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F₀(1370) And F₀(980) Controversies From Dispersive Data Analyses, Jose R. Pelaez, A. Rodas, J. Ruiz De Elvira Jan 2024

F₀(1370) And F₀(980) Controversies From Dispersive Data Analyses, Jose R. Pelaez, A. Rodas, J. Ruiz De Elvira

Physics Faculty Publications

We report on our recent works on dispersive analyses of ππ → ππ and ππ → K ¯ K scattering data and their use to address two controversial aspects of the f₀(1370) and f₀(980) scalar mesons. First, we show with model-independent techniques that the f₀(1370) pole does indeed appear in meson–meson scattering data, although there is tension between its values in the ππ and K ¯ K channels. Second, we explain the proper interpretation of the f₀(980) pole residue, which would otherwise lead to branching ratios larger than one. We have also provided simple ππ → ππ data parameterizations that …


Ultradeep Atca Imaging Of 47 Tucanae Reveals A Central Compact Radio Source, Alessandro Paduano, Arash Bahramian, James C. A. Miller-Jones, Adela Kawka, Tim J. Galvin, Liliana E. Rivera Sandoval, Sebastian Kamann, Jay Strader, Laura Chomiuk, Craig O. Heinke Jan 2024

Ultradeep Atca Imaging Of 47 Tucanae Reveals A Central Compact Radio Source, Alessandro Paduano, Arash Bahramian, James C. A. Miller-Jones, Adela Kawka, Tim J. Galvin, Liliana E. Rivera Sandoval, Sebastian Kamann, Jay Strader, Laura Chomiuk, Craig O. Heinke

Physics & Astronomy Faculty Publications

We present the results of an ultradeep radio continuum survey, containing ∼480 hr of observations, of the Galactic globular cluster 47 Tucanae with the Australia Telescope Compact Array. This comprehensive coverage of the cluster allows us to reach rms noise levels of 1.19 μJy beam−1 at 5.5 GHz, 940 nJy beam−1 at 9 GHz, and 790 nJy beam−1 in a stacked 7.25 GHz image. This is the deepest radio image of a globular cluster and the deepest image ever made with the Australia Telescope Compact Array. We identify ATCA J002405.702-720452.361, a faint (6.3 ± 1.2 μJy at 5.5 …


Advancements In Glitch Subtraction Systems For Enhancing Gravitational Wave Data Analysis: A Brief Review, Mohammad Abu Thaher Chowdhury Jan 2024

Advancements In Glitch Subtraction Systems For Enhancing Gravitational Wave Data Analysis: A Brief Review, Mohammad Abu Thaher Chowdhury

Physics & Astronomy Faculty Publications

Glitches are transitory noise artifacts that degrade the detection sensitivity and accuracy of interferometric observatories such as LIGO and Virgo in gravitational wave astronomy. Reliable glitch subtraction techniques are essential for separating genuine gravitational wave signals from background noise and improving the accuracy of astrophysical investigations. This review study summarizes the main glitch subtraction methods used in the industry. We talk about the efficacy of classic time-domain techniques in real-time applications, like matched filtering and regression methods. The robustness of frequency-domain approaches, such as wavelet transformations and spectral analysis, in detecting and mitigating non-stationary glitches is assessed. We also investigate …


Conventions, Definitions, Identities, And Other Useful Formulae, Robert A. Mcnees Iv Jan 2024

Conventions, Definitions, Identities, And Other Useful Formulae, Robert A. Mcnees Iv

Physics: Faculty Publications and Other Works

As the name suggests, these notes contain a summary of important conventions, definitions, identities, and various formulas that I often refer to. They may prove useful for researchers working in General Relativity, Supergravity, String Theory, Cosmology, and related areas.


Complexity, Entanglement And Codes In Quantum Field Theory, Nikolaos Angelinos Jan 2024

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 Jan 2024

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 …


Constraining Models For The Origin Of Ultra-High-Energy Cosmic Rays With A Novel Combined Analysis Of Arrival Directions, Spectrum, And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, A. Puyleart, Et Al. Jan 2024

Constraining Models For The Origin Of Ultra-High-Energy Cosmic Rays With A Novel Combined Analysis Of Arrival Directions, Spectrum, And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, A. Puyleart, Et Al.

