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Articles 33241 - 33270 of 294491
Full-Text Articles in Physical Sciences and Mathematics
Synthesis And Evaluation Of 5-(Heteroarylmethylene)Hydantoins As Glycogen Synthase Kinase-3Β Inhibitors, Nicholas O. Schneider, Keandra Gilreath, Daniel J. Burkett, Martin St. Maurice, William A. Donaldson
Synthesis And Evaluation Of 5-(Heteroarylmethylene)Hydantoins As Glycogen Synthase Kinase-3Β Inhibitors, Nicholas O. Schneider, Keandra Gilreath, Daniel J. Burkett, Martin St. Maurice, William A. Donaldson
Chemistry Faculty Research and Publications
Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase which plays a center role in the phosphorylation of a wide variety of proteins, generally leading to their inactivation. As such, GSK-3 is viewed as a therapeutic target. An ever-increasing number of small organic molecule inhibitors of GSK-3 have been reported. Phenylmethylene hydantoins are known to exhibit a wide range of inhibitory activities including for GSK-3β. A family of fourteen 2-heterocycle substituted methylene hydantoins (14, 17–29) were prepared and evaluated for the inhibition of GSK-3β at 25 μM. The IC50 values of five of these compounds was determined; the two best inhibitors …
Mixed Quantum/Classical Calculations Of Rotationally Inelastic Scattering In The Co + Co System: A Comparison With Fully Quantum Results, Dulat Bostan, Bikramaditya Mandal, Carolin Joy, Michał Żółtowski, François Lique, Jérôme Loreau, Ernesto Quintas-Sánchez, Adrian Batista-Planas, Richard Dawes, Dmitri Babikov
Mixed Quantum/Classical Calculations Of Rotationally Inelastic Scattering In The Co + Co System: A Comparison With Fully Quantum Results, Dulat Bostan, Bikramaditya Mandal, Carolin Joy, Michał Żółtowski, François Lique, Jérôme Loreau, Ernesto Quintas-Sánchez, Adrian Batista-Planas, Richard Dawes, Dmitri Babikov
Chemistry Faculty Research and Publications
An updated version of the CO + CO potential energy surface from [R. Dawes, X. G. Wang and T. Carrington, J. Phys. Chem. A 2013, 117, 7612] is presented, that incorporates an improved treatment of the asymptotic behavior. It is found that this new surface is only slightly different from the other popular PES available for this system in the literature [G. W. M. Vissers, P. E. S. Wormer and A. Van Der Avoird, Phys. Chem. Chem. Phys. 2003, 5, 4767]. The differences are quantified by expanding both surfaces over a set of analytic functions and comparing the behavior of …
Maximizing The Number Of H-Colorings Of Graphs With A Fixed Minimum Degree, John Engbers
Maximizing The Number Of H-Colorings Of Graphs With A Fixed Minimum Degree, John Engbers
Mathematical and Statistical Science Faculty Research and Publications
For graphs G and H, an H-coloring of G is an adjacency-preserving map from the vertex set of G to the vertex set of H.
Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers
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 …
The Discharge-Induced Polarity-Dependent Propagation Characteristics Of A Strong Shock Wave, Anna Markhotok
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 …
Proof Of The Kresch-Tamvakis Conjecture, John Caughman, Taiyo S. Terada
Proof Of The Kresch-Tamvakis Conjecture, John Caughman, Taiyo S. Terada
Mathematics and Statistics Faculty Publications and Presentations
In this paper we resolve a conjecture of Kresch and Tamvakis.
