391 results on '"V. A. Hughes"'
Search Results
2. Backpropagation of an Image Similarity Metric for Autoassociative Neural Networks.
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Claudia V. Kropas-Hughes, Steven K. Rogers, Mark E. Oxley, and Matthew Kabrisky
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- 2000
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3. Status of the BNL muon (g-2) experiment.
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Ralf Prigl, H. N. Brown, G. Bunce, R. M. Carey, Priscilla B. Cushman, G. T. Danby, P. T. Debevec, H. Deng, W. Deninger, S. K. Dhawan, V. P. Druzhinin, L. Duong, W. Earle, E. Efstathiadis, F. J. M. Farley, G. V. Fedotovich, S. Giron, Frederick Gray, Matthias Grosse Perdekamp, A. Grossmann, U. Haeberlen, M. Hare, E. S. Hazen, D. W. Hertzog, V. W. Hughes, Masahiko Iwasaki, K. Jungmann, D. Kawall, M. Kawamura, B. I. Khazin, J. Kindem, F. Krienen, I. Kronkvist, R. Larsen, Y. Y. Lee, W. Liu, I. Logashenko, R. McNabb, W. Meng, J.-L. Mi, D. Miller, J. P. Miller, W. M. Morse, P. Neumayer, C. J. G. Onderwater, Y. Orlov, C. Pai, C. Polly, J. Pretz, G. zu Putlitz, S. I. Redin, O. Rind, B. L. Roberts, N. Ryskulov, R. Sanders, S. Sedykh, Y. K. Semertzidis, S. Serednyakov, Yu. M. Shatunov, Evgeny Solodov, M. Sossong, A. Steinmetz, L. R. Sulak, M. Tanaka, C. Timmermans, A. Trofimov, D. Urner, D. Warburton, D. Winn, A. Yamamoto, and D. Zimmerman
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- 1999
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4. Continuous Quality Improvement Measured With Time-Driven Activity-Based Costing in an Outpatient Cancer Surgery Center
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Alexis B. Guzman, Iris Recinos, Jeffrey Cerny, Karen V Cleckler-Hughes, Katy E. French, Alicia M. Kowalski, Thomas A. Aloia, Mike Hernandez, Farzin Goravanchi, Spencer Stephen Kee, and Elizabeth Rebello
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medicine.medical_specialty ,Quality management ,Outpatient Clinics, Hospital ,Quality Assurance, Health Care ,ORIGINAL CONTRIBUTIONS ,Pacu ,03 medical and health sciences ,0302 clinical medicine ,Neoplasms ,Health care ,Outpatient clinic ,Medicine ,Humans ,Public Health Surveillance ,030212 general & internal medicine ,Activity-based costing ,biology ,Oncology (nursing) ,business.industry ,Health Policy ,Health Care Costs ,biology.organism_classification ,Quality Improvement ,Oncology ,Anesthesia information management system ,030220 oncology & carcinogenesis ,Emergency medicine ,business ,Quality assurance ,Delivery of Health Care ,Cancer surgery - Abstract
PURPOSE: As health care costs rise, continuous quality improvement and increased efficiency are crucial to reduce costs while providing high-quality care. Time-driven activity-based costing (TDABC) can help identify inefficiencies in processes of cancer care delivery. This study measured the process performance of Port-a-Cath placement in an outpatient cancer surgery center by using TDABC to evaluate patient care process. METHODS: Data were collected from the Anesthesia Information Management System database and OneConnect electronic health record (EHR) for Port-a-Cath cases performed throughout four phases: preintervention (phase I), postintervention, stabilization, and pre–new EHR (phases II and III), and post–new EHR (phase IV). TDABC methods were used to map and calculate process times and costs. RESULTS: Comparing all phases, as measured with TDABC methodology, a decrease in post-anesthesia care unit (PACU) length of stay (LOS) was identified (83 minutes v 67 minutes; P < .05). The decrease in PACU LOS correlated with increased efficiency and decreasing process costs and PACU nurse resource use by fast tracking patients for Port-a-Cath placement. Port-a-Cath placement success and the functionality of ports remained the same as patient experience improved. CONCLUSION: TDABC can be used to evaluate processes of care delivery to patients with cancer and to quantify changes made to those processes. Patients’ PACU LOS decreased on the basis of the 2013 Port-a-Cath process improvement initiative and after implementation of a new EHR, over the course of 3 years, as quantified by TDABC. TDABC use can lead to improved efficiencies in patient care delivery that are quantifiable and measurable.
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- 2019
5. De zorg voor zieke kinderen
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I. de Kock-van Beerendonk, K. Masolijn, H. van Eenooghe, J. Wagemaker, C. van Gelder-van Ooijen, M. Nijland, N. Kok, M. Jansen, C. Sintnicolaas, V. Vermeulen-Hughes, T. Montanus, A. Meursing-de Jong, and H. Vanheusden
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- 2018
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6. PRODUCTION OF NEUTRAL STRANGE PARTICLES IN MUON-NUCLEON SCATTERING AT 490 GEV
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H. J. Gebauer, J. F. Bartlett, M. Wilhelm, I. Derado, S. Krzywdzinski, H. E. Stier, Jan Figiel, S. Wolbers, W. Mohr, P. L. Anthony, S. Aïd, M. Erdmann, Jim Hanlon, S. Magill, M. D. Baker, Henry Lubatti, H. M. Braun, H. J. Seyerlein, S. K. Dhawan, Shuichi Kunori, G. A. Snow, M. Aderholz, D. E. Jaffe, D. Hantke, L.S. Osborne, K. Dziunikowska, S. O'Day, A. Manz, Michael Schmitt, G. Jancso, A. Röser, K. Kadija, F. M. Pipkin, A. Salvarani, U. Ecker, Mark Raymond Adams, S. Tentindo-Repond, D. McLeod, H. E. Jackson, D. G. Michael, R. L. Talaga, P. Malecki, Andris Skuja, J. J. Ryan, J. Wilkes, P. Stopa, Ronald Gilman, R. D. Kennedy, V. Eckardt, H. E. Montgomery, Norbert Schmitz, V. W. Hughes, C. W. Salgado, V. Papavassiliou, M. C. Green, D. F. Geesaman, T. Dreyer, H. J. Trost, Janet Conrad, Jorge G. Morfin, Wit Busza, H. Venkataramania, J. Haas, G. Coutrakon, C. Halliwell, S. Söldner-Rembold, Tiefu Zhao, S. B. Kaufman, A. A. Bhatti, K. Olkiewicz, R. B. Nickerson, A. Eskreys, R. A. Swanson, P. H. Steinberg, H. Schellman, J. J. Lord, W. Dougherty, D. M. Jansen, K. P. Schüler, E. J. Ramberg, T. Kirk, H. L. Melanson, B. Pawlik, Richard Wilson, R. Davisson, W. Wittek, and H. G. E. Kobrak
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Quantum chromodynamics ,Physics ,Particle physics ,Muon ,Physics and Astronomy (miscellaneous) ,Scattering ,Multiplicity (mathematics) ,Elementary particle ,Strangeness ,Lambda ,Nuclear physics ,High Energy Physics::Experiment ,Nuclear Experiment ,Nucleon ,Engineering (miscellaneous) - Abstract
The production of K0, Λ and {Mathematical expression} particles is studied in the E665 muon-nucleon experiment at Fermilab. The average multiplicities and squared transverse momenta are measured as a function of xF and W2. Most features of the data can be well described by the Lund model. Within this model, the data on the K0/π± ratios and on the average K0 multiplicity in the forward region favor a strangeness suppression factor s/u in the fragmentation process near 0.20. Clear evidence for QCD effects is seen in the average squared transverse momentum of K0 and Λ particles. © 1994 Springer-Verlag.
