Physics Commons^™

Observation Of The Ξ_B^-→Λ_B^0 Π^- Decay And Measurement Of B(Ξ_B^-→Λ_B^0 Π^-), Zhuoming Li

Dissertations - ALL

We present the first observation of the weak decay Ξ−b → Λ0b π−, which is mediated by an s → u ̄ud transitionwithin the Ξ_b^- baryon. The analysis uses a pp collision data sample at a center-of-mass energy of 13 TeV corresponding to 5.5 fb^(−1) of integrated luminosity. The sample of Λb0 baryons used in this analysis are reconstructed through their decays to Λ+c π− and Λ+c π−π+π−. From a fit to the Ξ−b → Λ0b π− mass spectrum, the Ξ−b → Λ0b π− decay is observed with a significance of 11.3 standard deviations, thus establishing observation of this decay. …

High Fidelity Universal Gates Performed On A Continuously-Decoupled Coherence Enhanced Transmon Qubit, Michael Senatore

Dissertations - ALL

Decoherence is the primary limiting factor for the utility of modern qubits and qubit networks; most chiefly, pure dephasing which limits the operational time any gate-sequence can produce a high-fidelity result. In this dissertation, I present the results of my experiment, performing fast, high fidelity, universal single-qubit gates, on a qubit which has been decoupled from pure dephasing resulting from environmental noise. This technique can expand operational ranges of qubits–such as allowing the high-coherence operation of a flux-tunable qubit far away from its flux-insensitive sweet-spot; broadening our selection of viable qubits by making otherwise low-coherence qubits operable with high coherence, …

Design And Modeling Of Superconducting Hardware For Implementing Quantum Stabilizers, Yebin Liu

Dissertations - ALL

Superconducting qubits are one of the leading systems for implementing quantum processors. Realizing fault-tolerant quantum computation requires some form of quantum error correction, which typically involves performing repeated stabilizer operations on groups of physical qubits in an array to form a logical qubit with enhanced protection against errors. Realizing a logical qubit that is suitable for running quantum algorithms requires an array with a significant number of physical qubits, which is extremely challenging. However, the physical qubit overhead can be reduced by lowering the error rate on the physical qubits. Current state-of-the-art superconducting qubit designs do not have robust protection …

Characterization Of Superconducting Hardware For Implementing Quantum Stabilizers, Kenneth Richard Dodge

Dissertations - ALL

Superconducting qubits are one of the leading approaches being investigated for building a scalable quantum computer. In the presence of external noise and perturbations plus local microscopic fluctuations and dissipation in the qubit environment, arbitrary quantum states will decohere, leading to bit-flip and phase-flip errors of the qubit. In order to build a fault-tolerant quantum computer that can preserve and process quantum information in the presence of noise and dissipation, one must implement some form of quantum error correction. Stabilizer operations are at the heart of quantum error correction and are typically implemented in software-controlled entangling gates and measurements of …

Search For Numi Mudar Electron Neutrinos In Microboone, Ohana Benevides Rodrigues

Dissertations - ALL

Muon Decay-at-Rest (μDAR) produces electron-neutrinos (νe) in the 0 to 53 MeV energy range. The given range is especially interesting for its similarity to Supernovae-produced νe. The Deep Underground Neutrino Experiment (DUNE) has as one of its main goals to measure Supernovae neutrinos on the occasion of a Galactic Supernova burst. To optimize the chances of detection, a low-energy neutrino-LAr cross-section (XS) measurement is a piece of important information to have at hand. MicroBooNE presents a good opportunity to explore the low-energy ν-LAr detection and XS using the μDAR neutrinos and therefore develop the tools necessary for DUNE to interpret …

Measurements Of B → D(∗)−,0d(∗)+,0k+Π− Branching Fractions In The K∗0 Mass Window, Harris Bernstein

Dissertations - ALL

This thesis presents measurements of 11 branching fractions of the form B →D(∗)−,0D(∗)+,0K+π− within the K∗0 mass window using LHCb data taken in 2016, 2017 and 2018. All 11 branching fractions are measured simultaneously and are reported alongside the covariance and correlation matrices for the final measurement.

