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Field, Frequency, And Temperature Dependencies Of The Surface Resistance Of Nitrogen Diffused Niobium Superconducting Radio Frequency Cavities, P. Dhakal, B. D. Khanal, A. Gurevich, G. Ciovati

Physics Faculty Publications

We investigate the rf performance of several single-cell superconducting radio-frequency cavities subjected to low temperature heat treatment in nitrogen environment. The cavities were treated at temperature 120–165 °C for an extended period of time (24–48 h) either in high vacuum or in a low partial pressure of ultrapure nitrogen. The improvement in 𝑄0 with a 𝑄 rise was observed when nitrogen gas was injected at ∼300 °C during the cavity cooldown from 800 °C and held at 165 °C, without any degradation in accelerating gradient over the baseline performance. The treatment was applied to several elliptical cavities with frequency ranging …

An Early Byzantine Ecclesiastical Complex At Ashdod-Yam: Correlating Geophysical Prospection With Excavated Remains, Yaniv Darvasi, Alexander Fantalkin, Paul Brindza, Amotz Agnon

Physics Faculty Publications

In this study we show the successful deployment of Ground Penetrating Radar (GPR) together with Electrical Resistivity Surveys (ERS) in guiding the archeological excavations at Ashdod-Yam (southern coast of Israel). This approach enabled the precise identification of excavation targets relating to an Early Byzantine ecclesiastical complex located in a residential neighborhood of the modern city of Ashdod. Applied over the course of five years, the combined use of GPR and ERS, interspersed with phases of archeological excavation, not only facilitated an efficient exploration but also ensured the preservation of valuable historical structures. The geophysical data, corroborated by drone images of …

Shock-Discharge Interaction Model Extended Into The Third Dimension, Anna Markhotok

Physics Faculty Publications

This work is an addition to the previously developed two-dimensional model of the shock-plasma interaction, extending it into the third dimension. The model can trace the evolution of the state of the hypersonic flow and the shock front refracted at a thermal discontinuity. The advantages of using the spherical coordinate system for this type of problem include increased transparency in interpreting the solution and a shortened calculation procedure, because all the changes to the front are reduced to one distortion component. Although the vorticity generation triggered at the interface is a consequence of the refraction and tied to the steep …

Is Infrared-Collinear Safe Information All You Need For Jet Classification?, Dimitrios Athanasakos, Andrew J. Larkoski, James Mulligan, Mateusz Ploskoń, Felix Ringer

Physics Faculty Publications

Machine learning-based jet classifiers are able to achieve impressive tagging performance in a variety of applications in high-energy and nuclear physics. However, it remains unclear in many cases which aspects of jets give rise to this discriminating power, and whether jet observables that are tractable in perturbative QCD such as those obeying infrared-collinear (IRC) safety serve as sufficient inputs. In this article, we introduce a new classifier, Jet Flow Networks (JFNs), in an effort to address the question of whether IRC unsafe information provides additional discriminating power in jet classification. JFNs are permutation-invariant neural networks (deep sets) that take as …

Mass And Isospin Breaking Effects In The Skyrme Model And In Holographic Qcd, Lorenzo Bartolini, Stefano Bolognesi, Sven Bjarke Gudnason, Tommaso Rainaldi

Physics Faculty Publications

We discuss how the quark masses and their mass splitting affect the baryons in the Skyrme model as well as the Witten-Sakai-Sugimoto (WSS) model. In both cases, baryons are described by solitonic objects, i.e., Skyrmions and instantons, respectively. After the quantization of their zero modes, the nucleons become quantum states of a rotor. We show how the quark mass affects the moment of inertia and we provide a semianalytic approach valid in the small-mass limit. Additionally, we show how the two lightest quarks’ mass splitting affects the moments of inertia of the Skyrmion and induces an isospin breaking effect. This …

Diffusion Model Approach To Simulating Electron-Proton Scattering Events, Peter Devlin, Jian-Wei Qiu, Felix Ringer, Nobuo Sato

Physics Faculty Publications

Generative artificial intelligence is a fast-growing area of research offering various avenues for exploration in high-energy nuclear physics. In this work, we explore the use of generative models for simulating electron-proton collisions relevant to experiments like the Continuous Electron Beam Accelerator Facility and the future Electron-Ion Collider (EIC). These experiments play a critical role in advancing our understanding of nucleons and nuclei in terms of quark and gluon degrees of freedom. The use of generative models for simulating collider events faces several challenges such as the sparsity of the data, the presence of global or eventwide constraints, and steeply falling …