Critical Conversations Of Engaging Withthe Amte Standards, Eva Thanheiser, Jennifer Bay-Williams, Richard Velasco, Liza Bondurant
Critical Conversations Of Engaging Withthe Amte Standards, Eva Thanheiser, Jennifer Bay-Williams, Richard Velasco, Liza Bondurant
Mathematics and Statistics Faculty Publications and Presentations
This article is based on an opening plenary session at the Association of Mathematics Teacher Educators (AMTE) 2024 conference in Orlando, Florida, USA. The authors, who delivered the plenary in a panel format, focus specifically on the AMTE standard indicator that addresses power and privilege. This article is the product of the five authors reflecting on their panel and discussing its contents—in the form of this manuscript—with an external Open Reviewer. The result is a “quintalog” of the five authors in critical conversation with each other about their own reflections on the ways in which mathematics teacher educators and the …
Variability In Semidiurnal Surface And Internal Tides In Global Ocean Model Simulations, Harpreet Kaur
Variability In Semidiurnal Surface And Internal Tides In Global Ocean Model Simulations, Harpreet Kaur
Dissertations
This dissertation focuses on semidiurnal (D2) surface and internal tides. Chapter 2 investigates the transition of M2 barotropic Kelvin waves into Hybrid Kelvin-Edge (HKE) waves and the associated generation of internal tides at widening shelves using theory and a realistic global baroclinic Hybrid Coordinate Ocean Model (HYCOM) simulation. To understand the effect of complex, realistic bathymetry on the HKE wave transition, we perform quasi-realistic barotropic HYCOM simulations of the Celtic Sea/Bay of Biscay shelf areas. We conclude that the HKE wave transition is most likely masked by the effects of complex bathymetry and offshelf baroclinic fluxes cannot be exclusively …
An Efficient And Trusted Deep Learning Framework For Real-Time Ppe Detection In Secure Iomt Environment, Anusha Verma
An Efficient And Trusted Deep Learning Framework For Real-Time Ppe Detection In Secure Iomt Environment, Anusha Verma
Browse all Theses and Dissertations
Occupationally-acquired infections impact thousands of healthcare workers (HCWs) in the U.S., with many cases preventable through proper use of personal protective equipment (PPE). This study seeks to develop a robust system to enhance PPE compliance and reduce infection risks among HCWs. The objectives of this thesis are twofold: (1) to create a hybrid machine learning model that combines object detection and keypoint detection to ensure correct donning and doffing of PPE, and (2) to design a real-time feedback system using LED indicators and a display interface to offer actionable guidance to HCWs during PPE usage. The goal is to optimize …
An Enhanced Real-Time Object Detection Of Helmets And License Plates Using A Lightweight Yolov8 Deep Learning Model, Mounika Thatikonda
An Enhanced Real-Time Object Detection Of Helmets And License Plates Using A Lightweight Yolov8 Deep Learning Model, Mounika Thatikonda
Browse all Theses and Dissertations
Traffic surveillance and enforcement heavily depend on the real-time detection of helmets and license plates, particularly in high-density urban environments. This study presents a dynamic and optimized lightweight model, the proposed G-YOLOv8n, designed for resource constrained edge devices like the Raspberry Pi. By integrating the GhostNet module into the YOLOv8n architecture, this research achieves a nearly 50% reduction in model size and computational load, while maintaining comparable detection accuracy to the original YOLOv8n. These enhancements enable real-time processing capabilities crucial for traffic monitoring operations. The growing demand for real-time, low-power solutions in intelligent transportation systems necessitates lightweight, efficient detection models. …
