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2016

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Articles 10141 - 10170 of 10866

Full-Text Articles in Physical Sciences and Mathematics

Turbulence And Overturning Gravity Wave Effects Deduced From Mesospheric Na Density Between 100-105 Km At Andes Lidar Observatory, Chile, Alan Z. Liu, Channing P. Philbrick, Gary R. Swenson, Fabio A. Vargas Jan 2016

Turbulence And Overturning Gravity Wave Effects Deduced From Mesospheric Na Density Between 100-105 Km At Andes Lidar Observatory, Chile, Alan Z. Liu, Channing P. Philbrick, Gary R. Swenson, Fabio A. Vargas

Publications

Atmospheric turbulence activity in the mesosphere and lower thermosphere (MLT) region is determined from narrowband Na lidar measurements obtained over 27 nights between 85-105 km altitude at the Andes Lidar Observatory (ALO) in Cerro Pachón, Chile (30.3ºS, 70.7ºW). Photocount perturbations in the applicable spectral subrange are used as a tracer of turbulence activity. Mean altitude profiles reveal a log-scale linear increase in turbulence perturbation amplitude above 95 km. The observed trend is compared against global mean constituent transport profiles derived from SABER and SCIAMACHY satellite borne measurements.

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Deep Level Lexical Features For Cross-Lingual Authorship Attribution, Marisa Llorens, Sarah Jane Delany Jan 2016

Deep Level Lexical Features For Cross-Lingual Authorship Attribution, Marisa Llorens, Sarah Jane Delany

Conference papers

Crosslingual document classification aims to classify documents written in different languages that share a common genre, topic or author. Knowledge-based methods and others based on machine translation deliver state-of-the-art classification accuracy, however because of their reliance on external resources, poorly resourced languages present a challenge for these type of methods. In this paper, we propose a novel set of language independent features that capture language use from a document at a deep level, using features that are intrinsic to the document. These features are based on vocabulary richness measurements and are text length independent and self-contained, meaning that no external …

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Characterisation Of Strip Silicon Detectors For The Atlas Phase-Ii Upgrade With A Micro-Focused X-Ray Beam, L. Poley, A. Blue, R. Bates, I. Bloch, S. Diez, J. Fernandez-Tejero, C. Fleta, B. Gallop, B. Greenall, I.M. Gregor, K. Hara, Y. Ikegami, C. Lacasta, K. Lohwasser, D. Maneuski, S. Nagorski, I. Pape, P.W. Phillips, D. Sperlich, K. Sawhney Jan 2016

Characterisation Of Strip Silicon Detectors For The Atlas Phase-Ii Upgrade With A Micro-Focused X-Ray Beam, L. Poley, A. Blue, R. Bates, I. Bloch, S. Diez, J. Fernandez-Tejero, C. Fleta, B. Gallop, B. Greenall, I.M. Gregor, K. Hara, Y. Ikegami, C. Lacasta, K. Lohwasser, D. Maneuski, S. Nagorski, I. Pape, P.W. Phillips, D. Sperlich, K. Sawhney

Articles

The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity up to 6centerdot1034 cm−2s−1. A consequence of this increased luminosity is the expected radiation damage at 3000 fb−1 after ten years of operation, requiring the tracking detectors to withstand fluences to over 1centerdot1016 1 MeV neq/cm2. In order to cope with the consequent increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk).

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Positive Organizational Leadership And Pro-Environmental Behavior: The Phenomenon Of Institutional Fossil Fuel Divestment, Abigail Abrash Walton Jan 2016

Positive Organizational Leadership And Pro-Environmental Behavior: The Phenomenon Of Institutional Fossil Fuel Divestment, Abigail Abrash Walton

Antioch University Dissertations & Theses

Climate change is one of the most significant dynamics of our time.The predominant contributor to climate change is combustion of fossil fuels by humans.This study deepened understanding of organizational leaders’ role in enacting one approach to addressing climate change:institutional fossil fuel divestment.The study used a qualitative research design to explore U.S.-based foundation leaders’ readiness to pursue fossil fuel divestment by their institutions.The study examined leaders’ motivations and actions in pursuing divestment, while simultaneously exercising their fiduciary duty to steward institutional assets.Research questions focused on the divestment behavior change process and the outcomes of divestment on leaders and their organizations.Data collection …

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Mobile Computing, Internet Of Things, And Big Data For Urban Informatics, Anirban Mondal, Praveen Rao, Sanjay Kumar Madria Jan 2016

Mobile Computing, Internet Of Things, And Big Data For Urban Informatics, Anirban Mondal, Praveen Rao, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

Urban informatics is emerging as a new discipline for cities and governments to improve the lives of citizens using information technology. In this advanced seminar, we introduce the key challenges and opportunities in urban informatics, discuss topics in mobile computing, Internet of Things (IoT) and big data analytics, to advance the state-of-the-art in urban informatics and provide interesting use cases. This seminar is designed for academicians, researchers, city administrators/planners, application developers, and research students with background in mobile computing and database systems.