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- 2016
7. DENSITY AND CORRELATION INTEGRALS IN DEEP-INELASTIC MUON-NUCLEON SCATTERING AT 490 GEV
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M. Wilhelm, G. A. Snow, D. E. Jaffe, R. Davisson, S. Aïd, F. M. Pipkin, H. E. Stier, Richard Wilson, W. Dougherty, H. Venkataramania, Norbert Schmitz, W. Wittek, Henry Lubatti, A. Manz, R. L. Talaga, S. O'Day, K. Kadija, Wit Busza, H. G. E. Kobrak, Shuichi Kunori, K. Dziunikowska, L.S. Osborne, K. Olkiewicz, D. G. Michael, Andris Skuja, M. R. Adams, Pa. Malecki, J. Wilkes, H. J. Gebauer, R. B. Nickerson, R. D. Kennedy, J. F. Bartlett, B. Pawlik, I. Derado, V. Eckardt, D. F. Geesaman, A. Salvarani, H. E. Montgomery, E. J. Ramberg, Martin Erdmann, U. Ecker, Jorge G. Morfin, M. C. Green, W. Mohr, Janet Conrad, J. J. Lord, V. Papavassiliou, H. J. Trost, S. Krzywdzinski, A. A. Bhatti, D. McLeod, G. Jancso, Michael Schmitt, Satish Dhawan, C. Halliwell, S. Tentindo-Repond, H. L. Melanson, Jan Figiel, D. M. Jansen, A. Röser, Ronald Gilman, H. E. Jackson, Jim Hanlon, V. W. Hughes, H. M. Braun, S. Wolbers, S. Magill, C. W. Salgado, P. Stopa, J. J. Ryan, M. D. Baker, K. P. Schüler, D. Hantke, F. Botterweck, A. Eskreys, R. A. Swanson, P. H. Steinberg, H. Schellman, T. Kirk, H. J. Seyerlein, T. Dreyer, J. Haas, P.L. Anthony, G. Coutrakon, S. Söldner-Rembold, Tiefu Zhao, and S. B. Kaufman
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Physics ,Nuclear and High Energy Physics ,Particle physics ,Muon ,Scattering ,Hadron ,Tevatron ,Deep inelastic scattering ,law.invention ,Nuclear physics ,law ,Intermittency ,High Energy Physics::Experiment ,Fermilab ,Nucleon - Abstract
Results on density integrals Fq(Q2) and correlation integrals Kq(Q2) are presented for the first time in muon-nucleon scattering at ∼ 490 GeV, using data from the E665 experiment at the Tevatron of Fermilab. A clear rise of the Fq integrals with decreasing size of the phase-space cells (“intermittency”) is observed for pairs and triplets of negative hadrons whereas the effect is much weaker for mixed charge combinations. From these findings it is concluded that the observed intermittency signal is mainly caused by Bose-Einstein interference. Furthermore, no energy (W) dependence of F2(Q2) is observed within the W range of the E665 experiment. Finally, the third-order correlation integrals K3(Q2) are found to be significantly different from zero which implies the presence of genuine three-particle correlations in muon-nucleon interactions.
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- 2016
8. A spectrometer for muon scattering at the Tevatron
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A. Eskreys, J. Wilkes, P. H. Steinberg, A. Salvarani, S. Söldner-Rembold, M. Vidal, S. A. Wolbers, L. S. Osborne, S. K. Dhawan, A. A. Bhatti, A. Röser, K. P. Schüler, D. G. Michael, D. M. Jansen, D. McLeod, Andris Skuja, C. Halliwell, P. Stopa, U. Ecker, H. E. Stier, B. Pawlik, S. B. Kaufman, M. Erdmann, G. Jancso, R. D. Kennedy, T. Kirk, H. Venkataramania, T. Lyons, H. M. Braun, P. Strube, E. Sexton, J. Hanlon, H. J. Gebauer, V. Eckardt, Michael Schmitt, S. Tentindo-Repond, Shuichi Kunori, H. E. Montgomery, T. Dreyer, Robert A. Swanson, Ronald Gilman, R. Davisson, P. L. Anthony, H. L. Melanson, F. M. Pipkin, Jorge G. Morfin, J. Haas, John P. Ryan, Richard Wilson, T. Burnett, M. D. Baker, H. J. Seyerlein, M. C. Green, S. O'Day, M. Wilhelm, A. M. Osborne, H. J. Trost, Janet Conrad, W. Dougherty, P. Malecki, H. Kobrak, E. J. Ramberg, G. Coutrakon, Tianchi Zhao, Wit Busza, V. W. Hughes, R. B. Nickerson, D. F. Geesaman, Mark Raymond Adams, R. L. Talaga, S. Magill, S. Aïd, A. Manz, Henry Lubatti, K. Eskreys, H. E. Jackson, J. F. Bartlett, W. Mohr, S. Krzywdzinski, and J. Lord
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Physics ,Nuclear and High Energy Physics ,Wire chamber ,Particle physics ,Muon ,Spectrometer ,Physics::Instrumentation and Detectors ,Scattering ,Tevatron ,Particle detector ,Particle identification ,Nuclear physics ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,Instrumentation ,Fermi Gamma-ray Space Telescope - Abstract
In this paper the spectrometer constructed by the E665 Collaboration is described. The spectrometer was built during the period 1982–87 and the first data were taken during the 1987–88 Fixed Target run of the Fermi National Accelerator Laboratory (FNAL) Tevatron. This is the first of a series of runs in which a comprehensive program of high energy muon scattering experiments will be performed.
