Author: "Borowski A" / Publication Type: Reports - Searchworks@Jio Institute Digital Library Search Results

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1. Rapid Mid-Infrared Spectral-Timing with JWST. I. The prototypical black hole X-ray Binary GRS 1915+105 during a MIR-bright and X-ray-obscured state

Author: Gandhi, P., Borowski, E. S., Byrom, J., Hynes, R. I., Maccarone, T. J., Shaw, A. W., Adegoke, O. K., Altamirano, D., Baglio, M. C., Bhargava, Y., Britt, C. T., Buckley, D. A. H., Buisson, D. J. K., Casella, P., Segura, N. Castro, Charles, P. A., Corral-Santana, J. M., Dhillon, V. S., Fender, R., Gúrpide, A., Heinke, C. O., Igl, A. B., Knigge, C., Markoff, S., Mastroserio, G., McCollough, M. L., Middleton, M., Miller, J. M., Miller-Jones, J. C. A., Motta, S. E., Paice, J. A., Pawar, D. D., Plotkin, R. M., Pradhan, P., Ressler, M. E., Russell, D. M., Russell, T. D., Santos-Sanz, P., Shahbaz, T., Sivakoff, G. R., Steeghs, D., Tetarenko, A. J., Tomsick, J. A., Vincentelli, F. M., George, M., Gurwell, M., and Rao, R.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract: We present mid-infrared (MIR) spectral-timing measurements of the prototypical Galactic microquasar GRS 1915+105. The source was observed with the Mid-Infrared Instrument (MIRI) onboard JWST in June 2023 at a MIR luminosity L(MIR)~10^{36} erg/s exceeding past IR levels by about a factor of 10. By contrast, the X-ray flux is much fainter than the historical average, in the source's now-persistent 'obscured' state. The MIRI low-resolution spectrum shows a plethora of emission lines, the strongest of which are consistent with recombination in the hydrogen Pfund (Pf) series and higher. Low amplitude (~1%) but highly significant peak-to-peak photometric variability is found on timescales of ~1,000 s. The brightest Pf(6-5) emission line lags the continuum. Though difficult to constrain accurately, this lag is commensurate with light-travel timescales across the outer accretion disc or with expected recombination timescales inferred from emission line diagnostics. Using the emission line as a bolometric indicator suggests a moderate (~5-30% Eddington) intrinsic accretion rate. Multiwavelength monitoring shows that JWST caught the source close in-time to unprecedentedly bright MIR and radio long-term flaring. Assuming a thermal bremsstrahlung origin for the MIRI continuum suggests an unsustainably high mass-loss rate during this time unless the wind remains bound, though other possible origins cannot be ruled out. PAH features previously detected with Spitzer are now less clear in the MIRI data, arguing for possible destruction of dust in the interim. These results provide a preview of new parameter space for exploring MIR spectral-timing in XRBs and other variable cosmic sources on rapid timescales., Comment: Dedicated to the memory of our colleague, Tomaso Belloni. Submitted 2024 June 21; Comments welcome
Published: 2024

2. scg-cli -- a Tool Supporting Software Comprehension via Extraction and Analysis of Semantic Code Graph

Author: Borowski, Krzysztof and Baliś, Bartosz
Subjects: Computer Science - Software Engineering
Abstract: We present scg-cli, a~command line tool facilitating software comprehension. The tool extracts semantic information about code structure and dependencies from the Java and Scala projects, and structures it as a~Semantic Code Graph (SCG), an information model underlying scg-cli. The SCG data, once written into a~portable, open protobuf-based format, can be used by the scg-cli command line tool to obtain project metrics, find the most critical code entities, and compute project partitionings. The results of this analysis and the SCG data can be exported for further investigation by external tools such as Gephi software (visualization) and, notably, as a Jupyter Notebook environment with helper APIs to enable advanced analysis of the project using data analytics methods. We explain functionalities of the scg-cli tool and demonstrate its capabilities by showing an example analysis of an open-source Java project commons-io.
Published: 2023

3. Semantic Code Graph -- an information model to facilitate software comprehension

Author: Borowski, Krzysztof, Baliś, Bartosz, and Orzechowski, Tomasz
Subjects: Computer Science - Software Engineering
Abstract: Software comprehension can be extremely time-consuming due to the ever-growing size of codebases. Consequently, there is an increasing need to accelerate the code comprehension process to facilitate maintenance and reduce associated costs. A crucial aspect of this process is understanding and preserving the high quality of the code dependency structure. While a variety of code structure models already exist, there is a surprising lack of models that closely represent the source code and focus on software comprehension. As a result, there are no readily available and easy-to-use tools to assist with dependency comprehension, refactoring, and quality monitoring of code. To address this gap, we propose the Semantic Code Graph (SCG), an information model that offers a detailed abstract representation of code dependencies with a close relationship to the source code. To validate the SCG model's usefulness in software comprehension, we compare it to nine other source code representation models. Additionally, we select 11 well-known and widely-used open-source projects developed in Java and Scala and perform a range of software comprehension activities on them using three different code representation models: the proposed SCG, the Call Graph (CG), and the Class Collaboration Network (CCN). We then qualitatively analyze the results to compare the performance of these models in terms of software comprehension capabilities. These activities encompass project structure comprehension, identifying critical project entities, interactive visualization of code dependencies, and uncovering code similarities through software mining. Our findings demonstrate that the SCG enhances software comprehension capabilities compared to the prevailing CCN and CG models. We believe that the work described is a step towards the next generation of tools that streamline code dependency comprehension and management.
Published: 2023
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4. Absence and presence of Lavrentiev's phenomenon for double phase functionals upon every choice of exponents

Author: Borowski, Michał, Chlebicka, Iwona, De Filippis, Filomena, and Miasojedow, Błażej
Subjects: Mathematics - Analysis of PDEs
Abstract: We study classes of weights ensuring the absence and presence of the Lavrentiev's phenomenon for double phase functionals upon every choice of exponents. We introduce a new sharp scale for weights for which there is no Lavrentiev's phenomenon up to a counterexample we provide. This scale embraces the sharp range for $\alpha$-H\"older continuous weights. Moreover, it allows excluding the gap for every choice of exponents $q,p>1$.
Published: 2023