A Systematic Study Of Freezing Behavior In Earthworms In Response To Auditory And Vibratory Stimuli, Navjot Singh, A. Burton, Dragana Ivkovich Claflin
A Systematic Study Of Freezing Behavior In Earthworms In Response To Auditory And Vibratory Stimuli, Navjot Singh, A. Burton, Dragana Ivkovich Claflin
Celebration of Undergraduate & Graduate Research, Scholarship, and Creative Activities Materials
This study examined the parameters needed to reliably induce a freezing fear response to a predator-like auditory stimulus in the earthworm species Eisenia Fetida. Previous work from our lab found that a grunting noise was more reliable in causing freezing compared to a mole sound, i.e. artificial versus natural predators of E. Fetida (Worthen et al., 2024). In the present study, 8 amplitude levels of grunting sound were presented in either serial or random order. The speaker location was varied so that it either did or did not touch the apparatus, thus producing a mechanical vibration in addition to the …
The Legal Crisis Within The Climate Crisis, Mark P. Nevitt
The Legal Crisis Within The Climate Crisis, Mark P. Nevitt
Faculty Articles
Climate change creates a difficult choice for property owners and governmental officials alike: Should they invest in costly climate adaptation measures or retreat from climate-exposed areas? Either decision is fraught with legal uncertainty, running headfirst into antiquated legal doctrines designed for a more stable world. Climate impacts to the coastline are forcing policymakers to consider four adaptation tools: (1) resisting climate impacts by building sea walls and armoring the shoreline; (2) accommodating those impacts by elevating existing structures; (3) managed retreat such as systematically and preemptively moving people out of harm’s way; and (4) reactively moving people to new locations …
Fairness And Fair Use In Generative Ai, Matthew Sag
Fairness And Fair Use In Generative Ai, Matthew Sag
Faculty Articles
Although we are still a long way from the science fiction version of “artificial general intelligence” that thinks, feels, and refuses to “open the pod bay doors,” recent advances in machine learning and artificial intelligence (AI) have captured the public’s imagination and lawmakers’ interest. We now have large language models (LLMs) that can pass the bar exam, carry on (what passes for) a conversation about almost any topic, create new music, and create new visual art. These artifacts are often indistinguishable from their human-authored counterparts and yet can be produced at a speed and scale surpassing human ability.
“Generative AI” …
Climate Risk, Insurance Retreat, And State Response, Mark P. Nevitt, Michael Pappas
Climate Risk, Insurance Retreat, And State Response, Mark P. Nevitt, Michael Pappas
Faculty Articles
Climate change is fundamentally destabilizing the private insurance industry, with many high-profile insurance companies exiting states in the face of catastrophic, climate-induced risk. This rapid "insurance retreat" represents a major market signal in response to climate-exacerbated risks. Private businesses are making actuarial decisions, assessing that some locations are just too vulnerable to insure. At the same time, this insurance retreat also poses a policy challenge for states as they react to the mounting insurance gaps left by exiting private insurers.
This Article analyzes insurance retreat, its attendant policy challenges, and the lessons that can be drawn from state responses. It …
Climatizing National Security, Mark P. Nevitt
Climatizing National Security, Mark P. Nevitt
Faculty Articles