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- 2016
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9. NUCLEAR SHADOWING, DIFFRACTIVE SCATTERING AND LOW MOMENTUM PROTONS IN MU-XE INTERACTIONS AT 490-GEV
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H. E. Stier, F. M. Pipkin, G. Coutrakon, Jim Hanlon, H. M. Braun, K. Kadija, K. Olkiewicz, A. Salvarani, Henry Lubatti, D. G. Michael, G. Jancso, P. Malecki, M. Wilhelm, S. Krzywdzinski, W. Wittek, A. Eskreys, M. Erdmann, H. G. E. Kobrak, Andris Skuja, R. A. Swanson, P. L. Anthony, P. H. Steinberg, T. Dreyer, Jan Figiel, S. Aïd, S. Wolbers, V. W. Hughes, J. F. Bartlett, C. Halliwell, M. C. Green, H. J. Trost, I. Derado, L.S. Osborne, P. Stopa, U. Ecker, M. D. Baker, C. W. Salgado, R. D. Kennedy, W. Mohr, J. Haas, B. Pawlik, D. Hantke, R. B. Nickerson, Shuichi Kunori, S. Söldner-Rembold, D. E. Jaffe, Mark Raymond Adams, Ronald Gilman, H. J. Seyerlein, Tiefu Zhao, V. Eckardt, R. L. Talaga, S. O'Day, D. F. Geesaman, H. E. Montgomery, S. Magill, T. Kirk, H. Schellman, S. B. Kaufman, H. E. Jackson, Janet Conrad, V. Papavassiliou, R. Davisson, Timothy J. Carroll, H. L. Melanson, E. J. Ramberg, Jorge G. Morfin, D. M. Jansen, S. K. Dhawan, M. Aderholz, A. Röser, J. Wilkes, A. A. Bhatti, H. Venkataramania, J. J. Ryan, K. P. Schüler, Richard Wilson, A. Manz, K. Dziunikowska, D. McLeod, G. A. Snow, Michael Schmitt, S. Tentindo-Repond, J. J. Lord, W. Dougherty, H. J. Gebauer, Norbert Schmitz, and Wit Busza
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Physics ,Particle physics ,Physics and Astronomy (miscellaneous) ,Spectrometer ,Scattering ,Hadron ,Tevatron ,Elementary particle ,Nuclear physics ,Particle acceleration ,Rapidity ,High Energy Physics::Experiment ,Fermilab ,Nuclear Experiment ,Engineering (miscellaneous) - Abstract
The production of charged hadrons is studied in μXe and μD interactions at 490 GeV beam energy. The data were taken at the Tevatron at Fermilab with the E665 spectrometer, equipped with a streamer chamber as vertex detector. Differences between the μXe and μD data are explained by cascading of hadrons in the Xe nucleus. The average multiplicity of charged hadrons in μXe scattering is compared to previously published pXe scattering data and is found to be strongly reduced. This is traced back to the low number of ‘projectile’ collisions in μXe interactions. From a study of thex Bj dependence of hadron production in μXe scattering, and by considering events with a large rapidity gap, evidence is found for a significant contribution of diffractive scattering, which is enhanced in the kinematic region where shadowing of the cross section is observed. This result supports recent models in which diffractive scattering and nuclear shadowing are closely related.
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- 2016
10. 1 De zorg voor zieke kinderen
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H. Vanheusden, M. Jansen, V. Vermeulen-Hughes, H. van Eenooghe, N. Kok, A. Meursing-de Jong, C. van Gelder-van Ooijen, J. Wagemaker, K. Masolijn, T. Montanus, C. Sintnicolaas, M. Nijland, and I. de Kock-van Beerendonk
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- 2016
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11. Statistical equations and methods applied to the precision muon experiment at BNL
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H. N. Brown, S. Sedykh, Lawrence Sulak, F. J. M. Farley, J. M. Paley, G. zu Putlitz, S. I. Redin, Klaus-Peter Jungmann, F. Krienen, L. Duong, I. Kronkvist, Masahiko Iwasaki, T. Qian, P. T. Debevec, Alexei Trofimov, Wuzheng Meng, J. P. Miller, D. Kawall, M. Grosse-Perdekamp, R. Prigl, J. Mi, R. McNabb, E. Efstathiadis, A. Steinmetz, A. Yamamoto, Yannis K. Semertzidis, D. Nikas, G. Bunce, B. L. Roberts, B. Bousquet, J. Kindem, C. Ozben, G. W. Bennett, B.I. Khazin, Q. Peng, C. Timmermans, A. Lam, I. Logashenko, M. Kawamura, Frederick Gray, M. Deile, William Morse, Yu. F. Orlov, M. Sossong, V. W. Hughes, Yu. M. Shatunov, O. Rind, G.V. Fedotovich, D.N. Grigoriev, N.M. Ryskulov, P. M. Shagin, A. Grossmann, Y.Y. Lee, D. Warburton, J. Pretz, G. T. Danby, P. von Walter, Satish Dhawan, E. P. Sichtermann, V. P. Druzhinin, Rasmus Larsen, H. Deng, M. F. Hare, D. Winn, D. Urner, X. Huang, C. J. G. Onderwater, E. P. Solodov, R. M. Carey, D. Zimmerman, C. C. Polly, William Deninger, D. W. Hertzog, S. Giron, and P. Cushman
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Physics ,Larmor precession ,Nuclear and High Energy Physics ,Muon ,Quality (physics) ,Nuclear magnetic resonance ,Minification ,Electron ,Function (mathematics) ,Instrumentation ,Spin-½ ,Computational physics ,Weighting - Abstract
In the muon ( g - 2 ) experiment at Brookhaven National Laboratory, the spin precession frequency ω a is obtained from a standard χ 2 minimization fit applied to the time distribution of decay electrons. The unusually high accuracy ( ∼ 0.5 ppm ) of the experiment puts stringent requirements on the quality of the fit and the level of understanding of the statistical properties of the fitted parameters. We discuss the properties of the fits and their implications on the derived value for ω a , including estimates of the effect of an imperfect fit function, methods of including additional external information to reduce the error, the effects of splitting the data into many smaller subsets of data, applying different weighting methods to the data using energy information, and various tests of data suitability.
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- 2007
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12. Neural Network Based Thickness Estimation from Multiple Radiographic Images
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P. Chen, A. Yenilmez, Claudia V. Kropas-Hughes, Feyzi Inanc, Ibrahim N. Tansel, Xiaoyu Wang, and N.S. Reen
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Artificial neural network ,business.industry ,Computer science ,Mechanical Engineering ,Radiography ,respiratory system ,Test object ,Grayscale ,Backpropagation ,respiratory tract diseases ,Mechanics of Materials ,Computer vision ,Artificial intelligence ,business - Abstract
Back propagation (BP) type artificial neural networks (ANN) have been trained and used for thickness estimations from radiographic images. Test objects have been assembled from different materials and radiographic images of the test objects were obtained for thickness estimations. While some of the study has been based on the synthetic images formed through the radiographic simulation program XRSIM, the rest of the study has used actual radiographic images. The average estimation errors were 7% and 9% when two and three synthetic radiographic images obtained at different x-ray tube settings were used. With the actual images, the thickness of only one of the materials has been estimated and the material was identified. This has been due to the fact that scattering of x-rays by the test object results in a non uniform gray scale variation in the radiographic images even though the object thickness is uniform.