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Estimating Freeway Travel Times Using The General Motors Model, Shu Yang, Yaojan Wu, Zhaozheng Yin, Yiheng Feng Jan 2016

Estimating Freeway Travel Times Using The General Motors Model, Shu Yang, Yaojan Wu, Zhaozheng Yin, Yiheng Feng

Computer Science Faculty Research & Creative Works

Travel time is a key transportation performance measure because of its diverse applications. Various modeling approaches to estimating freeway travel time have been well developed due to widespread installation of intelligent transportation system sensors. However, estimating accurate travel time using existing freeway travel time models is still challenging under congested conditions. Therefore, this study aimed to develop an innovative freeway travel time estimation model based on the General Motors (GM) car-following model. Since the GM model is usually used in a microsimulation environment, the concepts of virtual leading and virtual following vehicles are proposed to allow the GM model to …

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An Efficient Method For Optimizing Segmentation Parameters, Jacob D' Avy, Wei-Wen Hsu, Chung-Hao Chen, Andreas F. Koschan, Mongi Abidi Jan 2016

An Efficient Method For Optimizing Segmentation Parameters, Jacob D' Avy, Wei-Wen Hsu, Chung-Hao Chen, Andreas F. Koschan, Mongi Abidi

Electrical & Computer Engineering Faculty Publications

Segmenting an image into meaningful regions is an important step in many computer vision applications such as facial recognition, target tracking and medical image analysis. Because image segmentation is an ill-posed problem, parameters are needed to constrain the solution to one that is suitable for a given application. For a user, setting parameter values is often unintuitive. We present a method for automating segmentation parameter selection using an efficient search method to optimize a segmentation objective function. Efficiency is improved by utilizing prior knowledge about the relationship between a segmentation parameter and the objective function terms. An adaptive sampling of …

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Dragon Kings Of The Deep Sea: Marine Particles Deviate Markedly From The Common Number-Size Spectrum, Alexander B. Bochdansky, Melissa A. Clouse, Gerhard J. Herndl Jan 2016

Dragon Kings Of The Deep Sea: Marine Particles Deviate Markedly From The Common Number-Size Spectrum, Alexander B. Bochdansky, Melissa A. Clouse, Gerhard J. Herndl

OES Faculty Publications

Particles are the major vector for the transfer of carbon from the upper ocean to the deep sea. However, little is known about their abundance, composition and role at depths greater than 2000 m. We present the first number-size spectrum of bathy-and abyssopelagic particles to a depth of 5500 m based on surveys performed with a custom-made holographic microscope. The particle spectrum was unusual in that particles of several millimetres in length were almost 100 times more abundant than expected from the number spectrum of smaller particles, thereby meeting the definition of "dragon kings." Marine snow particles overwhelmingly contributed to …

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A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Jia-Pu Jang, Hsu-Kuang Chang, Fred C. Dobbs Jan 2016

A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Jia-Pu Jang, Hsu-Kuang Chang, Fred C. Dobbs

OES Faculty Publications

The turbid, low-light waters characteristic of aquaculture ponds have made it difficult or impossible for previous video cameras to provide clear imagery of the ponds' benthic habitat. We developed a highly sensitive, underwater video system (UVS) for this particular application and tested it in shrimp ponds having turbidities typical of those in southern Taiwan. The system's high-quality video stream and images, together with its camera capacity (up to nine cameras), permit in situ observations of shrimp feeding behavior, shrimp size and internal anatomy, and organic matter residues on pond sediments. The UVS can operate continuously and be focused remotely, a …

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A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Hsu-Kunag Chang, Fred C. Dobbs Jan 2016

A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Hsu-Kunag Chang, Fred C. Dobbs

