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1. Ocean-wide genomic variation in Gray's beaked whales, Mesoplodon grayi

Author

M. V. Westbury, K. F. Thompson, M. Louis, A. A. Cabrera, M. Skovrind, J. A. S. Castruita, R. Constantine, J. R. Stevens, and E. D. Lorenzen

Subjects
ziphiidae, mitogenomes, nuclear genomes, population structure, evolution, demographic history, Science
Abstract

The deep oceans of the Southern Hemisphere are home to several elusive and poorly studied marine megafauna. In the absence of robust observational data for these species, genetic data can aid inferences on population connectivity, demography and ecology. A previous investigation of genetic diversity and population structure in Gray's beaked whale (Mesoplodon grayi) from Western Australia and New Zealand found high levels of mtDNA diversity, no geographic structure and stable demographic history. To further investigate phylogeographic and demographic patterns across their range, we generated complete mitochondrial and partial nuclear genomes of 16 of the individuals previously analysed and included additional samples from South Africa (n = 2) and South Australia (n = 4), greatly expanding the spatial range of genomic data for the species. Gray's beaked whales are highly elusive and rarely observed, and our data represents a unique and geographically broad dataset. We find relatively high levels of diversity in the mitochondrial genome, despite an absence of population structure at the mitochondrial and nuclear level. Demographic analyses suggest these whales existed at stable levels over at least the past 1.1 million years, with an approximately twofold increase in female effective population size approximately 250 thousand years ago, coinciding with a period of increased Southern Ocean productivity, sea surface temperature and a potential expansion of suitable habitat. Our results suggest that Gray's beaked whales are likely to be resilient to near-future ecosystem changes, facilitating their conservation. Our study demonstrates the utility of low-effort shotgun sequencing in providing ecological information on highly elusive species.

Published
2021
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2. Initial performance of the GlueX DIRC detector

Author

A Ali, F Barbosa, J Bessuille, E Chudakov, R Dzhygadlo, C Fanelli, J Frye, J Hardin, A Hurley, E Ihloff, G Kalicy, J Kelsey, W B Li, M Patsyuk, J Schwiening, M Shepherd, J R Stevens, T Whitlatch, M Williams, and Y Yang

Subjects
History, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, FOS: Physical sciences, ddc:530, High Energy Physics::Experiment, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment, Computer Science Applications, Education
Abstract

The GlueX experiment at Jefferson Laboratory aims to perform quantitative tests of non-perturbative QCD by studying the spectrum of light-quark mesons and baryons. A Detector of Internally Reflected Cherenkov light (DIRC) was installed to enhance the particle identification (PID) capability of the GlueX experiment by providing clean $\pi$/K separation up to 3.7 GeV/$c$ momentum in the forward region ($\theta, Comment: International Conference on Technology and Instrumentation in Particle Physics 2021, 5 pages

Published
2022
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3. Ocean-wide genomic variation in Gray's beaked whales, Mesoplodon grayi

Author

Andrea A. Cabrera, Mikkel Skovrind, Kirsten F. Thompson, Michael V. Westbury, Marie Louis, Rochelle Constantine, José Alfredo Samaniego Castruita, Eline D. Lorenzen, and J. R. Stevens

Subjects
0106 biological sciences, Demographic history, Range (biology), Population, 010603 evolutionary biology, 01 natural sciences, Ziphiidae, 03 medical and health sciences, Beaked whale, Effective population size, Megafauna, evolution, lcsh:Science, education, Research Articles, 030304 developmental biology, 0303 health sciences, education.field_of_study, Ecology, Conservation, and Global Change Biology, Multidisciplinary, biology, Ecology, mitogenomes, nuclear genomes, Mesoplodon grayi, population structure, biology.organism_classification, demographic history, Phylogeography, lcsh:Q
Abstract

The deep oceans of the Southern Hemisphere are home to several elusive and poorly studied marine megafauna. In the absence of robust observational data for these species, genetic data can aid inferences on population connectivity, demography and ecology. A previous investigation of genetic diversity and population structure in Gray's beaked whale ( Mesoplodon grayi ) from Western Australia and New Zealand found high levels of mtDNA diversity, no geographic structure and stable demographic history. To further investigate phylogeographic and demographic patterns across their range, we generated complete mitochondrial and partial nuclear genomes of 16 of the individuals previously analysed and included additional samples from South Africa ( n = 2) and South Australia ( n = 4), greatly expanding the spatial range of genomic data for the species. Gray's beaked whales are highly elusive and rarely observed, and our data represents a unique and geographically broad dataset. We find relatively high levels of diversity in the mitochondrial genome, despite an absence of population structure at the mitochondrial and nuclear level. Demographic analyses suggest these whales existed at stable levels over at least the past 1.1 million years, with an approximately twofold increase in female effective population size approximately 250 thousand years ago, coinciding with a period of increased Southern Ocean productivity, sea surface temperature and a potential expansion of suitable habitat. Our results suggest that Gray's beaked whales are likely to be resilient to near-future ecosystem changes, facilitating their conservation. Our study demonstrates the utility of low-effort shotgun sequencing in providing ecological information on highly elusive species.

Published
2021

4. Measurement of beam asymmetry for π−Δ++ photoproduction on the proton at Eγ=8.5GeV

Author

E. S. Smith, T. Erbora, Ilya Larin, V. V. Tarasov, J. Schwiening, K. Luckas, B. E. Cannon, A. Austregesilo, C. Fanelli, A. Hurley, H. Marukyan, J. Fitches, R.S. Pedroni, W. McGinley, C. A. Meyer, L. Guo, J. Reinhold, A. Ali, T. D. Beattie, S. Furletov, M. M. Dalton, A. Smith, Z. Zhao, M. M. Ito, G. Rodriguez, F. Barbosa, D. Romanov, W. J. Briscoe, V. A. Matveev, A. M. Schertz, D. G. Ireland, V. Crede, T. Daniels, L. Gan, H. Egiyan, B. C.L. Sumner, A. LaDuke, G. J. Lolos, C. S. Akondi, V. Lyubovitskij, S. Somov, S. Fegan, R. Barsotti, S. Adhikari, M. R. Shepherd, A. Gasparian, E. Pooser, T. Whitlatch, N. Wickramaarachchi, Xiang Zhou, T. Britton, Sergey Kuleshov, B. Liu, M. Khatchatryan, H. Hakobyan, A. I. Ostrovidov, D. I. Lersch, K. Suresh, H. Li, P. Eugenio, W. B. Li, J. Barlow, Stephen Taylor, W. Phelps, J. Ritman, J. R. Stevens, M. McCaughan, Haiyan Gao, Mark Richard James Williams, Michael Dugger, Q. Zhou, Barry Ritchie, G. M. Huber, D. I. Sober, C. Gleason, K. Livingston, A. Thiel, A. Hamdi, I. I. Strakovsky, A. Schick, E. Barriga, V. S. Goryachev, A. Deur, Carlos A. Salgado, P. Pauli, V. Neelamana, Z. Baldwin, Z. Papandreou, O. Soto, R. Dzhygadlo, S. Schadmand, I. Jaegle, V. Khachatryan, J. Zarling, R. Dotel, Krisztian Peters, K. Goetzen, M. J. Amaryan, A. Asaturyan, F. Nerling, R. A. Schumacher, X. Shen, Christine Kourkoumelis, R. E. Mitchell, R. A. Miskimen, B. Zihlmann, L. Ng, A. Ernst, Zhiyong Zhang, V. V. Berdnikov, G. Vasileiadis, W.U. Boeglin, V. Kakoyan, D. J. Mack, D. Lawrence, Sean A Dobbs, A. Somov, William Brooks, Lubomir Pentchev, C. Paudel, A. M. Foda, G. Kalicy, N. S. Jarvis, A. Dolgolenko, S. Cole, O. Cortes, C.P. Romero, T. C. Black, R. T. Jones, M. E. McCracken, J. Zhou, K. Mizutani, M. Kamel, A. Teymurazyan, Y. Yang, and E. Chudakov

Subjects
Physics, Range (particle radiation), GlueX, Proton, Meson, 010308 nuclear & particles physics, media_common.quotation_subject, Momentum transfer, 01 natural sciences, Asymmetry, Pseudoscalar, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, media_common
Abstract

We report a measurement of the π − photoproduction beam asymmetry for the reaction → γ p → π − Δ + + using data from the GlueX experiment in the photon beam energy range 8.2–8.8 GeV. The asymmetry Σ is measured as a function of four-momentum transfer t to the Δ + + and compared to phenomenological models. We find that Σ varies as a function of t : negative at smaller values and positive at higher values of | t | . The reaction can be described theoretically by t -channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy.

Published
2021

5. The GlueX beamline and detector

Author

T. Whitlatch, N. Wickramaarachchi, N. Cao, Ilya Larin, Michael Dugger, N. K. Walford, V. V. Tarasov, Gerard Visser, W. Phelps, J. Frye, B. Liu, J. Stewart, V. Razmyslovich, S. Schadmand, B. E. Cannon, C.P. Romero, O. Cortes, F. Nerling, S. Adhikari, M. M. Dalton, G. Voulgaris, C. S. Akondi, W. J. Briscoe, J. R. Stevens, W. D. Crahen, G.H. Biallas, H. Marukyan, R.S. Pedroni, C. Gleason, W. McGinley, P. Eugenio, E. Wolin, V. Crede, C. Carlin, L. A. Teigrob, F. Mokaya, T. C. Black, A. Toro, D. G. Meekins, I. A. Semenova, Elton Smith, A. Thiel, Kamal K. Seth, G. J. Lolos, A. M. Schertz, Todd Satogata, G. Kalicy, T. Daniels, N. S. Jarvis, A. Hamdi, I. I. Strakovsky, N. Qin, Mark Richard James Williams, I. Vega, A. Tsaris, Y. Yang, K. Goetzen, T. Erbora, J. Leckey, W. U. Boeglin, R. T. Jones, S. Fegan, D. S. Carman, K. Suresh, V. V. Berdnikov, Barry Ritchie, G. Vasileiadis, T. Carstens, E. Barriga, H. Al Ghoul, K. Moriya, J. Hardin, A. Gerasimov, M. E. McCracken, A. Deur, C. D. Keith, M. J. Staib, Hovanes Egiyan, A. Ali, Vladimir Popov, Jay Benesch, A. Hurley, C. Dickover, Viktor Matveev, Dmitri Romanov, A. Dolgolenko, B. Pratt, Justin I. McIntyre, C. A. Meyer, R. Mendez, A. R. Dzierba, C. Hutton, N. Sandoval, G. M. Huber, L. Guo, Z. Papandreou, Zhiyong Zhang, D. I. Sober, E. Pooser, J. Foote, J. Zarling, M. M. Ito, O. Chernyshov, Blake Leverington, S. Cole, P. Brindza, H. Hakobyan, A. Barnes, Sean A Dobbs, E. G. Anassontzis, T. D. Beattie, D. Werthmüller, X. Shen, Amiran Tomaradze, M. Patsyuk, J. Ritman, M. McCaughan, C. Fanelli, Yujie Qiang, R. A. Miskimen, A. Somov, R. Kliemt, F. Barbosa, A. Austregesilo, R. Dzhygadlo, C. Salgado, B. C.L. Sumner, L. Robison, Joerg Reinhold, Ting Xiao, A. Schick, V. Kakoyan, William Brooks, D. J. Mack, W. I. Levine, N. Gevorgyan, S. Katsaganis, E. Chudakov, Pavlos Ioannou, Lubomir Pentchev, A. Goncalves, A. Yu. Semenov, A. I. Ostrovidov, A. M. Foda, R. Dotel, M. Kamel, R. A. Schumacher, D. G. Ireland, W. B. Li, M. R. Shepherd, Ashot Gasparian, A. Teymurazyan, Krisztian Peters, J. Barlow, B. Zihlmann, Xiang Zhou, J. Pierce, S. Taylor, N. Sparks, L. Gan, S. Somov, L. Ng, A. Ernst, D. Kolybaba, K. Livingston, V. S. Goryachev, Cornelius Schwarz, P. Mattione, Y. Van Haarlem, P. Pauli, I. Tolstukhin, J. Schwiening, M. J. Amaryan, D. Lawrence, J. Brock, H. Ni, C. Stanislav, V. Lyubovitskij, S. Furletov, T. Britton, R. Barsotti, C. Paudel, Christine Kourkoumelis, Sergey Kuleshov, R. E. Mitchell, D. I. Lersch, C. L. Henschel, Q. Zhou, O. Soto, Friedrich Klein, and S.T. Krueger