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- 2006
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13. German cockroach proteases regulate matrix metalloproteinase-9 in human bronchial epithelial cells
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V. S. Hughes, Kristen Page, Hector R. Wong, and Gary W. Bennett
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MAPK/ERK pathway ,Proteases ,Immunology ,Bronchi ,Matrix metalloproteinase ,Western blot ,biology.animal ,medicine ,Animals ,Humans ,Receptor, PAR-2 ,Immunology and Allergy ,Electrophoretic mobility shift assay ,RNA, Messenger ,Extracellular Signal-Regulated MAP Kinases ,Cell Line, Transformed ,Flavonoids ,Serine protease ,Cockroach ,German cockroach ,biology ,medicine.diagnostic_test ,Tumor Necrosis Factor-alpha ,Epithelial Cells ,Blattellidae ,biology.organism_classification ,Molecular biology ,Asthma ,respiratory tract diseases ,Transcription Factor AP-1 ,Matrix Metalloproteinase 9 ,Biochemistry ,biology.protein ,Insect Proteins ,Oligopeptides ,Signal Transduction - Abstract
Background: Matrix metalloproteinases (MMPs) digest extracellular matrix proteins and may play a role in the pathogenesis of bronchial asthma. MMP-9 levels are increased in the bronchoalveolar lavage fluid and sputum of asthmatics compared with that of controls. As exposure to cockroaches is an environmental risk factor for asthma, we sought to investigate the role of German cockroach fecal remnants (frass) on MMP-9 expression. Methods: Human bronchial epithelial cells (16HBE14o-) and primary normal human bronchial epithelial cells were treated with cockroach frass in the absence or presence of tumor necrosis factor (TNF)α. MMP-9 mRNA, protein levels and pro-MMP-9 activity were determined using real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA) and zymogram assays. Pretreatment of frass with aprotinin abolished protease activity. PD98059, a chemical inhibitor of extracellular signal regulated kinase (ERK), and SLIGKV, an activator of protease-activated receptor (PAR)-2 were also used. AP-1DNA binding was determined by electrophoretic mobility shift assay (EMSA) and ERK phosphorylation by Western blot analysis. Results: Cockroach frass augmented TNFα-mediated MMP-9 mRNA and protein expression by a mechanism dependent on active serine proteases within frass and not on endogenous endotoxin. Frass increased ERK phosphorylation, and chemical inhibition of ERK attenuated cockroaches’ effects on MMP-9. Serine proteases are known to activate the PAR-2 receptor. We found that selective activation of PAR-2 using the peptide SLIGKV augmented TNFα-induced MMP-9 protein levels and increased ERK phosphorylation. Frass and SLIGKV each increased AP-1 translocation and DNA binding. Conclusions: These data suggest that German cockroach frass contains active serine proteases which augment TNFα-induced MMP-9 expression by a mechanism involving PAR-2, ERK and AP-1.
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- 2006
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14. Advanced echo-dynamic measures for the characterisation of multiple ultrasonic signals in aircraft structures
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J. R. Mandeville, D. R. Judd, Jeremy S. Knopp, Eric A. Lindgren, C V Kropas-Hughes, and John C. Aldrin
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Engineering ,Signal processing ,business.industry ,Mechanical Engineering ,Speech recognition ,Acoustics ,Ultrasonic testing ,Metals and Alloys ,Signal ,Transducer ,Mechanics of Materials ,Feature (computer vision) ,Nondestructive testing ,Materials Chemistry ,Ultrasonic sensor ,Detection theory ,business - Abstract
A significant challenge in non-destructive evaluation is the ability to discern signals, originating from a crack and a geometric feature in a part, that are either closely spaced or superimposed in time. An example problem is the ultrasonic inspection of aircraft holes in vertical riser structures with limited accessibility for a transducer from an external wing surface. Characteristics of the path of the ultrasonic signal and the contact condition between the fastener and hole can hinder the use of traditional amplitude dynamics for signal classification and crack detection. A local correlation method was developed to detect the relative shift of signals in time for adjacent transducer locations due to the varying echo dynamics from crack and part geometries. This approach analyses a series of signals from a moving transducer by first accurately aligning the signals to the primary part signal feature and subsequently measuring the shifting of secondary signals of interest within multiple time windows. A methodology is proposed that supplements amplitude dynamic measures with both the change in time and signal variation measures. Feature maps of these dynamic measures are presented to demonstrate the methodology and provide a practical means for classification. Experimental John C Aldrin received his PhD in theoretical and applied mechanics from Northwestern University in 2001 and since has been working as an engineering consultant supporting research on modelling and signal processing in NDE and providing services to companies developing automated NDE techniques for in-field applications.
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- 2006
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15. Measurement of the pion form factor in the range 1.04–1.38 GeV with the CMD-2 detector
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V. M. Aul’chenko, R. R. Akhmetshin, V. Sh. Banzarov, L. M. Barkov, N. S. Bashtovoi, D. V. Bondarev, A. E. Bondar’, A. V. Bragin, A. A. Valishev, N. I. Gabyshev, D. A. Gorbachev, A. A. Grebenyuk, D. N. Grigor’ev, S. K. Dhawan, D. A. Epifanov, A. S. Zaitsev, S. G. Zverev, F. V. Ignatov, V. F. Kazanin, S. V. Karpov, I. A. Koop, P. P. Krokovny, A. S. Kuz’min, I. B. Logashenko, P. A. Lukin, A. P. Lysenko, A. I. Mil’shtein, K. Yu. Mikhailov, I. N. Nesterenko, M. A. Nikulin, A. V. Otboev, V. S. Okhapkin, E. A. Perevedentsev, A. A. Polunin, A. S. Popov, S. I. Redin, B. L. Roberts, N. I. Root, A. A. Ruban, N. M. Ryskulov, A. L. Sibidanov, V. A. Sidorov, A. N. Skrinsky, V. P. Smakhtin, I. G. Snopkov, E. P. Solodov, J. A. Thompson, G. V. Fedotovich, B. I. Khazin, V. W. Hughes, A. G. Shamov, Yu. M. Shatunov, B. A. Shwartz, S. I. Éidel’man, and Yu. V. Yudin
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Physics ,Particle physics ,Range (particle radiation) ,Pion ,Physics and Astronomy (miscellaneous) ,Detector ,Form factor (quantum field theory) ,Energy (signal processing) ,High Energy Physics - Experiment - Abstract
The cross section for the process $e^+e^-\to\pi^+\pi^-$ is measured in the c.m. energy range 1.04-1.38 GeV from 995 000 selected collinear events including 860000 $e^+e^-$ events, 82000 $\mu^+\mu^-$ events, and 33000 $\pi^+\pi^-$ events. The systematic and statistical errors of measuring the pion form factor are equal to 1.2-4.2 and 5-13%, respectively., Comment: 5 pages, 2 figures