5. Absence of Lavrentiev's gap for anisotropic functionals

Author: Borowski, Michał, Chlebicka, Iwona, and Miasojedow, Błażej
Subjects: Mathematics - Analysis of PDEs, Mathematics - Functional Analysis, 46E30
Abstract: We establish the absence of the Lavrentiev gap between Sobolev and smooth maps for a non-autonomous variational problem of a general structure, where the integrand is assumed to be controlled by a function which is convex and anisotropic with respect to the last variable. This fact results from new results on good approximation properties of the natural underlying unconventional function space. Scalar and vector-valued problems are studied.
Published: 2022

6. Boundedness of Wolff-type potentials and applications to PDEs

Author: Borowski, Michał, Chlebicka, Iwona, and Miasojedow, Błażej
Subjects: Mathematics - Analysis of PDEs
Abstract: We provide a short proof of a sharp rearrangement estimate for a generalized version of a potential of Wolff--Havin--Maz'ya type. As a consequence, we prove a reduction principle for that integral operators, that is, a characterization of those rearrangement invariant spaces between which the potentials are bounded via a one-dimensional inequality of Hardy-type. Since the special case of the mentioned potential is known to control precisely very weak solutions to a broad class of quasilinear elliptic PDEs of non-standard growth, we infer the local regularity properties of the solutions in rearrangement invariant spaces for prescribed classes of data.
Published: 2022

7. Does ridesourcing respond to unplanned rail disruptions? A natural experiment analysis of mobility resilience and disparity

Author: Borowski, Elisa, Soria, Jason, Schofer, Joseph, and Stathopoulos, Amanda
Subjects: Physics - Physics and Society, Statistics - Applications
Abstract: Urban rail transit networks provide critical access to opportunities and livelihood in many urban systems. Ensuring that these services are resilient (that is, exhibiting efficient response to and recovery from disruptions) is a key economic and social priority. Increasingly, the ability of urban rail systems to cope with disruptions is a function of a complex patchwork of mobility options, wherein alternative modes can complement and fill service gaps. This study analyzes the role of ridesourcing in providing adaptive mobility capacity that could be leveraged to fill no-notice gaps in rail transit services, addressing the question of distributional impacts of resilience. Using a natural experiment, we systematically identify 28 major transit disruptions over the period of one year in Chicago and match them, both temporally and spatially, with ridesourcing trip data. Using multilevel mixed modeling, we quantify variation in the adaptive use of on-demand mobility across the racially and economically diverse city of Chicago. Our findings show that the gap-filling potential of adaptive ridesourcing during rail transit disruptions is significantly influenced by station-, community-, and district-level factors. Specifically, greater shifts to ridesourcing occur during weekdays, nonholidays, and more severe disruptions, in community areas that have higher percentages of White residents and transit commuters, and in the more affluent North district of the city. These findings suggest that while ridesourcing appears to provide adaptive capacity during rail disruptions, its benefits do not appear to be equitable for lower-income communities of color that already experience limited mobility options., Comment: 20 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:2010.15889
Published: 2022

8. Protection or Peril of Following the Crowd in a Pandemic-Concurrent Flood Evacuation

Author: Borowski, Elisa and Stathopoulos, Amanda
Subjects: Economics - Econometrics, Statistics - Applications
Abstract: The decisions of whether and how to evacuate during a climate disaster are influenced by a wide range of factors, including sociodemographics, emergency messaging, and social influence. Further complexity is introduced when multiple hazards occur simultaneously, such as a flood evacuation taking place amid a viral pandemic that requires physical distancing. Such multi-hazard events can necessitate a nuanced navigation of competing decision-making strategies wherein a desire to follow peers is weighed against contagion risks. To better understand these nuances, we distributed an online survey during a pandemic surge in July 2020 to 600 individuals in three midwestern and three southern states in the United States with high risk of flooding. In this paper, we estimate a random parameter logit model in both preference space and willingness-to-pay space. Our results show that the directionality and magnitude of the influence of peers' choices of whether and how to evacuate vary widely across respondents. Overall, the decision of whether to evacuate is positively impacted by peer behavior, while the decision of how to evacuate is negatively impacted by peers. Furthermore, an increase in flood threat level lessens the magnitude of these impacts. These findings have important implications for the design of tailored emergency messaging strategies. Specifically, emphasizing or deemphasizing the severity of each threat in a multi-hazard scenario may assist in: (1) encouraging a reprioritization of competing risk perceptions and (2) magnifying or neutralizing the impacts of social influence, thereby (3) nudging evacuation decision-making toward a desired outcome., Comment: 31 pages, 7 figures
Published: 2022

9. Controlling monotonicity of nonlinear operators

Author: Borowski, Michał and Chlebicka, Iwona
Subjects: Mathematics - Analysis of PDEs
Abstract: Controlling the monotonicity and growth of Leray--Lions' operators including the $p$-Laplacian plays a fundamental role in the theory of existence and regularity of solutions to second order nonlinear PDE. We collect, correct, and supply known estimates including the discussion on the constants. Moreover, we provide a comprehensive treatment of related results for operators with Orlicz growth. We pay special attention to exposition of the proofs and the use of elementary arguments.
Published: 2021

10. Interactive Analysis of CNN Robustness

Author: Sietzen, Stefan, Lechner, Mathias, Borowski, Judy, Hasani, Ramin, and Waldner, Manuela
Subjects: Computer Science - Computer Vision and Pattern Recognition, Computer Science - Artificial Intelligence, Computer Science - Human-Computer Interaction
Abstract: While convolutional neural networks (CNNs) have found wide adoption as state-of-the-art models for image-related tasks, their predictions are often highly sensitive to small input perturbations, which the human vision is robust against. This paper presents Perturber, a web-based application that allows users to instantaneously explore how CNN activations and predictions evolve when a 3D input scene is interactively perturbed. Perturber offers a large variety of scene modifications, such as camera controls, lighting and shading effects, background modifications, object morphing, as well as adversarial attacks, to facilitate the discovery of potential vulnerabilities. Fine-tuned model versions can be directly compared for qualitative evaluation of their robustness. Case studies with machine learning experts have shown that Perturber helps users to quickly generate hypotheses about model vulnerabilities and to qualitatively compare model behavior. Using quantitative analyses, we could replicate users' insights with other CNN architectures and input images, yielding new insights about the vulnerability of adversarially trained models., Comment: Accepted at Pacific Graphics 2021
Published: 2021