Subjects
Nuclear and High Energy Physics, GlueX, детектор, Physics - Instrumentation and Detectors, Photon, Physics::Instrumentation and Detectors, фотонный пучок, FOS: Physical sciences, Scintillator, 01 natural sciences, Optics, Hodoscope, 0103 physical sciences, ddc:530, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation, Physics, GlueX, Spectrometer, Calorimeter (particle physics), 010308 nuclear & particles physics, business.industry, Detector, Instrumentation and Detectors (physics.ins-det), Beamline, High Energy Physics::Experiment, business
Abstract

The GlueX experiment at Jefferson Lab has been designed to study photoproduction reactions with a 9-GeV linearly polarized photon beam. The energy and arrival time of beam photons are tagged using a scintillator hodoscope and a scintillating fiber array. The photon flux is determined using a pair spectrometer, while the linear polarization of the photon beam is determined using a polarimeter based on triplet photoproduction. Charged-particle tracks from interactions in the central target are analyzed in a solenoidal field using a central straw-tube drift chamber and six packages of planar chambers with cathode strips and drift wires. Electromagnetic showers are reconstructed in a cylindrical scintillating fiber calorimeter inside the magnet and a lead-glass array downstream. Charged particle identification is achieved by measuring energy loss in the wire chambers and using the flight time of particles between the target and detectors outside the magnet. The signals from all detectors are recorded with flash ADCs and/or pipeline TDCs into memories allowing trigger decisions with a latency of 3.3 $\mu$s. The detector operates routinely at trigger rates of 40 kHz and data rates of 600 megabytes per second. We describe the photon beam, the GlueX detector components, electronics, data-acquisition and monitoring systems, and the performance of the experiment during the first three years of operation., Comment: Accepted by Nuclear Instruments and Methods A, 78 pages, 54 figures

Published
2021

7. Field Responsive Polymers

Author

ISHRAT M. KHAN, JOYCELYN S. HARRISON, P. Hourquebie, P. Buvat, D. Marsacq, Kazunori Yamada, Koki Sasaki, Mitsuo Hirata, M. Shahinpoor, Y. Bar-Cohen, T. Xue, Joycelyn S. Harrison, J. Smith, J. R. Stevens, W. Wieczorek, D. Raducha, K. R. Jeffrey, King-Fu Lin, Lu-Kuen Chang, Horng-Long Cheng, Zoubeida and ISHRAT M. KHAN, JOYCELYN S. HARRISON, P. Hourquebie, P. Buvat, D. Marsacq, Kazunori Yamada, Koki Sasaki, Mitsuo Hirata, M. Shahinpoor, Y. Bar-Cohen, T. Xue, Joycelyn S. Harrison, J. Smith, J. R. Stevens, W. Wieczorek, D. Raducha, K. R. Jeffrey, King-Fu Lin, Lu-Kuen Chang, Horng-Long Cheng, Zoubeida

Published
1999

8. Measurement of the photon beam asymmetry in γ⃗p→K+Σ0 at Eγ=8.5 GeV

Author

T. D. Beattie, K. Goetzen, W. J. Briscoe, P. Pauli, G. M. Huber, D. I. Sober, M. J. Amaryan, V. Crede, M. M. Dalton, V. S. Goryachev, Christine Kourkoumelis, A. Hurley, R. E. Mitchell, G. Kalicy, N. S. Jarvis, C. A. Meyer, L. Ng, D. Lawrence, A. Ernst, H. Hakobyan, V. Lyubovitskij, G. J. Lolos, I. Larin, C. Salgado, R. Barsotti, S. Adhikari, O. Cortes, Sean A Dobbs, T. Britton, A. Somov, A. Ali, Sergey Kuleshov, C.P. Romero, P. Eugenio, R. A. Schumacher, D. I. Lersch, K. Livingston, M. M. Ito, Barry Ritchie, N. Cao, Ashot Gasparian, A. Hamdi, Krisztian Peters, Michael Dugger, T. C. Black, I. I. Strakovsky, J. Barlow, Joerg Reinhold, S. Fegan, A. Deur, S. Cole, J. Frye, E. Pooser, V. A. Matveev, N. Qin, J. Schwiening, O. Soto, A. M. Schertz, T. Whitlatch, L. Robison, T. Daniels, B. E. Cannon, T. Erbora, H. Ni, Z. Papandreou, Ting Xiao, V. V. Berdnikov, William Brooks, J. R. Stevens, M. McCaughan, Mark Richard James Williams, Lubomir Pentchev, C. Gleason, S. Furletov, Q. Zhou, A. M. Foda, Dmitri Romanov, H. Marukyan, R.S. Pedroni, W. U. Boeglin, W. McGinley, E. Chudakov, N. Wickramaarachchi, A. Thiel, K. K. Seth, C. Fanelli, M. Kamel, W. Phelps, F. Nerling, Elton Smith, B. Liu, G. Vasileiadis, A. Austregesilo, Zhiyong Zhang, M. R. Shepherd, A. Teymurazyan, R. T. Jones, Y. Yang, M. E. McCracken, Xiang Zhou, S. Taylor, L. Gan, S. Somov, L. Guo, J. Zarling, C. Paudel, A. Dolgolenko, V. V. Tarasov, E. Barriga, M. Patsyuk, J. Foote, X. Shen, K. Suresh, Hovanes Egiyan, R. A. Miskimen, R. Dzhygadlo, F. Barbosa, V. Kakoyan, D. J. Mack, A. Goncalves, R. Dotel, B. Zihlmann, A. I. Ostrovidov, H. Li, D. G. Ireland, and W. B. Li

Subjects
Physics, Range (particle radiation), GlueX, Spectrometer, 010308 nuclear & particles physics, Linear polarization, media_common.quotation_subject, Theoretical models, 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Photon beam, Nuclear Experiment, 010306 general physics, Beam (structure), media_common
Abstract

We report measurements of the photon beam asymmetry Σ for the reaction γp→K+Σ0 (1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected by using a linearly polarized photon beam in the energy range of 8.2–8.8 GeV incident on a liquid hydrogen target. The beam asymmetry Σ was measured as a function of the Mandelstam variable t , and a single value of Σ was extracted for events produced in the u channel. These are the first exclusive measurements of the photon beam asymmetry Σ for the reaction in this energy range. For the t channel, the measured beam asymmetry is close to unity over the t range studied, − t = ( 0.1 – 1.4 ) ( GeV / c ) 2 , with an average value of Σ = 1.00 ± 0.05 . This agrees with theoretical models that describe the reaction via the natural-parity exchange of the K ∗ (892) Regge trajectory. A value of Σ = 0.41 ± 0.09 is obtained for the u channel integrated up to − u = 2.0 ( GeV / c ) 2 .

Published
2020

9. The GlueX DIRC Program

Author

J. Kelsey, M. Patsyuk, J. Hardin, J. Schwiening, A. Hurley, C. Schwarz, W. Li, E. Chudakov, Abbas J. Ali, F. Barbosa, Yang Yang, J. R. Stevens, C. Fanelli, M. Shepherd, R. Dzhygadlo, J. Bessuille, T. Whitlatch, Marian E. Williams, J. Frye, and G. Kalicy

Subjects
Physics, Particle physics, GlueX, Physics - Instrumentation and Detectors, Meson, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Nuclear Theory, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, 030218 nuclear medicine & medical imaging, Identification system, 03 medical and health sciences, 0302 clinical medicine, Detection of internally reflected Cherenkov light, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Photon beam, Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation, Mathematical Physics
Abstract

© 2020 IOP Publishing Ltd and Sissa Medialab. The GLUEX experiment is located in experimental Hall D at Jefferson Lab (JLab) and provides a unique capability to search for hybrid mesons in high-energy photoproduction, utilizing a ∼9 GeV linearly polarized photon beam. The initial, low-intensity phase of GLUEX was recently completed and a high-intensity phase has begun in 2020 which includes an upgraded kaon identification system, known as the DIRC (Detection of Internally Reflected Cherenkov light), utilizing components from the decommissioned BaBar DIRC. The identification of kaon final states will significantly enhance the GLUEX physics program, to aid in inferring the quark flavor content of conventional (and potentially hybrid) mesons. In these proceedings, we describe the installation of the GLUEX DIRC and the analysis of initial commissioning data.

Published
2020
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10. Beam asymmetry Σ for the photoproduction of η and η′ mesons at Eγ=8.8GeV

Author

A. Hurley, L. Gan, C. A. Meyer, J. Frye, C. Paudel, V. V. Tarasov, A. Dolgolenko, H. Hakobyan, C. Salgado, A. M. Schertz, E. Barriga, T. Daniels, C. Fanelli, R. T. Jones, W. Phelps, F. Nerling, M. E. McCracken, Krisztian Peters, Michael Dugger, V. Kakoyan, M. J. Staib, B. E. Cannon, T. Erbora, E. Pooser, I. A. Semenova, Z. Zhang, V. A. Matveev, A. Barnes, Dmitri Romanov, Sean A Dobbs, V. V. Berdnikov, A. Hamdi, J. Barlow, I. I. Strakovsky, Mark Richard James Williams, K. Suresh, T. Whitlatch, A. Somov, T. C. Black, D. Lawrence, A. Thiel, M. M. Dalton, H. Marukyan, Hovanes Egiyan, L. Ng, A. Ernst, M. McCaughan, R.S. Pedroni, W. McGinley, G. M. Huber, D. I. Sober, L. Robison, K. Livingston, V. Lyubovitskij, A. Deur, Ting Xiao, Q. Zhou, R. A. Miskimen, William Brooks, X. Zhou, P. Eugenio, G. Zhao, N. Wickramaarachchi, O. Cortes, N. Qin, L. Guo, E. Chudakov, R. Barsotti, Lubomir Pentchev, N. Cao, O. Soto, K. K. Seth, R. Dzhygadlo, F. Barbosa, B. Zihlmann, S. Fegan, M. Kamel, A. M. Foda, D. J. Mack, R. A. Schumacher, N. Gevorgyan, T. Britton, A. I. Ostrovidov, B. Liu, V. Crede, C.P. Romero, G. J. Lolos, I. Larin, G. Vasileiadis, H. Li, Ashot Gasparian, Sergey Kuleshov, D. I. Lersch, D. G. Ireland, A. Goncalves, Z. Papandreou, V. S. Goryachev, M. J. Amaryan, P. Mattione, S. Adhikari, M. Patsyuk, W. B. Li, A. Yu. Semenov, R. Dotel, Elton Smith, J. Schwiening, Barry Ritchie, J. R. Stevens, S. Somov, M. Boer, J. Foote, J. Zarling, M. R. Shepherd, A. Teymurazyan, C. Gleason, G. Kalicy, N. S. Jarvis, X. Shen, A. Austregesilo, S. Cole, Christine Kourkoumelis, Joerg Reinhold, A. Ali, R. E. Mitchell, W. U. Boeglin, Y. Yang, M. M. Ito, P. Pauli, S. Furletov, W. J. Briscoe, T. D. Beattie, and K. Goetzen

Subjects
Physics, GlueX, Meson, 010308 nuclear & particles physics, Linear polarization, media_common.quotation_subject, Momentum transfer, Parity (physics), 01 natural sciences, 7. Clean energy, Asymmetry, 0103 physical sciences, Quasiparticle, Atomic physics, Photon beam, 010306 general physics, media_common
Abstract

We report on the measurement of the beam asymmetry Σ for the reactions → γ p → p η and → γ p → p η ′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer − t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η ′ in this energy range. We compare the results to theoretical predictions based on t -channel quasiparticle exchange. We also compare the ratio of Σ η to Σ η ′ to these models as this ratio is predicted to be sensitive to the amount of s ¯ s exchange in the production. We find that photoproduction of both η and η ′ is dominated by natural parity exchange with little dependence on − t .

Published
2019

11. Design and R&D of RICH detectors for EIC experiments

Author

M. Sarsour, J. Huang, R. Mendez, J. Harris, Pawel Nadel-Turonski, Carl Zorn, H. W. Van Hecke, G. Kalicy, A. Datta, R. P. Pisani, K. Peters, E. Kistenev, John McKisson, A. Tate, B. Azmoun, Wenze Xi, M. Grosse-Perdekamp, Triveni Rao, M. Chiu, Yujie Qiang, S. Rescia, K. Park, R. S. Towell, P. Rossi, F. Barbosa, J. R. Stevens, R. Dzhygadlo, William Brooks, J. M. Durham, R. Majka, Tanja Horn, J. Toh, S. Syed, Ju Wang, Y. Kulinich, E. Cisbani, H. Stein, X. He, Rick Wagner, C. E. Hyde, Nikolai Smirnov, C.L. Towell, Z.W. Zhao, M. Contalbrigo, T. Cao, D. E. Fields, A. Del Dotto, L. Allison, T. Tsang, M. Demarteau, Yordanka Ilieva, B. Zihlmann, C. Schwarz, C. Gleason, Cheuk-Ping Wong, J. Schwiening, Y. Furletova, A. Sukhanov, C. L. Woody, C. L. Da Silva, M. Kimball, M. Awadi, Junqi Xie, and Minghui Liu

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Strong interaction, Detector, Elementary particle, 01 natural sciences, Particle identification, law.invention, Gluon, Nuclear physics, law, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Collider, Instrumentation, Lepton
Abstract

An Electron-Ion Collider (EIC) has been proposed to further explore the strong force and QCD, focusing on the structure and the interaction of gluon-dominated matter. A generic detector RD a dual-radiator RICH, consisting of an aerogel radiator and C2F6 gas in a mirror-focused configuration. We present the simulations of the two detectors and their estimated performance.

