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Tau Leptons In The Search For Charged Higgs Bosons, Juan Carlos Cardenas Jr

Physics Dissertations - Archive

The Standard Model (SM) of particle physics, a gracefully crafted collection of particle theories, has made an astounding number of accurate predictions about the properties of particles and the fundamental laws that govern our universe. Among its long list of remarkable successes are the unification of the electromagnetic and weak forces, the prediction of elementary particles such as the Higgs boson, and its ability to precisely predict a wide range of particle cross-sections and branching fractions which have been verified experimentally.

Yet despite its immense predictive power, some major problems with the standard model are its failure to accommodate dark …

Novel Time Projection Chamber Techniques With Applications Towards Neutrinoless Double Beta Decay Searches, Nicholas K. Byrnes

Physics Dissertations - Archive

One of the highest priority endeavors in nuclear and particle physics is the search for Neutrinoless Double Beta Decay (0νββ). The observation of 0νββ would prove that the neutrino is a Majorana particle i.e. its own antiparticle, offering a mechanism by which the matter-antimatter asymmetry observed in our universe could be explained. This theoretical decay mechanism is only energetically favored in certain neutron-rich isotopes and, if found, would be the rarest decay process ever observed. To compete with the exceedingly long half-life of 0νββ, all contemporary searches are focused on the following detector performance metrics: Increasing the instrumented isotopic mass …

Student Performance In Modern Physics In An Active, Partially-Flipped Classroom, Scott Yarbrough

Physics Dissertations - Archive

The effectiveness of the flipped classroom and hybrid-flipped (partially flipped, partially lecture-based) method of instruction has been extensively studied for high school and introductory undergraduate physics courses, and it has been shown to increase student understanding and performance. However, few studies have been done for upper-level undergraduate courses, and even fewer have been done for virtual courses. In Spring 2021 and Fall 2023, a fully virtual, hybrid-flipped Modern Physics course was taught, primarily to a class of primarily juniors and seniors, with some sophomores. All were STEM majors. The same course, with a similar enrolment and demographic of students, was …

Applications Of Independent And Identically Distributed (Iid) Random Processes In Polarimetry And Climatology, Dan Kestner

Dissertations, Master's Theses and Master's Reports

The unifying theme of this thesis is the characterization of “perfect randomness,” i.e., independent and identically distributed (IID) stochastic processes as these are applied in physical science. Two specific and mathematically distinct applications are chosen: (i) Radar and optical polarimetry; (ii) Analysis of time series in meteorology. In (i), IID process of a special kind, namely, with a distribution defined by symmetry, is used to link its multivariate Gaussian density to uniformity on the Poincaré sphere. This “statistical ellipsometry” approach is then used to relate polarimetric mismatches or imbalances to ellipsometric variables and suitably chosen cross-correlation measures. In (ii), recently …

Les-C Turbulence Models And Fluid Flow Modeling: Analysis And Application To Incompressible Turbulence And Fluid-Fluid Interaction, Kyle J. Schwiebert

Dissertations, Master's Theses and Master's Reports

In the first chapter of this dissertation, we give some background on the Navier-Stokes equations and turbulence modeling. The next two chapters in this dissertation focus on two important numerical difficulties arising in fluid flow modeling: poor mass-conservation and nonphysical oscillations. We investigate two different formulations of the Crank-Nicolson method for the Navier-Stokes equations. The most attractive implementation, second order accurate for both velocity and pressure, is shown to introduce non-physical oscillations. We then propose two options which are shown to avoid the poor behavior. Next, we show that grad-div stabilization, previously assumed to have no effect on the target …

Study Of Particle Accelerators In The Universe With The Hawc Observatory, Rishi Babu

Dissertations, Master's Theses and Master's Reports

HESS J1809-193 is an unidentified TeV source discovered in 2007 by the High Energy Stereoscopic System(H.E.S.S.) Collaboration. The emission originates in a region that is rich in cosmic-ray accelerators, including several supernova remnants and pulsars, including SNR G11.1+0.1, SNR G11.0-0.0, and the young radio pulsar PSR J1809-1917. Originally classified as a pulsar wind nebula candidate, recent studies show the peak of the TeV region overlapping with a system of molecular clouds and revising the original classification for other scenarios, including a pure hadronic scenario. This dissertation presents the morphological and spectral study of HESS J1809-193 using 2139 days of data …