11. How Well do Feature Visualizations Support Causal Understanding of CNN Activations?

Author: Zimmermann, Roland S., Borowski, Judy, Geirhos, Robert, Bethge, Matthias, Wallis, Thomas S. A., and Brendel, Wieland
Subjects: Computer Science - Computer Vision and Pattern Recognition, Computer Science - Artificial Intelligence, Computer Science - Human-Computer Interaction, Computer Science - Machine Learning
Abstract: A precise understanding of why units in an artificial network respond to certain stimuli would constitute a big step towards explainable artificial intelligence. One widely used approach towards this goal is to visualize unit responses via activation maximization. These synthetic feature visualizations are purported to provide humans with precise information about the image features that cause a unit to be activated - an advantage over other alternatives like strongly activating natural dataset samples. If humans indeed gain causal insight from visualizations, this should enable them to predict the effect of an intervention, such as how occluding a certain patch of the image (say, a dog's head) changes a unit's activation. Here, we test this hypothesis by asking humans to decide which of two square occlusions causes a larger change to a unit's activation. Both a large-scale crowdsourced experiment and measurements with experts show that on average the extremely activating feature visualizations by Olah et al. (2017) indeed help humans on this task ($68 \pm 4$% accuracy; baseline performance without any visualizations is $60 \pm 3$%). However, they do not provide any substantial advantage over other visualizations (such as e.g. dataset samples), which yield similar performance ($66\pm3$% to $67 \pm3$% accuracy). Taken together, we propose an objective psychophysical task to quantify the benefit of unit-level interpretability methods for humans, and find no evidence that a widely-used feature visualization method provides humans with better "causal understanding" of unit activations than simple alternative visualizations., Comment: Presented at NeurIPS 2021. Shared first and last authorship. Project website at https://brendel-group.github.io/causal-understanding-via-visualizations/
Published: 2021

12. Disparities in ridesourcing demand for mobility resilience: A multilevel analysis of neighborhood effects in Chicago, Illinois

Author: Borowski, Elisa, Soria, Jason, Schofer, Joseph, and Stathopoulos, Amanda
Subjects: Physics - Physics and Society, Economics - General Economics, Statistics - Applications
Abstract: Mobility resilience refers to the ability of individuals to complete their desired travel despite unplanned disruptions to the transportation system. The potential of new on-demand mobility options, such as ridesourcing services, to fill unpredicted gaps in mobility is an underexplored source of adaptive capacity. Applying a natural experiment approach to newly released ridesourcing data, we examine variation in the gap-filling role of on-demand mobility during sudden shocks to a transportation system by analyzing the change in use of ridesourcing during unexpected rail transit service disruptions across the racially and economically diverse city of Chicago. Using a multilevel mixed model, we control not only for the immediate station attributes where the disruption occurs, but also for the broader context of the community area and city quadrant in a three-level structure. Thereby the unobserved variability across neighborhoods can be associated with differences in factors such as transit ridership, or socio-economic status of residents, in addition to controlling for station level effects. Our findings reveal that individuals use ridesourcing as a gap-filling mechanism during rail transit disruptions, but there is strong variation across situational and locational contexts. Specifically, our results show larger increases in transit disruption responsive ridesourcing during weekdays, nonholidays, and more severe disruptions, as well as in community areas that have higher percentages of White residents and transit commuters, and on the more affluent northside of the city. These findings point to new insights with far-reaching implications on how ridesourcing complements existing transport networks by providing added capacity during disruptions but does not appear to bring equitable gap-filling benefits to low-income communities of color that typically have more limited mobility options.
Published: 2020

13. Exemplary Natural Images Explain CNN Activations Better than State-of-the-Art Feature Visualization

Author: Borowski, Judy, Zimmermann, Roland S., Schepers, Judith, Geirhos, Robert, Wallis, Thomas S. A., Bethge, Matthias, and Brendel, Wieland
Subjects: Computer Science - Computer Vision and Pattern Recognition, Computer Science - Artificial Intelligence, Computer Science - Human-Computer Interaction, Computer Science - Machine Learning
Abstract: Feature visualizations such as synthetic maximally activating images are a widely used explanation method to better understand the information processing of convolutional neural networks (CNNs). At the same time, there are concerns that these visualizations might not accurately represent CNNs' inner workings. Here, we measure how much extremely activating images help humans to predict CNN activations. Using a well-controlled psychophysical paradigm, we compare the informativeness of synthetic images by Olah et al. (2017) with a simple baseline visualization, namely exemplary natural images that also strongly activate a specific feature map. Given either synthetic or natural reference images, human participants choose which of two query images leads to strong positive activation. The experiments are designed to maximize participants' performance, and are the first to probe intermediate instead of final layer representations. We find that synthetic images indeed provide helpful information about feature map activations ($82\pm4\%$ accuracy; chance would be $50\%$). However, natural images - originally intended as a baseline - outperform synthetic images by a wide margin ($92\pm2\%$). Additionally, participants are faster and more confident for natural images, whereas subjective impressions about the interpretability of the feature visualizations are mixed. The higher informativeness of natural images holds across most layers, for both expert and lay participants as well as for hand- and randomly-picked feature visualizations. Even if only a single reference image is given, synthetic images provide less information than natural images ($65\pm5\%$ vs. $73\pm4\%$). In summary, synthetic images from a popular feature visualization method are significantly less informative for assessing CNN activations than natural images. We argue that visualization methods should improve over this baseline., Comment: Published at ICLR 2021. Joint first and last authors. Code is available at https://bethgelab.github.io/testing_visualizations/
Published: 2020