Published
2017

12. Modular focusing ring imaging Cherenkov detector for electron–ion collider experiments

Author

S. Syed, M. Chiu, P. Nadel-Turonski, Y. Kulinich, Yujie Qiang, F. Barbosa, M. Awadi, A. Del Dotto, Nikolai Smirnov, Junqi Xie, J. Bennett, C. Gleason, J. Schwiening, M. Contalbrigo, C. Butler, J. Toh, R. Mendez, C. L. Woody, William Brooks, Minghui Liu, M. Alfred, Carl Zorn, Ju Wang, C. Schwarz, Wenze Xi, A. Datta, H.D. Stien, T. Tsang, R. Majka, C. L. Da Silva, Olesya Sarajlic, M. Grosse-Perdekamp, T.O.S. Haseler, Yordanka Ilieva, R. P. Pisani, J. R. Stevens, K. Peters, H. W. Van Hecke, L. Barion, M. Sarsour, D. E. Fields, J. M. Durham, R. Dzhygadlo, X. He, Rick Wagner, Evaristo Cisbani, Triveni Rao, Tanja Horn, J. Huang, G. Kalicy, B. Zihlmann, M. Kimball, C.L. Towell, Charles Hyde, T. Cao, Cheuk-Ping Wong, L. Allison, A. Sukhanov, J. Harris, John McKisson, A. Tate, B. Azmoun, Z.W. Zhao, P. Rossi, Todd Elder, M. Demarteau, R. S. Towell, M. Turisini, E. Kistenev, S. Rescia, K. Park, Y. Furletova, and A. Hruschka

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Cherenkov detector, business.industry, Detector, Fresnel lens, 01 natural sciences, Particle detector, Ring-imaging Cherenkov detector, law.invention, Nuclear physics, Optics, law, 0103 physical sciences, High Energy Physics::Experiment, Fermilab, Nuclear Experiment, 010306 general physics, Collider, business, Instrumentation, Cherenkov radiation
Abstract

A powerful new electron–ioncollider (EIC) has been recommended in the 2015 Long Range Plan for Nuclear Science for probing the partonic structure inside nucleons and nuclei with unprecedented precision and versatility [1] . EIC detectors are currently under development [2] , all of which require hadron identification over a broad kinematic range. A prototype ring imaging Cherenkov detector has been developed for hadron identification in the momentum range from 3 GeV/c to 10 GeV/c. The key feature of this new detector is a compact and modular design, achieved by using aerogel as radiator and a Fresnel lens for ring focusing. In this paper, the results from a beam test of a prototype device at Fermilab are reported.

Published
2017

13. Measurements of dihadron correlations relative to the event plane in Au+Au collisions at GeV *

Author

H. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, G. S. Averichev, J. Balewski, D. R. Beavis, N. K. Behera, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, B. Biritz, L. C. Bland, W. Borowski, J. Bouchet, E. Braidot, A. V. Brandin, A. Bridgeman, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, Z. Chajecki, P. Chaloupka, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, K. E. Choi, W. Christie, P. Chung, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, S. Dash, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, A. A. Derevschikov, R. Derradi de Souza, L. Didenko, P. Djawotho, S. M. Dogra, X. Dong, J. L. Drachenberg, J. E. Draper, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, M. Estienne, L. Eun, O. Evdokimov, R. Fatemi, J. Fedorisin, A. Feng, R. G. Fersch, P. Filip, E. Finch, V. Fine, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, A. Geromitsos, F. Geurts, P. Ghosh, Y. N. Gorbunov, A. Gordon, O. Grebenyuk, D. Grosnick, S. M. Guertin, A. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, M. Heinz, S. Heppelmann, A. Hirsch, E. Hjort, G. W. Hoffmann, D. J. Hofman, B. Huang, H. Z. Huang, T. J. Humanic, L. Huo, G. Igo, P. Jacobs, W. W. Jacobs, C. Jena, F. Jin, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. Ke, D. Keane, A. Kechechyan, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, A. G. Knospe, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, V. Kouchpil, P. Kravtsov, K. Krueger, M. Krus, L. Kumar, P. Kurnadi, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, N. Li, W. Li, X. Li, Y. Li, Z. M. Li, M. A. Lisa, F. Liu, H. Liu, J. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, W. A. Love, Y. Lu, E. V. Lukashov, X. Luo, G. L. Ma, Y. G. Ma, D. P. Mahapatra, R. Majka, O. I. Mall, L. K. Mangotra, R. Manweiler, S. Margetis, C. Markert, H. Masui, H. S. Matis, Yu. A. Matulenko, D. McDonald, T. S. McShane, A. Meschanin, R. Milner, N. G. Minaev, S. Mioduszewski, A. Mischke, M. K. Mitrovski, B. Mohanty, M. M. Mondal, B. Morozov, D. A. Morozov, M. G. Munhoz, M. Naglis, B. K. Nandi, T. K. Nayak, P. K. Netrakanti, L. V. Nogach, S. B. Nurushev, G. Odyniec, A. Ogawa, null Oh, null Ohlson, V. Okorokov, E. W. Oldag, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. Pandit, Y. Panebratsev, T. Pawlak, H. Pei, T. Peitzmann, C. Perkins, W. Peryt, S. C. Phatak, P. Pile, M. Planinic, M. A. Ploskon, J. Pluta, D. Plyku, N. Poljak, A. M. Poskanzer, B. V. K. S. Potukuchi, C. B. Powell, D. Prindle, N. K. Pruthi, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, A. Rose, L. Ruan, J. Rusnak, N. R. Sahoo, S. Sakai, I. Sakrejda, T. Sakuma, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, I. Selyuzhenkov, P. Seyboth, E. Shahaliev, M. Shao, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, F. Simon, R. N. Singaraju, M. J. Skoby, N. Smirnov, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, D. Staszak, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, N. L. Subba, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, V. N. Tram, S. Trentalange, R. E. Tribble, null Tribedy, O. D. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, Jr., R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, F. Videbæk, Y. P. Viyogi, S. Vokal, M. Wada, M. Walker, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten Jr., H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, null Xiao, W. Xie, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, W. Zhan, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, J. Zhao, C. Zhong, W. Zhou, X. Zhu, Y. H. Zhu, R. Zoulkarneev, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Star (game theory), Elliptic flow, Zero (complex analysis), Astronomy and Astrophysics, Parton, Correlation function (quantum field theory), Nuclear matter, 01 natural sciences, 0103 physical sciences, 010306 general physics, Jet quenching, Centrality, Instrumentation
Abstract

Dihadron azimuthal correlations containing a high transverse momentum ( ) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20%-60%) Au+Au collisions at GeV as a function of the trigger particle's azimuthal angle relative to the event plane, . The azimuthal correlation is studied as a function of both the trigger and associated particle . The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with , with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity correlation) appears to drop with increasing while the jet-like component remains approximately constant. The correlation functions are further studied with the subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the -dependence of the ridge or the away-side double-peak structure. The dropping ridge with could be attributed to a -dependent elliptic anisotropy; however, the physics mechanism of the ridge remains an open question. Even with a -dependent elliptic flow, the away-side correlation structure is robust. These results, with extensive systematic studies of the dihadron correlations as a function of , trigger and associated particle , and the pseudo-rapidity range , should provide stringent inputs to help understand the underlying physics mechanisms of jet-medium interactions in high energy nuclear collisions.

Published
2021

14. The GlueX DIRC detector

Author

Mark Richard James Williams, J. R. Stevens, J. Bessuille, T. Whitlatch, J. Kelsey, J. Hardin, R. Dzhygadlo, F. Barbosa, C. Fanelli, M. R. Shepherd, J. Schwiening, E. Chudakov, M. Patsyuk, C. Schwarz, and J. Frye

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, GlueX, 010308 nuclear & particles physics, Detector, 01 natural sciences, Linear particle accelerator, Particle detector, Particle identification, Upgrade, Detection of internally reflected Cherenkov light, 0103 physical sciences, 010306 general physics, Instrumentation
Abstract

The GlueX DIRC (Detection of Internally Reflected Cherenkov light) detector is being developed to upgrade the particle identification capabilities in the forward region of the GlueX experiment at Jefferson Lab. The GlueX DIRC will utilize four existing decommissioned BaBar DIRC bar boxes, which will be oriented to form a plane roughly 4 m away from the fixed target of the experiment. A new photon camera has been designed that is based on the SuperB FDIRC prototype. The full GlueX DIRC system will consist of two such cameras, with the first planned to be built and installed in 2017. We present the current status of the design and R&D, along with the future plans of the GlueX DIRC detector.

Published
2017

15. Installation and Commissioning of the GLUEX DIRC

Author

M. Patsyuk, E. Ihloff, A. Hurley, E. Chudakov, J. Kelsey, C. Fanelli, R. Dzhygadlo, G. Kalicy, M. Shepherd, J. R. Stevens, J. Hardin, J. Bessuille, T. Whitlatch, J. Schwiening, J. Frye, Yang Yang, F. Barbosa, W. Li, Marian E. Williams, and Abbas J. Ali

Subjects
Physics, Particle physics, Strange quark, Physics - Instrumentation and Detectors, GlueX, Meson, Physics::Instrumentation and Detectors, Nuclear Theory, Detector, FOS: Physical sciences, BaBar experiment, Instrumentation and Detectors (physics.ins-det), Particle identification, Detection of internally reflected Cherenkov light, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Photon beam, Nuclear Experiment, Instrumentation, Mathematical Physics
Abstract

© 2020 IOP Publishing Ltd and Sissa Medialab. The GLUEX experiment takes place in experimental Hall D at Jefferson Lab (JLab). With a linearly polarized photon beam of up to 12 GeV energy, GLUEX is a dedicated experiment to search for hybrid mesons via photoproduction reactions. The low-intensity (Phase I) of GLUEX was recently completed; the high-intensity (Phase II) started in 2020 including an upgraded particle identification system, known as the DIRC (Detection of Internally Reflected Cherenkov light), utilizing components from the decommissioned BaBar experiment. The identification and separation of the kaon final states will significantly enhance the GLUEX physics program, by adding the capability of accessing the strange quark flavor content of conventional (and potentially hybrid) mesons. In these proceedings, we report that the installation and commissioning of the DIRC detector has been successfully completed.