Mechanologic: Designing Mechanical Devices That Compute, Michelle Berry

Dissertations - ALL

Despite their initial success and impact on the development of the modern computer, mechanical computers were quickly replaced once electronic computers became viable. Recently, there has been increased interest in designing devices that compute using modern and unconventional materials. In this dissertation, we investigate multiple ways to realize a mechanical device that can compute, with a main focus on designing mechanical equivalents for wires and transistors. For our first approach at designing mechanical wires, we present results on the propagation of signals in a soft mechanical wire composed of bistable elements. When we send a signal along bistable wires that …

Geometry Of Discrete And Continuous Bounded Surfaces, Kyung Eun Kim

Dissertations - ALL

We work on reconstructing discrete and continuous surfaces with boundaries using length constraints. First, for a bounded discrete surface, we discuss the rigidity and number of embeddings in three-dimensional space, modulo rigid transformations, for given real edge lengths. Our work mainly considers the maximal number of embeddings of rigid graphs in three-dimensional space for specific geometries (annulus, strip). We modify a commonly used semi-algebraic, geometrical formulation using Bézout's theorem, from Euclidean distances corresponding to edge lengths. We suggest a simple way to construct a rigid graph having a finite upper bound. We also implement a generalization of counting embeddings for …

Investigation Of Holographic Lattice Theories, Muhammad Asaduzzaman

Dissertations - ALL

The Anti-de Sitter/Conformal Field theory (AdS/CFT) correspondence, also known as holography, has been the focus of a great deal of interest and research for the last two decades. It has improved our understanding of general relativity and quantum field theories simultaneously through the interplay between these two different kinds of theories. However, there are still many aspects of holography that we do not understand or demand further analysis. Perturbative quantum field theory and perturbative metric expansion techniques are not equipped to investigate holography in some of the most interesting regimes such as the strongly interacting gravitational theory in anti-de Sitter …

Characterization Of Scintillation Light In Large Liquid Argon Detectors And The Implications For Proton Decay Searches, Kyle Spurgeon

Dissertations - ALL

The Deep Underground Neutrino Experiment (DUNE) is a planned long baseline neutrino experi- ment. The detector will be comprised of four modules with 10kt of active volume each, making it an ideal target to neutrino oscillation physics and searches for proton decay. ProtoDUNE-SP was a single-phase liquid argon time projection chamber - a prototype for the first far detector module of DUNE with an active volume of 700 tons operating until 2020. It was installed at the CERN Neutrino Platform and took particle beam and cosmic ray data over its two year lifespan. Liquid argon scin- tillation light is still …

Measurement Of |Vcb| Using The Semileptonic Decay Λb → Λcμνμ, Scott Edward Ely

Dissertations - ALL

A preliminary measurement of the quark-mixing parameter |Vcb| using the exclusive decay Λ0b→ Λ+c μ−νμ is presented. A sample of Λb semileptonic decays is provided by √s = 13TeV proton-proton collisions collected by the LHCb detector in 2017. Λ0b → Λ+c μ−νμX decays are identified from muon tracks, combined with a Λc baryon. The ground state Λ0b → Λ+c μ−νμ is isolated by a fit to the Λb corrected mass spectrum. The raw yield NRaw(Λ0b → Λ+c μ−νμ) is corrected, and the semileptonic width ΓMeas. (Λ0b → Λ+c μ−νμ) is obtained. Lattice QCD calculations predict ΓTh.(Λ0b → Λ+c μ−νμ)/|Vcb|2. A …

Constraining Beam Backgrounds And Analyzing The Detector Response In A Test Beam With The Nova Experiment, Abhilash Yallappa Dombara

Dissertations - ALL

NOvA is a long-baseline neutrino oscillation experiment with two functionallyidentical detectors with the Near Detector at Fermilab, Illinois, and the Far Detector at Ash River, Minnesota. NOvA measures the rate of muon neutrino disappearance and electron neutrino appearance using muon neutrinos generated by the NuMI beam from the Accelerator Division(AD), thus NOvA measures neutrino oscillation parameters in the Pontecorvo-Maki- Nakagawa-Sakata matrix. The main experimental goal of NOvA is to determine the mass hierarchy, probe Charge-Parity violation and measure sin2 θ23 precisely. In this dissertation, the experimental setup, the latest analysis methods used in NOvA, and its results from analyzing 6 …