Operation Of A Longitudinally Polarized Solid Nuclear Target Of Clas12, P. Pandey, J. Brock, T. Kageya, C. Keith, S. Kuhn, V. Lagerquist, J. Maxwell, X. Wei

Physics Faculty Publications

A suite of experiments measuring spin observables in electron-nucleon scattering (dubbed Run Group C) was recently executed in Jefferson Lab. These experiments involved the scattering of a polarized 11 GeV electron beam from longitudinally polarized nucleon targets located within the CLAS12 spectrometer in Hall B. The dynamically polarized target used in these experiments was designed and constructed exclusively for operation inside CLAS12 and further optimized for the requirements of Run Group C. We report on the complete target setup, operational experience with the target, the benchmarks achieved using various polarizable and unpolarized materials as well as the preliminary target polarization …

Analytic Solutions Of The Dglap Evolution And Theoretical Uncertainties, A. Simonelli

Physics Faculty Publications

The energy dependence for the singlet sector of Parton Distributions Functions (PDFs) is described by an entangled pair of ordinary linear differential equations. Although there are no exact analytic solutions, it is possible to provide approximated results depending on the assumptions and the methodology adopted. These results differ in their sub-leading, neglected terms and ultimately they are associated with different treatments of the theoretical uncertainties. In this work, a novel analytic approach in Mellin space is presented and a new methodology for obtaining closed and exponentiated analytic solutions is devised. Different results for the DGLAP evolution at Next-Leading-Order are compared, …

The Continuous Electron Beam Accelerator Facility At 12 Gev, P. A. Adderly, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. Bastaninejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, Y. Zhang, Et Al.

Physics Faculty Publications

This review paper describes the energy-upgraded Continuous Electron Beam Accelerator Facility (CEBAF) accelerator. This superconducting linac has achieved 12 GeV beam energy by adding 11 new high-performance cryomodules containing 88 superconducting cavities that have operated cw at an average accelerating gradient of 20 MV/m. After reviewing the attributes and performance of the previous 6 GeV CEBAF accelerator, we discuss the upgraded CEBAF accelerator system in detail with particular attention paid to the new beam acceleration systems. In addition to doubling the acceleration in each linac, the upgrade included improving the beam recirculation magnets, adding more helium cooling capacity to …

Towards Unpolarized Gpds From Pseudo-Distributions, Hervé Dutrieux, Robert G. Edwards, Colin Egerer, Joseph Karpie, Christopher Monahan, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Savvas Zafeiropoulos

Physics Faculty Publications

We present an exploration of the unpolarized isovector proton generalized parton distributions (GPDs) H^u−d(x, ξ, t) and E^u−d(x, ξ, t) in the pseudo-distribution formalism using distillation. Taking advantage of the large kinematic coverage made possible by this approach, we present results on the moments of GPDs up to the order x³ — including their skewness dependence — at a pion mass m_π = 358 MeV and a lattice spacing a = 0.094 fm.

Non-Symmetry In The Shock Refraction At A Closed Interface As A Recovery Mechanism, Anna Markhotok

Physics Faculty Publications

The possibility of a shock wave recovery at a discrete closed interface with a heated gas has been investigated. A two-dimensional model applied to conditions of optical discharges featuring spherical, elliptical, and drop-like configurations demonstrated that non-symmetry in the shock refraction contributes to the specific mechanism of recovery other than simply its compensation. Even though the full restoration of the hypersonic flow state does not occur in a strict sense of it, clear reverse changes toward the initial shape of the shock front eventually take place, thus creating an appearance of a full recovery seen in experiments. From analysis of …

Conformal Bk Equation At Qcd Wilson-Fisher Point, I. Balitsky, G. A. Chirilli

Physics Faculty Publications

High-energy scattering in pQCD in the Regge limit is described by the evolution of Wilson lines governed by the BK equation [1, 2]. In the leading order, the BK equation is conformally invariant and the eigenfunctions of the linearized BFKL equation are powers. It is a common belief that at d ≠ 4 the BFKL equation is useless since unlike d = 4 case it cannot be solved by usual methods. However, we demonstrate that at critical Wilson-Fisher point of QCD the relevant part of NLO BK restores the conformal invariance so the solutions are again powers. As a check …