OES Faculty Publications

The turbid, low-light waters characteristic of aquaculture ponds have made it difficult or impossible for previous video cameras to provide clear imagery of the ponds' benthic habitat. We developed a highly sensitive, underwater video system (UVS) for this particular application and tested it in shrimp ponds having turbidities typical of those in southern Taiwan. The system's high-quality video stream and images, together with its camera capacity (up to nine cameras), permit in situ observations of shrimp feeding behavior, shrimp size and internal anatomy, and organic matter residues on pond sediments. The UVS can operate continuously and be focused remotely, a …

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The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce Jan 2016

The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce

OES Faculty Publications

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …

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Dynamics Of Plume-Triple Junction Interaction: Results From A Series Of Three-Dimensional Numerical Models And Implications For The Formation Of Oceanic Plateaus, Mladen Dordevic, Jennifer Georgen Jan 2016

Dynamics Of Plume-Triple Junction Interaction: Results From A Series Of Three-Dimensional Numerical Models And Implications For The Formation Of Oceanic Plateaus, Mladen Dordevic, Jennifer Georgen

OES Faculty Publications

Mantle plumes rising in the vicinity of mid-ocean ridges often generate anomalies in melt production and seafloor depth. This study investigates the dynamical interactions between a mantle plume and a ridge-ridge-ridge triple junction, using a parameter space approach and a suite of steady state, three-dimensional finite element numerical models. The top domain boundary is composed of three diverging plates, with each assigned half-spreading rates with respect to a fixed triple junction point. The bottom boundary is kept at a constant temperature of 1350°C except where a two-dimensional, Gaussian-shaped thermal anomaly simulating a plume is imposed. Models vary plume diameter, plume …

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Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan Jan 2016

Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan

OES Faculty Publications

Environmental factors such as temp erature, irradiance, and nitrogen (N) supply affect the growth of Prorocentrum donghaiense, but the interactive effects of these physical factors and the effects of atmospheric CO2 (pCO2) on growth and N uptake have not been examined. We compared growth kinetics of P. donghaiense grown on 4 different N substrates (nitrate [NO3 -], ammonium [NH4 +], urea, and glutamic acid [glu]) with respect to temperature, irradiance, and pCO2. Temperature (15 to 30°C) had a positive effect on growth (max. growth rates: 0.17 to 0.65 d …

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Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick Jan 2016

Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick

OES Faculty Publications

Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, …

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An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble Jan 2016

An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble

OES Faculty Publications

In principle, tandem mass spectrometry can be used to detect and quantify the peptides present in a microbiome sample, enabling functional and taxonomic insight into microbiome metabolic activity. However, the phylogenetic diversity constituting a particular microbiome is often unknown, and many of the organisms present may not have assembled genomes. In ocean microbiome samples, with particularly diverse and uncultured bacterial communities, it is difficult to construct protein databases that contain the bulk of the peptides in the sample without losing detection sensitivity due to the overwhelming number of candidate peptides for each tandem mass spectrum. We describe a method for …

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The Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Cyanoximates, Adedamola Abraham Opalade Jan 2016

The Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Cyanoximates, Adedamola Abraham Opalade

Graduate Theses/Dissertations

The design of one-dimensional nickel wires were attempted. Metal complexes of hydrated Cu(II) and Ni(II) with several cyanoximates were synthesized and characterized by elemental analysis, thermal analysis, IR-, electronic- (solid state diffuse reflectance) spectroscopy, and the X-ray analysis (powder diffraction and single crystal studies). Hydrolysis of the HECO and HMeCO cyanoxime ligands leads to the formation of another dianionic cyanoxime – AACO2-, which forms multimetallic Cu(II) and Ni(II) complexes and oxamide as a side product. The crystal and molecular structures of 8 compounds were determined (6 metal complexes and 2 organic compounds). Two Ni metal complexes have distorted octahedral structures …

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Systematic Errors In Intro Lab Video Analysis, John Zwart, Kayt E. Frisch, Tim Martin Jan 2016

Systematic Errors In Intro Lab Video Analysis, John Zwart, Kayt E. Frisch, Tim Martin

Faculty Work Comprehensive List

In video analysis lab experiments, students frequently find large discrepancies between results based on self-filmed videos and expected values (e.g. for g determined by a fit to projectile motion data). These differences are frequently far larger than the uncertainty calculated from their fit. Using an inexpensive point-and-shoot camera with a 4x optical zoom to record video, we investigated two possible causes of this error: the effect of placing the reference meter stick at a different object-to-camera distance and the effect of the motion of interest being in a plane not perpendicular to the camera lens. When we observed these phenomena …

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A Hierarchical Statistical Engineering Modeling Methodology, Teddy Steven Cotter Jan 2016

A Hierarchical Statistical Engineering Modeling Methodology, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2015, Cotter (2015) proposed a systemic joint deterministic-stochastic dynamic causal Bayesian statistical engineering model that addressed the knowledge gap needed to integrate deterministic mathematical engineering models within a stochastic framework. However, Cotter did not specify the modeling methodology through which statistical engineering models could be developed, diagnosed, and applied to predict systemic mission performance. This paper updates research into the development a hierarchical statistical engineering modeling methodology and sets forth the initial theoretical foundation for the methodology.

