Elementary Particles and Fields and String Theory Commons^™

Search For Higgs Boson Pair Production In The Two Light Leptons And One Tau Final State Using Proton-Proton Collision Data With $\Sqrt{S} = 13$ Tev At The Lhc From The Atlas Detector, Susan Bataju

Physics Theses and Dissertations

In this thesis, a search is presented for the pair production of Higgs bosons in a final state containing two same-charge light leptons (e/$\mu$) and one opposite-charge hadronically decaying tau lepton ($\tau_{h}$). The search is based on a data sample of proton-proton (pp) collisions at a center-of-mass energy $\sqrt{s}$ = 13 TeV, collected by the ATLAS detector during Run 2 (2015-2018) of the Large Hadron Collider (LHC), corresponding to an integrated luminosity of 140 fb$^{-1}$. The Standard Model predicts that the Higgs potential has a non-zero expectation value leading to the spontaneous breaking of electroweak symmetry and when some fundamental …

Flux Trapping Sensitivity On The Metallurgical State Of Superconducting Radio Frequency Niobium, Bashu Dev Khanal

Physics Theses & Dissertations

Trapped magnetic flux in superconducting radio-frequency (SRF) niobium cavities due to the incomplete Meissner effect is a significant source of rf losses. The relationship between flux expulsion and flux trapping sensitivity to the metallurgical state of 1.3 GHz and 3.0 GHz SRF niobium cavities fabricated from standard and cold-worked Nb sheets and subjected to various heat treatments has been studied. Flux expulsion increased with higher heat treatment temperature in all cavities. Nb cavities made from cold-worked sheets showed better flux expulsion after 800 ◦C/3 h compared to the standard SRF-grade Nb cavities. Similar flux expulsion was observed after annealing at …

Unraveling Nonperturbative Qcd With Transverse Momentum Hadronic Structures, Tommaso Rainaldi

Physics Theses & Dissertations

The main purpose of this thesis is to investigate the theoretical foundations of the factorization theorems that involve transverse quark and gluon momentum distributions, and to better understand the interface between foundational questions and phenomenological applications. Many of these applications involve using transverse parton momentum dependent (TMD) correlation functions as tools for probing the complex nonperturbative structures of the hadrons.

We first introduce the concepts of collinear and TMD factorization in a toy-model theory and, by leveraging the comparative simplicity of such a model, we test the range of validity and limitations of the factorization approach. At the same time, …

Deep Neural Networks For Particle Identification In Simulated Proton-Proton Collisions At Lhc And Rhic, Omar Mazhar Khalaf

Theses and Dissertations

Particle identification is an essential part of experimental high-energy physics, which allows the study of the most fundamental constituents of matter. This thesis explores the use of deep neural networks for identifying particles in simulated proton-proton collisions at the Large Hadron Collider (LHC) and the Relativistic Heavy Ion Collider (RHIC). The deep neural networks were trained on LHC datasets which have various momentum ranges including regions of high transverse momentum above 3 GeV/c. The key findings of thesis include achieving an accuracy of 99.99%, 98.3%, and 90.14% for 3-5 pt, 5-7 pt and above 7 pt regions respectively for the …

The Gauge/Gravity Holographic Duality Between String Theory And Quantum Field Theory: A Full Introduction, Alex A. Short

Physics

The Anti-deSitter Spacetime / Conformal Field Theory (AdS/CFT) correspondence is a well known holographic duality between ten dimensional superstring theories and conformal quantum field theories. The existence of such a correspondence is fascinating and the duality provides a powerful tool-set for working out problems in both string theory and quantum field theory. The correspondence defines a dictionary of terms that exist dual to one another in each theory, allowing theorists to understand the dynamics in one system based on quantities from another. Furthermore, when one side of the duality has strong coupling (meaning the approximations of perturbation theory are no …

A Novel Approach To Model The Pion Structure Using Advanced Polynomial Functions, Lucas Kotz

Physics Theses and Dissertations

In the coming years, new experiments at the Electron-Ion Collider (EIC) and the Large Hadron Collider (LHC) will provide unprecedented insight into the building blocks of matter. To make the most of these opportunities, scientists must reduce uncertainties in the theoretical models that connect what we observe in experiments to what is happening inside particles like protons and pions. A critical part of these models involves describing how a particles momentum is shared among its internal components – quarks and gluons.

