Physics Commons^™

Energy Dependence Of Polarized Γγ → E+E− In Peripheral Au + Au Collisions At √Snn = 54.4 And 200 Gev With The Star Experiment At Rhic, Star Collaboration

Physics and Astronomy Faculty Publications

We report the differential yields at mid-rapidity of the Breit-Wheeler process (γ γ → e+e−) in peripheral Au + Au collisions at √s NN = 54.4 and 200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), as a function of energy √s NN , e+e− transverse momentum pT , p2 T , invariant mass Mee, and azimuthal angle. In the invariant mass range of 0.4 < Mee < 2.6 GeV/c2 at low transverse momentum (pT < 0.15 GeV/c), the yields increase while the pair √〈p2 T〉 decreases with increasing √s NN , a feature that is correctly predicted by the QED calculation. The energy dependencies of the measured quantities are sensitive to the nuclear form factor, infrared divergence and photon polarization. The data are compiled and used to extract the charge radius of the Au nucleus.

The Implosion Of The Titan Submersible: A Stress–Strain Experiment, Gregory A. Dilisi, Steven J. Eppell, Richard A. Rarick

2025 Faculty Bibliography

No abstract provided.

Fabrication Of Microscale Oxide Architectures On Silicon Via A Cmos-Compatible, Deposition-Last Process, Jamal A. Brown

Material Science and Engineering Theses - Archive

This work explores the feasibility of integrating complex oxide devices on silicon using a CMOS-compatible, deposition-last approach. While previous demonstrations of this method have succeeded at larger scales, this study focuses on extending the process to microscale features, with lateral dimensions as small as two microns. The fabrication sequence begins with photolithographic patterning and reactive ion etching of the silicon substrate, followed by the deposition of a silicon nitride mask to delineate device regions. We then epitaxially grew SrTiO3 and La-doped SrTiO3 layers on top of the nitride mask via molecular beam epitaxy. Electrical transport measurements of the La:STO layer …

An Evaluation On The Uncertainty For The Routine Of Dosimetry Calibration At The National Secondary Standard Dosimetry Laboratory, Albania, Klotilda Nikaj

International Journal of Nuclear Security

Every employer must, in relation to any work with ionizing radiation that they undertake, take all necessary steps to restrict so far as is reasonably practicable the extent to which their employees and other persons are exposed to ionizing radiation. This goal leads to an increased awareness about the proper maintenance and annual calibration of the personal dosimeters to ensure an accurate and precise radiation dose. The present work has described the performance of the radiation system of the ¹³⁷Cs source at the National Secondary Standard Dosimetry Laboratory (SSDL), located at the Institute of Applied Nuclear Physics at the …

Detection Of Hybrid Optical Anapoles In Dielectric Microspheres, Uttam Manna, Iker Gómez-Viloria, Robert Sevik, Isaac Tribaldo, Mahua Biswas, Gabriel Molina-Terriza, Jorge Olmos-Trigo

Faculty publications – Physics

Nonradiating optical anapoles are special configurations of charge-current distributions that do not radiate. It was theoretically predicted that, for microspheres, electric and magnetic dipolar coefficients can simultaneously vanish by engineering the incident light, leading to the excitation of nonradiating hybrid optical anapoles. In this work, the experimental detection of hybrid optical anapoles in dielectric microspheres (TiO₂) is reported using dual detection optical spectroscopy, developed to enable sequential measurement of forward and backward scattering under tightly-focused Gaussian beam (TFGB) illumination. The results show that the excitation of TiO₂ microspheres (diameter, d ≈1 µm) under TFGB illumination leads to …

Neutron Star Low-Mass X-Ray Binaries In And Out Of Focus: Nustar Stray Light, Songwei Li

Wayne State University Dissertations

Neutron star low-mass X-ray binaries (NS LMXBs) provide crucial insights into the physics of accretion under extreme gravity. In this dissertation, we explore the capabilities of NuSTAR’s stray light (SL) observations to supplement, and in some cases, surpass focused data in spectral studies of bright LMXBs. Utilizing the use of SL datasets, we perform detailed spectral analyses of two Z sources: GX 340+0 and Sco X-1.