Probing Lepton Flavour Universality With $\Bz \To \Kstarz \Taup \Taum$, Aravindhan Venkateswaran

Dissertations - ALL

Neutral current $\bquark \to \squark ll$ processes have long been known to be precise probes of physics beyond the Standard Model. A pattern of anomalies seen in $\bquark \to \squark \mup \mun$ and in $\bquark \to \cquark \tau \nu$ data has hinted at the violation of lepton flavour universality. Effective field theories which attempt to find an explanation for these anomalies predict sizeable enhancements to the rate of $\bquark \to \squark \taup \taum$ currents. We use $pp$ collision data collected by the LHCb detector to estimate a sensitivity of $\BF(\Bz \to \Kstarz \taup \taum) < 1.5 \times 10^{-3}$ at 95\% C.L.

Monitoring Bacteria Cultures Using Near Infrared (Nir) Binary Spectronephelometry (Bsn), Raman Spectra And Principal Component Analysis (Pca), Steven Ortiz

Dissertations - ALL

Current noninvasive methods cannot continuously and simultaneously monitor the concentrations of cells and media components that define the state of native bacterial cultures, because of changing turbidity. A new technique, binary spectronephelometry (BSN) has the same or better sensitivity and precision for population monitoring as optical density at 600nm (OD600), while simultaneously measuring metabolic processes. The BSN algorithm uses laser induced emission to probe mildly turbid media i.e., propagation of light occurs in the single scattering regime. A BSN "training set" associates a grid of elastic emission measurements, comprising Rayleigh and Mie scattering, and inelastic emission measurements, comprising fluorescence and …

A Solid-State Phase Camera For Advanced Gravitational Wave Detectors, Erik Muniz

Dissertations - ALL

I present a novel way of wavefront sensing using a commercially available, continuouswavetime-of- ight camera with QVGA-resolution. This CMOS phase camera is capable of sensing externally modulated light sources with frequencies up to 100 MHz. The high-spatial-resolution of the sensor, combined with our integrated control electronics, allows the camera to image power modulation index as low as -62 dBc/second/pixel. The phase camera is applicable to problems where alignment and mode-mismatch sensing is needed and suited for diagnostic and control applications in gravitationalwave detectors. Specically, I explore the use of the phase camera in sensing the beat signals due to thermal …

Observation Of Ω Contribution In The C1(3872) → Π+Π−J/Ψ Decays, Baasansuren Batsukh

Dissertations - ALL

Resonant structure in the dipion mass spectrum produced via \decay{\Bu}{\X\Kp}, \decay{\X}{\jpsi \pip \pim}, with \decay{\jpsi}{\mu^+\mu^-} is analyzed using Run 1 and Run 2 data samples from the LHCb experiment. The spectrum is dominated by $\rhoz\to\pi^+\pi^-$, but cannot be described by this contribution alone. A significant $\omega\to\pi^+\pi^-$ contribution, interfering with $\rhoz$, is observed for the first time. This is a more significant observation ($>7.1\sigma$) of $\X\to\omega\jpsi$ decays, than previously achieved with $\omega\to\pi^+\pi^-\pi^0$ decays. The relative contribution of $\omega$ to the total $\X\to\pi^+\pi^-\jpsi$ rate is at the level expected from the measured $\X\to(\omega\to\pi^+\pi^-\pi^0)\jpsi$ rate, if the interference between the $\rho^0$ and …

Utilizing Parity Violating Electron Scattering As A Probe To Measure The Neutron Radius Of 208-Pb, David Eric King

Dissertations - ALL

The Lead Radius Experiment 2 (PREX-II) and Calcium Radius Experiment (CREX) carried out in Hall A of the Thomas Jefferson National Accelerator Facility were designed to measure the neutron skins of 208-Pb and 48-Ca nuclei by measuring the parity-violating asymmetry APV of the elastic scattering of polarized electrons on 208-Pb and 48-Ca targets. In order to achieve a precision measurement of the neutron skins of 208-Pb and 48-Ca it is imperative to maintain precise control over many experimental parameters–one of which is a precision measurement of the electron beam polarization (which is the largest contributor to experimental error making control …