14. NWChem: Past, Present, and Future

Author: Aprà, E., Bylaska, E. J., de Jong, W. A., Govind, N., Kowalski, K., Straatsma, T. P., Valiev, M., van Dam, H. J. J., Alexeev, Y., Anchell, J., Anisimov, V., Aquino, F. W., Atta-Fynn, R., Autschbach, J., Bauman, N. P., Becca, J. C., Bernholdt, D. E., Bhaskaran-Nair, K., Bogatko, S., Borowski, P., Boschen, J., Brabec, J., Bruner, A., Cauët, E., Chen, Y., Chuev, G. N., Cramer, C. J., Daily, J., Deegan, M. J. O., Dunning Jr., T. H., Dupuis, M., Dyall, K. G., Fann, G. I., Fischer, S. A., Fonari, A., Früuchtl, H., Gagliardi, L., Garza, J., Gawande, N., Ghosh, S., Glaesemann, K., Götz, A. W., Hammond, J., Helms, V., Hermes, E. D., Hirao, K., Hirata, S., Jacquelin, M., Jensen, L., Johnson, B. G., Jónsson, H., Kendall, R. A., Klemm, M., Kobayashi, R., Konkov, V., Krishnamoorthy, S., Krishnan, M., Lin, Z., Lins, R. D., Littlefield, R. J., Logsdail, A. J., Lopata, K., Ma, W., Marenich, A. V., del Campo, J. Martin, Mejia-Rodriguez, D., Moore, J. E., Mullin, J. M., Nakajima, T., Nascimento, D. R., Nichols, J. A., Nichols, P. J., Nieplocha, J., de la Roza, A. Otero, Palmer, B., Panyala, A., Pirojsirikul, T., Peng, B., Peverati, R., Pittner, J., Pollack, L., Richard, R. M., Sadayappan, P., Schatz, G. C., Shelton, W. A., Silverstein, D. W., Smith, D. M. A., Soares, T. A., Song, D., Swart, M., Taylor, H. L., Thomas, G. S., Tipparaju, V., Truhlar, D. G., Tsemekhman, K., Van Voorhis, T., Vázquez-Mayagoitia, Á., Verma, P., Villa, O., Vishnu, A., Vogiatzis, K. D., Wang, D., Weare, J. H., Williamson, M. J., Windus, T. L., Woliński, K., Wong, A. T., Wu, Q., Yang, C., Yu, Q., Zacharias, M., Zhang, Z., Zhao, Y., and Harrison, R. J.
Subjects: Physics - Chemical Physics, Physics - Computational Physics
Abstract: Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principledriven methodologies to model complex chemical and materials processes. Over the last few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach and outlook., Comment: This article appeared in volume 152, issue 18, page 184102 of the Journal of Chemical Physics. It can be found at https://doi.org/10.1063/5.0004997
Published: 2020
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15. Five Points to Check when Comparing Visual Perception in Humans and Machines

Author: Funke, Christina M., Borowski, Judy, Stosio, Karolina, Brendel, Wieland, Wallis, Thomas S. A., and Bethge, Matthias
Subjects: Computer Science - Computer Vision and Pattern Recognition, Computer Science - Artificial Intelligence, Computer Science - Machine Learning, Quantitative Biology - Neurons and Cognition, Statistics - Machine Learning
Abstract: With the rise of machines to human-level performance in complex recognition tasks, a growing amount of work is directed towards comparing information processing in humans and machines. These studies are an exciting chance to learn about one system by studying the other. Here, we propose ideas on how to design, conduct and interpret experiments such that they adequately support the investigation of mechanisms when comparing human and machine perception. We demonstrate and apply these ideas through three case studies. The first case study shows how human bias can affect how we interpret results, and that several analytic tools can help to overcome this human reference point. In the second case study, we highlight the difference between necessary and sufficient mechanisms in visual reasoning tasks. Thereby, we show that contrary to previous suggestions, feedback mechanisms might not be necessary for the tasks in question. The third case study highlights the importance of aligning experimental conditions. We find that a previously-observed difference in object recognition does not hold when adapting the experiment to make conditions more equitable between humans and machines. In presenting a checklist for comparative studies of visual reasoning in humans and machines, we hope to highlight how to overcome potential pitfalls in design or inference., Comment: V3: minor changes like in published JOV version (https://doi.org/10.1167/jov.21.3.16) V2: New title; added general section (checklist); manuscript restructured such that each case study is one chapter; adversarial examples in first study replaced by different analysis
Published: 2020
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16. Comprehensive procedure for personalized dosimetry in computed tomography

Author: Rosendahl, Stephan, Büermann, Ludwig, Borowski, Markus, Kortesniemi, Mika, Kosunen, Antti, Siiskonen, Teemu, and Sundell, Veli-Matti
Subjects: Physics - Medical Physics
Abstract: The purpose of this work is to develop viable procedures for verifying the applicability of personalized dosimetry in computed tomography (CT) using Monte Carlo-based simulations. Mobile equipment together with customized software was developed and used for rapid, non-invasive determination of equivalent source models of CT scanners under clinical conditions. Standard and anthropomorphic CT dose phantoms equipped with real-time CT dose probes at five representative positions were scanned. The accumulated dose was measured during the scan at the five positions. ImpactMC, a Monte Carlo-based CT dose software program, was used to simulate the scan. The necessary inputs were obtained from the scan parameters, from the equivalent source models and from the material-segmented CT images of the phantoms. Post-scan 3D dose distributions in the phantoms were simulated and the dose values calculated at the five positions inside the phantom were compared to measured dose values. Initial results were obtained by means of a General Electric Optima CT 660 and a Toshiba (Canon) Aquilion ONE. In general, the measured and calculated dose values were within relative uncertainties that had been estimated to be less than 10%. The procedures developed, which allow the post-CT scan dose to be measured and calculated at five points inside anthropomorphic phantoms, were found to be viable and rapid. The procedures are applicable to any scanner type under clinical conditions. Results show that the procedures are well suited for verifying the applicability of personalized CT dosimetry based on post-scan Monte Carlo calculations.
Published: 2018

17. Security Against Impersonation Attacks in Distributed Systems

Author: Brown, Philip N., Borowski, Holly, and Marden, Jason R.
Subjects: Computer Science - Computer Science and Game Theory, Computer Science - Cryptography and Security, Computer Science - Multiagent Systems, Computer Science - Systems and Control
Abstract: In a multi-agent system, transitioning from a centralized to a distributed decision-making strategy can introduce vulnerability to adversarial manipulation. We study the potential for adversarial manipulation in a class of graphical coordination games where the adversary can pose as a friendly agent in the game, thereby influencing the decision-making rules of a subset of agents. The adversary's influence can cascade throughout the system, indirectly influencing other agents' behavior and significantly impacting the emergent collective behavior. The main results in this paper focus on characterizing conditions under which the adversary's local influence can dramatically impact the emergent global behavior, e.g., destabilize efficient Nash equilibria.
Published: 2017

18. Are Multiagent Systems Resilient to Communication Failures?

Author: Brown, Philip N., Borowski, Holly P., and Marden, Jason R.
Subjects: Computer Science - Computer Science and Game Theory, Computer Science - Multiagent Systems, Computer Science - Systems and Control, Mathematics - Optimization and Control
Abstract: A challenge in multiagent control systems is to ensure that they are appropriately resilient to communication failures between the various agents. In many common game-theoretic formulations of these types of systems, it is implicitly assumed that all agents have access to as much information about other agents' actions as needed. This paper endeavors to augment these game-theoretic methods with policies that would allow agents to react on-the-fly to losses of this information. Unfortunately, we show that even if a single agent loses communication with one other weakly-coupled agent, this can cause arbitrarily-bad system states to emerge as various solution concepts of an associated game, regardless of how the agent accounts for the communication failure and regardless of how weakly coupled the agents are. Nonetheless, we show that the harm that communication failures can cause is limited by the structure of the problem; when agents' action spaces are richer, problems are more susceptible to these types of pathologies. Finally, we undertake an initial study into how a system designer might prevent these pathologies, and explore a few limited settings in which communication failures cannot cause harm.
Published: 2017