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Valuing Natural Space And Landscape Fragmentation In Richmond, Va, Lee Wyatt Carpenter Jan 2016

Valuing Natural Space And Landscape Fragmentation In Richmond, Va, Lee Wyatt Carpenter

Theses and Dissertations

Hedonic pricing methods and GIS (Geographic Information Systems) were used to evaluate relationships between sale price of single family homes and landscape fragmentation and natural land cover. Spatial regression analyses found that sale prices increase as landscapes become less fragmented and the amount of natural land cover around a home increases. The projected growth in population and employment in the Richmond, Virginia region and subsequent increases in land development and landscape fragmentation presents a challenge to sustaining intact healthy ecosystems in the Richmond region. Spatial regression analyses helped illuminate how land cover patterns influence sale prices and landscape patterns that …

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Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton Jan 2016

Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton

OES Faculty Publications

The primary input of organic matter to almost all marine sediments comes from deposition at the sediment surface. However, in many continental margin settings, reduced carbon can also be added to sediments from below—for example, from “deep” geologic hydrocarbon reservoirs derived from ancient source rocks or from the decomposition of deeply buried gas hydrate deposits. To examine the impact of these two differing reduced carbon inputs on sediment biogeochemistry, a modified reaction-transport model for anoxic marine sediments is described here and applied to data from sediment cores in Santa Barbara Basin to a depth of 4.6 m. Excellent model fits …

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Some Convergence Properties Of Minkowski Functionals Given By Polytopes, Jesse Moeller Jan 2016

Some Convergence Properties Of Minkowski Functionals Given By Polytopes, Jesse Moeller

Dissertations and Theses @ UNI

In this work we investigate the behavior of the Minkowski Functionals admitted by a sequence of sets which converge to the unit ball ‘from the inside’. We begin in R 2 and use this example to build intuition as we extend to the more general R n case. We prove, in the penultimate chapter, that convergence ‘from the inside’ in this setting is equivalent to two other characterizations of the convergence: a geometric characterization which has to do with the sizes of the faces of each polytope in the sequence converging to zero, and the convergence of the Minkowski functionals …

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Results And Challenges In Visualizing Analytic Provenance Of Text Analysis Tasks Using Interaction Logs, Rhema Linder, Alyssa M. Peña, Sampath Jayarathna, Eric D. Ragan Jan 2016

Results And Challenges In Visualizing Analytic Provenance Of Text Analysis Tasks Using Interaction Logs, Rhema Linder, Alyssa M. Peña, Sampath Jayarathna, Eric D. Ragan

Computer Science Faculty Publications

After data analysis, recalling and communicating the steps and rationale followed during the analysis can be difficult. This paper explores the use of interaction logs to generate summaries of an analyst's interest based on interactions with specific data items in a text analysis scenario. Our approach uses data-interaction events as a proxy for user interest in and experience of information. Logging can produce verbose logs that detail all available readable content, so the discussed approach uses topic modeling (LDA) over different time segments to summarize the verbose information and generate visualizations of the history of user interest. Our preliminary results …

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The Effects Of Blended Learning On Critical Thinking In A High School Earth Science Class, Renee Nicole Borglum Jan 2016

The Effects Of Blended Learning On Critical Thinking In A High School Earth Science Class, Renee Nicole Borglum

Dissertations and Theses @ UNI

This study analyzed the effects of differing levels of technology use in a high school Earth Science class on student performance on the Classroom Test of Scientific Reasoning (CTSR). Blended learning manipulates the combination of hands-on activities, classroom discussions, online discussions, interactive simulations and a variety of assessments that engage, instruct and assess student learning. Critical thinking is the set of skills and dispositions that foster problem solving, reasoning ability and selfregulation. The increasing use of technology in the classroom and fluctuation of content standards prompted this research. The results have implications for the classroom teacher of a wide range …

