State University Dissertations

Despite the attention that Raman Spectroscopy has gained recently in the area of pathogen identification, the spectra analyses techniques are not well developed. In most scenarios, they rely on expert intervention to detect and assign the peaks of the spectra to specific molecular vibration. Although some investigators have used machine-learning techniques to classify pathogens, these studies are usually limited to a specific application, and the generalization of these techniques is not clear. Also, a wide range of algorithms have been developed for classification problems, however, there is less insight to applying such methods on Raman spectra. Furthermore, analyzing the Raman …

Applications Of Effective Field Theories To New Physics, Derek Edward Hazard

Wayne State University Dissertations

We apply an effective field theory approach and argue that lepton flavor violating (LFV) decays M → l1l2 of meson states M with different quantum numbers could be used to put constraints on the Wilson coefficients of effective operators describing LFV interactions at low energy scales. We note that the restricted kinematics of the two-body decay of quarkonium or a heavy quark meson allows us to select operators with particular quantum numbers, significantly reducing the reliance on the single operator dominance assumption that is prevalent in constraining parameters of the effective LFV Lagrangian. We shall also argue that studies of …