For GX 340+0, we compare 7 focused and 25 SL observations across multiple spectral states, demonstrating that SL data significantly expand temporal coverage and allow for the detection of long-term spectral evolution not evident …

Coding In Webassign, Gary Malek

Sabbatical Projects

Sabbatical presentation from a 2024 Spring Sabbatical

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 …

Photoionization Of Spin-Polarized Rydberg Atoms Out Of A Continuous Wave Optical Dipole Trap, Kevin Lee Romans

Doctoral Dissertations

"Recent research has demonstrated the need for a fully differential experiment on the photoionization of ⁶Li Rydberg atoms in a continuous wave (cw) laser field, as this would provide a new path forward for studying never before accessible atom-light interactions. Rydberg atoms are back in the focus of intense research due to their peculiar properties, which make them interesting candidates for quantum optics and information applications. In this work, we study the ionization of such Rydberg atoms, due to their interaction with a trapping laser field, by utilizing a reaction microscope (ReMi) capable of measuring photoelectron momentum distributions with …

Polycaprolactone—Based Block Copolymers For Nanopatterning Oxide Materials Via Sequential Infiltration Synthesis, Sudarshana Patra, Carter Herbert, Lane Nichols, Prachi Sarwara, Uttam Manna, Mahua Biswas

Faculty publications – Physics

Sequential infiltration synthesis (SIS) has emerged as a powerful technique to integrate inorganic materials into polymeric templates for fabricating functional hybrid and inorganic-only nanostructures. While several polymers, including self-assembled block copolymers (BCPs), have been widely used as templates for inorganic and hybrid oxide nanostructures, biocompatible polymers such as polycaprolactone (PCL) have not been explored for nanopatterning. In this work, we investigate SIS in polystyrene-block-polycaprolactone (PS-b-PCL) BCPs to demonstrate the feasibility of PCL as a guiding polymer for selective infiltration of Al₂O₃. Fourier transform infrared (FTIR) spectroscopy confirmed the strong interaction of TMA–H₂O precursors with …

A Random Walk Simulation Of Positron Annihilation Depth As A Function Of Positron Beam Energy, Saniya Anjum Aqeel Ahmed Yadgeer

Physics Theses - Archive

Depth resolved defect and chemical characterization studies using positron annihilation spectroscopy depend on the ability to estimate the fraction of positrons annihilating at surface, in the bulk, at defects or as Positronium. The depth resolution is limited by the implantation profile of the energetic positrons and the diffusion of the thermalized positrons. Here we implement a random walk simulation as described in S. Eichler et al. [1] to track the monoenergetic positrons implanted into multilayer graphene on Cu. For our simulations the implantation depths were sampled from a Makhovian distribution that has been shown to accurately represent the implantation profile …

Measurement Of Two-Point Energy Correlators Within Jets In P+P Collisions At Sqrt[S]=200  Gev, Star Collaboration

Physics and Astronomy Faculty Publications

Hard-scattered partons ejected from high-energy proton-proton collisions undergo parton shower and hadronization, resulting in collimated collections of particles that are clustered into jets. A substructure observable that highlights the transition between the perturbative and nonperturbative regimes of jet evolution in terms of the angle between two particles is the two-point energy correlator (EEC). In this Letter, the first measurement of the EEC at RHIC is presented, using data taken from 200 GeV p þ p collisions by the STAR experiment. The EEC is measured both for all the pairs of particles in jets and separately for pairs with like and …

Design Of The Ecce Detector For The Electron Ion Collider, J. K. Adkins

Physics and Astronomy Faculty Publications

The EIC Comprehensive Chromodynamics Experiment (ECCE) detector has been designed to address the full scope of the proposed Electron Ion Collider (EIC) physics program as presented by the National Academy of Science and provide a deeper understanding of the quark–gluon structure of matter. To accomplish this, the ECCE detector offers nearly acceptance and energy coverage along with excellent tracking and particle identification. The ECCE detector was designed to be built within the budget envelope set out by the EIC project while simultaneously managing cost and schedule risks. This detector concept has been selected to be the basis for the EIC …

Design And Construction Of An Affordable Adjustable Repetition Rate Optical Frequency Comb, Christopher Latchford