Published
2020

16. AI-optimized detector design for the future Electron-Ion Collider: the dual-radiator RICH case

Author

D. E. Fields, A. Denisov, M. Alfred, Carl Zorn, S. Syed, X. He, Minghui Liu, Markus Diefenthaler, Junqi Xie, C. Gleason, M. Grosse-Perdekamp, Yordanka Ilieva, Douglas Higinbotham, J. R. Stevens, L. Barion, M. Sarsour, M. Hattawy, Charles Hyde, F. Barbosa, X. Sun, M. Contalbrigo, William Brooks, Ian L. Pegg, Dmitri Romanov, A. Datta, M. Demarteau, H. W. Van Hecke, G. Kalicy, T. Cao, B. Kim, A. Durum, Zhongliang Zhao, C. L. Da Silva, A. Del Dotto, V. V. Berdnikov, C. Fanelli, S. Danagoulian, B. Zihlmann, R. S. Towell, Tanja Horn, Y. Furletova, John McKisson, Marian E. Williams, A. Kebede, R. Mendez, E. Cisbani, and P. Nadel-Turonski

Subjects
FOS: Computer and information sciences, Computer Science - Machine Learning, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Computer science, FOS: Physical sciences, 01 natural sciences, Particle identification, High Energy Physics - Experiment, Machine Learning (cs.LG), 030218 nuclear medicine & medical imaging, law.invention, Computational science, High Energy Physics - Experiment (hep-ex), 03 medical and health sciences, 0302 clinical medicine, law, Component (UML), 0103 physical sciences, Collider, Instrumentation, Mathematical Physics, Cherenkov radiation, 010308 nuclear & particles physics, Bayesian optimization, Detector, Instrumentation and Detectors (physics.ins-det), Gluon, Quark–gluon plasma, High Energy Physics::Experiment
Abstract

Advanced detector R&D requires performing computationally intensive and detailed simulations as part of the detector-design optimization process. We propose a general approach to this process based on Bayesian optimization and machine learning that encodes detector requirements. As a case study, we focus on the design of the dual-radiator Ring Imaging Cherenkov (dRICH) detector under development as part of the particle-identification system at the future Electron-Ion Collider (EIC). The EIC is a US-led frontier accelerator project for nuclear physics, which has been proposed to further explore the structure and interactions of nuclear matter at the scale of sea quarks and gluons. We show that the detector design obtained with our automated and highly parallelized framework outperforms the baseline dRICH design within the assumptions of the current model. Our approach can be applied to any detector R&D, provided that realistic simulations are available., 22 pages, 11 figures

Published
2020

17. Status of the GlueX DIRC

Author

J. Schwiening, Mark Richard James Williams, T. Whitlatch, J. Hardin, M. Shepherd, C. Fanelli, J. Frye, W. Li, C. Schwarz, Y. Yang, R. Dzhygadlo, J. R. Stevens, E. Chudakov, Abbas J. Ali, M. Patsyuk, F. Barbosa, G. Kalicy, J. Kelsey, A. Hurley, and J. Bessuille

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, GlueX, Upgrade, 010308 nuclear & particles physics, Bar (music), 0103 physical sciences, Detector, 010306 general physics, 01 natural sciences, Instrumentation, Particle identification
Abstract

This year we start assembling the DIRC detector to upgrade the particle identification capabilities in the forward region of the GlueX detector in Hall D at Jefferson Lab. The main components of the GlueX DIRC are the four bar boxes (reused from the decommissioned BaBar DIRC) and two photon cameras, which were designed based on the prototype for the SuperB FDIRC. The delicate bar boxes have already arrived at JLab from SLAC, where they have been stored for the last ten years. They will be attached to the newly built photon cameras and installed in Hall D already for the 2019 spring run. We present the status of the GlueX DIRC project including the ongoing R&D and the plan for the future.

Published
2020

18. Understanding and managing fish populations: keeping the toolbox fit for purpose

Author

J R, Paris, K D, Sherman, E, Bell, C, Boulenger, C, Delord, M B M, El-Mahdi, E A, Fairfield, A M, Griffiths, C, Gutmann Roberts, R D, Hedger, L E, Holman, L H, Hooper, N E, Humphries, I, Katsiadaki, R A, King, A, Lemopoulos, C J, Payne, G, Peirson, K K, Richter, M I, Taylor, C N, Trueman, B, Hayden, J R, Stevens, Biosciences, Swansea University, School of Life Sciences, University of Sussex, University of East Anglia, Écologie et santé des écosystèmes (ESE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), South Valley University, Partenaires INRAE, Bournemouth University [Poole] (BU), Norwegian Institute for Nature Research (NINA), University of Southampton, Marine Biological Association of the United Kingdom (MBA), Weymouth Laboratory, Centre for Environment, Fisheries and Aquaculture Science [Weymouth] (CEFAS), Department of Environmental and Biological Sciences, University of Eastern Finland, Department of Biology, Northern Arizona University [Flagstaff], University of Stirling, Environment Agency, BioArch-Department of Archaeology, and University of New Brunswick (UNB)

Subjects
Conservation of Natural Resources, [SDV]Life Sciences [q-bio], Population Dynamics, telemetry, Fisheries, Fishes, stable isotopes, archaeology, Congresses as Topic, Models, Biological, modelling, Policy, surveys, Animals, Interdisciplinary Communication, genetics
Abstract

50th Anniversary Annual Symposium of the Fisheries-Society-of-the-British-Isles (FSBI) - Understanding Fish Populations Jul 03-07, 2017 Symposium paper SAMARCH project; International audience; Wild fish populations are currently experiencing unprecedented pressures, which are projected to intensify in the coming decades. Developing a thorough understanding of the influences of both biotic and abiotic factors on fish populations is a salient issue in contemporary fish conservation and management. During the 50th Anniversary Symposium of The Fisheries Society of the British Isles at the University of Exeter, UK, in July 2017, scientists from diverse research backgrounds gathered to discuss key topics under the broad umbrella of Understanding Fish Populations'. Below, the output of one such discussion group is detailed, focusing on tools used to investigate natural fish populations. Five main groups of approaches were identified: tagging and telemetry; molecular tools; survey tools; statistical and modelling tools; tissue analyses. The appraisal covered current challenges and potential solutions for each of these topics. In addition, three key themes were identified as applicable across all tool-based applications. These included data management, public engagement, and fisheries policy and governance. The continued innovation of tools and capacity to integrate interdisciplinary approaches into the future assessment and management of fish populations is highlighted as an important focus for the next 50years of fisheries research.

Published
2018

20. Construction and Performance of the Barrel Electromagnetic Calorimeter for the GlueX Experiment

Author

A. Toro, G. J. Lolos, Z. Papandreou, E. G. Anassontzis, Sergey Kuleshov, M.J. Staib, H. Hakobyan, C. A. Meyer, E. S. Smith, E. Chudakov, M. Shepherd, E.L. Plummer, William Brooks, Stephen Taylor, I. Vega, C. L. Henschel, Yujie Qiang, A. Yu. Semenov, A. M. Foda, O. Soto, M. M. Dalton, S.T. Krueger, C.P. Romero, W. McGinley, N. Sandoval, Christine Kourkoumelis, I. A. Semenova, Rimsky Alejandro Rojas, D. Lawrence, J. R. Stevens, T. Whitlatch, F. Barbosa, G. Vasileiadis, G. Voulgaris, C. Stanislav, S. Katsaganis, B. Zihlmann, W. Levine, and T. D. Beattie

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Physics - Instrumentation and Detectors, GlueX, Spectrometer, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Detector, Monte Carlo method, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, 7. Clean energy, Calorimeter, Nuclear physics, Silicon photomultiplier, 0103 physical sciences, Calibration, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation
Abstract

The barrel calorimeter is part of the new spectrometer installed in Hall D at Jefferson Lab for the GlueX experiment. The calorimeter was installed in 2013, commissioned in 2014 and has been operating routinely since early 2015. The detector configuration, associated Monte Carlo simulations, calibration and operational performance are described herein. The calorimeter records the time and energy deposited by charged and neutral particles created by a multi-GeV photon beam. It is constructed as a lead and scintillating-fiber calorimeter and read out with 3840 large-area silicon photomultiplier arrays. Particles impinge on the detector over a wide range of angles, from normal incidence at 90 degrees down to 11.5 degrees, which defines a geometry that is fairly unique among calorimeters. The response of the calorimeter has been measured during a running experiment and performs as expected for electromagnetic showers below 2.5 GeV. We characterize the performance of the BCAL using the energy resolution integrated over typical angular distributions for $\pi^0$ and $\eta$ production of $\sigma_E/E$=5.2\%/$\sqrt{E(\rm{GeV})} \oplus$ 3.6\% and a timing resolution of $\sigma$\,=\,150\,ps at 1\,GeV., Comment: 46 pages, 33 figures

Published
2018
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21. Detecting a heavy neutrino electric dipole moment at the LHC

Author

J. R. Stevens and Marc Sher

Subjects
Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, Physics beyond the Standard Model, FOS: Physical sciences, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Effective field theory, Physics::Atomic Physics, 010306 general physics, Physics, Range (particle radiation), Large Hadron Collider, 010308 nuclear & particles physics, Detector, High Energy Physics::Phenomenology, lcsh:QC1-999, Electric dipole moment, High Energy Physics - Phenomenology, Neutrino detector, Neutrino, lcsh:Physics
Abstract

The milliQan Collaboration has proposed to search for millicharged particles by looking for very weakly ionizing tracks in a detector installed in a cavern near the CMS experiment at the LHC. We note that another form of exotica can also yield weakly ionizing tracks. If a heavy neutrino has an electric dipole moment (EDM), then the milliQan experiment may be sensitive to it as well. In particular, writing the general dimension-5 operator for an EDM with a scale of a TeV and a one-loop factor, one finds a potential EDM as high as a few times $10^{-17}$ e-cm, and models exist where it is an order of magnitude higher. Redoing the Bethe calculation of ionization energy loss for an EDM, it is found that the milliQan detector is sensitive to EDMs as small as $10^{-17}$ e-cm. Using the production cross-section and analyzing the acceptance of the milliQan detector, we find the expected $95\%$ exclusion and $3\sigma$ sensitivity over the range of neutrino masses from $5-1000$ GeV for integrated luminosities of $300$ and $3000\ {\rm fb}^{-1}$ at the LHC., Comment: 5 pages, 1 figure, version accepted for publication in PLB

Published
2017

22. Atlantic salmon Salmo salar in the chalk streams of England are genetically unique

Author

C, Ikediashi, J R, Paris, R A, King, W R C, Beaumont, A, Ibbotson, and J R, Stevens

Subjects
Europe, Genetics, Population, Homing Behavior, England, Rivers, Salmo salar, Animals, Genetic Variation, Animal Migration, Microsatellite Repeats
Abstract

Recent research has identified genetic groups of Atlantic salmon Salmo salar that show association with geological and environmental boundaries. This study focuses on one particular subgroup of the species inhabiting the chalk streams of southern England, U.K. These fish are genetically distinct from other British and European S. salar populations and have previously demonstrated markedly low admixture with populations in neighbouring regions. The genetic population structure of S. salar occupying five chalk streams was explored using 16 microsatellite loci. The analysis provides evidence of the genetic distinctiveness of chalk-stream S. salar in southern England, in comparison with populations from non-chalk regions elsewhere in western Europe. Little genetic differentiation exists between the chalk-stream populations and a pattern of isolation by distance was evident. Furthermore, evidence of temporal stability of S. salar populations across the five chalk streams was found. This work provides new insights into the temporal stability and lack of genetic population sub-structuring within a unique component of the species' range of S. salar.

Published
2017

23. Contrasting patterns of population structure and gene flow facilitate exploration of connectivity in two widely distributed temperate octocorals

Author

L P, Holland, T L, Jenkins, and J R, Stevens

Subjects
Gene Flow, Population Density, Genetics, Population, Geography, Animals, Genetic Variation, Original Article, Anthozoa, Atlantic Ocean, Microsatellite Repeats
Abstract

Connectivity is an important component of metapopulation dynamics in marine systems and can influence population persistence, migration rates and conservation decisions associated with Marine Protected Areas (MPAs). In this study, we compared the genetic diversity, gene flow and population structure of two octocoral species, Eunicella verrucosa and Alcyonium digitatum, in the northeast Atlantic (ranging from the northwest of Ireland and the southern North Sea, to southern Portugal), using two panels of 13 and 8 microsatellite loci, respectively. Our results identified regional genetic structure in E. verrucosa partitioned between populations from southern Portugal, northwest Ireland and Britain/France; subsequent hierarchical analysis of population structure also indicated reduced gene flow between southwest Britain and northwest France. However, over a similar geographical area, A. digitatum showed little evidence of population structure, suggesting high gene flow and/or a large effective population size; indeed, the only significant genetic differentiation detected in A. digitatum occurred between North Sea samples and those from the English Channel/northeast Atlantic. In both species the vast majority of gene flow originated from sample sites within regions, with populations in southwest Britain being the predominant source of contemporary exogenous genetic variants for the populations studied. Overall, historical patterns of gene flow appeared more complex, though again southwest Britain appeared to be an important source of genetic variation for both species. Our findings have major conservation implications, particularly for E. verrucosa, a protected species in UK waters and listed by the IUCN as ‘Vulnerable’, and for the designation and management of European MPAs.

Published
2016

24. The lifetimes and intensities of positron states in several solid polymers as an indication of structure

Author

M. J. Edwards and J. R. Stevens

Subjects
chemistry.chemical_classification, chemistry.chemical_compound, Range (particle radiation), Materials science, Annihilation, Positron, chemistry, Polymer, Polyethylene, Atomic physics, Microstructure, Intensity (heat transfer), Spectral line
Abstract

Positrons which penetrate and become trapped in polymeric solids form states which display complex annihilation time spectra. The average lifetimes and intensities of the posiltron states can be obtained from the exponentially decaying components of the time spectra. Usually three components can be resolved for solid polymers; with long, Intermediate and short average lifetimes. Experimental results of lifetimes and intensities for positrons annihilating in trans 1–4 polybutadiene, polyethylene, polyethyleneterephthalate are used to conclude that the intensity can be associated with regions of short range order and the intermediate lifetime and intensity with regions of long range order. It is also concluded that for both regions of long range and short range order there is a tightening of the microstructure in the polymer as the amount of long range order increases and/or molecular weight decreases.