This work focuses on improving how we model the internal structure of the pion. We propose a new approach …

Bismuth-207 For Purity Monitoring System For Lartpc: Dune And Proto-Dune, Rohit Raut

2025 Spring Honors Capstone Projects - Archive

The Deep Underground Neutrino Experiment (DUNE), the U.S. flagship neutrino experiment, relies on high purity liquid argon (LAr) for optimal detector performance. Ensuring and monitoring LAr purity is crucial, as electronegative impurities can degrade signal quality in detectors. As part of Proto-DUNE, a prototype detector at CERN for DUNE, this study explores the use of Bismuth-207 (Bi-207) as a novel tool for real-time LAr purity monitoring and calibration. Bi-207 emits monochromatic internal conversion electrons, allowing precise impurity assessment without interfering with standard detector operations. By simulating the behavior of radioactive Bi-207 and analyzing data from the Proto-DUNE Vertical Drift detector, …

Geometric Algebra For Field Theory In Curved Spacetime, Kevin Rhine

All Graduate Reports and Creative Projects, Fall 2023 to Present

Physics seeks to understand the universe by uncovering the fundamental laws that govern matter, energy, space, and time. At its heart lies the challenge of unification: finding a mathematical framework that consistently describes these interactions across all scales, from the subatomic to the cosmological.

This thesis explores geometric algebra, a mathematical language that unifies algebra and geometry, as a tool for advancing this understanding. By extending this framework to curved spacetimes, where gravity influences the structure of space and time, we investigate its ability to describe physical phenomena such as electromagnetism and general relativity. A notable contribution includes the geometric …

Measuring Cosmic Rays With Muon Detectors (Quarknet), Aiden Burton, Jack W. Maseberg

SACAD: Scholarly Activities

We report measurement of atmospheric muon particles originating from cosmic rays. Using four QuarkNet project scintillators in an unstacked geometry, we are counting muons in coincidence with each other. We are currently refurbishing a second detector apparatus and will soon be capable of measuring coincidence events for larger shower surface areas using a total of eight scintillators.

On Static Equilibrium State Of An Electron-Positron Pair Interacting By Electrostatic And Magnetic Forces, Polievkt Perov, Natasha Perova-Mello

College of Arts & Sciences Faculty Works

An electron-positron pair can be in static equilibrium where the magnetic torque is zero and the attractive Coulomb’s force between unlike charges and the repelling force between the spin magnetic moments of these two particles balance each other out. An electron-positron pair near the equilibrium position can be modeled as an oscillator consisting of two masses on a spring. The calculations of the equilibrium distance, the effective “electromagnetic spring constant”, and the frequency of oscillations of an electron-positron pair near the equilibrium are presented. The calculations might be useful for the students in their studies of electricity, magnetism, and particle …

Muon Veto Panel Uniformity Tests At Yale Wright Laboratory For The Cuore And Cupid Experiments And Visualizing Dirac Spinors In The Chiral Basis With The Bloch Sphere, Reagen Neeva Garcia

Physics

This senior project is divided into three sections that describe my path and experiences in under graduate research. The first provides an introduction to the field of particle physics and the search for neutrinoless double beta decay (0νββ) with the Cryogenic Underground Observatory for Rare Events (CUORE) experiment, as well as its upgrade, CUPID (CUORE Upgrade with Particle IDentification). The second section details my contributions to these experiments, including my summer working at Yale’s Wright Laboratory on R&D for the CUPID experiment. In this section I describe my work on the experiment’s muon veto system and on light detector development …

Fragmentation Functions For Light And Heavy Quarks In Simulated Proton-Proton Collisions, Nermin Kamal Sadoun

Theses and Dissertations

In the first microsecond after the Big Bang, the early universe is believed to have been in an excited state known as the Quark-Gluon Plasma (QGP) state, a state of free quarks and gluons. Conducted experiements, like Heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), have showed some evidences of the formation of this extreme states in the collisions. Jet quenching and elliptic flow are two phenomena that provide significant evidence for the creation of QGP and its distinctive characteristics. Although the major framework for studying QGP is still heavy-ion collisions, new research …

Baryon Number Violation Search, Tyler D. Stokes

LSU Doctoral Dissertations

Understanding the fundamental forces and symmetries of nature has long been a central goal of particle physics. While the Standard Model (SM) provides a successful framework, it does not guarantee the conservation of baryon number B or lepton number L, thus motivating searches for their violation. Proton decay, a fundamental process violating B, has been at the forefront of experimental searches for decades.

The discovery of the weak neutral current in 1973 unified the electromagnetic and weak forces and inspired the creation of Grand Unified Theories (GUTs) that also unify the strong force. In 1974, the first-ever GUT, …

Advancing Particle Detection In High-Energy Physics Through Simulation And Experimentation, Ilker Parmaksiz

Physics Dissertations - Archive

Particle detectors are the cornerstone of experimental high energy physics. They enable physicists to study fundamental interactions and characterize subatomic particles. Recent advancements in detector technology have been propelled by the inventive integration of simulation, advanced materials, and improved electronic readouts. The primary motivation of this thesis is to advance the detector technologies to enhance sensitivity to neutrinoless double beta decay in high pressure xenon time projection chambers. Additionally, it includes work on other detector technologies, such as liquid argon time projection chambers, and documents my involvement in assembly, measurement, and simulation efforts.