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- 2005
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16. The muonic hydrogen Lamb-shift experiment
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Livia Ludhova, V. W. Hughes, Randolf Pohl, C.M.B. Monteiro, Françoise Mulhauser, J.F.C.A. Veloso, Satish Dhawan, Yi-Wei Liu, F. J. Hartmann, L.M.P. Fernandes, Lucile Julien, J.M.F. dos Santos, João Cardoso, Franz Kottmann, Theodor W. Hänsch, Aldo Antognini, Paul E. Knowles, David Taqqu, L. A. Schaller, Catherine Schwob, François Nez, F. D. Amaro, François Biraben, Paul Indelicato, O. Huot, A. Dax, C.A.N. Conde, and Paul Rabinowitz
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Physics ,Nuclear physics ,Muon ,Proton ,Charge radius ,Excited state ,General Physics and Astronomy ,Radius ,Atomic physics ,Spectroscopy ,Lamb shift ,Exotic atom - Abstract
The charge radius of the proton, the simplest nucleus, is known from electron-scattering experiments only with a surprisingly low precision of about 2%. The poor knowledge of the proton charge radius restricts tests of bound-state quantum electrodynamics (QED) to the precision level of about 6 × 106, although the experimental data themselves (1S Lamb shift in hydrogen) have reached a precision of 2 × 106. The determination of the proton charge radius with an accuracy of 103 is the main goal of our experiment, opening a way to check bound-state QED predictions to a level of 107. The principle is to measure the 2S2P energy difference in muonic hydrogen (µp) by infrared laser spectroscopy. The first data were taken in the second half of 2003. Muons from our unique very-low-energy muon beam are stopped at a rate of ~100 s1 in 0.6 mbar H2 gas where the lifetime of the formed µp(2S) atoms is about 1.3 µs. An incoming muon triggers a pulsed multistage laser system that delivers ~0.2 mJ at λ ≈ 6 µm. Following the laser excitation µp(2S) → µp(2P) we observe the 1.9 keV X-rays from 2P1S transitions using large area avalanche photodiodes. The resonance frequency, and, hence, the Lamb shift and the proton radius, is determined by measuring the intensity of these X-rays as a function of the laser wavelength. A broad range of laser frequencies was scanned in 2003 and the analysis is currently under way. PACS Nos.: 36.10.Dr, 14.20.Dh, 42.62.Fi
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- 2005
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17. Genetic tool monitor (GTM) for micro-end-milling operations
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Ibrahim N. Tansel, N.S. Reen, W.Y. Bao, and Claudia V. Kropas-Hughes
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Engineering ,Cutting tool ,business.industry ,Mechanical Engineering ,End milling ,computer.software_genre ,Industrial and Manufacturing Engineering ,Expression (mathematics) ,Expert system ,Machining ,Knowledge base ,Genetic algorithm ,Artificial intelligence ,Data mining ,business ,Monitoring tool ,computer - Abstract
Almost all existing tool condition monitoring methods require either the critical parameters of models which are experimentally found or the self-learning algorithms that are trained with existing data. Genetic Tool Monitor (GTM) is proposed to identify the problems by using an analytical model for micro-end-milling operations and genetic algorithm. The current version of the GTM is capable to monitor the micro-end-milling operations without any previous experience and is able to estimate symmetrical wear and local damages at the cutting edges of a tool. Genetic algorithms (GA) are found as a promising health monitoring tool if an expression exists and the necessary computational time is allowable in that particular application. GTM generates meaningful information about the ongoing operation and allows the establishment of rules based on the operators' experience.
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- 2005
- Full Text
- View/download PDF
18. Precise measurements of the hadronic cross sections at the VEPP-2M collider with the CMD-2 detector
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B.I. Khazin, V.Sh. Banzarov, Yu.V. Yudin, Alexander Valishev, P. Krokovny, N.M. Ryskulov, N.I. Root, G.V. Fedotovich, A.L. Sibidanov, A.A. Grebeniuk, V.A. Sidorov, A. Bondar, V. W. Hughes, L.M. Barkov, A.A. Ruban, A. P. Lysenko, S.I. Redin, V.M. Titov, D.V. Bondarev, A.S. Kuzmin, S. Eidelman, I.G. Snopkov, D.A. Gorbachev, K.Yu. Mikhailov, A.N. Skrinsky, J. P. Miller, V.S. Okhapkin, Yu. M. Shatunov, B. L. Roberts, E. P. Solodov, Ivan Koop, D.N. Grigoriev, I.B. Logashenko, Vassili Kazanin, S.E. Baru, N.S. Bashtovoy, J. A. Thompson, S.G. Zverev, R.R. Akhmetshin, A.V. Bragin, Fedor Ignatov, A.A. Polunin, V. M. Aulchenko, S.V. Karpov, A.S. Popov, P.A. Lukin, N. Gabyshev, and B. Shwartz
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Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Particle physics ,Annihilation ,Luminosity (scattering theory) ,Meson ,Hadron ,Detector ,Atomic and Molecular Physics, and Optics ,law.invention ,Nuclear physics ,law ,High Energy Physics::Experiment ,Nuclear Experiment ,Collider ,Astrophysics::Galaxy Astrophysics - Abstract
The current status of the updated results from the CMD-2 detector is presented. The cross sections of e + e − annihilation into hadrons were measured in the c.m. energy range from 0.37 to 1.39 GeV and are based on the total integrated luminosity of about 30 pb −1 . Results of refitting experimental data for the ρ, ω and mesons are reviewed.
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- 2004
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19. Update: A reanalysis of hadronic cross section measurements at CMD-2
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Semen Eidelman, M. A. Nikulin, L.M. Barkov, A. I. Milstein, D. Epifanov, E.V. Anashkin, P.Yu. Stepanov, A.E. Bondar, B. L. Roberts, V.A. Sidorov, E. A. Kuraev, L.M. Kurdadze, Yu. M. Shatunov, Pavel Krokovny, E. P. Solodov, Andrej Arbuzov, J. A. Thompson, V. W. Hughes, J. P. Miller, D.V. Bondarev, G.V. Fedotovich, Andrey Vladimirovich Bogdan, N.M. Ryskulov, A.S. Zaitsev, Vladimir Smakhtin, R.R. Akhmetshin, B. Shwartz, A.S. Kuzmin, D.A. Gorbachev, A.L. Sibidanov, A.S. Popov, A. Baratt, P.A. Lukin, K.Yu. Mikhailov, Yu.E Lischenko, Vassili Kazanin, N. Gabyshev, V.Sh. Banzarov, A. A. Grebenuk, A.N. Skrinsky, I. Logashenko, B.I. Khazin, N.I. Root, F.V. Ignatov, and D.N. Grigoriev
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Cross section (physics) ,Particle physics ,Luminosity (scattering theory) ,Pion ,010308 nuclear & particles physics ,Electron–positron annihilation ,0103 physical sciences ,Hadron ,010306 general physics ,01 natural sciences - Abstract
The updated results of the precise measurements of the processes e + e − → ρ → π + π − , e + e − → ω → π + π − π 0 and e + e − → φ → K 0 L K 0 S performed by the CMD-2 Collaboration are presented. The update appeared necessary due to an overestimate of the integrated luminosity in previous analyses.