Published
2007

25. Model selection for amplitude analysis

Author

Mike Williams, B. Guegan, J. R. Stevens, J. Hardin, Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Laboratory for Nuclear Science, Guegan, Baptiste, Hardin, John Melvin, Stevens, Justin Ryan, and Williams, Mateo S.

Subjects
Multivariate statistics, Computer science, Model selection, FOS: Physical sciences, Probability and statistics, Context (language use), Regularization (mathematics), Regression, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Amplitude, Physics - Data Analysis, Statistics and Probability, A priori and a posteriori, Instrumentation, Algorithm, Data Analysis, Statistics and Probability (physics.data-an), Mathematical Physics
Abstract

Model complexity in amplitude analyses is often a priori under-constrained since the underlying theory permits a large number of possible amplitudes to contribute to most physical processes. The use of an overly complex model results in reduced predictive power and worse resolution on unknown parameters of interest. Therefore, it is common to reduce the complexity by removing from consideration some subset of the allowed amplitudes. This paper studies a method for limiting model complexity from the data sample itself through regularization during regression in the context of a multivariate (Dalitz-plot) analysis. The regularization technique applied greatly improves the performance. An outline of how to obtain the significance of a resonance in a multivariate amplitude analysis is also provided.

Published
2015

26. Λ Λ correlation function in Au+Au collisions at sNN =200GeV

Author

L, Adamczyk, J K, Adkins, G, Agakishiev, M M, Aggarwal, Z, Ahammed, I, Alekseev, J, Alford, C D, Anson, A, Aparin, D, Arkhipkin, E C, Aschenauer, G S, Averichev, A, Banerjee, D R, Beavis, R, Bellwied, A, Bhasin, A K, Bhati, P, Bhattarai, H, Bichsel, J, Bielcik, J, Bielcikova, L C, Bland, I G, Bordyuzhin, W, Borowski, J, Bouchet, A V, Brandin, S G, Brovko, S, Bültmann, I, Bunzarov, T P, Burton, J, Butterworth, H, Caines, M, Calderón de la Barca Sánchez, J M, Campbell, D, Cebra, R, Cendejas, M C, Cervantes, P, Chaloupka, Z, Chang, S, Chattopadhyay, H F, Chen, J H, Chen, L, Chen, J, Cheng, M, Cherney, A, Chikanian, W, Christie, J, Chwastowski, M J M, Codrington, G, Contin, J G, Cramer, H J, Crawford, X, Cui, S, Das, A, Davila Leyva, L C, De Silva, R R, Debbe, T G, Dedovich, J, Deng, A A, Derevschikov, R, Derradi de Souza, B, di Ruzza, L, Didenko, C, Dilks, F, Ding, P, Djawotho, X, Dong, J L, Drachenberg, J E, Draper, C M, Du, L E, Dunkelberger, J C, Dunlop, L G, Efimov, J, Engelage, K S, Engle, G, Eppley, L, Eun, O, Evdokimov, O, Eyser, R, Fatemi, S, Fazio, J, Fedorisin, P, Filip, Y, Fisyak, C E, Flores, C A, Gagliardi, D R, Gangadharan, D, Garand, F, Geurts, A, Gibson, M, Girard, S, Gliske, L, Greiner, D, Grosnick, D S, Gunarathne, Y, Guo, A, Gupta, S, Gupta, W, Guryn, B, Haag, A, Hamed, L-X, Han, R, Haque, J W, Harris, S, Heppelmann, A, Hirsch, G W, Hoffmann, D J, Hofman, S, Horvat, B, Huang, H Z, Huang, X, Huang, P, Huck, T J, Humanic, G, Igo, W W, Jacobs, H, Jang, E G, Judd, S, Kabana, D, Kalinkin, K, Kang, K, Kauder, H W, Ke, D, Keane, A, Kechechyan, A, Kesich, Z H, Khan, D P, Kikola, I, Kisel, A, Kisiel, D D, Koetke, T, Kollegger, J, Konzer, I, Koralt, L K, Kosarzewski, L, Kotchenda, A F, Kraishan, P, Kravtsov, K, Krueger, I, Kulakov, L, Kumar, R A, Kycia, M A C, Lamont, J M, Landgraf, K D, Landry, J, Lauret, A, Lebedev, R, Lednicky, J H, Lee, C, Li, W, Li, X, Li, Y, Li, Z M, Li, M A, Lisa, F, Liu, T, Ljubicic, W J, Llope, M, Lomnitz, R S, Longacre, X, Luo, G L, Ma, Y G, Ma, D P, Mahapatra, R, Majka, S, Margetis, C, Markert, H, Masui, H S, Matis, D, McDonald, T S, McShane, N G, Minaev, S, Mioduszewski, B, Mohanty, M M, Mondal, D A, Morozov, M K, Mustafa, B K, Nandi, Md, Nasim, T K, Nayak, J M, Nelson, G, Nigmatkulov, L V, Nogach, S Y, Noh, J, Novak, S B, Nurushev, G, Odyniec, A, Ogawa, K, Oh, A, Ohlson, V, Okorokov, E W, Oldag, D L, Olvitt, B S, Page, Y X, Pan, Y, Pandit, Y, Panebratsev, T, Pawlak, B, Pawlik, H, Pei, C, Perkins, P, Pile, M, Planinic, J, Pluta, N, Poljak, K, Poniatowska, J, Porter, A M, Poskanzer, N K, Pruthi, M, Przybycien, J, Putschke, H, Qiu, A, Quintero, S, Ramachandran, R, Raniwala, S, Raniwala, R L, Ray, C K, Riley, H G, Ritter, J B, Roberts, O V, Rogachevskiy, J L, Romero, J F, Ross, A, Roy, L, Ruan, J, Rusnak, O, Rusnakova, N R, Sahoo, P K, Sahu, I, Sakrejda, S, Salur, J, Sandweiss, E, Sangaline, A, Sarkar, J, Schambach, R P, Scharenberg, A M, Schmah, W B, Schmidke, N, Schmitz, J, Seger, P, Seyboth, N, Shah, E, Shahaliev, P V, Shanmuganathan, M, Shao, B, Sharma, W Q, Shen, S S, Shi, Q Y, Shou, E P, Sichtermann, M, Simko, M J, Skoby, D, Smirnov, N, Smirnov, D, Solanki, P, Sorensen, H M, Spinka, B, Srivastava, T D S, Stanislaus, J R, Stevens, R, Stock, M, Strikhanov, B, Stringfellow, M, Sumbera, X, Sun, X M, Sun, Y, Sun, Z, Sun, B, Surrow, D N, Svirida, T J M, Symons, M A, Szelezniak, J, Takahashi, A H, Tang, Z, Tang, T, Tarnowsky, J H, Thomas, A R, Timmins, D, Tlusty, M, Tokarev, S, Trentalange, R E, Tribble, P, Tribedy, B A, Trzeciak, O D, Tsai, J, Turnau, T, Ullrich, D G, Underwood, G, Van Buren, G, van Nieuwenhuizen, M, Vandenbroucke, J A, Vanfossen, R, Varma, G M S, Vasconcelos, A N, Vasiliev, R, Vertesi, F, Videbæk, Y P, Viyogi, S, Vokal, A, Vossen, M, Wada, F, Wang, G, Wang, H, Wang, J S, Wang, X L, Wang, Y, Wang, G, Webb, J C, Webb, G D, Westfall, H, Wieman, S W, Wissink, R, Witt, Y F, Wu, Z, Xiao, W, Xie, K, Xin, H, Xu, J, Xu, N, Xu, Q H, Xu, Y, Xu, Z, Xu, W, Yan, C, Yang, Y, Yang, Z, Ye, P, Yepes, L, Yi, K, Yip, I-K, Yoo, N, Yu, H, Zbroszczyk, W, Zha, J B, Zhang, J L, Zhang, S, Zhang, X P, Zhang, Y, Zhang, Z P, Zhang, F, Zhao, J, Zhao, C, Zhong, X, Zhu, Y H, Zhu, Y, Zoulkarneeva, M, Zyzak, 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., Calderón De La Barca Sánchez, M., 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., Davila Leyva, A., De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., Derradi De Souza, R., 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, 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., 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, 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., 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
Physics and Astronomy (all), RHIC, STAR
Abstract

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Published
2015

27. Amplification of DNA from preserved specimens shows blowflies were preadapted for the rapid evolution of insecticide resistance

Author

C. J. Hartley, R. D. Newcomb, R. J. Russell, C. G. Yong, J. R. Stevens, D. K. Yeates, J. La Salle, and J. G. Oakeshott

Subjects
Diazinon, Molecular Sequence Data, Genes, Insect, Locus (genetics), Polymerase Chain Reaction, Lucilia, Evolution, Molecular, Insecticide Resistance, chemistry.chemical_compound, Organophosphorus Compounds, Animals, Allele, Phylogeny, Genetics, Polymorphism, Genetic, Multidisciplinary, Australasia, biology, Diptera, Organophosphate, Haplotype, Biological Sciences, biology.organism_classification, Adaptation, Physiological, Amino Acid Substitution, Haplotypes, chemistry, Lucilia cuprina, Malathion, Tissue Preservation
Abstract

Mutations of esterase 3 confer two forms of organophosphate resistance on contemporary Australasian Lucilia cuprina . One form, called diazinon resistance, is slightly more effective against commonly used insecticides and is now more prevalent than the other form, called malathion resistance. We report here that the single amino acid replacement associated with diazinon resistance and two replacements associated with malathion resistance also occur in esterase 3 in the sibling species Lucilia sericata , suggesting convergent evolution around a finite set of resistance options. We also find parallels between the species in the geographic distributions of the polymorphisms: In both cases, the diazinon-resistance change is absent or rare outside Australasia where insecticide pressure is lower, whereas the changes associated with malathion resistance are widespread. Furthermore, PCR analysis of pinned specimens of Australasian L. cuprina collected before the release of organophosphate insecticides reveals no cases of the diazinon-resistance change but several cases of those associated with malathion resistance. Thus, the early outbreak of resistance in this species can be explained by the preexistence of mutant alleles encoding malathion resistance. The pinned specimen analysis also shows much higher genetic diversity at the locus before organophosphate use, suggesting that the subsequent sweep of diazinon resistance in Australasia has compromised the scope for the locus to respond further to the ongoing challenge of the insecticides.

Published
2006

28. Probing Sea Quark and Gluon Polarization at STAR

Author

J. R. Stevens

Subjects
Quark, Physics, Particle physics, Annihilation, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Helicity, Gluon, Nuclear physics, Quark star, Quark–gluon plasma, High Energy Physics::Experiment, Nuclear Experiment, Relativistic Heavy Ion Collider, Boson
Abstract

One of the primary goals of the spin program at the Relativistic Heavy Ion Collider (RHIC) is to determine the polarization of the sea quarks and gluons in the proton. The polarization of the sea quarks is probed through the production of W−(+) bosons via the annihilation of ū+ d (d + u), at leading order. In this proceedings we report measurements of the single-spin asymmetry, AL, for W boson production at √ s = 510 GeV, and the new constraints these results place on the antiquark helicity distributions. Recent results on the longitudinal double-spin asymmetry, ALL, for inclusive and di-jet production at √ s = 200 GeV are also presented. The inclusive jet results provide the first experimental indication of non-zero gluon polarization in the x range probed at RHIC.

Published
2014

29. Dielectron mass spectra from Au+Au collisions at √[s(NN)]=200 GeV

Author

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

Abstract

We report the STAR measurements of dielectron (e(+)e(-)) production at midrapidity (|y(ee)|1) in Au+Au collisions at √[s(NN)]=200 GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like) GeV/c(2). The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ 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

31. Dynamics of sodium ions in NaClO4 complexed in poly(propylene-oxide): A 23Na nuclear magnetic resonance study

Author

K. R. Jeffrey, J. R. Stevens, and S. H. Chung

Subjects
Spin–spin relaxation, Magnetization, chemistry.chemical_compound, Nuclear magnetic resonance, Chemistry, Relaxation (NMR), General Physics and Astronomy, Ionic bonding, Propylene oxide, Physical and Theoretical Chemistry, Atmospheric temperature range, Glass transition, Amorphous solid
Abstract

Amorphous poly(propylene oxide), PPO (molecular weights, 425 and ∼106), complexed with NaClO4 salt has ionic conductivities as high as 10−5 S/cm at room temperature. In an attempt to directly study the dynamics of the Na+ ions, (I=3/2) nuclear magnetic resonance (NMR) spin-lattice relaxation times, T1, and spin–spin relaxation times, T2, at a resonance frequency of 77.0 MHz have been measured over the temperature range from 150 to 390 K. A range of salt compositions [(PPO)nNaClO4; n=8–30] have been investigated. In addition, the glass transition temperature for each sample is reported. The recovery of equilibrium magnetization following a π/2 pulse is biexponential as expected for a spin I=3/2 system in the viscous liquid region. Below Tg a better fit to the magnetization recovery curve can be obtained if Kohlrausch–Williams–Watts (KWW) functions are used in place of the exponential functions. At low temperature the molecular motion has slowed to the point where a common spin temperature is not achieved b...