19. Learning Efficient Correlated Equilibria

Author: Borowski, Holly P., Marden, Jason R., and Shamma, Jeff S.
Subjects: Computer Science - Computer Science and Game Theory
Abstract: The majority of distributed learning literature focuses on convergence to Nash equilibria. Correlated equilibria, on the other hand, can often characterize more efficient collective behavior than even the best Nash equilibrium. However, there are no existing distributed learning algorithms that converge to specific correlated equilibria. In this paper, we provide one such algorithm which guarantees that the agents' collective joint strategy will constitute an efficient correlated equilibrium with high probability. The key to attaining efficient correlated behavior through distributed learning involves incorporating a common random signal into the learning environment., Comment: 11 pages, 1 figure
Published: 2015

20. Fast Convergence in Semi-Anonymous Potential Games

Author: Borowski, Holly and Marden, Jason
Subjects: Computer Science - Computer Science and Game Theory
Abstract: Log-linear learning has been extensively studied in both the game theoretic and distributed control literature. It is appealing for many applications because it often guarantees that the agents' collective behavior will converge in probability to the optimal system configuration. However, the worst case convergence time can be prohibitively long, i.e., exponential in the number of players. We formalize a modified log-linear learning algorithm whose worst case convergence time is roughly linear in the number of players. We prove this characterization for a class of potential games where agents' utility functions can be expressed as a function of aggregate behavior within a finite collection of populations. Finally, we show that the convergence time remains roughly linear in the number of players even when the players are permitted to enter and exit the game over time., Comment: 12 pages, 5 figures (including bio pictures)
Published: 2015

21. Isolation of Flow and Nonflow Correlations by Two- and Four-Particle Cumulant Measurements of Azimuthal Harmonics in $\sqrt{s_{_{\rm NN}}} =$ 200 GeV Au+Au Collisions

Author: Abdelwahab, N. M., Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderóndela Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Page, B. S., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simko, M., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: A data-driven method was applied to measurements of Au+Au collisions at $\sqrt{s_{_{\rm NN}}} =$ 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance $\Delta\eta$-dependent and $\Delta\eta$-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a component of the correlation that is $\Delta\eta$-independent, which is likely dominated by anisotropic flow and flow fluctuations. It was also found to be independent of $\eta$ within the measured range of pseudorapidity $|\eta|<1$. The relative flow fluctuation was found to be $34\% \pm 2\% (stat.) \pm 3\% (sys.)$ for particles of transverse momentum $p_{T}$ less than $2$ GeV/$c$. The $\Delta\eta$-dependent part may be attributed to nonflow correlations, and is found to be $5\% \pm 2\% (sys.)$ relative to the flow of the measured second harmonic cumulant at $|\Delta\eta| > 0.7$.
Published: 2014
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22. Charged-to-neutral correlation at forward rapidity in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV

Author: STAR Collaboration, Abdelwahab, N. M., Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Page, B. S., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simko, M., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Event-by-event fluctuations of the ratio of inclusive charged to photon multiplicities at forward rapidity in Au+Au collision at $\sqrt{s_{NN}}$=200 GeV have been studied. Dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidences of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as baselines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A non-zero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation due to particle decay. Results are compared to the expectations based on the generic production mechanism of pions due to isospin symmetry, for which no significant (<1%) deviation is observed., Comment: 14 pages, 6 figures
Published: 2014
Full Text: View/download PDF

23. Precision Measurement of the Longitudinal Double-spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at $\sqrt{s}=200$ GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bultmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sanchez, M. Calderon de la Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cudd, A. B., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L. -X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report a new high-precision measurement of the mid-rapidity inclusive jet longitudinal double-spin asymmetry, $A_{LL}$, in polarized $pp$ collisions at center-of-mass energy $\sqrt{s}=200$ GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep inelastic scattering (DIS), semi-inclusive DIS, and RHIC $pp$ data. The measured asymmetries provide evidence for positive gluon polarization in the Bjorken-$x$ region $x>0.05$., Comment: 7 pages, 3 figures
Published: 2014
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24. Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report measurements of single- and double- spin asymmetries for $W^{\pm}$ and $Z/\gamma^*$ boson production in longitudinally polarized $p+p$ collisions at $\sqrt{s} = 510$ GeV by the STAR experiment at RHIC. The asymmetries for $W^{\pm}$ were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the $W$ mass. The results are compared to theoretical predictions, constrained by recent polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range $0.05
Published: 2014
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25. Observation of $D^0$ meson nuclear modifications in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV

Author: Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report the first measurement of charmed-hadron ($D^0$) production via the hadronic decay channel ($D^0\rightarrow K^- + \pi^+$) in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200\,GeV with the STAR experiment. The charm production cross-section per nucleon-nucleon collision at mid-rapidity scales with the number of binary collisions, $N_{bin}$, from $p$+$p$ to central Au+Au collisions. The $D^0$ meson yields in central Au+Au collisions are strongly suppressed compared to those in $p$+$p$ scaled by $N_{bin}$, for transverse momenta $p_{T}>3$ GeV/$c$, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate $p_{T}$ is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements., Comment: 7 pages including author list, 4 figures, submit to PRL with revised version
Published: 2014
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26. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Local parity-odd domains are theorized to form inside a Quark-Gluon-Plasma (QGP) which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect (CME). The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this paper, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy, and tends to vanish by 7.7 GeV. The implications of these results for the CME will be discussed., Comment: 6 pages, 4 figures, accepted by Phys. Rev. Lett (more model comparisons have been added in version 2)
Published: 2014
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27. Beam energy dependent two-pion interferometry and the freeze-out eccentricity of pions in heavy ion collisions at STAR

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We present results of analyses of two-pion interferometry in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV measured in the STAR detector as part of the RHIC Beam Energy Scan program. The extracted correlation lengths (HBT radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass ($m_{T}$) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model., Comment: 27 pages; 27 figures
Published: 2014
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28. Beam-Energy Dependence of Directed Flow of Protons, Antiprotons and Pions in Au+Au Collisions