Bayesian Inference In Reinforcement Learning Neural Networks During A Markov Decision Processes?, Katherine Graham

Scripps Senior Theses

The predictive mind theory proposes that brains work in a way that makes predictions about future stimuli to process information efficiently and accurately. Bayesian brain theory suggests that the brain utilizes Bayesian probability models to make predictions, while the free-energy minimization hypothesis proposes that these predictions are made to minimize energy or uncertainty, ensuring accurate perceptions. Vertechi et al. (2020) explored animal participants’ utilization of stimulus-bound strategy versus inference-based strategy to solve a Markov decision process with a 2-state environment, one of which is always active. These sites have a certain probability of switching to a different site and the …

Transient Diode Laser Absorption Spectroscopy For Measuring Collisional Quenching Rates Of Co And Its Potential For Studying H2o, Jordan M. Polvere

Master’s Theses

Motivated by the necessity of non-LTE models that account for species that are not in Local Thermodynamic Equilibrium (LTE) in Titan’s and Earth’s atmospheres, collisional quenching rates of CO and H2O_(g) have been studied. Providing more accurate and precise values of collisional quenching rate coefficients is crucial in the development of more advanced atmospheric models, which are important to fields of science such as meteorology and astronomy. Rates of collisional quenching of CO(v=1,2) by CO and CO(v=2) by N₂ at approximately 301-321 K were measured by transient diode laser absorption spectroscopy. The rate coefficients of CO(v=1)-CO, CO(v=2)-CO, and …

Revisiting The Divergent Multipole Expansion Of Atom-Surface Interactions: Hydrogen And Positronium, Α -Quartz, And Physisorption, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We revisit the derivation of multipole contributions to the atom-wall interaction previously presented in Łach et al. [G. Łach, M. DeKieviet, and U. D. Jentschura, Phys. Rev. A 81, 052507 (2010)10.1103/PhysRevA.81.052507]. A careful reconsideration of the angular momentum decomposition of the second-, third-, and fourth-rank tensors composed of the derivatives of the electric-field modes leads to a modification for the results for the quadrupole, octupole, and hexadecupole contributions to the atom-wall interaction. Asymptotic results are given for the asymptotic long-range forms of the multipole terms, in both the short-range and long-range limits. Calculations are carried out for hydrogen and positronium …

Accelerating Cavity Fault Prediction Using Deep Learning At Jefferson Laboratory, Md M. Rahman, A. Carpenter, K. Iftekharuddin, C. Tennant

Electrical & Computer Engineering Faculty Publications

Accelerating cavities are an integral part of the continuous electron beam accelerator facility (CEBAF) at Jefferson Laboratory. When any of the over 400 cavities in CEBAF experiences a fault, it disrupts beam delivery to experimental user halls. In this study, we propose the use of a deep learning model to predict slowly developing cavity faults. By utilizing pre-fault signals, we train a long short-term memory-convolutional neural network binary classifier to distinguish between radio-frequency (RF) signals during normal operation and RF signals indicative of impending faults. We optimize the model by adjusting the fault confidence threshold and implementing a multiple consecutive …

Mathematical Formulae For Neutron Self-Shielding Properties Of Media In An Isotropic Neutron Field, Elsayed Salama, Elsayed K. Elmaghraby, Ateia W. Mahmoud, A. Elghazaly, S. A. El-Fiki

Basic Science Engineering

In the current study, an ab initio derivation of the neutron self-shielding factor to solve the complex neutron transport problem of the decrease of the neutron flux as it penetrates into a material placed in an isotropic neutron field having equal flux in all directions. The theory of steady-state neutron transport was employed, starting from Stuart’s formula, to derive simple analytical formulae based on the integral cross-section parameters. The formulae could be adopted by the user according to various variables, such as the neutron flux distribution and geometry of the simulation at hand. The concluded formulae of the self-shielding factors …

General Physics Ii - Lab Manual, David Goldberg, Peter Glass

Open Educational Resources

No abstract provided.