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

Physics Faculty Publications

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

Crabbing Cavity System Development For International Linear Collider, Subashini De Silva

Physics Faculty Publications

The International Liner Collider requires a crabbing system to increase the luminosity of the colliding electron bunches. The ILC has a large crossing angle that requires compensation in order to meet the luminosity requirements. There are several frequency options proposed for the crabbing cavity design. Two crab cavity designs were selected to be prototyped in the pre-lab phase, following the Down Selection Review on Crab Cavity Design held in April 2023. The two rf designs selected are the 1.3 GHz rf-dipole cavity and the 2.6 GHz QMiR cavity. We will be presenting the electromagnetic and mechanical design details of the …

Proof Of Principle For A Self-Governing Prediction And Forecasting Reward Algorithm, Jose Osvaldo Gonzalez-Hernandez, Jonathan Marino, Ted Rogers, Brandon Velasco

Physics Faculty Publications

We use Monte Carlo techniques to simulate an organized prediction competition between a group of scientific experts acting under the influence of a "self-governing" prediction reward algorithm. Our aim is to illustrate the advantages of a specific type of reward distribution rule that is designed to address some of the limitations of traditional forecast scoring rules. The primary extension of this algorithm as compared with standard forecast scoring is that it incorporates measures of both group consensus and question relevance directly into the reward distribution algorithm. Our model of the prediction competition includes parameters that control both the level of …

Phenomenology Of Tmd Parton Distributions In Drell-Yan And Z⁰ Boson Production In A Hadron Structure Oriented Approach, F. Aslan, M. Boglione, J. O. Gonzalez-Hernandez, T. Rainaldi, T. C. Rogers, A. Simonelli

Physics Faculty Publications

We present a first practical implementation of a recently proposed hadron structure oriented (HSO) approach to transverse momentum dependent (TMD) phenomenology applied to Drell-Yan-like processes, including lepton pair production at moderate Q² and Z⁰ boson production. We compare and contrast general features of our methodology with other common practices and emphasize aspects that we view as improvements. Separately, we discuss the importance of treatments that preserve various theoretical properties of the nonperturbative parts of TMD parametrizations for future applications that have the extraction of hadron structure as a primary goal. These include the HSO’s preservation of a basic TMD parton-model-like …

Charge Lifetime Improvement Of The Continuous Electron Beam Accelerator Facility Photogun With A Biased Anode, J. T. Yoskowitz, G. A. Krafft, G. Palacios-Serrano, S.A.K. Wijethunga, J. Grames, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, M. L. Stutzman, R. Suleiman, C. A. Valerio-Lizarraga, S. B. Van Der Geer

Physics Faculty Publications

GaAs photocathodes in dc high-voltage photoguns are highly susceptible to ion back-bombardment, which reduces the photocathode quantum efficiency and limits the useful operating lifetime for producing polarized electron beams. This paper demonstrates that applying a small positive bias to the photogun anode can significantly suppress ion back-bombardment and increase charge lifetime. This technique was studied extensively using the Continuous Electron Beam Accelerator Facility photogun, where highly polarized electron beams created using a strained-superlattice GaAs/GaAsP photocathode were used and charge lifetimes improved by almost a factor of 2. A new simulation code ionator was developed to model ion production and tracking …

Coulomb Confinement In The Hamiltonian Limit, Sebastian M. Dawid, Wyatt A. Smith, Arkaitz Rodas, Robert J. Perry, César Fernández-Ramírez, Eric S. Swanson, Adam P. Szczepaniak

Physics Faculty Publications

The Gribov-Zwanziger scenario attributes the phenomenon of confinement to the instantaneous interaction term in the QCD Hamiltonian in the Coulomb gauge. For a static quark-antiquark pair, it leads to a potential energy that increases linearly with the distance between them. Lattice studies of the SU(2) Yang-Mills theory determined the corresponding (Coulomb) string tension for sources in the fundamental representation, 𝜎_𝐶, to be about 3 times larger than the Wilson loop string tension, 𝜎_𝐹. It is far above the Zwanziger variational bound, 𝜎_𝐶 ≥𝜎_𝐹. We argue that the value often reported in the literature …

First Measurement Of Deeply Virtual Compton Scattering On The Neutron With Detection Of The Active Neutron, A. Hobart, S. Niccolai, M. Čuic, K. Kumerički, P. Achenbach, J. S. Alvarado, W. R. Armstrong, H. Atac, H. Avakian, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, M. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, S. Boiarinov, M. Zurek, Et Al.