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- 2004
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20. Study of the process e+e−→ωπ0→π0π0γ in c.m. energy range 920–1380 MeV at CMD-2
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E. P. Solodov, Igor Nesterenko, Yu.V. Yudin, Vassili Kazanin, D. Epifanov, N.I. Root, R.R. Akhmetshin, Alexander Valishev, A.A. Polunin, B. L. Roberts, A.V. Otboev, P.Yu. Stepanov, A.V. Bragin, V.S. Okhapkin, E.A. Perevedentsev, I.B. Logashenko, Fedor Ignatov, G.V. Fedotovitch, I.G. Snopkov, L.M. Barkov, N.S. Bashtovoy, S.E. Baru, A.S. Kuzmin, K.Yu. Mikhailov, A. P. Lysenko, N.M. Ryskulov, S.I. Eidelman, Yu. M. Shatunov, D.N. Grigoriev, A.A. Grebeniuk, A.G. Shamov, B.A. Shwartz, S.G. Zverev, J. A. Thompson, A.S. Zaitsev, P. Krokovny, A. Baratt, V.M. Aulchenko, V.Sh. Banzarov, V.A. Sidorov, A. I. Milstein, Alexey Pak, D.V. Bondarev, A.S. Popov, P.A. Lukin, A.N. Skrinsky, V. W. Hughes, N. Gabyshev, S.V. Karpov, A.L. Sibidanov, I. A. Koop, A.A. Ruban, S.I. Redin, D.A. Gorbachev, A.E. Bondar, and B.I. Khazin
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Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Antiparticle ,Annihilation ,Pion ,Meson ,Electron–positron annihilation ,Hadron ,Atomic physics ,Omega baryon ,Lepton - Abstract
The cross section of the process e + e − → ωπ 0 → π 0 π 0 γ has been measured in the c.m. energy range 920–1380 MeV with the CMD-2 detector. Its energy dependence is well described by the interference of the ρ (770) and ρ (1450) mesons decaying to ωπ 0 . Upper limits for the cross sections of the direct processes e + e − → π 0 π 0 γ , ηπ 0 γ have been set.
- Published
- 2003
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21. Selection of optimal material and operating conditions in composite manufacturing. Part I: computational tool
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S.Y. Yang, Claudia V. Kropas-Hughes, and Ibrahim N. Tansel
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Engineering ,Optimization problem ,Artificial neural network ,business.industry ,Mechanical Engineering ,Computer Science::Neural and Evolutionary Computation ,Process (computing) ,Industrial and Manufacturing Engineering ,Material selection ,Genetic algorithm ,Computer-aided manufacturing ,Composite material ,Engineering design process ,business ,Selection (genetic algorithm) - Abstract
The Genetically Optimized Neural Network System (GONNS) is proposed as a human-like decision-making tool for the selection of optimum composite material and operating conditions. Multiple neural networks represent the characteristics of the system after a training process and genetic algorithms find the optimum operating conditions. The error of the GONNS was found to be less than 1% when the neural networks-represented analytical functions and genetic algorithms were used to select the optimal conditions. The GONNS is very promising for many complex optimization problems when analytical equations are not available to represent the characteristics of the system.
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- 2003
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22. Selection of optimal material and operating conditions in composite manufacturing. Part II: complexity, representation of characteristics and decision making
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V. Girivasan, Claudia V. Kropas-Hughes, N.R. Singh, Ibrahim N. Tansel, and S.Y. Yang
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Engineering ,Artificial neural network ,business.industry ,Mechanical Engineering ,Complex system ,CAD ,computer.software_genre ,Industrial and Manufacturing Engineering ,Material selection ,Computer-aided manufacturing ,Genetic algorithm ,Computer Aided Design ,Composite material ,business ,Representation (mathematics) ,computer - Abstract
An automated procedure is proposed to select the optimum material and processing conditions for composite materials. The complexity of the part is estimated from the STL files of the CAD/CAM programs by evaluating the angles between the triangles, which cover the surface. A correction algorithm identifies the holes and calculates the complexity without considering the triangles at their surfaces if they will be drilled later. Using multiple neural networks represented the most important characteristics of the composite material manufacturing for the user. For each considered material one genetic algorithm is assigned to select the optimal operating conditions. The optimal material is selected by comparing the good qualities of each material after the optimization. The proposed procedure is very attractive for optimization of complex systems when multiple approaches and their several characteristics are considered.
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- 2003
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23. Recent results from the BNL g-2 experiment
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D.N. Grigoriev, D. Zimmerman, M. Sossong, C. Ozben, C. C. Polly, P. Cushman, Satish Dhawan, J. Pretz, F. J. M. Farley, I. Logashenko, P. von Walter, E. P. Solodov, G. zu Putlitz, S. I. Redin, R. M. Carey, Klaus-Peter Jungmann, D. W. Hertzog, A. Grossman, Frederick Gray, F. Krienen, D. Urner, Masahiko Iwasaki, S. Giron, C. J. G. Onderwater, L. Duong, Wuzheng Meng, Y.Y. Lee, H. N. Brown, Rasmus Larsen, R. Prigl, J. Mi, L. R. Sulak, J. P. Miller, O. Rind, H. Deng, B. L. Roberts, R. McNabb, A. Yamamoto, J. M. Paley, N.M. Ryskulov, William Deninger, D. Winn, C. Timmermans, D. Warburton, Alexei Trofimov, Yannis K. Semertzidis, E. P. Sichtermann, E. Efstathiadis, A. Steinmetz, M. F. Hare, S. Sedykh, G.V. Fedotovich, William Morse, I. Kronkvist, M. Deile, G. T. Danby, D. Kawall, V. P. Druzhinin, D. Nikas, P. T. Debevec, V. W. Hughes, M. Grosse-Perdekamp, Yu. M. Shatunov, J. Kindem, B.I. Khazin, M. Kawamura, G. Bunce, and Yuri F. Orlov
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Physics ,Nuclear and High Energy Physics ,Particle physics ,Muon ,Anomalous magnetic dipole moment ,Electron ,Atomic and Molecular Physics, and Optics ,Nuclear physics ,Data set ,Magnetic-moment ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,National laboratory ,Storage ring - Abstract
The status of the muon g — 2 experiment at the AGS facility of Brookhaven National Laboratory is discussed. Data obtained in 1999 with positive muons has been analyzed and published. The final data set contained 0.95 × 10 9 events and had an accuracy of 1.3 ppm . Approximately four times more data with positive muons and three times more data with negative muons were obtained in 2000 and 2001, respectively. These data were obtained with a more uniform magnetic field and with different storage ring tunes. An accuracy of the order of 0.5 ppm is anticipated.