Michigan Tech Publications

The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical models with homogeneous source distributions. Studies of the distribution of the cosmic-ray arrival directions show a better agreement with models in which a fraction of the flux is non-isotropic and associated with the nearby radio galaxy Centaurus A or with catalogs such as that of starburst galaxies. Here, we present a novel combination of both analyses by a simultaneous fit of arrival directions, energy spectrum, and composition data measured at the Pierre Auger Observatory. The …


การศึกษาความเป็นไปได้ในการประยุกต์ใช้น้ำเสียที่ผ่านการบำบัดในกระบวนการอบยาง, สิรวิชญ์ โพธิ์ระหง Jan 2024

การศึกษาความเป็นไปได้ในการประยุกต์ใช้น้ำเสียที่ผ่านการบำบัดในกระบวนการอบยาง, สิรวิชญ์ โพธิ์ระหง

Chulalongkorn University Theses and Dissertations (Chula ETD)

บริษัท สยามมิชลิน จำกัด (โรงงานพระประแดง) จังหวัดสมุทรปราการ มุ่งมั่นในการจัดการทรัพยากรน้ำอย่างมีประสิทธิภาพและยั่งยืนในกระบวนการผลิตยางรถยนต์ การผลิตยางรถยนต์และยางรถจักรยานยนต์มีการใช้น้ำจำนวนมากในกระบวนการผลิต จึงเป็นเหตุให้เกิดน้ำเสียจำนวนมากตามมาเช่นกัน น้ำเสียเหล่านี้จะถูกส่งเข้าระบบบำบัดน้ำเสียแบบเลี้ยงตะกอนเร่งเพื่อบำบัดและมีสมบัติได้ตามมาตรฐานน้ำทิ้ง แนวทางในการลดการปล่อยน้ำเสียหลังการบำบัดแล้วสู่สาธารณะ คือ การนำน้ำเสียที่ผ่านการบำบัดเหล่านี้กลับมาใช้เพื่อสามารถหมุนเวียนทรัพยากรให้กลับมาใช้ใหม่อย่างมีประสิทธิภาพสูงสุด และยังสอดคล้องกับแผนการบริหารด้านความยั่งยืนในการจัดการสิ่งแวดล้อมของบริษัทอีกทางหนึ่งด้วย ในงานวิจัยนี้จึงศึกษาความเป็นไปได้ในการนำน้ำเสียที่ผ่านการบำบัดแล้วกลับมาใช้ใหม่ในกระบวนการอบยาง โดยศึกษาและปรับปรุงประสิทธิภาพอัตราการไฟล (%Recovery) ของระบบรีไซเคิลรีเวอร์สออสโมซิสแบบขั้นตอนเดียวด้วยสารกรองแก้ว (AFM®ng) พบว่ามีประสิทธิภาพเพิ่มขึ้นจากเป็นร้อยละ 64 จากนั้นศึกษาเปรียบเทียบความเป็นไปได้ของโครงการระหว่างระบบรีไซเคิลแบบสองขั้นตอน (Double-pass RO) มีร้อยละผลตอบแทนของโครงการ (%ROI) และระยะเวลาคืนทุน (Payback period) เท่ากับ ร้อยละ 242, 1.22 ปีและระบบรีไซเคิลแบบสองขั้นตอนร่วมกับระบบการกรองระดับอัลตร้า (UF-RO/RO) เท่ากับร้อยละ 189, 1.97 ปีตามลำดับ แสดงให้เห็นว่าระบบรีไซเคิลแบบสองขั้นตอน (Double-pass RO) มีผลตอบแทนด้านการลงทุน (ROI) ที่ดีที่สุด และระยเวลาการคืนทุนที่เร็วกว่า แม้ว่าระบบรีไซเคิลแบบสองขั้นตอนร่วมกับระบบการกรองระดับอัลตร้า (UF-RO/RO) จะมีคุณภาพน้ำดีกว่า แต่เมื่อพิจารณาต้นทุนแล้ว พบว่าไม่แตกต่างกันมากนัก เนื่องจากระบบรีไซเคิลแบบสองขั้นตอน (Double-pass RO)มีร้อยละผลตอบแทนการลงทุนที่ดีที่สุด และระยะเวลาคืนทุนเร็วกว่า บริษัทฯ จึงเลือกใช้ระบบนี้ในการผลิตน้ำป้อนเข้าสู่หม้อต้มไอน้ำ ส่งผลให้สัดส่วนการใช้น้ำประปาในการอบยางลดลงร้อยละ 26 สัดส่วนการใช้น้ำรีไซเคิลเพิ่มขึ้นถึงร้อยละ 42 และลดการปลดปล่อยก๊าซคาร์บอนไดดอกไซด์ได้ 111.63 ตันคาร์บอนไดออกไซด์ต่อปี