Is climate change a national security issue? Human security? Ecological security? This Article addresses the growing nexus between climate change and various conceptions of security with a particular emphasis on climate change's national security impacts. This Article argues that there is a growing connection between national security and climate change and a corresponding need to address the normative implications of "climatizing national security." This connection can be observed through three lenses: mitigation (reducing greenhouse gas emissions from military and national security sources); adaptation (investing in climate resilient infrastructure in an effort to prepare for climate impacts), and response (addressing climate-exacerbated …
Environmental War, Climate Security, And The Russia-Ukraine Crisis, Mark P. Nevitt
Environmental War, Climate Security, And The Russia-Ukraine Crisis, Mark P. Nevitt
Faculty Articles
This Article addresses the Russia-Ukraine conflict’s broad implications for energy security, climate security, and environment protections during wartime. I assert that in the short-term the Russian-Ukraine war is poised to hinder much-needed international climate progress. It will stymie international decarbonization efforts and cause greater uncertainty in other climate-destabilized parts of the world, such as the Arctic. While Russia has become a pariah in the eyes of the United States and other Western nations, it has forged new partnerships and capitalized on new, lucrative energy markets outside the West and Global South. But in the long term, the global renewable energy …
Agn Storm 2. Ix. Studying The Dynamics Of The Ionized Obscurer In Mrk 817 With High-Resolution X-Ray Spectroscopy, Fatima Zaidouni, Erin Kara, Peter Kosec, Missagh Mehdipour, Daniele Rogantini, Gerard A. Kriss, Ehud Behar, Jelle Kaastra, Aaron J. Barth, Edward M. Cackett, Gisella De Rosa, Yasaman Homayouni, Keith Horne, Hermine Landt, Nahum Arav, Misty C. Bentz, Michael S. Brotherton, Elena Dalla Bontà, Maryam Dehghanian, Gary Ferland, Carina Fian, Jonathan Gelbord, Michael R. Goad, Diego H. González Buitrago, Catherine J. Grier, Patrick B. Hall, Chen Hu, Dragana Ilić, Shai Kaspi, Christopher S. Kochanek, Andjelka B. Kovačević, Daniel Kynoch, Collin Lewin, John Montano, Hagai Netzer, Jack M. M. Neustadt, Christos Panagiotou, Ethan R. Partington, Rachel Plesha, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini, Marianne Vestergaard, Tim Waters, Ying Zu
Agn Storm 2. Ix. Studying The Dynamics Of The Ionized Obscurer In Mrk 817 With High-Resolution X-Ray Spectroscopy, Fatima Zaidouni, Erin Kara, Peter Kosec, Missagh Mehdipour, Daniele Rogantini, Gerard A. Kriss, Ehud Behar, Jelle Kaastra, Aaron J. Barth, Edward M. Cackett, Gisella De Rosa, Yasaman Homayouni, Keith Horne, Hermine Landt, Nahum Arav, Misty C. Bentz, Michael S. Brotherton, Elena Dalla Bontà, Maryam Dehghanian, Gary Ferland, Carina Fian, Jonathan Gelbord, Michael R. Goad, Diego H. González Buitrago, Catherine J. Grier, Patrick B. Hall, Chen Hu, Dragana Ilić, Shai Kaspi, Christopher S. Kochanek, Andjelka B. Kovačević, Daniel Kynoch, Collin Lewin, John Montano, Hagai Netzer, Jack M. M. Neustadt, Christos Panagiotou, Ethan R. Partington, Rachel Plesha, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini, Marianne Vestergaard, Tim Waters, Ying Zu
Physics and Astronomy Faculty Publications
We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multiwavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the AGN Space Telescope and Optical Reverberation Mapping 2 (AGN STORM 2) Project. The campaign revealed an unexpected and transient obscuring outflow, never before seen in this source. Of our four XMM-Newton/NuSTAR epochs, one fortuitously taken during a bright X-ray state has strong narrow absorption lines in the high-resolution grating spectra. From these absorption features, we determine that the obscurer is in fact a multiphase ionized wind with an outflow velocity of …