Summary of the Chapters and Appendices Included …

Boundary Conditions, Symmetries, And Bootstrap In 2d Conformal Field Theory, Yucong Cai

Electronic Theses & Dissertations (2024 - present)

This dissertation contains two parts of study on the Friedan states and on the conformal bootstrap with symmetries.

The Friedan states are potential physical boundary states of the free boson. However, they exhibited a continuous spectrum in the open string sector, in contrast to more standard examples. The explicit expressions for the density of states of the Friedan states is obtained. Some pathologies and possible contradictions of these states are explored. The $g$ functions of the Friedan states are shown to be infinite, suggesting an infinite number of degrees of freedom in the theory.

The modular conformal bootstrap using the …

Integrable Deformations, T-Dualities And Higher Order Corrections In String Theory, Parita Shah

Electronic Theses & Dissertations (2024 - present)

This thesis explores the interplay of hidden symmetries and dualities in string theory, with a particular emphasis on the role of T-duality. As a fundamental symmetry of string theory, T-duality offers a powerful lens through which one can study integrability, solution-generating techniques, and quantum corrections, all essential aspects of modern string theoretic frameworks.

A central focus of this work is the application of the duality covariant formalism of Double Field Theory (DFT) to address problems involving integrable deformations and higher-order quantum corrections. We examine how generalized integrable models can be embedded into DFT and how the formalism captures hidden symmetries …

Studying 𝜋⁺𝜋⁻ Photoproduction Beyond Pomeron Exchange, Łukasz Bibrzycki, Nadine Hammoud, Vincent Mathieu, Robert J. Perry, Alex Akridge, César Fernández-Ramirez, Gloria Montaña, Alessandro Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Daniel Winney, Adam P. Szczepaniak

Physics Faculty Publications

Forward photoproduction of 𝜋⁺𝜋⁻ pairs with invariant mass of the order of 𝑚𝜌 ∼770  MeV is traditionally attributed to Pomeron exchange. Based on a detailed analysis of the CEBAF Large Acceptance Spectrometer photoproduction data collected at photon energies below 4 GeV, it is shown from a study of the angular moments that the dynamics of two-pion photoproduction for |𝑡|≳0.5  GeV² cannot be explained by Pomeron exchange alone. This motivates the development of a new theoretical model of two-pion photoproduction which incorporates both two-pion and pion-nucleon resonant contributions. After fitting free parameters, the model provides an excellent description of the low …

Nonperturbative Aspects Of The Electromagnetic Pion Form Factor At High Energies, K. Quirion, C. Fernandez-Ramirez, V. Mathieu, G. Montaña, R. J. Perry, A. Pilloni, A. Rodas, V. Shastry, W. A. Smith, A. P. Szczepaniak, D. Winney

Physics Faculty Publications

The structure of hadronic form factors at high energies and their deviations from perturbative quantum chromodynamics provide insight on nonperturbative dynamics. Using an approach that is consistent with dispersion relations, we construct a model that simultaneously accounts for the pion wave function, gluonic exchanges, and quark Reggeization. In particular, we find that quark Reggeization can be investigated at high energies by studying scaling violation of the form factor.

Nonlocal Nucleon Matrix Elements In The Rest Frame, Joe Karpie, Christopher Monahan, Anatoly Radyushkin

Physics Faculty Publications

Extracting parton structure from lattice quantum chromodynamics (QCD) calculations requires studying the coordinate scale 𝑧3 dependence of the matrix elements of bilocal operators. The most significant contribution comes from the 𝑧3 dependence induced by ultraviolet (UV) renormalization of the Wilson line. We demonstrate that the next-to-leading order perturbative calculations of the renormalization factor can describe, to a few percent accuracy, the logarithm of the lattice QCD rest frame matrix elements with separations up to distances of 0.6 fm on multiple lattice spacings. The residual discrepancies can be modeled by a leading effect from the structure of the nucleon.

Qcd Factorization With Multihadron Fragmentation Functions, T. C. Rogers, M. Radici, A. Courtoy, T. Rainaldi

Physics Faculty Publications

Important aspects of quantum chromodynamics (QCD) factorization theorems are the properties of the objects involved that can be identified as universal. One example is that the definitions of parton densitiesand fragmentation functions for different types of hadrons differ only in the identity of the nonperturbative states that form the matrix elements, but are otherwise the same. This leads to independence of perturbativecalculations on nonperturbative details of external states. It also lends support to interpretations ofcorrelation functions as encapsulations of intrinsic nonperturbative properties. These characteristics have usually been presumed to still hold true in fragmentation functions even when the observed nonperturbative …