Physics, Astronomy and Geophysics Honors Papers

Two different adjustable repetition rate optical frequency combs were designed and constructed with off-the-shelf components, including several improvements to established erbium fiber designs. These designs were assembled at a fraction of the cost of a commercial comb. Both combs were constructed with a repetition rate of roughly 100 MHz, with one combs tuning range being 2 MHz and the others being 3 MHz. These combs followed different designs, the first being a modification of an established nonlinear polarization rotation (NPR) design, the second being a modification to a “figure 9” design. A stabilization control loop for frep achieved long-term drifts …

Jack Reacher And The Deployment Of An Airbag, Gregory A. Dilisi, Richard A. Rarick

2025 Faculty Bibliography

No abstract provided.

Determining The Transient Electric Field And The Effect Of Pulse Repetition Frequency On The Field In A Repetitive 10-Ns Pulsed Discharge In A Quiescent Ch₄-Air Mixture, Chunqi Jiang

Bioelectrics Publications

The goal of this research is to understand the underlying physics enabled by nanosecond pulsed power in a discharge initiation and the following physicochemical processes that favor lean-fuel plasma ignition for combustion. The hypothesis of this project is that pulsed power waveforms such as the pulse repetition frequency (PRF), voltage amplitude, and dielectric surface alter the reduced electric field during the initiation of the discharge, resulting in different plasma properties, which will vary the physicochemical processes for efficient and selective radical productions. This is especially important for lean-burn combustion and reducing emission.

Polarized Positrons At Ce⁺Baf, A. Ushakov, J. Benesch, M. Bruker, L. Cardman, J. Conway, S. Covrig Dusa, P. Degtiarenko, Y. Enomoto, S. Gessner, P. Ghoshal, S. Gopinath, J. Grames, C. Gulliford, S. Habet, G. Hays, C. Hernández-García, A. Hofler, R. Kazimi, M. Kostin, V. O. Kostroun, F. Lin, V. Lizárraga-Rubio, K. Mahler, Y. Morikawa, S. Nagaitsev, S. Ogur, G. Palacios-Serrano, N. Raut, B. Rimmer, Y. Roblin, A. Seryi, K. Smolenski, M. Stutzman, R. Suleiman, A. Sy, N. Taylor, D. Turner, A. Ushakov, C. Valerio-Lizarraga, E. Voutier, S. Wang, Y. Zhang

Mechanical & Aerospace Engineering Faculty Publications

A baseline concept for a continuous wave (CW) polarized positron injector was developed for the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab [1]. This concept is based on positron beam generation by a high current polarized electron beam (1 mA, 120 MeV, >85% polarization) irradiating a rotating water-cooled tungsten target or liquid metal target. The update on the development of the Ce⁺BAF injector concept including the polarized electron source, the development of high power targets, simulations of positron capture, the design of the transport line from the positron injector to the CEBAF North Linac and the planned experiment …

Optimal Manipulation Motion Action Planner Enabled By Physics Informed Neural Networks, Jonathon E. Slightam, Logan E. Beaver

Mechanical & Aerospace Engineering Faculty Publications

Autonomous robotic manipulation in unstructured environments faces many challenges and is hindered by capabilities that bridge the gap between perception and acting on the world. Action plans that are centric to object motion rather than end-of-arm tooling behavior may aid this. This paper presents an autonomous action planner for a feedback linearizeable system comprised of three base motions that can be leveraged on their own or in combination to give custom motion plans. The optimization routine for the three different types of motion are presented, which are integrated into physics informed neural networks. A component of this is the autonomy …

Deep Underground Neutrino Experiment Data Caching With Frontier, Alexander Rahe

Graduate Research Theses & Dissertations

The Deep Underground Neutrino Experiment (DUNE) is an unprecedented long baseline neutrino experiment that aims to measure various neutrino mixing parameters. With state-of-the-art technology, DUNE will measure neutrino mixing angles (θ13, θ12, θ23) and a Charge-Parity (CP) violating phase (δcp) with precision and will determine the elusive mass ordering. In order to accomplish these goals, scientists all over the world must have quick and reliable access to the data provided by the DUNE detectors. The data caching system known as Frontier is a distributed database caching system that was previously used in other large particle physics experiments for this purpose. …