Agn Storm 2. Viii. Investigating The Narrow Absorption Lines In Mrk 817 Using Hst-Cos Observations, Maryam Dehghanian, Nahum Arav, Gerard A. Kriss, Missagh Mehdipour, Doyee Byun, Gwen Walker, Mayank Sharma, Aaron J. Barth, Misty C. Bentz, Benjamin D. Boizelle, Michael S. Brotherton, Edward M. Cackett, Elena Dalla Bontà, Gisella De Rosa, Gary Ferland, Carina Fian, Alexei V. Filippenko, Jonathan Gelbord, Michael R. Goad, Keith Horne, Yasaman Homayouni, Dragana Ilić, Michael D. Joner, Erin A. Kara, Shai Kaspi, Christopher S. Kochanek, Kirk T. Korista, Peter Kosec, Andjelka B. Kovačević, Hermine Landt, Collin Lewin, Ethan R. Partington, Luka Č. Popović, Daniel Proga, Daniele Rogantini, Matthew R. Siebert, Thaisa Storchi-Bergmann, Marianne Vestergaard, Timothy Waters, Jian-Min Wang, Fatima Zaidouni, Ying Zu
Agn Storm 2. Viii. Investigating The Narrow Absorption Lines In Mrk 817 Using Hst-Cos Observations, Maryam Dehghanian, Nahum Arav, Gerard A. Kriss, Missagh Mehdipour, Doyee Byun, Gwen Walker, Mayank Sharma, Aaron J. Barth, Misty C. Bentz, Benjamin D. Boizelle, Michael S. Brotherton, Edward M. Cackett, Elena Dalla Bontà, Gisella De Rosa, Gary Ferland, Carina Fian, Alexei V. Filippenko, Jonathan Gelbord, Michael R. Goad, Keith Horne, Yasaman Homayouni, Dragana Ilić, Michael D. Joner, Erin A. Kara, Shai Kaspi, Christopher S. Kochanek, Kirk T. Korista, Peter Kosec, Andjelka B. Kovačević, Hermine Landt, Collin Lewin, Ethan R. Partington, Luka Č. Popović, Daniel Proga, Daniele Rogantini, Matthew R. Siebert, Thaisa Storchi-Bergmann, Marianne Vestergaard, Timothy Waters, Jian-Min Wang, Fatima Zaidouni, Ying Zu
Physics and Astronomy Faculty Publications
We observed the Seyfert 1 galaxy Mrk 817 during an intensive multiwavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in the Hubble Space Telescope/ Cosmic Origins Spectrograph spectra, both during the campaign and in other epochs extending over 14 yr. We conclude that, while the narrow absorption outflow system (at −3750 km s−1 with FWHM = 177 km s−1) responds to the variations of the UV continuum as modified by the X-ray obscurer, its total column density (log NH = 19.5 - +0.13 0.61 cm−2) did not change across all …
Agn Storm 2. Vi. Mapping Temperature Fluctuations In The Accretion Disk Of Mrk 817, Jack M. M. Neustadt, Christopher S. Kochanek, John Montano, Jonathan M. Gelbord, Aaron J. Barth, Gisella De Rosa, Gerard A. Kriss, Edward M. Cackett, Keith Horne, Erin A. Kara, Hermine Landt, Hagai Netzer, Nahum Arav, Misty C. Bentz, Elena Dalla Bontà, Maryam Dehghanian, Pu Du, Rick Edelson, Gary Ferland, Carina Fian, Travis Fischer, Michael R. Goad, Diego H. González Buitrago, Varoujan Gorjian, Catherine J. Grier, Patrick B. Hall, Yasaman Homayouni, Chen Hu, Dragana Ilić, Michael D. Joner, Jelle Kaastra, Shai Kaspi, Kirk T. Korista, Andjelka B. Kovačević, Collin Lewin, Yan-Rong Li, Ian M. Mchardy, Missagh Mehdipour, Jake A. Miller, Christos Panagiotou, Ethan Partington, Rachel Plesha, Richard W. Pogge, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini
Agn Storm 2. Vi. Mapping Temperature Fluctuations In The Accretion Disk Of Mrk 817, Jack M. M. Neustadt, Christopher S. Kochanek, John Montano, Jonathan M. Gelbord, Aaron J. Barth, Gisella De Rosa, Gerard A. Kriss, Edward M. Cackett, Keith Horne, Erin A. Kara, Hermine Landt, Hagai Netzer, Nahum Arav, Misty C. Bentz, Elena Dalla Bontà, Maryam Dehghanian, Pu Du, Rick Edelson, Gary Ferland, Carina Fian, Travis Fischer, Michael R. Goad, Diego H. González Buitrago, Varoujan Gorjian, Catherine J. Grier, Patrick B. Hall, Yasaman Homayouni, Chen Hu, Dragana Ilić, Michael D. Joner, Jelle Kaastra, Shai Kaspi, Kirk T. Korista, Andjelka B. Kovačević, Collin Lewin, Yan-Rong Li, Ian M. Mchardy, Missagh Mehdipour, Jake A. Miller, Christos Panagiotou, Ethan Partington, Rachel Plesha, Richard W. Pogge, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini