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- 2002
24. Recent results and current status of the muon g-2 experiment at BNL
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Alexei Trofimov, E. Efstathiadis, A. Steinmetz, Q. Peng, Yu. F. Orlov, P. von Walter, E. P. Solodov, D.N. Grigoriev, R. M. Carey, Yannis K. Semertzidis, Rasmus Larsen, Wuzheng Meng, H. Deng, A. Yamamoto, D. Nikas, D. Urner, G. T. Danby, D. Winn, J. M. Paley, R. Prigl, J. Mi, R. McNabb, S. K. Dhawan, V. P. Druzhinin, B. L. Roberts, F. Krinen, T. Qian, P. Cushman, Frederick Gray, C. J. G. Onderwater, J. Kindem, F. J. M. Farley, C. Ozben, P. T. Debevec, G. zu Putlitz, Yu. M. Shatunov, M. Deile, P. M. Shagin, S. I. Redin, X. Huang, E. P. Sichtermann, C. Timmermans, M. F. Hare, I. Kronkvist, B. Bousquet, O. Rind, I.B. Logashenko, B.I. Khazin, L. Duong, M. Kawamura, J. P. Miller, D. Warburton, M. Sossong, J. Pretz, D. Kawall, A. Grossmann, G. Bunce, Klaus-Peter Jungmann, Masahiko Iwasaki, V. W. Hughes, A. Lam, H. N. Brown, N.M. Ryskulov, S. Sedykh, M. Grosse-Perdekamp, G. W. Bennett, D. Zimmerman, William Deninger, L. R. Sulak, Y. Y. Lee, William Morse, D. W. Hertzog, S. Giron, and G.V. Fedotovich
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Physics ,Particle physics ,Muon ,Anomalous magnetic dipole moment ,General Physics and Astronomy ,Charge (physics) ,Elementary particle ,Electron ,Nmr ,Standard Model ,Nuclear physics ,Anomalous magnetic-moment ,Positive muon ,Storage ring ,Lepton - Abstract
The measurement of the (g−2) value of leptons provides a unique test of theory since it is the only quantity (unlike charge and mass) calculable in the framework of the Standard Model of elementary particles. The muon (g−2) experiment E821 is currently in progress at Brookhaven National Laboratory. Four data taking runs for positive muons and one run for negative muons were successfully accomplished in 1997–2000 and 2001, respectively. Results of the 1997–2000 runs have been published, thus completing our experiment for μ+. Data analysis for the 2001 run for μ− is currently in progress. To provide measurement of \(a_\mu = \tfrac{1} {2}(g - 2)_{\mu ^ - }\) at the same level of accuracy as for \(a_{\mu ^ + } = \tfrac{1} {2}(g - 2)_{\mu ^ + }\), we need to have one more data taking run.
- Published
- 2002
25. The superconducting inflector for the BNL g-2 experiment
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M. Mapes, H. N. Brown, L. X. Jia, E. P. Sichtermann, V. W. Hughes, H. Hseuh, William Morse, G. T. Danby, A. Grossmann, M Suenaga, W. B. Sampson, H Otsuka, D. Kawall, Klaus-Peter Jungmann, M G-Perdekamp, Y.Y. Lee, J. Pretz, B. L. Roberts, Y Tachiya, J. Sandberg, G. Bunce, C. Pai, H Tanaka, F. Krienen, Akira Yamamoto, T. Tallerico, K. Woodle, Y Saito, R. Prigl, S. K. Dhawan, H. Deng, T Ozawa, A. Steinmetz, Yasuhiro Makida, Wuzheng Meng, Kazuhiro Tanaka, I Itoh, G. zu Putlitz, S. I. Redin, F. Toldo, and Michael A. Green
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Muon ,Anomalous magnetic dipole moment ,Dipole magnet ,Magnet ,Superconducting magnet ,Cryogenics ,Instrumentation ,Storage ring ,Magnetic field - Abstract
The muon g-2 experiment at Brookhaven National Laboratory (BNL) has the goal of determining the muon anomalous magnetic moment, a μ (=( g- 2)/2) , to the very high precision of 0.35 parts per million and thus requires a storage ring magnet with great stability and homogeneity. A super-ferric storage ring has been constructed in which the field is to be known to 0.1 ppm . In addition, a new type of air core superconducting inflector has been developed and constructed, which successfully serves as the injection magnet. The injection magnet cancels the storage ring field, 1.5 T , seen by the entering muon beam very close to the storage ring aperture. At the same time, it gives negligible influence to the knowledge of the uniform main magnetic field in the muon storage region located at just 23 mm away from the beam channel. This was accomplished using a new double cosine theta design for the magnetic field which traps most of the return field, and then surrounding the magnet with a special superconducting sheet which traps the remaining return field. The magnet is operated using a warm-to-cold cryogenic cycle which avoids affecting the precision field of the storage ring. This article describes the design, research development, fabrication process, and final performance of this new type of superconducting magnet.
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- 2002
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- View/download PDF
26. Muon g — 2 experiment at Brookhaven National Laboratory
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N.M. Ryskulov, L. Duong, C. Ozben, P. Cushman, F. Krienen, D.N. Grigoriev, H. N. Brown, Rasmus Larsen, Wuzheng Meng, Y.Y. Lee, P. von Walter, Yu. M. Shatunov, G.V. Fedotovich, H. Deng, M. Sossong, William Deninger, D. Winn, A. Grossmann, J. Pretz, E. P. Sichtermann, D. Urner, M. F. Hare, E. P. Solodov, R. M. Carey, C. Timmermans, William Morse, V. W. Hughes, F. J. M. Farley, Alexei Trofimov, R. Prigl, J. Mi, E. Efstathiadis, A. Steinmetz, D. Warburton, R. McNabb, D. Zimmerman, G. zu Putlitz, D. Kawall, S. I. Redin, D. Nikas, C. C. Polly, J. Kindem, Satish Dhawan, J. M. Paley, L. R. Sulak, Klaus-Peter Jungmann, J. P. Miller, B. L. Roberts, Masahiko Iwasaki, Yannis K. Semertzidis, G. T. Danby, C. J. G. Onderwater, M. Kawamur, V. P. Druzhinin, M. Deile, Frederick Gray, P. T. Debevec, A. Yamamoto, D. W. Hertzog, O. Rind, S. Giron, I. Kronkvist, Yuri F. Orlov, G. Bunce, B.I. Khazin, S. Sedykh, I. Logashenko, and M. Grosse-Perdekamp
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Muon ,Alternating Gradient Synchrotron ,National laboratory ,Atomic and Molecular Physics, and Optics - Abstract
A precise measurement of the anomalous g value, a(mu)(+) = (g - 2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result a(mu)(+) = 11 659 202(14)(6) x 10(-10) (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is a(mu) (SM)= 11 659 159.6(6.7) x 10(-10) (0.57 ppm) and a(mu)(exp)-a(mu)(SM) = 42(16) x 10(-10) in which a(mu)(exp) is the world average experimental value.