Buckling Patterns And Mechanics Of Thin Interfacial Polymer Films, Monica M. Ripp

Dissertations - ALL

Thin elastic solids are easily deformed and will readily collapse into complex buckling modes. They can also transition between distinct buckling modes when the confining forces evolve over time, forming a variety of robust and striking patterns. Here we explore how thin interfacial films and the buckling modes they present couple with evolving macroscopic forces and how multi-scale features of the systems give rise to patterns.

In the indentation of a circular film floating on a liquid bath three buckling modes arise: wrinkling, crumpling, and folding. This work shows that striking transitions between these states accompany four regimes in the …

Direct Single Molecule Imaging Of Enhanced Diffusion For Enzymes And Enzyme-Conjugated Dna Origami, Mengqi Xu

Dissertations - ALL

Enzymes have been shown to diffuse faster in the presence of their substrates. Recently, we revealed new insights into this process of enhanced diffusion using single-particle tracking (SPT) with total internal reflection fluorescence (TIRF) microscopy. We found that the mobility of individual enzymes was enhanced three-fold in the presence of the substrate, and the motion remained Brownian. We showed that the relative increase in diffusion is independent of the total enzyme concentrations; and the oligomerization state of enzymes did not change during the catalytic turnover. These experiments ruled out the possibility that the enhanced enzyme diffusion was caused by the …

First Measurement Of B(Ξc0 → Π−Λ+C ), Michael Kent Wilkinson

Dissertations - ALL

The first measurement of the branching fraction of the Ξc0 baryon in its decay to π− and Λ+c hadrons, B(Ξc0 → π−Λ+c ), is presented. This measurement was conducted with the LHCb detector, located on the Large Hadron Collider, using 13 TeV proton-proton collisions. There have been a number of theoretical predictions for the size of this branching fraction, spanning more than an order of magnitude; this large difference is primarily due to differing assumptions about the internal interactions contributing to the decay. The branching fraction measured here provides the first experimental evidence for the nature of these interactions; it …

Self-Organization In Models Of Cyclically Sheared Suspensions, Jikai Wang

Dissertations - ALL

This thesis presents a study of random self-organized systems using computer-simulated models inspired by cyclically-sheared non-Brownian suspensions of monodisperse spherical particles in a density-matched fluid. When driven at low Reynolds number, such systems have vanishing thermal fluctuations and only short-range interactions between individual particles. Nevertheless, they show intriguing collective behaviors at large length scales, such as a strong suppression of fluctuations in the number density. Such self-organized "hyperuniform" states can useful in industrial applications where well-controlled states can ease the processing of such materials.In Chapter 2, we propose a new way of generating hyperuniform suspensions, by incorporating slow gravity-driven sedimentation …

Multimode Circuit Quantum Electrodynamics With Superconducting Metamaterial Resonators, . Indrajeet

Dissertations - ALL

Superconducting devices in circuit quantum electrodynamics (cQED) systems are one of the leading approaches for realizing scalable quantum information processors. The combination of cQED architectures with multimode resonator systems can provide a flexible platform for performing analog quantum simulations, storing quantum information, and generating complex entangled states. Metamaterial resonant structures made from arrays of superconducting lumped circuit elements can exhibit microwave mode spectra with left-handed dispersion, resulting in a high density of modes in the same frequency range where superconducting qubits are typically operated, as well as a bandgap at lower frequencies that extends down to dc. In this thesis, …

Interplay Of Geometry And Mechanics: Disordered Spring Networks And Shape-Changing Cerebella, Mahesh Chandrasekhar Gandikota