Physics and Astronomy Faculty Publications
We fit the UV/optical lightcurves of the Seyfert 1 galaxy Mrk 817 to produce maps of the accretion disk temperature fluctuations δT resolved in time and radius. The δT maps are dominated by coherent radial structures that move slowly (v = c) inward and outward, which conflicts with the idea that disk variability is driven only by reverberation. Instead, these slow-moving temperature fluctuations are likely due to variability intrinsic to the disk. We test how modifying the input lightcurves by smoothing and subtracting them changes the resulting δT maps and find that most of the temperature fluctuations exist over relatively …
Correlations Of Event Activity With Hard And Soft Processes In P + Au Collisions At √S Nn = 200 Gev At The Rhic Star Experiment, Star Collaboration
Correlations Of Event Activity With Hard And Soft Processes In P + Au Collisions At √S Nn = 200 Gev At The Rhic Star Experiment, Star Collaboration
Physics and Astronomy Faculty Publications
With the STAR experiment at the BNL Relativistic Heavy Ion Collider, we characterize √s NN = 200 GeV p + Au collisions by event activity (EA) measured within the pseudorapidity range η ∈ [−5, −3.4] in the Au-going direction and report correlations between this EA and hard- and soft-scale particle production at midrapidity (η ∈ [−1, 1]). At the soft scale, charged particle production in low-EA p + Au collisions is comparable to that in p + p collisions and increases monotonically with increasing EA. At the hard scale, we report measurements of high transverse momentum (pT ) jets in …
Collision-Energy Dependence Of Deuteron Cumulanorrelations In Au+Au Collisions At Rhicts And Proton-Deuteron C, The Star Collaboration
Collision-Energy Dependence Of Deuteron Cumulanorrelations In Au+Au Collisions At Rhicts And Proton-Deuteron C, The Star Collaboration
Physics and Astronomy Faculty Publications
We report the first measurements of cumulants, up to 4𝑡ℎ order, of deuteron number distributions and proton-deuteron correlations in Au+Au collisions recorded by the STAR experiment in phase-I of Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider. Deuteron cumulants, their ratios, and proton-deuteron mixed cumulants are presented for different collision centralities covering a range of center-of-mass energy per nucleon pair √𝑠NN = 7.7 to 200 GeV. It is found that the cumulant ratios at lower collision energies favor a canonical ensemble over a grand canonical ensemble in thermal models. An anti-correlation between proton and deuteron multiplicity is …
Estimate Of Background Baseline And Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At √S Nn = 200 Gev At The Bnl Relativistic Heavy Ion Collider, Star Collaboration
Estimate Of Background Baseline And Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At √S Nn = 200 Gev At The Bnl Relativistic Heavy Ion Collider, Star Collaboration
Physics and Astronomy Faculty Publications
For the search of the chiral magnetic effect (CME), STAR previously presented the results from isobar collisions ( 96/44 Ru + 96/44 Ru, 96/40 Zr + 96/40 Zr) obtained through a blind analysis. The ratio of results in Ru + Ru to Zr + Zr collisions for the CME-sensitive charge-dependent azimuthal correlator (Δγ), normalized by elliptic anisotropy (v2 ), was observed to be close to but systematically larger than the inverse multiplicity ratio. The background baseline for the isobar ratio, Y = (Δγ /v2 )Ru (Δγ /v2 )Zr , is naively expected to be …