Physics Faculty Publications

Measuring deeply virtual Compton scattering (DVCS) on the neutron is one of the necessary steps to understand the structure of the nucleon in terms of generalized parton distributions (GPDs). Neutron targets play a complementary role to transversely polarized proton targets in the determination of the GPD 𝐸. This poorly known and poorly constrained GPD is essential to obtain the contribution of the quarks’ angular momentum to the spin of the nucleon. DVCS on the neutron was measured for the first time selecting the exclusive final state by detecting the neutron, using the Jefferson Lab longitudinally polarized electron beam, with energies …

The Discharge-Induced Polarity-Dependent Propagation Characteristics Of A Strong Shock Wave, Anna Markhotok

Physics Faculty Publications

The specifics of a shock wave propagation down a positive column of a DC discharge in molecular chemically inert gases has been investigated. It was shown that axial gradients caused by the imbalance in the charged particle momentum transfer to the gas molecules can be a reason for the shock velocity dependence on the electric field direction. In pure nitrogen gas, the calculated shock velocity difference of up to 13.5% is in good agreement with the 12% value obtained in the experiment. A returning gas flow organizing in the discharge as a possible mechanism for an extended shock structure and …

Toward A Unified Description Of Hadron Scattering At All Energies, D. Stamen, D. Winney, A. Rodas, C. Fernandez-Ramirez, V. Mathieu, G. Montaña, A. Pilloni, A. P. Szczepaniak

Physics Faculty Publications

The construction of general amplitudes satisfying symmetries and 𝑆-matrix constraints has been the primary tool in studying the spectrum of hadrons for over half a century. In this work, we present a new parametrization, which can fulfill many expectations of 𝑆-matrix and Regge theory and connects the essential physics of hadron scattering in the resonance region and in asymptotic limits. In this construction, dynamical information is entirely contained in Regge trajectories that generalize resonance poles in the complex energy plane to moving poles in the angular momentum plane. We highlight the salient features of the model, compare with existing literature …

Revisiting Gauge Invariance And Reggeization Of Pion Exchange, Glòria Montaña, Daniel Winney, Łukasz Bibrzycki, César Fernández-Ramirez, Giorgio Foti, Nadine Hammoud, Vincent Mathieu, Robert J. Perry, Alessandro Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Adam P. Szczepaniak

Physics Faculty Publications

The Reggeized pion is expected to provide the main contribution to the forward cross section in light meson photoproduction reactions with charge exchange at high energies. We discuss the Reggeization of pion exchange in charged pion photoproduction with an emphasis on consistency with current conservation. We show that the gauge-invariant amplitude for the exchange of a particle with a generic even spin J ≥ 2 in the t channel is analytic at J = 0 and that it can be interpreted in terms of the nucleon electric current. This enables us to reconcile the dynamics in the s and u …

Particle Accelerator Spin-Transparent Storage Rings For Beyond State-Of-The-Art Science, R. Suleiman, Y. Derbenev, M. Grau, V. Morozov

Physics Faculty Publications

We will describe spin-transparent storage rings that exhibit spin-coherence times of several hours and store a large number of particles and their use in novel applications. For example, these rings can be used to directly measure the electric dipole moment of the electron, relevant to CP violation and matter-antimatter asymmetry in the universe, and to search for dark energy and ultra-light dark matter*. These rings can also serve as a compelling platform for quantum computing. In this presentation, we will describe how spin-transparent rings can be used in conjunction with ion traps to enhance scalability and increase quantum coherence times …

Comparison Of Enhanced And Standard Data Sheets On Treatment Fidelity And Data Collection For Tact Training, Mary Halbur, Jessi Reidy, Tiffany Kodak, Landon Scott Cowan, Michael Harman