Published
1998

32. Freeze-out dynamics via charged kaon femtoscopy insNN=200GeV central Au + Au collisions

Author

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

Subjects
Physics, Source function, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Nuclear Theory, Resonance, Bose–Einstein correlations, 01 natural sciences, Nuclear physics, Pion, Correlation function, 0103 physical sciences, Quark–gluon plasma, Transverse mass, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Scaling
Abstract

We present measurements of three-dimensional correlation functions of like-sign, low-transverse-momentum kaon pairs from root 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

Published
2013

33. Long-term effects of stock transfers: synergistic introgression of allochthonous genomes in salmonids

Author

J L, Horreo, G, Machado-Schiaffino, A M, Griffiths, D, Bright, J R, Stevens, and E, Garcia-Vazquez

Subjects
Europe, Genetics, Population, Genome, Species Specificity, RNA, Ribosomal, 5S, Animals, Genetic Variation, Hybridization, Genetic, Salmonidae, Microsatellite Repeats
Abstract

The genus Salmo was employed as a model to study introgression of genes between species due to secondary contacts. Seven microsatellite loci, the LDH-C1* locus and the 5S ribosomal DNA were studied. Results showed the mutually enhanced introgression of allochthonous genomes into southern European salmonids. This phenomenon appears to go beyond a simple consequence of the altered behaviour of domestic individuals. Invasions of autochthonous genomes by allochthonous genes would be enhanced by human activities such as stock transfers, which would simultaneously promote allochthonous and allospecific (from other species) introgressions in a synergistic process in Atlantic salmon Salmo salar and brown trout Salmo trutta. As a minor result, the data do not support the value of the microsatellite locus SsaD486 as a species-specific marker.

Published
2013

34. Third harmonic flow of charged particles in Au+Au collisions atsNN=200 GeV

Author

L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, E. Flores, C. A. Gagliardi, D. R. Gangadharan, D. Garand, F. Geurts, A. Gibson, S. Gliske, Y. N. Gorbunov, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, G. Igo, W. W. Jacobs, C. Jena, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. P. Kikola, J. Kiryluk, I. Kisel, A. Kisiel, V. Kizka, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, M. A. C. Lamont, J. M. Landgraf, K. D. Landry, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, P. Ostrowski, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, A. Quintero, S. Ramachandran, R. Raniwala, S. Raniwala, R. Redwine, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, P. K. Sahu, I. Sakrejda, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, L. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak

Subjects
Physics, Nuclear and High Energy Physics, Time projection chamber, 010308 nuclear & particles physics, Plane (geometry), Gaussian, 01 natural sciences, Charged particle, Nuclear physics, symbols.namesake, Pseudorapidity, 0103 physical sciences, symbols, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Anisotropy, Relativistic Heavy Ion Collider, Event (particle physics)
Abstract

We report measurements of the third harmonic coefficient of the azimuthal anisotropy, upsilon(3), known as triangular flow. The analysis is for charged particles in Au + Au collisions at root s(NN) = 200 GeV, based on data from the STAR experiment at the BNL 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.

Published
2013

35. Elliptic flow of identified hadrons in Au+Au collisions atsNN=7.7–62.4 GeV

Author

L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, B. di Ruzza, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, E. Flores, C. A. Gagliardi, D. R. Gangadharan, D. Garand, F. Geurts, A. Gibson, S. Gliske, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, G. Igo, W. W. Jacobs, C. Jena, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. P. Kikola, J. Kiryluk, I. Kisel, A. Kisiel, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, M. A. C. Lamont, J. M. Landgraf, K. D. Landry, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, S. Ramachandran, R. Raniwala, S. Raniwala, R. L. Ray, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, P. K. Sahu, I. Sakrejda, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, L. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Hadron, Elliptic flow, Lambda, 01 natural sciences, Omega, Nuclear physics, Baryon, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider
Abstract

Measurements of the elliptic flow, upsilon(2), of identified hadrons (pi(+/-), K-+/-, K-s(0), p, (p) over bar, phi, Lambda, (Lambda) over bar, Xi(-), (Xi) over bar (+), Omega(-), (Omega) over bar (+)) in Au + Au collisions at root s(NN) = 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV are presented. The measurements were done at midrapidity using the time-projection chamber and the time-of-flight detectors of the Solenoidal Tracker at RHIC experiment during the beam-energy scan program at Relativistic Heavy Ion Collider. A significant difference in the upsilon(2) values for particles and the corresponding antiparticles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, root 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 antiparticles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of upsilon(2) that was observed at root s(NN) = 200 GeV. However, for the selected group of particles (p(+), K+, K-s(0), p, Lambda, Xi(-), Omega(-)) NCQ scaling at (m(T) - m(0))/n(q) > 0.4 GeV/c(2) is not violated within +/- 10%. The upsilon(2) values for f 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

36. System-size dependence of transverse momentum correlations atsNN=62.4and 200 GeV at the BNL Relativistic Heavy Ion Collider

Author

L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, null Bhattarai, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, B. di Ruzza, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, E. Flores, C. A. Gagliardi, D. R. Gangadharan, D. Garand, F. Geurts, A. Gibson, S. Gliske, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, G. Igo, W. W. Jacobs, C. Jena, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. P. Kikola, J. Kiryluk, I. Kisel, A. Kisiel, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, M. A. C. Lamont, J. M. Landgraf, K. D. Landry, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, S. Ramachandran, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, P. K. Sahu, I. Sakrejda, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, L. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Star (game theory), Monte Carlo method, Jet (particle physics), 7. Clean energy, 01 natural sciences, Charged particle, Nuclear physics, Pseudorapidity, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider, Size dependence, Energy (signal processing)
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 $\ensuremath{\eta}$, and the azimuthal angle $\ensuremath{\phi}$. 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.

Published
2013

37. uBoost: A boosting method for producing uniform selection efficiencies from multivariate classifiers

Author

J. R. Stevens, Mike Williams, Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Laboratory for Nuclear Science, Stevens, Justin, and Williams, Michael

Subjects
Physics, Multivariate statistics, Boosting (machine learning), Artificial neural network, business.industry, Decision tree, FOS: Physical sciences, Pattern recognition, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Figure of merit, Artificial intelligence, Nuclear Experiment (nucl-ex), business, Instrumentation, Nuclear Experiment, Mathematical Physics
Abstract

The use of multivariate classifiers, especially neural networks and decision trees, has become commonplace in particle physics. Typically, a series of classifiers is trained rather than just one to enhance the performance; this is known as boosting. This paper presents a novel method of boosting that produces a uniform selection efficiency in a selected multivariate space. Such a technique is well suited for amplitude analyses or other situations where optimizing a single integrated figure of merit is not what is desired., United States. Dept. of Energy (Cooperative Research Agreement DE-FG02-94ER-40818), United States. Dept. of Energy (Early Career Award DE-SC0010497)

Published
2013

38. Experimental studies of di-jets in Au plus Au collisions using angular correlations with respect to back-to-back leading hadrons

Author

L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, A. Gibson, S. Gliske, Y. N. Gorbunov, O. G. Grebenyuk, D. Grosnick, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, L. Huo, G. Igo, W. W. Jacobs, C. Jena, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. P. Kikola, J. Kiryluk, I. Kisel, A. Kisiel, V. Kizka, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, O. I. Mall, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, P. Ostrowski, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, P. K. Sahu, I. Sakrejda, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, Y. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak

Subjects
Physics, AuAu, Nuclear and High Energy Physics, Particle physics, STAR, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, Di-jets, 01 natural sciences, Asymmetry, NATURAL SCIENCES. Physics, Nuclear physics, PRIRODNE ZNANOSTI. Fizika, hadrons, Deuterium, Angular correlation, 0103 physical sciences, Transverse momentum, High Energy Physics::Experiment, 010306 general physics, Relativistic Heavy Ion Collider, Nuclear Experiment, media_common
Abstract

Jet-medium interactions are studied via a multihadron correlation technique ( called "2 + 1"), where a pair of back-to-back hadron triggers with large transverse momentum is used as a proxy for a di-jet. This work extends the previous analysis for nearly symmetric trigger pairs with the highest momentum threshold of trigger hadron of 5 GeV/c with the new calorimeter-based triggers with energy thresholds of up to 10 GeV and above. The distributions of associated hadrons are studied in terms of correlation shapes and per-trigger yields on each trigger side. In contrast with di-hadron correlation results with single triggers, the associated hadron distributions for back-to-back triggers from central Au + Au data at root S-NN = 200 GeV show no strong modifications compared to d + Au data at the same energy. An imbalance in the total transverse momentum between hadrons attributed to the near-side and away-side of jetlike peaks is observed. The relative imbalance in the Au + Au measurement with respect to d + Au reference is found to increase with the asymmetry of the trigger pair, consistent with the expectation from medium-induced energy-loss effects. In addition, this relative total transverse momentum imbalance is found to decrease for softer associated hadrons. Such evolution indicates that the energy missing at higher associated momenta is converted into softer hadrons. DOI:10.1103/PhysRevC.87.044903

Published
2013

39. Comments on the distribution of Botrychium lunarioides (Ophioglossaceae) in Texas

Author

R D Gooch, Walter C. Holmes, T L Morgan, and J R Stevens

Subjects
Botrychium lunarioides, Geography, biology, Ophioglossaceae, business.industry, Ecology, Biogeography, Distribution (economics), Botrychium, biology.organism_classification, business
Abstract

Botrychium lunarioides (Michx.) Sw. (Ophioglossaceae) is now known to be widespread and abundant throughout the eastern portio~ of Texas.