Exploring Physics Teacher Identity: Pathways Toward Equitable Instruction Among Teachers, Clausell Mathis, Jomo Mutegi, Turhan Carroll, Maya Patel, Andrea Wooley

Teaching & Learning Faculty Publications

Physics teacher identity encompasses teachers' beliefs and views toward being a physics teacher. Physics teacher identity is influenced by teachers' perspectives on physics teaching and learning. Previous studies on teacher identity in general suggest that the construct is complex and malleable. Studies further suggest that it influences instructional methods, student engagement, and classroom environment. However, within physics education, there has yet to be an examination of how physics teacher identity influences "equitable" teaching approaches. This qualitative study sought to identify various dimensions of physics teacher identity and its implications for physics education research. We interviewed secondary and postsecondary physics teachers …

Plasma And Magnetic Coil Optimization, William Lee Austin, Lachlan Dean

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Lachlan Dean Coil Optimization for a High-Beta Stellarator-Tokamak Hybrid Magnetic coil configurations are developed for a tokamak-stellarator hybrid that is stable to both pressure- and current-driven modes for high values of beta. Previous work on this configuration [A. S. Ware, et al., Phys. Rev. Lett, 89, 125003 (2002)] was carried out using a fixed-boundary equilibrium (i.e., with no set of external coils) and prior attempts to develop an initial coil set using the COILOPT code were not successful. In this work, the recently developed SIMSOPT code [M. Landreman, et. al., J. Open Source Software 6, 3525 (2021)] is used to …

Demonstration And Assessment Of Dark Field And Phase X-Ray Computed Tomography, Wadiah Hamed Allahyani

Electronic Theses & Dissertations (2024 - present)

Conventional computed tomography produces a 2D slice or 3D image from multiple conventional images to avoid overlapping structures and increase visualization of the internal features of the object. A set up, macro controls and processing for computed tomography was created for the Center for X-ray Optics for the first time, and demonstrated in this work. Adding differential phase contrast to conventional x-ray images highlights edges. Two more channels of information, dark field and integrated phase, improve the contrast and increase the signal-to-noise ratios of the image. Combining these channels with computed tomography is an important development. This work is the …

Physicists As Environmental Experts, Rachel Rothschild

Articles

The question of which scientists are qualified to provide expert guidance in legal controversies is a perennial debate among scholars, judges, and lawyers. Scientists who participate in legal disputes can achieve enormous power and influence, not only over the case at hand but over long-term developments in legal doctrine. While these issues arise in many areas of the law, environmental litigation has been a particularly active site of contestations over epistemic authority. Courts have frequently relied on scientists to understand whether the government is justified in regulating pollution and who may be liable for environmental and public health harms.

This …

Computational Approaches For Diagnosing Neurological Impairments And Restoring Functional Movement, Serhii Bahdasariants

Graduate Theses, Dissertations, and Problem Reports (ETD)

Movement is the primary means by which the nervous system converts intention into interaction with the environment. Voluntary limb motion enables standing, walking, reaching, and grasping—actions that underpin self‑care, communication, and economic participation. When diseases or injuries disrupt the pathways that couple neural commands to muscle forces—whether through cortical stroke, spinal cord injury, or peripheral nerve damage—mechanical outcomes such as weakness, loss of coordination, and ultimately reduced mobility emerge. These impairments cascade into secondary complications, increased dependence on caregivers, and diminished quality of life. Quantifying how the lesion alters the mechanics of movement is therefore essential for designing targeted interventions …

Optical Measurements Of Magnetic Fields In Low-Temperature Plasmas Via Quantum Spectroscopy, Tyler James Gilbert

Graduate Theses, Dissertations, and Problem Reports (ETD)

Accurate characterization of the magnetic field strength and direction within a plasma is increasingly important as experiments attempt to probe the physics of plasmas at kinetic scales. Non-perturbative laser-based diagnostics which are spatially and temporally localized—such as laser-induced fluorescence (LIF) and Thomson scattering for the measurement of ion and electron distribution functions, respectively—are increasingly relied on for measurements in laboratory plasmas. This work seeks to develop a spatially and temporally localized non-perturbative laser-based diagnostic for the measurement of magnetic fields in laboratory-relevant plasmas. Two such techniques are investigated here: Zeeman-split LIF and quantum beat spectroscopy (QBS).