Interpreting Neural Operators: How Nonlinear Waves Propagate In Non-Reciprocal Solids, Jonathan Colen, Alexis Poncet, Denis Bartolo, Vincenzo Vitelli

Data Science Faculty Publications

We present a data-driven pipeline for model building that combines interpretable machine learning, hydrodynamic theories, and microscopic models. The goal is to uncover the underlying processes governing nonlinear dynamics experiments. We exemplify our method with data from microfluidic experiments where crystals of streaming droplets support the propagation of nonlinear waves absent in passive crystals. By combining physics-inspired neural networks, known as neural operators, with symbolic regression tools, we generate the solution, as well as the mathematical form, of a nonlinear dynamical system that accurately models the experimental data. Finally, we interpret this continuum model from fundamental physics principles. Informed by …

Robust Inverse Parameter Fitting Of Thermal Properties From The Laser-Based Angstrom Method In The Presence Of Measurement Noise Using Physics-Informed Neural Networks (Pinns), Shanmukhi Sripada, Aalok U. Gaitonde, Justin A. Weibel, Amy M. Marconnet

CTRC Research Publications

The two-dimensional laser-based Ångstrom method measures the in-plane thermal properties for anisotropic film-like materials. It involves periodic laser heating at the center of a suspended film sample and records its transient thermal response by infrared imaging. These spatiotemporal temperature data must be analyzed to extract the unknown thermal conductivity values in the orthotropic directions, an inverse parameter fitting problem. Previous demonstration of the metrology technique used a least-squares fitting method that relies on numerical differentiation to evaluate the second-order partial derivatives in the differential equation describing transient conduction in the physical system. This fitting approach is susceptible to measurement noise, …

Design And Performance Of Superconducting Switches For Nanowire Detectors In Magnetic Fields, Timothy James Draher

Graduate Research Theses & Dissertations

Superconducting nanowire devices fit a broad spectrum of applications, including particle detection and quantum computing, and their expanding use across various fields highlights their role in the hybridization of superconducting and conventional semiconductor electronics. Despite their potential, the low signal output of these devices raises challenges in scalability and integration, particularly in applications for nuclear and high-energy physics, where resilience in magnetic fields is becoming a critical optimization factor. The superconducting nanowire cryotron (nTron) addresses these issues by providing operational gain and logic switching in superconducting nanowire circuits, demonstrating adaptability to multiple materials. This dissertation focuses on modifying the conventional …

Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov

Theses and Dissertations

This study explores the potential of beryllium (Be) as an alternative dopant to magnesium (Mg) for achieving higher hole concentrations in gallium nitride (GaN). Despite Mg prominence as an acceptor in optoelectronic and high-power devices, its deep acceptor level at 0.22 eV above the valence band limits its effectiveness. By examining Be, this research aims to pave the way to overcoming these limitations and extend the findings to aluminum nitride and aluminum gallium nitride (AlGaN) alloy. Key contributions of this work include. i)Identification of three Be-related luminescence bands in GaN through photoluminescence spectroscopy, improving the understanding needed for further material …

Orbital And Spin Angular Momentum Light Generation, Interactions, Special Photons, And Applications In Liquids, Solids, Vapors And Biological Tissue Media, Sandra Mamani Reyes

Dissertations and Theses

Photons possess many characteristics such as wavelength, coherence, speed, polarization and wavefront. The aim of this thesis is the study of two salient properties of light exploring light carrying polarization and space degree of freedom of the wavefront. The wavefront of light is complex with different states of polarization. Special light beams are generated and characterized for interaction with liquids, solids, vapors, and bio- materials to understand fundamental processes such as Transmission, Raman scattering, and Optical Kerr Effect in steady state and temporal domains.

It has been more than hundred years since it is known that light can carry other …

Hydrodynamics Of Drops And Particles Driven By Marangoni And Diffusiophoretic Forces, Subramaniam Chembai Ganesh

Dissertations and Theses

This study investigates the hydrodynamics of particles and drops driven by forces generated by an asymmetrical physical and chemical surrounding environment. In the first part, a novel colloidal motor design driven by surface tension forces is proposed, utilizing an active Janus particle encapsulated in an immiscible liquid drop to form a compound drop/particle. Marangoni forces induced by asymmetric solute adsorption at the liquid-liquid interface of the drop propels the compound system. The propulsion speeds of the motor are analyzed for various relative sizes and configurations of the Janus particle and the encapsulating drop and the effects of varying the transport …