Dissertations - ALL

This thesis reports work in three topics - I) isotropic strain-induced rigidity transitions in under-constrained spring networks II) uniaxial strain-induced stiffening transitions in semiflexible networks with area-conserving inclusions and III) non-linearities in the buckling without bending morphogenesis model for growing cerebella. All models are two dimensional and we employ either discrete and continuum models to study these systems.In I), motivated by the rigidity transitions in isotropically strained disordered spring networks, we study rigidity transitions in isotropically strained area-conserving random polygonal loops. We find a crossover transition in these loops. We also provide arguments towards showing convexity as a necessary condition …

Eccentricity Of Merging Neutron Star Binaries: Searches, Parameter Estimation, And Future Prospects, Amber Kiana Lenon

Dissertations - ALL

Since the start of the first observing run the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Advanced Virgo observatory have detected 48 binary black hole mergers and two binary neutron star mergers. Knowledge about the properties of the binary can be gained from the gravitational-wave observations. Binary neutron star systems can form with significant orbital eccentricity. Gravitational radiation efficiently removes this eccentricity from the binary's orbit as the star's inspiral together. This thesis describes a search for neutron star binaries that have an eccentric orbits when their gravitational waves enter the sensitive band of Advanced LIGO and Virgo. For …

Effective Computational Cosmology, Eva Nesbit

Dissertations - ALL

Effective Field Theories (EFTs) provide a unique framework in which to attempt to answer outstanding questions in cosmology (and all field of physics, for that matter). This work investigates how the use of both EFTs and computational tools can help us to advance our knowledge of how the universe evolved and formed over time. Specifically, we review the successful EFT of Inflation, the EFT of Dark Energy (EFTDE), and introduce the EFT of Reheating as a generalized model of particle formation after inflation. In this way, we show how effective EFTs are at quantifying physical phenomenology at many different energy …

Beyond The Standard Models Of Particle Physics And Cosmology, Gabriele Rigo

Dissertations - ALL

Despite their numerous successes both from the theoretical and experimental point of view, conceptual and observational evidence suggests the Standard Models of Particle Physics and Cosmology should be considered incomplete theories, reliable only within their well-defined regime of validity. This dissertation covers various possible extensions of those models from the theoretical, phenomenological and model-building perspective. The topics analyzed range from extra-dimensional approaches to the hierarchy problem, to the AdS/CFT description of perturbative anomaly inflow, and new probes of vacuum energy in neutron stars and gravitational waves.

Beyond The Standard Models Of Particle Physics And Cosmology, Gabriele Rigo

Dissertations - ALL

Despite their numerous successes both from the theoretical and experimental point of view, conceptual and observational evidence suggests the Standard Models of Particle Physics and Cosmology should be considered incomplete theories, reliable only within their well-defined regime of validity. This dissertation covers various possible extensions of those models from the theoretical, phenomenological and model-building perspective. The topics analyzed range from extra-dimensional approaches to the hierarchy problem, to the AdS/CFT description of perturbative anomaly inflow, and new probes of vacuum energy in neutron stars and gravitational waves.

Gravity 2, Yi Jin

Honors Capstone Projects - All

The project that I chose to tackle for my capstone was coding my own physics based music visualizer. Doing so first required a strong foundational understanding of the OpenGL and GLUT visualization libraries. To build the visualizer, I took five main steps. First, I needed to open the music file and read the header. Second, I had to read in the file data window by window. Afterwards, I needed to apply a fast Fourier transform to each window. Lastly, I had to visualize the data and play the music. My end result was a Macintosh based music visualizer that allows …

An Improved Pipeline To Search For Gravitational Waves From Compact Binary Coalescence, Samantha Usman

Honors Capstone Projects - All

We describe the search pipeline, called PyCBC , used to identify gravitational wave candidates in Advanced LIGO's O1 search. We give an overall summary of the pipeline including a general layout and the methods for calculating the signal-to-noise ratio and the chi-squared statistic. We then give detailed explanations of removing noise transient before processing, called gating ; the way to create a bank of template waveforms and the process of matched filtering these waveforms against the data; the chi-squared statistic's role in eliminating noise transients; the latest coincidence testing method, which requires candidates to be both nearly simultaneous and have …

The Mechanism Of Self-Organized Beating Of Cilia, Jyothish Vidyadharan

Dissertations - ALL

No abstract provided.