Exclusive J/Ψ, Ψ(2s), And E+E− Pair Production In Au + Au Ultraperipheral Collisions At The Bnl Relativistic Heavy Ion Collider, Star Collaboration
Exclusive J/Ψ, Ψ(2s), And E+E− Pair Production In Au + Au Ultraperipheral Collisions At The Bnl Relativistic Heavy Ion Collider, Star Collaboration
Physics and Astronomy Faculty Publications
Measurements of exclusive J/ψ, ψ (2s), and electron-positron (e+e−) pair photoproduction in Au + Au ultraperipheral collisions are reported by the STAR experiment at √sNN = 200 GeV. We report several first measurements at the BNL Relativistic Heavy Ion Collider, which are (i) J/ψ photoproduction with large momentum transfer up to 2.2 (GeV/c)2 , (ii) coherent J/ψ photoproduction associated with neutron emissions from nuclear breakup, (iii) the rapidity dependence of incoherent J/ψ photoproduction, (iv) the ψ (2s) photoproduction cross section at midrapidity, and (v) e+e− pair photoproduction up to high invariant mass of 6 GeV/c2 . For measurement (ii), the …
Jet-Hadron Correlations With Respect To The Event Plane In √S Nn = 200 Gev Au + Au Collisions In Star, Star Collaboration
Jet-Hadron Correlations With Respect To The Event Plane In √S Nn = 200 Gev Au + Au Collisions In Star, Star Collaboration
Physics and Astronomy Faculty Publications
Angular distributions of charged particles relative to jet axes are studied in √s NN = 200 GeV Au+Au collisions as a function of the jet orientation with respect to the event plane. This differential study tests the expected path-length dependence of energy loss experienced by a hard-scattered parton as it traverses the hot and dense medium formed in heavy-ion collisions. A second-order event plane is used in the analysis as an experimental estimate of the reaction plane formed by the collision impact parameter and the beam direction. Charged-particle jets with 15 < pT,jet < 20 and 20 < pT,jet < 40 GeV/c were reconstructed with the anti-kT algorithm with radius parameter setting of R = 0.4 in the 20–50% centrality bin to maximize the initial-state eccentricity of the interaction region. The reaction plane fit method is implemented to remove the flow-modulated background with better precision than prior methods. Yields and widths of jet-associated charged-hadron distributions are extracted in three angular bins between the jet axis and the event plane. The event-plane (EP) dependence is further quantified by ratios of the associated yields in different EP bins. No dependence on orientation of the jet axis with respect to the event plane is seen within the uncertainties in the kinematic regime studied. This finding is consistent with a similar experimental observation by ALICE in √s NN = 2.76 TeV Pb-Pb collision data.
Measurements Of Charged-Particle Multiplicity Dependence Of Higher-Order Net-Proton Cumulants In 𝑝+𝑝 Collisions At √𝑠 = 200 Gev From Star At Rhic, Star Collaboration
Measurements Of Charged-Particle Multiplicity Dependence Of Higher-Order Net-Proton Cumulants In 𝑝+𝑝 Collisions At √𝑠 = 200 Gev From Star At Rhic, Star Collaboration
Physics and Astronomy Faculty Publications
We report on the charged-particle multiplicity dependence of net-proton cumulant ratios up to sixth order from√𝑠 = 200 GeV 𝑝+𝑝 collisions at the Relativistic Heavy Ion Collider (RHIC). The measured ratios 𝐶4 ∕𝐶2, 𝐶5 ∕𝐶1, and 𝐶6 ∕𝐶2 decrease with increased charged-particle multiplicity and rapidity acceptance. Neither the Skellam baselines nor PYTHIA8 calculations account for the observed multiplicity dependence. In addition, the ratios 𝐶5 ∕𝐶1 and 𝐶6 ∕𝐶2 approach negative values in the highest-multiplicity events, which implies that thermalized QCD matter may be formed in 𝑝+𝑝 collisions.