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Rapidity-odd directed flow($v_1$) measurements for charged pions, protons and antiprotons near mid-rapidity ($y=0$) are reported in $\sqrt{s_{NN}} =$ 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV Au + Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). At intermediate impact parameters, the proton and net-proton slope parameter $dv_1/dy|_{y=0}$ shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton $dv_1/dy|_{y=0}$ changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations., Comment: Post-referee version, accepted by PRL. Fig. 2 now includes panels for 62.4 and 200 GeV
Published: 2014
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29. Dielectron Mass Spectra from Au+Au Collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderóndze la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report the STAR measurements of dielectron ($e^+e^-$) production at midrapidity ($|y_{ee}|<$1) in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200\,GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 ($\rho$-like), 0.76-0.80 ($\omega$-like), and 0.98-1.05 ($\phi$-like) GeV/$c^{2}$. The spectrum in the $\omega$-like and $\phi$-like regions can be well described by the hadronic cocktail simulation. In the $\rho$-like region, however, the vacuum $\rho$ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77$\pm$0.11(stat.)$\pm$0.24(sys.)$\pm$0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the $\rho$ meson. The excess yield in the $\rho$-like region increases with the number of collision participants faster than the $\omega$ and $\phi$ yields. Theoretical models with broadened $\rho$ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.
Published: 2013
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30. Suppression of Upsilon Production in d+Au and Au+Au Collisions at sqrt(s_NN) = 200 GeV

Author: Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hill, K., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Peterson, A., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wimsatt, G., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report measurements of Upsilon meson production in p+p, d+Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p+p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon(1S+2S+3S) in the rapidity range |y|<1 in d+Au collisions of R_dAu = 0.79 +/- 0.24 (stat.) +/- 0.03 (sys.) +/- 0.10 (pp sys.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au+Au collisions, we measure a nuclear modification factor of R_AA=0.49 +/- 0.1 (stat.) +/- 0.02 (sys.) +/- 0.06 (pp sys.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au+Au collisions. The additional suppression in Au+Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark-Gluon Plasma. However, understanding the suppression seen in d+Au is still needed before any definitive statements about the nature of the suppression in Au+Au can be made., Comment: 13 pages, 7 figures
Published: 2013
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31. $J/\psi$ polarization in p+p collisions at $\sqrt{s}$ = 200 GeV in STAR

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report on a polarization measurement of inclusive $J/\psi$ mesons in the di-electron decay channel at mid-rapidity at 2 $
Published: 2013
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32. $J/\psi$ production at low $p_T$ in Au+Au and Cu+Cu collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV at STAR

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: The $\jpsi$ $\pt$ spectrum and nuclear modification factor ($\raa$) are reported for $\pt < 5 \ \gevc$ and $|y|<1$ from 0\% to 60\% central Au+Au and Cu+Cu collisions at $\snn = 200 \ \gev$ at STAR. A significant suppression of $\pt$-integrated $\jpsi$ production is observed in central Au+Au events. The Cu+Cu data are consistent with no suppression, although the precision is limited by the available statistics. $\raa$ in Au+Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with $\pt$. The data are compared to high-$\pt$ STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low $\pt$ are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration., Comment: 14 pages, 13 figures. Accepted by Phys. Rev. C
Published: 2013
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33. Energy Dependence of Moments of Net-proton Multiplicity Distributions at RHIC

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderóndela Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Peterson, A., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Lattice, High Energy Physics - Phenomenology, Nuclear Theory
Abstract: We report the beam energy (\sqrt s_{NN} = 7.7 - 200 GeV) and collision centrality dependence of the mean (M), standard deviation (\sigma), skewness (S), and kurtosis (\kappa) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y| < 0.5) and within the transverse momentum range 0.4 < pT < 0.8 GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the Quantum Chromodynamic (QCD) phase diagram. The products of the moments, S\sigma and \kappa\sigma^{2}, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and anti-proton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation, and also to a hadron resonance gas model., Comment: 7 pages and 4 figures
Published: 2013
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34. Neutral pion cross section and spin asymmetries at intermediate pseudorapidity in polarized proton collisions at sqrt{s} = 200 GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barber, B., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., He, W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Nord, P. M., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Peterson, A., Pile, P., Planinic, M., Pluta, J., Plyku, D., Pochron, W., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schaub, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8 < {\eta} < 2.0 in polarized proton-proton collisions at sqrt{s} = 200 GeV are presented. Neutral pions were detected using the endcap electromagnetic calorimeter in the STAR detector at RHIC. The cross section was measured over a transverse momentum range of 5 < p_T < 16 GeV/c and is found to be within the scale uncertainty of a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry, A_LL, is measured in the same pseudorapidity range. This quantity is sensitive to the gluonic contribution to the proton spin, {\Delta}g(x), at low Bjorken-x (down to x approx 0.01), where it is less constrained by measurements at central pseudorapidity. The measured A_LL is consistent with model predictions. The parity-violating asymmetry, A_L, is also measured and found to be consistent with zero. The transverse single-spin asymmetry, A_N, is measured within a previously unexplored kinematic range in Feynman-x and p_T. Such measurements may aid our understanding of the on-set and kinematic dependence of the large asymmetries observed at more forward pseudorapidity ({\eta} approx 3) and their underlying mechanisms. The A_N results presented are consistent with a twist-3 model prediction of a small asymmetry within the present kinematic range., Comment: 11 pages, 9 figures, REVTeX 4.1, Submitted to Phys. Rev. D. Changes for version 2: minor textual updates, modified discussion of gluonic polarization, clarified description of Fig. 4, and corrected sign convention in Fig. 8
Published: 2013
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35. Measurement of Charge Multiplicity Asymmetry Correlations in High Energy Nucleus-Nucleus Collisions at 200 GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Powell, C. B., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at 200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, $\Delta$, between the like- and unlike-sign up/down $-$ left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic $v^{\rm obs}_{2}$), where $\Delta=(1.3\pm1.4({\rm stat})^{+4.0}_{-1.0}({\rm syst}))\times10^{-5}+(3.2\pm0.2({\rm stat})^{+0.4}_{-0.3}({\rm syst}))\times10^{-3}v^{\rm obs}_{2}$ for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed., Comment: 27 pages, 25 figures, 2 tables
Published: 2013
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36. Jet-Hadron Correlations in sqrt{s_{NN}} = 200 GeV p+p and Central Au+Au Collisions