Published
1996

40. Measurement of J/ψ azimuthal anisotropy in Au+Au collisions at sqrt[s(NN)]=200 GeV

Author

L, Adamczyk, J K, Adkins, G, Agakishiev, M M, Aggarwal, Z, Ahammed, I, Alekseev, J, Alford, C D, Anson, A, Aparin, D, Arkhipkin, E, Aschenauer, G S, Averichev, J, Balewski, A, Banerjee, Z, Barnovska, D R, Beavis, R, Bellwied, M J, Betancourt, R R, Betts, A, Bhasin, A K, Bhati, P, Bhattarai, H, Bichsel, J, Bielcik, J, Bielcikova, L C, Bland, I G, Bordyuzhin, W, Borowski, J, Bouchet, A V, Brandin, S G, Brovko, E, Bruna, S, Bültmann, I, Bunzarov, T P, Burton, J, Butterworth, X Z, Cai, H, Caines, M, Calderón de la Barca Sánchez, D, Cebra, R, Cendejas, M C, Cervantes, P, Chaloupka, Z, Chang, S, Chattopadhyay, H F, Chen, J H, Chen, J Y, Chen, L, Chen, J, Cheng, M, Cherney, A, Chikanian, W, Christie, P, Chung, J, Chwastowski, M J M, Codrington, R, Corliss, J G, Cramer, H J, Crawford, X, Cui, S, Das, A, Davila Leyva, L C, De Silva, R R, Debbe, T G, Dedovich, J, Deng, R, Derradi de Souza, S, Dhamija, B, di Ruzza, L, Didenko, F, Ding, A, Dion, P, Djawotho, X, Dong, J L, Drachenberg, J E, Draper, C M, Du, L E, Dunkelberger, J C, Dunlop, L G, Efimov, M, Elnimr, J, Engelage, G, Eppley, L, Eun, O, Evdokimov, R, Fatemi, S, Fazio, J, Fedorisin, R G, Fersch, P, Filip, E, Finch, Y, Fisyak, E, Flores, C A, Gagliardi, D R, Gangadharan, D, Garand, F, Geurts, A, Gibson, S, Gliske, O G, Grebenyuk, D, Grosnick, A, Gupta, S, Gupta, W, Guryn, B, Haag, O, Hajkova, A, Hamed, L-X, Han, J W, Harris, J P, Hays-Wehle, S, Heppelmann, A, Hirsch, G W, Hoffmann, D J, Hofman, S, Horvat, B, Huang, H Z, Huang, P, Huck, T J, Humanic, G, Igo, W W, Jacobs, C, Jena, E G, Judd, S, Kabana, K, Kang, J, Kapitan, K, Kauder, H W, Ke, D, Keane, A, Kechechyan, A, Kesich, D P, Kikola, J, Kiryluk, I, Kisel, A, Kisiel, S R, Klein, D D, Koetke, T, Kollegger, J, Konzer, I, Koralt, W, Korsch, L, Kotchenda, P, Kravtsov, K, Krueger, I, Kulakov, L, Kumar, M A C, Lamont, J M, Landgraf, K D, Landry, S, Lapointe, J, Lauret, A, Lebedev, R, Lednicky, J H, Lee, W, Leight, M J, LeVine, C, Li, W, Li, X, Li, Y, Li, Z M, Li, L M, Lima, M A, Lisa, F, Liu, T, Ljubicic, W J, Llope, R S, Longacre, Y, Lu, X, Luo, A, Luszczak, G L, Ma, Y G, Ma, D M M D, Madagodagettige Don, D P, Mahapatra, R, Majka, S, Margetis, C, Markert, H, Masui, H S, Matis, D, McDonald, T S, McShane, S, Mioduszewski, M K, Mitrovski, Y, Mohammed, B, Mohanty, M M, Mondal, M G, Munhoz, M K, Mustafa, M, Naglis, B K, Nandi, Md, Nasim, T K, Nayak, J M, Nelson, L V, Nogach, J, Novak, G, Odyniec, A, Ogawa, K, Oh, A, Ohlson, V, Okorokov, E W, Oldag, R A N, Oliveira, D, Olson, M, Pachr, B S, Page, S K, Pal, Y X, Pan, Y, Pandit, Y, Panebratsev, T, Pawlak, B, Pawlik, H, Pei, C, Perkins, W, Peryt, P, Pile, M, Planinic, J, Pluta, N, Poljak, J, Porter, A M, Poskanzer, C B, Powell, C, Pruneau, N K, Pruthi, M, Przybycien, P R, Pujahari, J, Putschke, H, Qiu, S, Ramachandran, R, Raniwala, S, Raniwala, R L, Ray, C K, Riley, H G, Ritter, J B, Roberts, O V, Rogachevskiy, J L, Romero, J F, Ross, L, Ruan, J, Rusnak, N R, Sahoo, P K, Sahu, I, Sakrejda, S, Salur, A, Sandacz, J, Sandweiss, E, Sangaline, A, Sarkar, J, Schambach, R P, Scharenberg, A M, Schmah, B, Schmidke, N, Schmitz, T R, Schuster, J, Seger, P, Seyboth, N, Shah, E, Shahaliev, M, Shao, B, Sharma, M, Sharma, S S, Shi, Q Y, Shou, E P, Sichtermann, R N, Singaraju, M J, Skoby, D, Smirnov, N, Smirnov, D, Solanki, P, Sorensen, U G, Desouza, H M, Spinka, B, Srivastava, T D S, Stanislaus, J R, Stevens, R, Stock, M, Strikhanov, B, Stringfellow, A A P, Suaide, M C, Suarez, M, Sumbera, X M, Sun, Y, Sun, Z, Sun, B, Surrow, D N, Svirida, T J M, Symons, A, Szanto de Toledo, J, Takahashi, A H, Tang, Z, Tang, L H, Tarini, T, Tarnowsky, J H, Thomas, J, Tian, A R, Timmins, D, Tlusty, M, Tokarev, S, Trentalange, R E, Tribble, P, Tribedy, B A, Trzeciak, O D, Tsai, J, Turnau, T, Ullrich, D G, Underwood, G, Van Buren, G, van Nieuwenhuizen, J A, Vanfossen, R, Varma, G M S, Vasconcelos, F, Videbæk, Y P, Viyogi, S, Vokal, S A, Voloshin, A, Vossen, M, Wada, F, Wang, G, Wang, H, Wang, J S, Wang, Q, Wang, X L, Wang, Y, Wang, G, Webb, J C, Webb, G D, Westfall, C, Whitten, H, Wieman, S W, Wissink, R, Witt, Y F, Wu, Z, Xiao, W, Xie, K, Xin, H, Xu, N, Xu, Q H, Xu, W, Xu, Y, Xu, Z, Xu, L, Xue, Y, Yang, P, Yepes, L, Yi, K, Yip, I-K, Yoo, M, Zawisza, H, Zbroszczyk, J B, Zhang, S, Zhang, X P, Zhang, Y, Zhang, Z P, Zhang, F, Zhao, J, Zhao, C, Zhong, X, Zhu, Y H, Zhu, Y, Zoulkarneeva, and M, Zyzak

Subjects
Anisotropy, Quantum Theory, Gold, Elementary Particles
Abstract

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Published
2012

41. Anomalous centrality evolution of two-particle angular correlations from Au-Au collisions atsNN=62and 200 GeV

Author

G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, G. S. Averichev, J. Balewski, D. R. Beavis, N. K. Behera, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, E. Braidot, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, M. S. Daugherity, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, L. Didenko, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, M. Estienne, L. Eun, O. Evdokimov, R. Fatemi, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, V. Fine, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, P. Ghosh, Y. N. Gorbunov, A. Gordon, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, B. Haag, O. Hajkova, A. Hamed, L.-X. Han, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, B. Huang, H. Z. Huang, T. J. Humanic, L. Huo, G. Igo, W. W. Jacobs, C. Jena, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, E. V. Lukashov, X. Luo, G. L. Ma, Y. G. Ma, D. P. Mahapatra, R. Majka, O. I. Mall, R. Manweiler, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, A. Meschanin, R. Milner, N. G. Minaev, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, D. A. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, T. K. Nayak, L. V. Nogach, S. B. Nurushev, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. Pandit, Y. Panebratsev, T. Pawlak, H. Pei, T. Peitzmann, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, D. Plyku, N. Poljak, J. Porter, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, J. Schaub, A. M. Schmah, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, I. Selyuzhenkov, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, F. Simon, R. N. Singaraju, M. J. Skoby, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, T. A. Trainor, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, F. Videbæk, Y. P. Viyogi, S. Vokal, M. Wada, M. Walker, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, K. Yip, I.-K. Yoo, M. Zawisza, H. Zbroszczyk, W. Zhan, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Scattering, Elliptic flow, Perturbative QCD, Parton, 01 natural sciences, Charged particle, Nuclear physics, Pseudorapidity, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Jet quenching, QCD matter
Abstract

We present two-dimensional (2D) two-particle angular correlations measured with the STAR detector on relative pseudorapidity η and azimuth ϕ for charged particles from Au-Au collisions at √sNN=62 and 200 GeV with transverse momentum pt≥0.15 GeV/c, |η|≤1, and 2π in azimuth. Observed correlations include a same-side (relative azimuth

Published
2012

42. Inclusive charged hadron elliptic flow in Au+Au collisions atsNN=7.7–39 GeV

Author

L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, A. Gibson, S. Gliske, Y. N. Gorbunov, O. G. Grebenyuk, D. Grosnick, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, L. Huo, G. Igo, W. W. Jacobs, C. Jena, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. Kettler, D. P. Kikola, J. Kiryluk, I. Kisel, A. Kisiel, V. Kizka, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, O. I. Mall, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, P. Ostrowski, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, G. S. F. Stephans, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, Y. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, 010308 nuclear & particles physics, Hadron, Elliptic flow, Collision, 01 natural sciences, Nuclear physics, Critical point (thermodynamics), Pseudorapidity, 0103 physical sciences, High Energy Physics::Experiment, Coordinate space, Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider
Abstract

A systematic study is presented for centrality, transverse momentum (p(T)), and pseudorapidity (eta) dependence of the inclusive charged hadron elliptic flow (v(2)) at midrapidity (vertical bar eta vertical bar < 1.0) in Au + Au collisions at root s(NN) = 7.7, 11.5, 19.6, 27, and 39 GeV. The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and four-particle cumulants (v(2){4}), are presented to investigate nonflow correlations and v(2) fluctuations. We observe that the difference between v(2){2} and v(2){4} is smaller at the lower collision energies. Values of v(2), scaled by the initial coordinate space eccentricity, v(2)/epsilon, as a function of p(T) are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results at higher collision energies. These results are compared to measurements at higher energies at the Relativistic Heavy Ion Collider (root s(NN) = 62.4 and 200 GeV) and at the Large Hadron Collider (Pb + Pb collisions at root s(NN) = 2.76 TeV). The v(2)(pT) values for fixed pT rise with increasing collision energy within the pT range studied (

Published
2012

43. High-performance DIRC detector for the future Electron Ion Collider experiment

Author

R. Dzhygadlo, Yordanka Ilieva, J. Schwiening, Tongtong Cao, G. Kalicy, C. Schwarz, J. R. Stevens, Pawel Nadel-Turonski, Carl Zorn, L. Allison, Wenze Xi, Charles Hyde, Tanja Horn, Kijun Park, and K. Peters

Subjects
Physics, Particle physics, Range (particle radiation), 010308 nuclear & particles physics, Monte Carlo method, Detector, Electron, 01 natural sciences, Particle identification, law.invention, Momentum, Nuclear physics, law, Detection of internally reflected Cherenkov light, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Collider, Instrumentation, Mathematical Physics
Abstract

A radially-compact subsystem providing particle identification (e/π, π/K, K/p) over a wide momentum range is an essential requirement for the central detector of an Electron-Ion Collider (EIC). With a radial size of only a few cm, a detector based on Detection of Internally Reflected Cherenkov light (DIRC) principle is a very attractive solution. The R&D undertaken by the EIC PID consortium achieved the goal of showing feasibility of a high-performance DIRC that would extend the momentum coverage well beyond state-of-the-art allowing 3σ separation of π/K up to 6 GeV/c, e/K up to 1.8 GeV/c and p/K up to 10 GeV/c. A key component to reach such a performance is a special 3-layer spherical compound lens. This article describes the status of the design and R&D for the DIRC at EIC detector, with a focus on the detailed Monte Carlo simulation results for the high-performance DIRC.

Published
2016

44. The GlueX DIRC project

Author

Tim Whitlatch, R. Dzhygadlo, J. Hardin, J. R. Stevens, J. Schwiening, M. Patsyuk, J. Kelsey, J. Bessuille, E. Chudakov, J. Frye, Carsten Schwartz, Fernando Barbosa, M. Shepherd, C. Fanelli, and Michael Williams

Subjects
Physics, Particle physics, Physics - Instrumentation and Detectors, GlueX, Meson, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Detector, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, Particle identification, Detection of internally reflected Cherenkov light, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Photon beam, Nuclear Experiment, 010306 general physics, Instrumentation, Mathematical Physics
Abstract

The GlueX experiment was designed to search for and study the pattern of gluonic excitations in the meson spectrum produced through photoproduction reactions at a new tagged photon beam facility in Hall D at Jefferson Laboratory. The particle identification capabilities of the GlueX experiment will be enhanced by constructing a DIRC (Detection of Internally Reflected Cherenkov light) detector, utilizing components of the decommissioned BaBar DIRC. The DIRC will allow systematic studies of kaon final states that are essential for inferring the quark flavor content of both hybrid and conventional mesons. The design for the GlueX DIRC is presented, including the new expansion volumes that are currently under development., 8 pages, 6 figures

Published
2016

46. Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarizedp+pcollisions ats=200 GeV

Author

L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, A. Bridgeman, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, S. Gliske, Y. N. Gorbunov, O. G. Grebenyuk, D. Grosnick, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, L. Huo, G. Igo, W. W. Jacobs, C. Jena, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, K. Kowalik, P. Kravtsov, K. Krueger, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, O. I. Mall, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, J. Millane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, P. Ostrowski, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, T. Sakuma, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, M. Sarsour, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, D. Staszak, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, T. A. Trainor, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, Y. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, media_common.quotation_subject, Sigma, Polarization (waves), 01 natural sciences, Asymmetry, Gluon, Nuclear physics, Transverse plane, 0103 physical sciences, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, 010306 general physics, Nucleon, Relativistic Heavy Ion Collider, media_common
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.

Published
2012

47. Di-electron spectrum at mid-rapidity inp+pcollisions ats=200GeV

Author

L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, E. Aschenauer, G. S. Averichev, J. Balewski, A. Banerjee, Z. Barnovska, D. R. Beavis, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, J. Butterworth, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, P. Chung, J. Chwastowski, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, R. Derradi de Souza, S. Dhamija, L. Didenko, F. Ding, A. Dion, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, L. Eun, O. Evdokimov, R. Fatemi, S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, A. Gibson, S. Gliske, Y. N. Gorbunov, O. G. Grebenyuk, D. Grosnick, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, P. Huck, T. J. Humanic, L. Huo, G. Igo, W. W. Jacobs, C. Jena, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, A. Kesich, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, S. R. Klein, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, P. Kravtsov, K. Krueger, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, X. Luo, A. Luszczak, G. L. Ma, Y. G. Ma, D. M. M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, O. I. Mall, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, Md. Nasim, T. K. Nayak, L. V. Nogach, J. Novak, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, P. Ostrowski, M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, S. Salur, A. Sandacz, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, B. Schmidke, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, T. A. Trainor, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, Y. Yi, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Branching fraction, High Energy Physics::Phenomenology, 01 natural sciences, 7. Clean energy, Omega, Particle identification, Nuclear physics, Pseudoscalar, 0103 physical sciences, Mass spectrum, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider
Abstract

We report on the mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via e(+) e(-) decays, from root s = 200 GeV p + p collisions, measured by the large-acceptance experiment STAR at the Relativistic Heavy Ion Collider. 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 -> 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 -> K+ K- and J/psi -> e(+) e(-). Our results suggest a new upper limit of the branching ratio of the eta -> e(+) e(-) of 1.7 x 10(-5) at the 90% confidence level.