การประเมินคาร์บอนฟุตพริ้นท์องค์กรและการลดก๊าซเรือนกระจกภายใต้โครงการสนับสนุนกิจกรรมลดก๊าซเรือนกระจก: กรณีศึกษาโรงงานผลิตยางคอมพาวด์, ปภาวรินท์ ทรงพัฒนาศิลป์ Jan 2024

การประเมินคาร์บอนฟุตพริ้นท์องค์กรและการลดก๊าซเรือนกระจกภายใต้โครงการสนับสนุนกิจกรรมลดก๊าซเรือนกระจก: กรณีศึกษาโรงงานผลิตยางคอมพาวด์, ปภาวรินท์ ทรงพัฒนาศิลป์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัญหาการเปลี่ยนแปลงสภาพภูมิอากาศในปัจจุบันเกิดจากการเพิ่มขึ้นของปริมาณก๊าซเรือนกระจก ซึ่งมีความรุนแรงและมีแนวโน้มที่จะส่งผลกระทบที่เพิ่มมากขึ้น ประเทศต่าง ๆ และองค์กรทั่วโลกได้กำหนดเป้าหมายในการลดการปล่อยก๊าซเรือนกระจก จึงเป็นสิ่งสำคัญที่ต้องตระหนักถึงและแก้ไขผลกระทบที่เห็นได้ชัดจากการเปลี่ยนแปลงสภาพภูมิอากาศ เพื่อส่งเสริมความร่วมมือในการบรรเทาปัญหาอย่างมีประสิทธิภาพ การศึกษานี้มีวัตถุประสงค์เพื่อประเมินปริมาณคาร์บอนฟุตพริ้นท์องค์กรของโรงงานผลิตยางคอมพาวด์ และประเมินปริมาณการลดการปล่อยก๊าซเรือนกระจกจากกิจกรรมในองค์กร ภายใต้โครงการสนับสนุนกิจกรรมลดก๊าซเรือนกระจก (Low Emission Support Scheme: LESS) ขององค์การบริหารจัดการก๊าซเรือนกระจก (องค์การมหาชน) ในปี พ.ศ. 2565 และ 2566 ผลการศึกษาพบว่าปริมาณการปล่อยก๊าซเรือนกระจกทั้งหมดมีแนวโน้มลดลงจาก 41,675.07 ตันคาร์บอนไดออกไซด์เทียบเท่าต่อปี ในปี พ.ศ. 2565 สู่ 38,043.30 ตันคาร์บอนไดออกไซด์เทียบเท่าต่อปีในปี พ.ศ. 2566 โดยขอบเขตที่ 3 การปล่อยก๊าซเรือนกระจกทางอ้อมอื่นๆ มีสัดส่วนที่สูงที่สุด คิดเป็นร้อยละ 78.55 และ 79.81 ตามลำดับ รองลงมา คือ ขอบเขตที่ 2 การปล่อยจากการใช้พลังงาน มีสัดส่วนคิดเป็นร้อยละ 20.05 และ 18.40 และขอบเขตที่ 1 การปล่อยทางตรงขององค์กร มีสัดส่วนต่ำที่สุด คิดเป็นร้อยละ 1.39 และ 1.80 เมื่อวิเคราะห์ต่อยอดการผลิต พบว่า ปริมาณการปล่อยก๊าซเรือนกระจกประเภทที่ 1 และ 2 ต่อยอดผลิตในปี พ.ศ. 2565 และ 2566 เท่ากับ 0.1717 และ 0.1699 ตามลำดับ ขณะที่ปริมาณการปล่อยก๊าซเรือนกระจกขอบเขตที่ 1 2 และ 3 ต่อยอดผลิต เท่ากับ 0.8005 และ 0.8413 ตันคาร์บอนไดออกไซด์เทียบเท่าต่อตัน ผลการศึกษาในการลดก๊าซเรือนกระจกจากการดำเนินกิจกรรมภายในองค์กรสามารถลดปริมาณการปล่อยก๊าซเรือนกระจกในปี พ.ศ. 2565 และ 2566 เท่ากับ 2,255.29 ตันคาร์บอนไดออกไซด์เทียบเท่า โดยการติดตั้งระบบพลังงานหมุนเวียนจากแสงอาทิตย์ (Solar Rooftop) สามารถลดปริมาณก๊าซเรือนกระจกได้ในปี พ.ศ. 2565 …