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at $\sqrt{s_{\text{NN}}} = 200 \text{GeV}$ in STAR are presented. The trigger jet population in Au+Au collisions is biased towards jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum ($p_{\text{T}}^{\text{assoc}}$) and enhanced at low $p_{\text{T}}^{\text{assoc}}$ in 0-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions., Comment: v2 is the version accepted by PRL
Published: 2013
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37. Fluctuations of charge separation perpendicular to the event plane and local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Previous experimental results based on data (15 million events) collected by the STAR detector at RHIC suggest event-by-event charge separation fluctuations perpendicular to the event plane in non-central heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high statistics 200 GeV Au+Au collisions data set (57 million events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same and opposite charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion., Comment: 10 pages, 9 figures
Published: 2013

38. Freeze-out Dynamics via Charged Kaon Femtoscopy in sqrt(sNN)=200 GeV Central Au+Au Collisions

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We present measurements of three-dimensional correlation functions of like-sign low transverse momentum kaon pairs from sqrt(sNN)=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass m_T over the interval of 0.55<=m_T<=1.15 GeV/c^2. While the kaon radii are adequately described by the m_T-scaling in the outward and sideward directions, in the longitudinal direction the lowest m_T value exceeds the expectations from a pure hydrodynamical model prediction., Comment: 8 pages, 4 figures
Published: 2013
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39. System size dependence of transverse momentum correlations at $\sqrt{s_{NN}}=$ 62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We present a study of the average transverse momentum ($p_t$) fluctuations and $p_t$ correlations for charged particles produced in Cu+Cu collisions at midrapidity for $\sqrt{s_{NN}} =$ 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the $p_t$ correlation results have been studied as functions of the collision centralities, the ranges in $p_t$, the pseudorapidity $\eta$, and the azimuthal angle $\phi$. The square root of the measured $p_t$ correlations when scaled by mean $p_t$ is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations., Comment: 12 pages and 9 figures. Published in Physical Review C
Published: 2013
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40. Observation of an energy-dependent difference in elliptic flow between particles and anti-particles in relativistic heavy ion collisions

Author: Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Elliptic flow ($v_{2}$) values for identified particles at mid-rapidity in Au+Au collisions, measured by the STAR experiment in the Beam Energy Scan at RHIC at $\sqrt{s_{NN}}=$ 7.7--62.4 GeV, are presented. A beam-energy dependent difference of the values of $v_{2}$ between particles and corresponding anti-particles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and anti-particles are not consistent with the universal number-of-constituent-quark (NCQ) scaling of $v_{2}$ that was observed at $\sqrt{s_{NN}}=$ 200 GeV.
Published: 2013
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41. Elliptic flow of identified hadrons in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7--62.4 GeV

Author: Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Measurements of the elliptic flow, $v_{2}$, of identified hadrons ($\pi^{\pm}$, $K^{\pm}$, $K_{s}^{0}$, $p$, $\bar{p}$, $\phi$, $\Lambda$, $\bar{\Lambda}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$) in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV are presented. The measurements were done at mid-rapidity using the Time Projection Chamber and the Time-of-Flight detectors of the STAR experiment during the Beam Energy Scan program at RHIC. A significant difference in the $v_{2}$ values for particles and the corresponding anti-particles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, $\sqrt{s_{NN}}$ (or increasing baryon chemical potential, $\mu_{B}$) and is larger for the baryons as compared to the mesons. This implies that particles and anti-particles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of $v_{2}$ that was observed at $\sqrt{s_{NN}}=$ 200 GeV. However, for the group of particles NCQ scaling at $(m_{T}-m_{0})/n_{q}>$ 0.4 GeV/$c^{2}$ is not violated within $\pm$10%. The $v_{2}$ values for $\phi$ mesons at 7.7 and 11.5 GeV are approximately two standard deviations from the trend defined by the other hadrons at the highest measured $p_{T}$ values.
Published: 2013
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42. Third Harmonic Flow of Charged Particles in Au+Au Collisions at sqrtsNN = 200 GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L. -X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I. -K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v_3, known as triangular flow. The analysis is for charged particles in Au+Au collisions at sqrtsNN = 200 GeV, based on data from the STAR experiment at the Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are reported as a function of transverse momentum and centrality. A large dependence on the pseudorapidity gap is found. Results are compared with other experiments and model calculations., Comment: 12 pages, 12 figures
Published: 2013
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43. Single Spin Asymmetry $A_N$ in Polarized Proton-Proton Elastic Scattering at $\sqrt{s}=200$ GeV

Author: STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report a high precision measurement of the transverse single spin asymmetry $A_N$ at the center of mass energy $\sqrt{s}=200$ GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The $A_N$ was measured in the four-momentum transfer squared $t$ range $0.003 \leqslant |t| \leqslant 0.035$ $\GeVcSq$, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of $A_N$ and its $t$-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this $\sqrt{s}$, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering., Comment: 12 pages, 6 figures
Published: 2012
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44. Transverse Single-Spin Asymmetry and Cross-Section for pi0 and eta Mesons at Large Feynman-x in Polarized p+p Collisions at sqrt(s)=200 GeV

Author: The STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Bannerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr, C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Measurements of the differential cross-section and the transverse single-spin asymmetry, A_N, vs. x_F for pi0 and eta mesons are reported for 0.4 < x_F < 0.75 at an average pseudorapidity of 3.68. A data sample of approximately 6.3 pb^{-1} was analyzed, which was recorded during p+p collisions at sqrt{s} = 200 GeV by the STAR experiment at RHIC. The average transverse beam polarization was 56%. The cross-section for pi0 is consistent with a perturbative QCD prediction, and the eta/pi0 cross-section ratio agrees with previous mid-rapidity measurements. For 0.55 < x_F < 0.75, A_N for eta (0.210 +- 0.056) is 2.2 standard deviations larger than A_N for pi0 (0.081 +- 0.016)., Comment: 7 pages, 5 figures, Submitted to Phys. Rev. D R.C
Published: 2012
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45. Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarized p+p collisions at sqrt{s}=200 GeV

Author: The STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kowalik, K., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Millane, J., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Sakuma, T., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Sarsour, M., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: We report STAR measurements of the longitudinal double-spin asymmetry A_LL, the transverse single-spin asymmetry A_N, and the transverse double-spin asymmetries A_Sigma and A_TT for inclusive jet production at mid-rapidity in polarized p+p collisions at a center-of-mass energy of sqrt{s} = 200 GeV. The data represent integrated luminosities of 7.6 /pb with longitudinal polarization and 1.8 /pb with transverse polarization, with 50-55% beam polarization, and were recorded in 2005 and 2006. No evidence is found for the existence of statistically significant jet A_N, A_Sigma, or A_TT at mid-rapidity. Recent model calculations indicate the A_N results may provide new limits on the gluon Sivers distribution in the proton. The asymmetry A_LL significantly improves the knowledge of gluon polarization in the nucleon., Comment: 18 pages, 16 figures, 8 tables
Published: 2012