Hyperspectral And Polarimetric Imaging Of The Ocean For The Characterization Of The Surface Effects And Measurement Uncertainties, Mateusz Malinowski

Dissertations and Theses

Ocean and coastal waters are monitored by Ocean Color satellite sensors to determine concentrations of chlorophyll and water properties and identify areas of algal blooms and other events. The light radiance from the ocean is weak in comparison with the sky radiance, which requires very accurate atmospheric correction of the radiance measured at the top of the atmosphere (TOA) on the satellite and heavy validation of the derived water leaving radiance by field measurements from the ships and ocean platforms. For TOA and especially above water radiance the skylight reflected from the ocean surface represents one of the main sources …

Optimizing Deep Inspiration Breath Hold Technique For Personalized Breast Cancer Radiotherapy, Srinidhi Rajagopalan

Theses and Dissertations

The purpose of this research is entrenched in advancing the practice of 3D Conformal Radiation Therapy (3D CRT) for breast cancer patients by meticulously evaluating the impact of different Deep Inspiration Breath Hold (DIBH) techniques on dosimetric parameters. This study aims to ascertain the quantitative benefits of varied breathing techniques, primarily focusing on the 'Ultimate DIBH' method's efficacy in sparing critical organs such as the heart and lungs.

The comprehensive analysis of different DIBH techniques in this research is not merely an academic exercise but is geared towards substantiating the hypothesized advantages of these techniques with empirical data. By generating …

Mathematical Analysis Of Eukaryotic Pericentromere, Puranjan Ghimire

Theses and Dissertations

The centromere is crucial for chromosomal stability and their proper segregation during cell division in eukaryotes. Surrounding the centromere are pericentromeres, made of repetitive DNA elements called pericentromeric repeats, varying from 10 in fission yeast to thousands in humans. These repeats form densely packed heterochromatin, where genes are usually silenced. The silencing mechanism across different pericentromeric repeats remains unclear.

Despite variations in sequence and length, pericentromeric repeats are conserved across eukaryotes, indicating their functional importance. This dissertation presents mathematical models to quantify gene silencing in fission yeast and humans. In fission yeast, my model predicts that silencing occurs only with …

Theory Of Ultrafast Spin Crossover In Divalent Iron Systems, William Baker

Graduate Research Theses & Dissertations

A theory to account for the ultrafast, i.e. femtosecond timescale, singlet to quintet spin crossover in divalent iron molecules is developed. The model considers an iron cluster with ligands extending in all 6 cardinal directions initially at rest in a low spin singlet ground state. An optical excitation excites an electron from the d orbitals to the ligands, changing the system from the metal centered (MC) singlet state to the metal to ligand charge transfer (MLCT) singlet state. Experimentally, it is known that the system eventually relaxes into the quintet MC state, but there are no satisfactory explanations that model …

Cold Testing Of A Prototype Superconducting Radiofrequency Electron Gun And Ancillary Systems For The Lcls-Ii-He Project, Kaela Michele Villafania

Graduate Research Theses & Dissertations

Argonne National Laboratory is collaborating with Michigan State University (MSU), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), and Stanford Linear Accelerator Center (SLAC) on the design, fabrication, and testing of a prototype superconducting radiofrequency (SRF) gun for the planned LCLS-II-HE upgrade at SLAC. This electron source will enable the generation of higher-brightness beams at a high repetition rate opening the path to expand LCLS-II-HE FEL performances. This thesis focuses on the cold testing of the prototype gun cavity and ancillary structures including the fundamental input-power coupler and tuning system. Numerical simulations are also presented to understand fields inside of the cavity as well as …

Advancements In Nuclear Magnetic Resonance, Electron Paramagnetic Resonance, Multipole Moments, And Lie Group Proprieties, Zhichen Liu

Graduate Thesis and Dissertation 2023-2024

To accurately solve the general nuclear spin state function in Nuclear Magnetic Resonance (NMR), a rotation wave approach was employed, allowing the reference frame to rotate in sync with the oscillating magnetic field. The spin state system was analogously treated as a Rubik's Cube, ensuring the diagonalization of only the time-dependent part of the state function. Although Gottfried's equation (1966) aligns with transitions between specific spin states m and m′, his second rotation contradicts the conservation of angular momentum, resulting in inaccuracies for spin states with initial phase shifts or entangled states. Contrarily, Schwinger (1937) efficiently computed the coefficients for …