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Student Performance In Curricula Centered On Simulation-Based Inference: A Preliminary Report, Beth Chance, Jimmy Wong, Nathan L. Tintle Jan 2016

Student Performance In Curricula Centered On Simulation-Based Inference: A Preliminary Report, Beth Chance, Jimmy Wong, Nathan L. Tintle

Faculty Work Comprehensive List

"Simulation-based inference"(e.g., bootstrapping and randomization tests) has been advocated recently with the goal of improving student understanding of statistical inference, as well as the statistical investigative process as a whole. Preliminary assessment data have been largely positive. This article describes the analysis of the first year of data from a multi-institution assessment effort by instructors using such an approach in a college-level introductory statistics course, some for the first time. We examine several pre-/post-measures of student attitudes and conceptual understanding of several topics in the introductory course. We highlight some patterns in the data, focusing on student level and instructor …

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Anisotropic Thermodynamic And Transport Properties Of Single-Crystalline Cakfe4As4, W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, M. A. Tanatar, R. Prozorov, A. I. Goldman, Fedor F. Balakirev, Alex Gurevich, S. L. Bud'ko, P. C. Canfield Jan 2016

Anisotropic Thermodynamic And Transport Properties Of Single-Crystalline Cakfe4As4, W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, M. A. Tanatar, R. Prozorov, A. I. Goldman, Fedor F. Balakirev, Alex Gurevich, S. L. Bud'ko, P. C. Canfield

Physics Faculty Publications

Single-crystalline, single-phase CaKFe4As4 has been grown out of a high-temperature, quaternary melt. Temperature-dependent measurements of x-ray diffraction, anisotropic electrical resistivity, elastoresistivity, thermoelectric power, Hall effect, magnetization, and specific heat, combined with field-dependent measurements of electrical resistivity and field and pressure-dependent measurements of magnetization indicate that CaKFe4As4 is an ordered, stoichiometric, Fe-based superconductor with a superconducting critical temperature, Tc = 35.0 ± 0.2 K. Other than superconductivity, there is no indication of any other phase transition for 1.8K ≤ T ≤ 300 K. All of these thermodynamic and transport data reveal striking similarities to …

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Rapidity Evolution Of Gluon Tmd From Low To Moderate X, Ian Balitsky Jan 2016

Rapidity Evolution Of Gluon Tmd From Low To Moderate X, Ian Balitsky

Physics Faculty Publications

I discuss how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at small x ≪ 1 to linear evolution at moderate x ~ 1.

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A Search For The Lhcb Charmed "Pentaquark" Using Photoproduction Of J/Ψ At Threshold In Hall C At Jefferson Lab, A. Asaturyan, H. Mkrtchyan, T. Tadevosyan, S. Zhamkochyan, J. Arrington, W. Armstrong, K. Hafidi, M. Hattawy, Z. Ye, K. Aniol, H. Gao, Z. Zhao, T. Liu, X. Yan, C. Gu, C. Peng, X. Li, W. Xiong, P. Markowitz, K. Adhikari, H. Bhatt, D. Bhetuwal, J. Dunne, D. Dutta, L. El-Fassi, L. Ye, F. R. Wesselmann, X. Chen, Q. Fu, R. Wang, Y. Zhang, F. Zhao, R. Dupré, G. M. Huber, W. Li, A. Zafar, S. Bae, H. Choi, S. Choi, H. Go, J. Ha, H. Atac, B. Duran, S. Joosten, Z.-E. Meziani, M. Paolone, M. Rehfuss, N. Sparveris, J.-P. Chen, E. Chudakov, M. Diefenthaler, O. Hansen, D. Higinbotham, M. Jones, D. Meekins, L. Pentchev, E. Pooser, S. Wood Jan 2016

A Search For The Lhcb Charmed "Pentaquark" Using Photoproduction Of J/Ψ At Threshold In Hall C At Jefferson Lab, A. Asaturyan, H. Mkrtchyan, T. Tadevosyan, S. Zhamkochyan, J. Arrington, W. Armstrong, K. Hafidi, M. Hattawy, Z. Ye, K. Aniol, H. Gao, Z. Zhao, T. Liu, X. Yan, C. Gu, C. Peng, X. Li, W. Xiong, P. Markowitz, K. Adhikari, H. Bhatt, D. Bhetuwal, J. Dunne, D. Dutta, L. El-Fassi, L. Ye, F. R. Wesselmann, X. Chen, Q. Fu, R. Wang, Y. Zhang, F. Zhao, R. Dupré, G. M. Huber, W. Li, A. Zafar, S. Bae, H. Choi, S. Choi, H. Go, J. Ha, H. Atac, B. Duran, S. Joosten, Z.-E. Meziani, M. Paolone, M. Rehfuss, N. Sparveris, J.-P. Chen, E. Chudakov, M. Diefenthaler, O. Hansen, D. Higinbotham, M. Jones, D. Meekins, L. Pentchev, E. Pooser, S. Wood