Magnetic Spin Transport Coils For The N2edm Experiment, David C. Bowles Jan 2024

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 Jan 2024

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 …


Techniques For Optimizing Neutron Beta Decay Particle Detection, Austin W. Nelsen Jan 2024

Techniques For Optimizing Neutron Beta Decay Particle Detection, Austin W. Nelsen

Theses and Dissertations--Physics and Astronomy

Over the last couple decades, use of free neutron beta decay (n → p + e- + νe) to extract the up-down quark transition element Vud has become competitive with more conventional Fermi decays. Extraction of Vud requires measurements of the vector to axial-vector coupling constant ratio λ and the free neutron lifetime τn. With a precise determination of Vud, the 2.8σ departure from CKM unitarity can be addressed.

Nab, located at the Spallation Neutron Source at ORNL, will measure the electron-neutrino momentum correlation coefficient a (which couples quadratically …


Development Of A Source To Detector Simulation Of The Los Alamos National Lab Neutron Electric Dipole Moment Experiment, Dillon Buskirk Jan 2024

Development Of A Source To Detector Simulation Of The Los Alamos National Lab Neutron Electric Dipole Moment Experiment, Dillon Buskirk

Theses and Dissertations--Physics and Astronomy

The Los Alamos National Laboratory (LANL) neutron electric dipole moment (nEDM) experiment is planning an increased precision measurement of the neutron’s permanent electric dipole moment. LANL nEDM expects to lower the statistical uncertainty to δdLANL = 2 × 10−27 e cm after a year of live-time, which puts a more stringent upper bound on the nEDM. This statistical uncertainty is an order of magnitude less than the current best measurement set by nEDM at PSI. To reach this goal, the LANL nEDM collaboration requires a simulation tool that can tackle optimization problems, investigate systematic effects, and provide mock data …


Development Of A Novel Beam-Type Neutron Lifetime Experiment Using Ultracold Neutrons, Nicholas Floyd Jan 2024

Development Of A Novel Beam-Type Neutron Lifetime Experiment Using Ultracold Neutrons, Nicholas Floyd

Theses and Dissertations--Physics and Astronomy

Precision measurements of the neutron lifetime are critical to tests of the Standard Model. The CKM quark mixing matrix has recently been shown to deviate from unitarity in the top row, motivating the development of alternative extractions of the first element. Complementary measurements of the neutron’s lifetime and decay correlations can be used to accomplish this.