Measurements Of The 𝑍0 ∕𝛾∗ Cross Section And Transverse Single Spin Asymmetry In 510 Gev 𝑝+𝑝 Collisions, The Star Collaboration
Measurements Of The 𝑍0 ∕𝛾∗ Cross Section And Transverse Single Spin Asymmetry In 510 Gev 𝑝+𝑝 Collisions, The Star Collaboration
Physics and Astronomy Faculty Publications
The differential cross section for 𝑍0 production, measured as a function of the boson’s transverse momentum (𝑝T), provides important constraints on the evolution of the transverse momentum dependent parton distribution functions (TMDs). The transverse single spin asymmetry (TSSA) of the 𝑍0 is sensitive to one of the polarized TMDs, the Sivers function, which is predicted to have the opposite sign in 𝑝 + 𝑝 → 𝑊 ∕𝑍 + 𝑋 from that which enters in semi-inclusive deep inelastic scattering. In this Letter, the STAR Collaboration reports the first measurement of the 𝑍0 ∕𝛾∗ differential cross section as a function of its …
Measurement Of Flow Coefficients In High-Multiplicity P + Au, D + Au, And 3 He + Au Collisions At √S Nn = 200 Gev, Star Collaboration
Measurement Of Flow Coefficients In High-Multiplicity P + Au, D + Au, And 3 He + Au Collisions At √S Nn = 200 Gev, Star Collaboration
Physics and Astronomy Faculty Publications
Flow coefficients (v2 and v3 ) are measured in high-multiplicity p + Au, d + Au, and 3 He + Au collisions at a center-of-mass energy of √s NN = 200 GeV using the STAR detector. The measurements utilize two-particle correlations with a pseudorapidity requirement of |η| < 0.9 and a pair gap of |Δη| > 1.0. The primary focus is on analysis methods, particularly the subtraction of nonflow contributions. Four established nonflow subtraction methods are applied to determine vn, validated using the HIJING event generator. vn values are compared across the three collision systems at similar multiplicities; this comparison cancels the final-state effects and isolates the …
Reaction Plane Correlated Triangular Flow In Au+Au Collisions At √S Nn = 3 Gev, Star Collaboration
Reaction Plane Correlated Triangular Flow In Au+Au Collisions At √S Nn = 3 Gev, Star Collaboration
Physics and Astronomy Faculty Publications
We measure triangular flow relative to the reaction plane at 3 GeV center-of-mass energy in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. A significant v3 signal for protons is observed, which increases for higher rapidity, higher transverse momentum, and more peripheral collisions. The triangular flow is essentially rapidity-odd with a slope at midrapidity, dv3/dy|(y=0), opposite in sign compared to the slope for directed flow. No significant v3 signal is observed for charged pions and kaons. Comparisons with models suggest that a mean field potential is required to describe these results, and that the triangular shape of the participant …
Results On Elastic Cross Sections In Proton–Proton Collisions At √𝑠 = 510 Gev With The Star Detector At Rhic, The Star Collaboration
Results On Elastic Cross Sections In Proton–Proton Collisions At √𝑠 = 510 Gev With The Star Detector At Rhic, The Star Collaboration
Physics and Astronomy Faculty Publications
We report results on an elastic cross section measurement in proton–proton collisions at a center-of-mass energy√𝑠 = 510 GeV, obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section is measured in the four-momentum transfer squared range 0.23 ≤ −𝑡 ≤ 0.67 GeV2. This is the only measurement of the proton-proton elastic cross section in this 𝑡 range for collision energies above the Intersecting Storage Rings (ISR) and below the Large Hadron Collider (LHC) colliders. We find that a constant slope 𝐵 does not fit the data in …
Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At The Relativistic Heavy-Ion Collider, Star Collaboration
Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At The Relativistic Heavy-Ion Collider, Star Collaboration
Physics and Astronomy Faculty Publications
The chiral magnetic effect (CME) is a phenomenon that arises from the QCD anomaly in the presence of an external magnetic field. The experimental search for its evidence has been one of the key goals of the physics program of the Relativistic Heavy-Ion Collider. The STAR Collaboration has previously presented the results of a blind analysis of isobar collisions (96 44 Ru + 96 44 Ru, 96 40 Zr + 96 40 Zr) in the search for the CME. The isobar ratio (Y ) of CME-sensitive observable, charge separation scaled by elliptic anisotropy, is close to but systematically larger than …