46. Measurements of $D^{0}$ and $D^{*}$ Production in $p$ + $p$ Collisions at $\sqrt{s}$ = 200 GeV

Author: STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report measurements of charmed-hadron ($D^{0}$, $D^{*}$) production cross sections at mid-rapidity in $p$ + $p$ collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays $D^{0}\rightarrow K^{-}\pi^{+}$, $D^{*+}\rightarrow D^{0}\pi^{+}\rightarrow K^{-}\pi^{+}\pi^{+}$ and their charge conjugates, covering the $p_T$ range of 0.6$-$2.0 GeV/$c$ and 2.0$-$6.0 GeV/$c$ for $D^{0}$ and $D^{*+}$, respectively. From this analysis, the charm-pair production cross section at mid-rapidity is $d\sigma/dy|_{y=0}^{c\bar{c}}$ = 170 $\pm$ 45 (stat.) $^{+38}_{-59}$ (sys.) $\mu$b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a Fixed-Order Next-to-Leading Logarithm calculation., Comment: 15 pages, 16 figures. Revised version submitted to Phys. Rev. D
Published: 2012
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47. Di-electron spectrum at mid-rapidity in $p+p$ collisions at $\sqrt{s} = 200$ GeV

Author: Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report on mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via $e^{+}e^{-}$ decays, from $\sqrt{s} = 200$ GeV $p+p$ collisions, measured by the large acceptance experiment STAR at RHIC. The ratio of the di-electron continuum to the combinatorial background is larger than 10% over the entire mass range. Simulations of di-electrons from light-meson decays and heavy-flavor decays (charmonium and open charm correlation) are found to describe the data. The extracted $\omega\rightarrow e^{+}e^{-}$ invariant yields are consistent with previous measurements. The mid-rapidity yields ($dN/dy$) of $\phi$ and $J/\psi$ are extracted through their di-electron decay channels and are consistent with the previous measurements of $\phi\rightarrow K^{+}K^{-}$ and $J/\psi\rightarrow e^{+}e^{-}$. Our results suggest a new upper limit of the branching ratio of the $\eta \rightarrow e^{+}e^{-}$ of $1.7\times10^{-5}$ at 90% confidence level., Comment: 15 pages, 17 figures, 4 tables. Published
Published: 2012
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48. Measurement of the $W \to e \nu$ and $Z/\gamma^* \to e^+e^-$ Production Cross Sections at Mid-rapidity in Proton-Proton Collisions at $\sqrt{s}$ = 500 GeV

Author: STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Banerjee, Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report measurements of the charge-separated $W^{+(-)} \to e^{+(-)} + \nu_e(\bar{\nu}_e)$ and $Z/\gamma^* \to e^+e^-$ production cross sections at mid-rapidity in proton-proton collisions at $\sqrt{s}$ = 500 GeV. These results are based on 13.2 pb$^{-1}$ of data recorded in 2009 by the STAR detector at RHIC. Production cross sections for W bosons that decay via the $e \nu$ channel were measured to be $\sigma(pp \to W^+ X) \cdot BR(W^+ \to e^+ \nu_e)$ = 117.3 \pm 5.9(stat) \pm 6.2(syst) \pm 15.2(lumi) pb, and $\sigma(pp \to W^- X) \cdot BR(W^- \to e^- \bar{\nu}_e)$ = 43.3 \pm 4.6(stat) \pm 3.4(syst) \pm 5.6(lumi) pb. For $Z/\gamma^*$ production, $\sigma(pp \to Z/\gamma^* X) \cdot BR(Z/\gamma^* \to e^+ e^-)$ = 7.7 \pm 2.1(stat) $^{+0.5}_{-0.9}$(syst) \pm 1.0(lumi) pb for di-lepton invariant masses $m_{e^+e^-}$ between 70 and 110 GeV/$c^2$. First measurements of the W cross section ratio, $\sigma(pp \to W^+ X) / \sigma(pp \to W^- X)$, at $\sqrt{s}$ = 500 GeV are also reported. Theoretical predictions, calculated using recent parton distribution functions, are found to agree with the measured cross sections., Comment: 14 pages, 12 figures, submitted to Physical Review D
Published: 2011
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49. Energy and system-size dependence of two- and four-particle $v_2$ measurements in heavy-ion collisions at RHIC and their implications on flow fluctuations and nonflow

Author: The STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., de Souza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants $v_2$ ($v_2\{2\}$ and $v_2\{4\}$) for Au+Au and Cu+Cu collisions at center of mass energies $\sqrt{s_{_{\mathrm{NN}}}} = 62.4$ and 200 GeV. The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ is related to $v_{2}$ fluctuations ($\sigma_{v_2}$) and nonflow $(\delta_{2})$. We present an upper limit to $\sigma_{v_2}/v_{2}$. Following the assumption that eccentricity fluctuations $\sigma_{\epsilon}$ dominate $v_2$ fluctuations $\frac{\sigma_{v_2}}{v_2} \approx \frac{\sigma_{\epsilon}}{\epsilon}$ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with $v_2\{2\}$ and $v_2\{4\}$. We also present results on the ratio of $v_2$ to eccentricity., Comment: 15 pages, 12 Figures
Published: 2011
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50. System size and energy dependence of near-side di-hadron correlations

Author: STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bombara, M., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., Didenko, L., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gaillard, L., Gangadharan, D. R., Geurts, F., Ghosh, P., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nattrass, C., Nasim, Md., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbæ, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: Two-particle azimuthal ($\Delta\phi$) and pseudorapidity ($\Delta\eta$) correlations using a trigger particle with large transverse momentum ($p_T$) in $d$+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both $\Delta\phi$ and $\Delta\eta$, and the ridge, narrow in $\Delta\phi$ but broad in $\Delta\eta$. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated $p_T$. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at $\sqrt{s_{{NN}}}$ = 200 GeV, is also found in Cu+Cu collisions and in collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV, but is found to be substantially smaller at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV than at $\sqrt{s_{{NN}}}$ = 200 GeV for the same average number of participants ($ \langle N_{\mathrm{part}}\rangle$). Measurements of the ridge are compared to models., Comment: 17 pages, 14 figures, submitted to Phys. Rev. C
Published: 2011
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