While the reported neutron lifetime by the Particle Data Group is taken from ultracold neutron (UCN) measurements, a separate class of experiments suggest a value in four sigma disagreement, meriting further study. The goal of the UCNProBe experiment at Los Alamos National Laboratory is …


The Application Of Novel Machine Learning Algorithms To Study Multi-Dimensional Fragmentation Functions Of Hadrons In Jets At Star, Hannah A. Harrison-Smith Jan 2024

The Application Of Novel Machine Learning Algorithms To Study Multi-Dimensional Fragmentation Functions Of Hadrons In Jets At Star, Hannah A. Harrison-Smith

Theses and Dissertations--Physics and Astronomy

Hadronization, the process by which colored quarks and gluons shower from high energy collisions and recombine to form stable, experimentally-observable particles, is a fundamental aspect of Quantum Chromodynamics (QCD) that is not yet fully understood. Fragmentation functions, typically measured in electron-positron collisions, encapsulate this hadronization process well for quarks. Studying proton-proton collisions offers direct access to gluon fragmentation that other channels like electron-positron do not. Recent theoretical developments have proposed the study of hadronic showers in groupings called jets, introducing the concept of multi-dimensional jet fragmentation functions. This thesis presents the extraction of collinear and transverse momentum-dependent fragmentation functions for …


Precision Neutrino Interactions In And Beyond The Standard Model, Kaushik Borah Jan 2024

Precision Neutrino Interactions In And Beyond The Standard Model, Kaushik Borah

Theses and Dissertations--Physics and Astronomy

This dissertation investigates precision measurements of neutrino interactions within the framework of the Standard Model and explores potential extensions beyond it. Neutrinos, often referred to as ghostly particles due to their weak interactions and elusive nature, have long been a frontier in particle physics. Through detailed theoretical modeling and comparison with experimental data, this work focuses on improving our understanding of neutrino-nucleon cross-sections, nucleon form factors, and generalized neutrino interactions. The study begins with a comprehensive examination of the role of vector and axial-vector form factors in neutrino-nucleon scattering and their impact on the interpretation of neutrino oscillation data from …


Scattering Of Electromagnetic Radiation By Bianisotropic Spheres, Maxwell A. Wallace Jan 2024

Scattering Of Electromagnetic Radiation By Bianisotropic Spheres, Maxwell A. Wallace

College of Graduate Studies: Theses & Dissertations

Modern developments in materials science have led to the increased demand for the ability to control electromagnetic radiation at scales smaller than ever. One of the most important areas of research for controlling the manipulation of electromagnetic radiation, has been the studying of novel optical metamaterials, including the most general and complex form, bianisotropic metamaterials (BAMs). With modern developments in nano- engineering, paired with the advancement of more robust theoretical studies of BAMs, the demand for more novel BAM technologies has increased. With the advent of research of unbounded BAM media, as well as the recent extensions of Mie theory …


Spiral Wave Teleportation And Multiplex Network Synchronization In Light Sensitive Belousov-Zhabotinsky Systems, Shannyn Alicia Tyler Jan 2024

Spiral Wave Teleportation And Multiplex Network Synchronization In Light Sensitive Belousov-Zhabotinsky Systems, Shannyn Alicia Tyler

Graduate Theses, Dissertations, and Problem Reports (ETD)

We experimentally and computationally investigate dynamical behaviors in excitable and oscillatory media using light sensitive Belousov-Zhabotinsky (BZ) systems. These systems are not in a state of thermodynamic equilibrium, and have been proven to show various interesting phenomena including spatiotemporal patterns, self-organization, and chaos. We utilize the BZ reaction, a nonlinear chemical reaction, known for its relaxation-type oscillations, to explore the dynamics of these systems.

We examine spiral wave teleportation in an excitable media as an effective alternate defibrillation method. Spiral waves have emerged as a key phenomenon associated with the initiation and persistence of cardiac arrhythmias. Using a light sensitive …


A Floquet Solver For Time Periodic Open Quantum Systems, Fenton Ross Clawson Jan 2024

A Floquet Solver For Time Periodic Open Quantum Systems, Fenton Ross Clawson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Computational physics has been a backbone of experimental and theoretical physics since the 1940’s, when the first nuclear bomb and ballistic simulations were per- formed at Los Alamos Laboratory. Nowadays, however, simulation of open quan- tum systems has been formalized into coding packages and user-friendly functions, such as QuTiP or Qiskit, which allow users to simulate these systems without hav- ing the in-depth knowledge required to build the computational backbone from the ground-up. With the shift in modern quantum physics towards the realization of quantum computation, a strong computational background is still necessary to lend validity to theoretical results and …