Zeeman-split LIF measures the …

Explorations Of Dna-Single-Walled Carbon Nanotube Interactions To Develop Multiplexed Molecularly Specific Biosensors For Inflammation, Amelia K. Ryan

Dissertations and Theses

Inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-12 (IL-12) are central regulators of immune signaling and key biomarkers of disease, yet existing assays for their detection remain slow, invasive, and lack multiplexing ability. This dissertation advances the development of single-walled carbon nanotube (SWCNT) optical nanosensors capable of real-time, multiplexed, and molecularly specific cytokine detection through innovative use of single-stranded DNA (ssDNA) interfaces.

First, an IL-6-specific DNA aptamer was employed as both a dispersing agent and recognition probe for SWCNT fluorescence sensing. Sequence modifications, including anchor domains, truncations, and thermally induced refolding, were systematically tested to optimize sensitivity and selectivity. The …

Metasurfaces And Their Applications In Photonic Devices, Shuwei Guo

Dissertations and Theses

Metasurfaces are flat artificial optical elements composed of dielectric and/or metallic nanostructures. They can manipulate light in unprecedented ways by altering amplitude, phase, and polarization at subwavelength scales. The ability of these two-dimensional elements to perform multiple optical functions within compact optical systems—while offering high functionality, small form factors, and easy integration into optoelectronic devices—has sparked significant interest across various fields and industries. These applications span imaging, sensing, nonlinear and quantum optics, optical computing, automotive technology, augmented and virtual reality, and more.

In this dissertation, we explore and design new multifunctional metasurfaces with a focus on manipulating spectral responses. First, …

Light Nuclei Femtoscopy And Baryon Interactions In 3 Gev Au+Au Collisions At Rhic, The Star Collaboration

Physics and Astronomy Faculty Publications

We report the measurements of proton-deuteron (𝑝-𝑑) and deuteron-deuteron (𝑑-𝑑) correlation functions in Au+Au collisions at √𝑠NN = 3 GeV using fixed-target mode with the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). For the first time, the source size (𝑅 𝐺), scattering length (𝑓0), and effective range (𝑑0) are extracted from the measured correlation functions with a simultaneous fit. The spin-averaged 𝑓0 for 𝑝-𝑑 and 𝑑-𝑑 interactions are determined to be -5.28 ± 0.11(stat.) ± 0.82(syst.) fm and -2.62 ± 0.02(stat.) ± 0.24(syst.) fm, respectively. The measured 𝑝-𝑑 interaction is consistent with theoretical calculations and low- energy scattering experiment …

Electric-Charge-Dependent Directed Flow Splitting Of Produced Quarks In Au+Au Collisions, The Star Collaboration

Physics and Astronomy Faculty Publications

We report directed flow (𝑣1) of multistrange baryons (Ξ and Ω) and improved 𝑣1 data for 𝐾−, ̄ 𝑝, ̄ Λ and 𝜙 in Au+Au collisions at √𝑠NN =27 and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). We focus on particles whose constituent quarks are not transported from the incoming nuclei but instead are produced in the collisions. At intermediate impact parameters, we examine quark coalescence behavior for particle combinations with identical quark content, and search for any departure from this behavior (“splitting”) for combinations having non-identical quark content. Under the assumption of quark …

Measurement Of Directed Flow In Au+Au Collisions At √Snn = 19.6 And 27 Gev With The Star Event Plane Detector, Star Collaboration

Physics and Astronomy Faculty Publications

In heavy-ion collision experiments, the global collectivity of final-state particles can be quantified by anisotropic flow coefficients (vn). The first-order flow coefficient, also referred to as the directed flow (v1 ), describes the collective sideward motion of produced particles and nuclear fragments in heavy-ion collisions. It carries information on the very early stage of the collision, especially at large pseudorapidity (η), where it is believed to be generated during the nuclear passage time. Directed flow therefore probes the onset of bulk collective dynamics during thermalization, providing valuable experimental guidance to models of the pre-equilibrium stage. In 2018, the Event Plane …