Physics Faculty Publications

We propose to measure the photo-production cross section of J/Ψ near threshold in search of the recently observed LHCb hidden charm resonances Pc(4380) and Pc(4450) consistent with "pentaquarks." The observation of these resonances in photo-production is important to differentiate the true resonance nature of the LHCb states from kinematics enhancements. The bremsstrahlung photon beam produced with an 11 GeV electron beam at CEBAF enables us to cover the energy range of J/Ψ production from the threshold photo-production energy of 8.2 GeV to an energy beyond the presumed Pc(4450) resonance production. The proposed experiment will be carried out in Hall C …

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Heavy Quark Production At An Electron-Ion Collider, E. Chudakov, D. Higinbotham, C. Hyde, S. Furletov, Yu Furletova, D. Nguyen, M. Stratmann, M. Strickman, C. Weiss Jan 2016

Heavy Quark Production At An Electron-Ion Collider, E. Chudakov, D. Higinbotham, C. Hyde, S. Furletov, Yu Furletova, D. Nguyen, M. Stratmann, M. Strickman, C. Weiss

Physics Faculty Publications

An Electron-Ion Collider (EIC) with center-of-mass energies √seN ∼ 20-100 GeV and luminosity L ∼ 10³⁴ cm-² s-¹ would offer new opportunities to study heavy quark production in high-energy electron or photon scattering on protons and nuclei. We report about an R&D project exploring the feasibility of direct measurements of nuclear gluon densities at x >∼ 0.1 (gluonic EMC effect, antishadowing) using open charm production at EIC. We describe the charm production rates and angle-momentum distributions at large x and discuss methods of charm reconstruction using next-generation detector capabilities (π/K identification, vertex reconstruction). The results could be …

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Probing Nuclear Gluons With Heavy Flavors At An Electron-Ion Collider, E. Chudakov, D. Higinbotham, C. Hyde, S. Furletov, Y. Furletova, D. Nguyen, M. Stratmann, M. Strikman, C. Weiss, R. Yoshida Jan 2016

Probing Nuclear Gluons With Heavy Flavors At An Electron-Ion Collider, E. Chudakov, D. Higinbotham, C. Hyde, S. Furletov, Y. Furletova, D. Nguyen, M. Stratmann, M. Strikman, C. Weiss, R. Yoshida

Physics Faculty Publications

We explore the feasibility of direct measurements of nuclear gluon densities using heavy-quark production (open charm, beauty) at a future Electron-Ion Collider (EIC). We focus on the regions x> 0.3 (EMC effect) and x ~ 0.05-0.1 (antishadowing), where the nuclear modifications of the gluon density offer insight into non-nucleonic degrees of freedom and the QCD structure of nucleon-nucleon interactions. We describe the charm production rates and momentum distributions in nuclear deep-inelastic scattering (DIS) at Large XB, and comment on the possible methods for charm reconstruction using next-generation detectors at the EIC (π/K identification, tracking, vertex detection).

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Relating Transverse-Momentum-Dependent And Collinear Factorization Theorems In A Generalized Formalism, J. Collins, L. Gamberg, A. Prokudin, T. C. Rogers, N. Sato, B. Wang Jan 2016

Relating Transverse-Momentum-Dependent And Collinear Factorization Theorems In A Generalized Formalism, J. Collins, L. Gamberg, A. Prokudin, T. C. Rogers, N. Sato, B. Wang

Physics Faculty Publications

We construct an improved implementation for combining transverse-momentum-dependent (TMD) factorization and collinear factorization. TMD factorization is suitable for low transverse momentum physics, while collinear factorization is suitable for high transverse momenta and for a cross section integrated over transverse momentum. The result is a modified version of the standard 𝑊 + 𝑌 prescription traditionally used in the Collins-Soper-Sterman (CSS) formalism and related approaches. We further argue that questions regarding the shape and 𝑄 dependence of the cross sections at lower 𝑄 are largely governed by the matching to the 𝑌 term.

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