Experimental Verification And Time-Resolved Bispectral Analysis Of Nonlinear Coupling In The Toroidicity-Induced Alfv´En Eigenmode Spectrum, Gregory Allen Riggs Jan 2024

Experimental Verification And Time-Resolved Bispectral Analysis Of Nonlinear Coupling In The Toroidicity-Induced Alfv´En Eigenmode Spectrum, Gregory Allen Riggs

Graduate Theses, Dissertations, and Problem Reports (ETD)

In magnetically-confined fusion devices, the toroidicity-induced Alfv´en eigenmode (TAE) is a well-studied, weakly stable solution of the linearized ideal magnetohydrodynamic (MHD) equations. Due to intrinsic coupling of poloidal harmonics of the shear Alfv´en wave (SAW) in toroidal geometry, the rotational transform of magnetic field lines modulates the effective index of refraction, ensuring gaps in the so-called “Alfv´en continuum.” Experimental verification of theoretical predictions for various parameters of interest (i.e., frequency, mode structure, instability threshold, etc.) is established in the literature.

We present the first systematic study of TAE-TAE phase coherence in an experimental device, using the DIII-D tokamak. Crucially, nonlinear …


Snow Spheres And Ice Cubes: Solutions For Fermi Questions, February 2024, John Adam Jan 2024

Snow Spheres And Ice Cubes: Solutions For Fermi Questions, February 2024, John Adam

Mathematics & Statistics Faculty Publications

No abstract provided.


The Weighty Words Of Lord Rayleigh: Solutions For Fermi Questions, January 2024, John Adam Jan 2024

The Weighty Words Of Lord Rayleigh: Solutions For Fermi Questions, January 2024, John Adam

Mathematics & Statistics Faculty Publications

No abstract provided.


Sky Smiley Face, John Adam Jan 2024

Sky Smiley Face, John Adam

Mathematics & Statistics Faculty Publications

The article discusses the formation of a circumzenithal arc (CZA) in the sky, caused by specific light ray paths through hexagonal ice crystals in cirrus clouds. The CZA is visible when the Sun's altitude is about 32° or less. The text includes questions for readers to explore the physics behind the formation of CZAs and circumhorizontal arcs (CHAs). The author acknowledges photographers for providing images and invites readers to find answers online.


Cats, Dogs, And Roll Waves: Solutions For Fermi Questions, April 2024, John Adam Jan 2024

Cats, Dogs, And Roll Waves: Solutions For Fermi Questions, April 2024, John Adam

Mathematics & Statistics Faculty Publications

On a hot afternoon in western North Carolina, the heavens opened and (to mix metaphors) it started raining “cats and dogs.” The rain was torrential, and soon a river of water was flowing downhill into the parking lot. In rivers and dam spillways, these are known as flood waves. The picture shows a particular type of flood waves known s roll waves—shock-like patterns separated by smooth profiles. In a steady-state situation, the drag forces on the water in the channel are balanced by the down-slope gravitational force. The dimensionless friction coefficient is C, the stream depth is h, v is …


Cats, Dogs, And Roll Waves, John Adam Jan 2024

Cats, Dogs, And Roll Waves, John Adam

Mathematics & Statistics Faculty Publications

This article discusses the phenomenon of roll waves, which are shock-like patterns separated by smooth profiles that occur in flood waves. The author mentions that in a steady-state situation, the drag forces on the water in the channel are balanced by the down-slope gravitational force. The article also includes questions for readers to estimate the speed and length of the roll waves, as well as determine the stability of the flow. The author provides additional information about the Chezy formula, an empirical equation used in fluid mechanics to estimate the mean flow velocity of open channel flow.


Exploring Crystal Polymorphism In Additive-Assisted Chemical Vapor-Deposited Transition Metal Chalcogenides And Oxides, Lawrence Kirimi Mubwika Jan 2024

Exploring Crystal Polymorphism In Additive-Assisted Chemical Vapor-Deposited Transition Metal Chalcogenides And Oxides, Lawrence Kirimi Mubwika

Graduate Theses, Dissertations, and Problem Reports (ETD)

Crystal polymorphism is a phenomenon in which compounds with the same chemical formula can be crystallized into different crystal structures. This phenomenon can be observed in elemental materials, such as diamond and graphite, as well as in compounds, such as the trigonal (1H) or octahedral (1T) prismatic MoS2. Crystals can also exhibit polytypism by stacking different polymorphs in a certain order, with the stacking sequence determining the variation between polytypes. Although all polymorphs and polytypes have the same chemical composition, each polymorph and polytype possesses unique electronic and physical properties.