Simulation Of Wave Propagation In Granular Particles Using A Discrete Element Model, Syed Tahmid Hussan

College of Graduate Studies: Theses & Dissertations

The understanding of Bender Element mechanism and utilization of Particle Flow Code (PFC) to simulate the seismic wave behavior is important to test the dynamic behavior of soil particles. Both discrete and finite element methods can be used to simulate wave behavior. However, Discrete Element Method (DEM) is mostly suitable, as the micro scaled soil particle cannot be fully considered as continuous specimen like a piece of rod or aluminum. Recently DEM has been widely used to study mechanical properties of soils at particle level considering the particles as balls. This study represents a comparative analysis of Voigt and Best …

Dual-Energy Electron Storage Ring, B. Dhital, Y. S. Derbenev, A. Hutton, H. Zhang, G. A. Krafft, Y. Zhang, F. Lin, V. S. Morozov

Physics Faculty Publications

A dual-energy electron storage ring is a novel concept initially proposed to cool hadron beams at high energies. The design consists of two closed rings operating at significantly different energies: the low-energy ring and the high-energy ring. These two rings are connected by an energy recovery linac (ERL) that provides the necessary energy difference. The ERL features superconducting radio-frequency (SRF) cavities that first accelerate the beam from the low energy E_L to the high energy E_H and then decelerate the beam from E_H to E_L in the next pass. The different SRF cavities in the ERL …

Complexity, Entanglement And Codes In Quantum Field Theory, Nikolaos Angelinos

Theses and Dissertations--Physics and Astronomy

In recent decades many deep connections between quantum information theory and quantum field theory have been unearthed. In this dissertation we study topics in high-energy physics through the lens of quantum information: 1) We develop connections between error-correcting codes and Narain conformal field theories. 2) We study the entanglement entropy of one-dimensional fermionic chains with long-range interactions. 3) We study the temperature dependence of Lanczos coefficients and Krylov complexity.

Topics In Quantum Information, Complexity And Chaos, Debarghya Chakraborty

Theses and Dissertations--Physics and Astronomy

This dissertation explores quantum information, the use of codes to describe quantum field theories, and introduces new concepts to characterize the dynamics of quantum many-body systems. The contributions of this dissertation are the following: 1) We constructed Narain Conformal Field Theories (CFTs) using additive codes, where the modular bootstrap constraints translate into algebraic conditions on the codes, extending previous approaches. This helps express key CFT data, including the torus partition function, in terms of codewords. We constructed optimal Narain CFTs for small central charges, and described CFT ensembles for asymptotically large central charge with large spectral gap. 2) We studied …

Magnetic Spin Transport Coils For The N2edm Experiment, David C. Bowles

Theses and Dissertations--Physics and Astronomy

The n2EDM experiment is being construct at Paul Scherrer Institute to measure the electric dipole moment of the neutron (nEDM), in a search for new physics which could help explain the baryon asymmetry of the universe. To reach the experimental sensitivity goal of $d_n \sim 10^{-27}$, over an order of magnitude improvement from the current world limit, a spin polarization transfer efficiency of 99\% for ultracold neutrons entering or exiting the precession chamber is required, placing a stringent requirement on the adiabaticity of the magnetic field taper in the neutron guide system. The spin transport fields transition from 5~T (longitudinal) …

Qcd Analysis Of Flavor-Nonchanging Hadronic Weak Processes Through Next-To-Leading Order, Girish Lingadahalli Muralidhara

Theses and Dissertations--Physics and Astronomy

Studies in quantum chromodynamics (QCD), the fundamental theory of the strong interactions, of low-energy hadronic weak processes utilize an effective Hamiltonian framework. Below the weak-mass scale, an effective Hamiltonian contains a series of Wilson coefficients and four-quark operators that come from the operator product expansion in the Standard Model. The effective hadronic Hamiltonian pertinent to a weak process is then obtained via a renormalization group analysis in QCD from the weak-mass scale to the low-energy scale of O(2 GeV). In this thesis, the construction and phenomenological implications of such an effective Hamiltonian for flavor-conserving, parity-violating quark processes in the Standard …