Published
2012

48. Energy and system-size dependence of two- and four-particlev2measurements in heavy-ion collisions atsNN=62.4and 200 GeV and their implications on flow fluctuations and nonflow

Author

G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, G. S. Averichev, J. Balewski, D. R. Beavis, N. K. Behera, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, E. Braidot, A. V. Brandin, A. Bridgeman, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, K. E. Choi, W. Christie, P. Chung, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, X. Cui, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, L. Didenko, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, M. Estienne, L. Eun, O. Evdokimov, R. Fatemi, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, V. Fine, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, P. Ghosh, Y. N. Gorbunov, A. Gordon, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, M. Heinz, S. Heppelmann, A. Hirsch, G. W. Hoffmann, D. J. Hofman, B. Huang, H. Z. Huang, T. J. Humanic, L. Huo, G. Igo, W. W. Jacobs, C. Jena, F. Jin, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, S. R. Klein, A. G. Knospe, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, V. Kouchpil, P. Kravtsov, K. Krueger, M. Krus, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, N. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, H. Liu, J. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, E. V. Lukashov, X. Luo, G. L. Ma, Y. G. Ma, D. P. Mahapatra, R. Majka, O. I. Mall, R. Manweiler, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, A. Meschanin, R. Milner, N. G. Minaev, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, D. A. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, T. K. Nayak, L. V. Nogach, S. B. Nurushev, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. Pandit, Y. Panebratsev, T. Pawlak, H. Pei, T. Peitzmann, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. Redwine, R. Reed, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, J. Schaub, A. M. Schmah, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, I. Selyuzhenkov, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, B. Sharma, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, F. Simon, R. N. Singaraju, M. J. Skoby, N. Smirnov, D. Solanki, P. Sorensen, U. G. de Souza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, N. L. Subba, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, M. Wada, M. Walker, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, W. Zhan, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, media_common.quotation_subject, Star (game theory), Elliptic flow, 01 natural sciences, Azimuth, Nuclear physics, 0103 physical sciences, Particle, Eccentricity (behavior), 010306 general physics, Anisotropy, Cumulant, Energy (signal processing), media_common
Abstract

We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants v2 (v2{; ; 2}; ; and v2{; ; 4}; ; ) for Au+Au and Cu+Cu collisions at center-of-mass energies √sNN=62.4 and 200 GeV. The difference between v2{; ; 2}; ; 2 and v2{; ; 4}; ; 2 is related to v2 fluctuations (σv2) and nonflow (δ2). We present an upper limit to σv2/v2. Following the assumption that eccentricity fluctuations σɛ dominate v2 fluctuations σv2/v2≈σɛ/ɛ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with v2{; ; 2}; ; and v2{; ; 4}; ; . We also present results on the ratio of v2 to eccentricity.

Published
2012

49. ρ0photoproduction in AuAu collisions atsNN=62.4GeV measured with the STAR detector

Author

G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, G. S. Averichev, J. Balewski, D. R. Beavis, N. K. Behera, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, E. Braidot, A. V. Brandin, A. Bridgeman, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, K. E. Choi, W. Christie, P. Chung, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, L. Didenko, P. Djawotho, S. M. Dogra, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, M. Estienne, L. Eun, O. Evdokimov, R. Fatemi, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, V. Fine, Y. Fisyak, C. A. Gagliardi, F. Geurts, P. Ghosh, Y. N. Gorbunov, A. Gordon, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L-X. Han, J. W. Harris, J. P. Hays-Wehle, M. Heinz, S. Heppelmann, A. Hirsch, E. Hjort, G. W. Hoffmann, D. J. Hofman, B. Huang, H. Z. Huang, T. J. Humanic, L. Huo, G. Igo, P. Jacobs, W. W. Jacobs, C. Jena, F. Jin, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, S. R. Klein, A. G. Knospe, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, V. Kouchpil, P. Kravtsov, K. Krueger, M. Krus, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, N. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, H. Liu, J. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, E. V. Lukashov, X. Luo, G. L. Ma, Y. G. Ma, D. P. Mahapatra, R. Majka, O. I. Mall, R. Manweiler, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, A. Meschanin, R. Milner, N. G. Minaev, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, D. A. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, T. K. Nayak, L. V. Nogach, S. B. Nurushev, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. Pandit, Y. Panebratsev, T. Pawlak, H. Pei, T. Peitzmann, C. Perkins, W. Peryt, P. Pile, M. Planinic, M. A. Ploskon, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, B. V. K. S. Potukuchi, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, J. Schaub, A. M. Schmah, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, I. Selyuzhenkov, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, F. Simon, R. N. Singaraju, M. J. Skoby, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, N. L. Subba, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, T. A. Trainor, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, M. Wada, M. Walker, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, K. Yip, I-K. Yoo, M. Zawisza, H. Zbroszczyk, W. Zhan, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Theoretical models, Virtual particle, 01 natural sciences, Nuclear physics, medicine.anatomical_structure, 0103 physical sciences, medicine, High Energy Physics::Experiment, Vector meson, Center of mass, Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider, Nucleus, STAR detector
Abstract

Vector mesons may be photoproduced in relativistic heavy-ion collisions when a virtual photon emitted by one nucleus scatters from the other nucleus, emerging as a vector meson. The STAR Collaboration has previously presented measurements of coherent rho(0) photoproduction at center of mass energies of 130 GeV and 200 GeV in AuAu collisions. Here, we present a measurement of the cross section at 62.4 GeV; we find that the cross section for coherent rho(0) photoproduction with nuclear breakup is 10.5 +/- 1.5 +/- 1.6mb at 62.4 GeV. The cross-section ratio between 200 GeV and 62.4 GeV is 4.4 +/- 0.6, less than is predicted by most theoretical models. It is, however, proportionally much larger than the previously observed 15% +/- 55% increase between 130 GeV and 200 GeV.

Published
2012

50. Directed and elliptic flow of charged particles in Cu+Cu collisions atsNN=22.4GeV

Author

G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, G. S. Averichev, J. Balewski, D. R. Beavis, N. K. Behera, R. Bellwied, M. J. Betancourt, R. R. Betts, A. Bhasin, A. K. Bhati, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, E. Braidot, A. V. Brandin, A. Bridgeman, S. G. Brovko, E. Bruna, S. Bueltmann, I. Bunzarov, T. P. Burton, X. Z. Cai, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, S. Chattopadhyay, H. F. Chen, J. H. Chen, J. Y. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, K. E. Choi, W. Christie, P. Chung, M. J. M. Codrington, R. Corliss, J. G. Cramer, H. J. Crawford, null Cui, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, L. Didenko, P. Djawotho, S. M. Dogra, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, J. C. Dunlop, L. G. Efimov, M. Elnimr, J. Engelage, G. Eppley, M. Estienne, L. Eun, O. Evdokimov, R. Fatemi, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, V. Fine, Y. Fisyak, C. A. Gagliardi, D. R. Gangadharan, F. Geurts, P. Ghosh, Y. N. Gorbunov, A. Gordon, O. G. Grebenyuk, D. Grosnick, A. Gupta, S. Gupta, W. Guryn, B. Haag, O. Hajkova, A. Hamed, L.-X. Han, J. W. Harris, J. P. Hays-Wehle, M. Heinz, S. Heppelmann, A. Hirsch, E. Hjort, G. W. Hoffmann, D. J. Hofman, B. Huang, H. Z. Huang, T. J. Humanic, L. Huo, G. Igo, P. Jacobs, W. W. Jacobs, C. Jena, F. Jin, J. Joseph, E. G. Judd, S. Kabana, K. Kang, J. Kapitan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, D. Kettler, D. P. Kikola, J. Kiryluk, A. Kisiel, V. Kizka, S. R. Klein, A. G. Knospe, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. Koroleva, W. Korsch, L. Kotchenda, V. Kouchpil, P. Kravtsov, K. Krueger, M. Krus, L. Kumar, M. A. C. Lamont, J. M. Landgraf, S. LaPointe, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, W. Leight, M. J. LeVine, C. Li, L. Li, N. Li, W. Li, X. Li, Y. Li, Z. M. Li, L. M. Lima, M. A. Lisa, F. Liu, H. Liu, J. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, Y. Lu, E. V. Lukashov, X. Luo, G. L. Ma, Y. G. Ma, D. P. Mahapatra, R. Majka, O. I. Mall, R. Manweiler, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, A. Meschanin, R. Milner, N. G. Minaev, S. Mioduszewski, M. K. Mitrovski, Y. Mohammed, B. Mohanty, M. M. Mondal, B. Morozov, D. A. Morozov, M. G. Munhoz, M. K. Mustafa, M. Naglis, B. K. Nandi, T. K. Nayak, L. V. Nogach, S. B. Nurushev, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, R. A. N. Oliveira, D. Olson, M. Pachr, B. S. Page, S. K. Pal, Y. Pandit, Y. Panebratsev, T. Pawlak, H. Pei, T. Peitzmann, C. Perkins, W. Peryt, P. Pile, M. Planinic, M. A. Ploskon, J. Pluta, D. Plyku, N. Poljak, J. Porter, A. M. Poskanzer, B. V. K. S. Potukuchi, C. B. Powell, D. Prindle, C. Pruneau, N. K. Pruthi, P. R. Pujahari, J. Putschke, H. Qiu, R. Raniwala, S. Raniwala, R. L. Ray, R. Redwine, R. Reed, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, L. Ruan, J. Rusnak, N. R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, J. Schaub, A. M. Schmah, N. Schmitz, T. R. Schuster, J. Seele, J. Seger, I. Selyuzhenkov, P. Seyboth, N. Shah, E. Shahaliev, M. Shao, M. Sharma, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, F. Simon, R. N. Singaraju, M. J. Skoby, N. Smirnov, D. Solanki, P. Sorensen, U. G. deSouza, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, S. G. Steadman, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. C. Suarez, N. L. Subba, M. Sumbera, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, A. Szanto de Toledo, J. Takahashi, A. H. Tang, Z. Tang, L. H. Tarini, T. Tarnowsky, D. Thein, J. H. Thomas, J. Tian, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, J. A. Vanfossen, R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, F. Videbæk, Y. P. Viyogi, S. Vokal, S. A. Voloshin, M. Wada, M. Walker, F. Wang, G. Wang, H. Wang, J. S. Wang, Q. Wang, X. L. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, C. Whitten, H. Wieman, S. W. Wissink, R. Witt, W. Witzke, Y. F. Wu, Z. Xiao, W. Xie, H. Xu, N. Xu, Q. H. Xu, W. Xu, Y. Xu, Z. Xu, L. Xue, Y. Yang, P. Yepes, K. Yip, I.-K. Yoo, M. Zawisza, H. Zbroszczyk, W. Zhan, J. B. Zhang, S. Zhang, W. M. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, and Y. Zoulkarneeva

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Time projection chamber, Quantitative Biology::Neurons and Cognition, 010308 nuclear & particles physics, Elliptic flow, 01 natural sciences, Charged particle, Nuclear physics, 0103 physical sciences, Quark–gluon plasma, Particle, Atomic physics, Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider, STAR detector
Abstract

This paper reports results for directed flow v1 and elliptic flow v2 of charged particles in Cu + Cu collisions at √sNN=22.4 GeV at the Relativistic Heavy Ion Collider. The measurements are for the 0–60% most central collisions, using charged particles observed in the STAR detector. Our measurements extend to 22.4-GeV Cu + Cu collisions the prior observation that v1 is independent of the system size at 62.4 and 200 GeV and also extend the scaling of v1 with η/ybeam to this system. The measured v2(pT) in Cu + Cu collisions is similar for √sNN throughout the range 22.4 to 200 GeV. We also report a comparison with results from transport model (ultrarelativistic quantum molecular dynamics and multiphase transport model) calculations. The model results do not agree quantitatively with the measured v1(η), v2(pT), and v2(η).

Published
2012

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