This study explores the additive-assisted chemical vapor deposition …


High-Resolution Spectroscopy Of Interstellar Lines And Comets, Chemeda Tadese Ejeta Jan 2024

High-Resolution Spectroscopy Of Interstellar Lines And Comets, Chemeda Tadese Ejeta

Doctoral Dissertations

"The study of interstellar molecules such as CO is crucial because interstellar ices in the core of a pre-solar molecular cloud provide the starting point for volatile evolution in the protoplanetary disk. A record of the initial volatile composition of the protoplanetary disk can be obtained from the study of the chemical composition of cometary nuclei. Because of their long residence in the Oort cloud and infrequent passage through the inner solar system, long-period comets are one of the most primitive bodies in our solar system that can tell us about the composition of the early solar system. High-resolution infrared …


Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers Jan 2024

Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers

Physics Faculty Publications

We point out a problem with the formulation and derivations of sum rules for quark fragmentation functions that impacts their validity in QCD, but which potentially points toward an improved understanding of final states in inclusive hard processes. Fragmentation functions give the distribution of final-state hadrons arising from a parton exiting a hard scattering, and the sum rules for momentum, electric charge, etc. express conservation of these quantities. The problem arises from a mismatch between the quark quantum numbers of the initial quark and the fact that all observed final-state hadrons are confined bound states with color zero. We point …


Understanding Sextupole, T. Zolkin, I. Morozov, S. Nagaitsev Jan 2024

Understanding Sextupole, T. Zolkin, I. Morozov, S. Nagaitsev

Physics Faculty Publications

In this study, we reassess the dynamics within a simple accelerator lattice featuring a single degree of freedom and incorporating a sextupole magnet. In the initial segment, we revisit the Hénon quadratic map, a representation of a general transformation with quadratic nonlinearity. In the subsequent section, we unveil that a conventional sextupole is essentially a composite structure, comprising an integrable McMillan sextupole and octupole, along with non-integrable corrections of higher orders. This fresh perspective sheds light on the fundamental nature of the sextupole magnet, providing a more nuanced understanding of its far-from-trivial chaotic dynamics. Importantly, it enables the description of …


𝑋⁢𝑌𝑍 Spectroscopy At Electron-Hadron Facilities. Iii. Semi-Inclusive Processes With Vector Exchange, D. Winney, A. Pilloni, R. J. Perry, Ł. Bibrzycki, C. Fernández-Ramírez, N. Hammoud, V. Mathieu, G. Montaña, A. Rodas, V. Shastry, W. A. Smith, A. P. Szczepaniak Jan 2024

𝑋⁢𝑌𝑍 Spectroscopy At Electron-Hadron Facilities. Iii. Semi-Inclusive Processes With Vector Exchange, D. Winney, A. Pilloni, R. J. Perry, Ł. Bibrzycki, C. Fernández-Ramírez, N. Hammoud, V. Mathieu, G. Montaña, A. Rodas, V. Shastry, W. A. Smith, A. P. Szczepaniak

Physics Faculty Publications

Inclusive production processes will be important for the first observations of 𝑋⁢𝑌𝑍 states at new generation electron-hadron colliders, as they generally benefit from larger cross sections than their exclusive counterparts. We make predictions of semi-inclusive photoproduction of the 𝜒𝑐1(1𝑃) and 𝑋(3872), whose peripheral production is assumed to be dominated by vector exchanges. We validate the applicability of vector meson dominance in the axial-vector charmonium sector and calculate production rates at center-of-mass energies relevant for future experimental facilities. We find the semi-inclusive cross sections near the threshold to be enhanced by a factor of ∼2–3 compared to the exclusive …