Psychology Faculty Research and Publications

Specifically designed data sheets have been recommended to assist with the fidelity of implementation of treatment procedures. The present study extended previous research (e.g., Bottini et al. Behavior Analysis: Research & Practice 21(2), 140–152, 2021; LeBlanc et al. Behavior Analysis in Practice 13(1), 53–62, 2020) by comparing an enhanced data sheet (i.e., the inclusion of randomized targets, prompts for treatment components of securing attending and reinforcement) to a standard data sheet (i.e., targets not preset, no prompts for treatment components) on the fidelity of tact training of features. Ten behavior therapists participated in each condition (n = …

Editorial: Insights In Neurocognitive Aging And Behavior: 2022, Kristy A. Nielson, Annalena Venneri, Shin Murakami

Psychology Faculty Research and Publications

No abstract provided.

Genetic Risk For Alzheimer’S Disease Alters Perceived Executive Dysfunction In Cognitively Healthy Middle-Aged And Older Adults, Sarah A. Evans, Elizabeth R. Paitel, Riya Bhasin, Kristy A. Nielson

Psychology Faculty Research and Publications

Background:

Subjective cognitive complaints (SCC) may be an early indicator of future cognitive decline. However, findings comparing SCC and objective cognitive performance have varied, particularly in the memory domain. Even less well established is the relationship between subjective and objective complaints in non-amnestic domains, such as in executive functioning, despite evidence indicating very early changes in these domains. Moreover, particularly early changes in both amnestic and non-amnestic domains are apparent in those carrying the Apolipoprotein-E ɛ4 allele, a primary genetic risk for Alzheimer’s disease (AD).

Objective:

This study investigated the role of the ɛ4 allele in the consistency between subjective …

Sexual Minority Behavioral Health Outcomes: The Role Of Identity Authenticity And Self-Regulation., Zane B. Ballard, Debra L. Oswald

Psychology Faculty Research and Publications

No abstract provided.

Team Situation Awareness, Cohesion, And Autonomic Synchrony, Stephen J. Guastello, Cooper Bednarczyk, Ryan Hagan, Camerhon Johnson, Laura Marscisek, Laura M. Mcguigan, Anthony F. Peressini

Psychology Faculty Research and Publications

Objective

This study evaluated the causal relationships among situation awareness (SA), cohesion, and autonomic synchrony (SE) within teams. SA is often a team effort and should be more accurate in better-functioning teams.

Background

Cohesive teams perform better overall, although the relationship appears reciprocal; the relationship to SA has not been considered previously. SEis a collective neurocognitive activity that has been connected to team coordination, communication, and performance in some circumstances.

Method

In this experiment, 71 undergraduates, organized into 16 teams, played two matches of a first-person shooter computer game and completed self-report measures of cohesion …

Listening To Families: Qualitative Analysis Of Family Perspectives On The Impact Of Participating In A Complex Care Program, Jessica L. Schnell, Astrida S. Kaugars, Sarah Johaningsmeir, Sara K. Quates, K. Jane Lee

Psychology Faculty Research and Publications

Background

Complex Care Programs (CCPs) provide care for children with medical complexity (CMC). The broad impact of CCP participation on families is unknown. This study sought to elucidate what families value about participation in a CCP and what additional benefit families hope CCPs will provide.

Methods

Surveys from families of CMC in a CCP were collected over the course of two years. Responses were summarized for two fixed response satisfaction questions. Qualitative responses to two open-ended questions exploring CCP value were analyzed using content analysis.

Results

Most families (95% and 97%) were somewhat or very satisfied with the CCP. All …

The Impact Of The Covid-19 Pandemic On U.S. Latinx Mental Health: A Validation Of The Epidemic–Pandemic Impacts Inventory (Epii) Scale., Lucas Torres, Cristalís Capielo Rosario, Fiorella L. Carlos Chavez

Psychology Faculty Research and Publications

Known and emerging data continue to document the significant impact of the COVID-19 pandemic on traditionally marginalized communities living in the United States, particularly Latinx. However, at the onset of the COVID-19 pandemic, no validated measures were available to assess how this health crisis affected Latinx communities. The present study sought to assess the negative impact of the COVID-19 pandemic in a sample of Latinx adults living in the United States (N = 2,300). Because Latinx are a heterogeneous group, we employed a person-centered approach to evaluate potential differences across negative COVID-19 pandemic impact indicators using the Epidemic–Pandemic Impacts Inventory …