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- 2002
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27. The Spectra of Young Protostars of Cepheus A
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V. A. Hughes
- Subjects
Physics ,Space and Planetary Science ,Ionization ,Thermal ,Astronomy ,Synchrotron radiation ,Protostar ,Astronomy and Astrophysics ,Outflow ,Electron ,Astrophysics ,Radiation ,Spectral line - Abstract
Radio data obtained over more than 13 years of monitoring give detailed spectra of the youngest known protostars in the young star formation region Cepheus A. Two sources, namely HW 2 and HW 3(d), increase in flux density from 15 to 43 GHz, as previously known. The data confirm that HW 2 appears to be thermal, producing two ionized jets, and these jets show an averaged separation speed of 95 km s-1, in comparison with the difference in the red and blue HCO+ outflow velocities of 54 km s-1. The jets appear to be acting as pistons to produce the molecular outflows. HW 3(c) has time-dependent spectra which decrease between 1.4 and 4.9 GHz, rise to a peak near to 15 GHz, and then fall rapidly to 43.3 GHz. The low-frequency emission appears to be synchrotron radiation from a jet, and the high-frequency emission indicates gyrosynchrotron radiation. HW 3(d) is somewhat similar at the lower frequencies but at the higher frequencies is doubly peaked. One component has a steeply rising spectrum, as for HW 2. HW 3(d) is similar to the double source of L1551 NW but is unlikely to be a double protostar. The data from the whole region, including previous analyses, show time-dependent events that are less than 1000 yr old. The events consist of variations in both flux density and spectra and involve high-energy electrons. These time-dependent variations, together with measured proper motions, indicate that extremely energetic events occur in protostars before they reach the Class 0 stage and could play an important part in dispersing the surrounding gas. Caution must be observed when interpreting processes in protostar-forming regions if they are observed only in the snapshot mode.
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- 2001
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- View/download PDF
28. Radial magnetic field measurements with a Hall probe device in the muon (g-2) storage ring magnet at BNL
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B.I. Khazin, G. T. Danby, P. von Walter, A. Grossmann, B. L. Roberts, William Morse, M. Grosse-Perdekamp, Yannis K. Semertzidis, F. J. M. Farley, G. Bunce, G. zu Putlitz, S. I. Redin, S. K. Dhawan, V. W. Hughes, J. W. Jackson, E. Efstathiadis, D. Kawall, Klaus-Peter Jungmann, N.M. Ryskulov, G.V. Fedotovich, and R. Prigl
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Muon ,Hall effect ,Magnet ,Measure (physics) ,Orbit (dynamics) ,National laboratory ,Instrumentation ,Storage ring ,Magnetic field - Abstract
A Hall probe device has been built to measure the radial component of the magnetic field in the muon (g-2) storage ring at Brookhaven National Laboratory. The ultraprecise (g-2) magnet provides a dominantly vertical magnetic field of about 1:45 T. In order to limit the vertical shift of the muon orbit, the average radial field component should be no more than 5 � 10 � 5 of the vertical field. Our measurements with the Hall probe device achieved an accuracy of 1 � 10 � 5 , which is one of the most precise measurements with Hall probes. This provides adequate accuracy for shimming and control of the radial field. # 2001 Elsevier Science B.V. All rights reserved.
- Published
- 2001
- Full Text
- View/download PDF
29. Study of conversion decays φ→ηe+e−, η→e+e−γ and η→π+π−e+e− at CMD-2
- Author
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Alexander Valishev, M. Arpagaus, A.S. Kuzmin, V.A. Sidorov, N.I. Root, Igor Nesterenko, L.M. Kurdadze, M. Lechner, A.V. Otboev, A.A. Grebeniuk, P.Yu. Stepanov, B.A. Shwartz, V.M. Aulchenko, V.S. Okhapkin, A.G. Shamov, R.R. Akhmetshin, A.V. Bragin, A.S. Popov, V.Sh. Banzarov, V. W. Hughes, V.M. Titov, S.I. Eidelman, P.M. Ivanov, J. A. Thompson, S.G. Zverev, E. P. Solodov, K.Yu. Mikhailov, G.V. Fedotovitch, A.N. Skrinsky, Yu. M. Shatunov, N.M. Ryskulov, S.V. Karpov, Vassili Kazanin, Ivan Koop, A.L. Sibidanov, N.S. Bashtovoy, I.B. Logashenko, I.G. Snopkov, D.V. Bondarev, D.V. Chernyak, P.A. Lukin, A.I. Sukhanov, D.N. Grigoriev, P. Krokovny, A.A. Ruban, V.P. Smakhtin, Yu.V. Yudin, E.A. Perevedentsev, L.M. Barkov, E.V. Anashkin, T.A. Purlatz, F.V. Ignatov, N. Gabyshev, A.E. Bondar, and B.I. Khazin
- Subjects
Physics ,Nuclear and High Energy Physics ,Meson ,Electron–positron annihilation ,Mass spectrum ,Physical chemistry ,Atomic physics - Abstract
Using 15.1 pb −1 of data collected by CMD-2 in the φ -meson energy range, the branching ratios of the following conversion decays have been measured: B ( φ → ηe + e − )=(1.14±0.10±0.06)×10 −4 , B ( η → e + e − γ )=(7.10±0.64±0.46)×10 −3 , B ( η → π + π − e + e − )=(3.7 +2.5 −1.8 ±0.3)×10 −4 . The upper limits for the following rare conversion decays have been obtained at the 90% confidence level: B ( φ → ημ + μ − ) −6 , B ( η → e + e − e + e − ) −5 .
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- 2001
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30. [Untitled]
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J.F.C.A. Veloso, Satish Dhawan, Randolf Pohl, David Taqqu, F. Nez, Wolfgang Schott, Lukas A. Schaller, Yi-Wei Liu, Hubert Schneuwly, L. Julien, Paul E. Knowles, F. J. Hartmann, Paul Indelicato, C.A.N. Conde, Franz Kottmann, J.M.F. dos Santos, Paul Rabinowitz, W. Amir, S. Kazamias, O. Huot, F. Mulhauser, Theodor W. Hänsch, François Biraben, and V. W. Hughes
- Subjects
Physics ,Nuclear and High Energy Physics ,Muon ,Proton ,Physics::Instrumentation and Detectors ,Condensed Matter Physics ,Laser ,Atomic and Molecular Physics, and Optics ,Lamb shift ,law.invention ,Nuclear physics ,Root mean square ,Charge radius ,law ,Physics::Atomic Physics ,Physical and Theoretical Chemistry ,Atomic physics ,Spectroscopy ,Lepton - Abstract
A measurement of the 2S Lamb shift in muonic hydrogen (µ − p) is being prepared at the Paul Scherrer Institute (PSI). The goal of the experiment is to measure the energy difference �E( 2 5 P3/2 − 2 3 S1/2) by laser spectroscopy (λ ≈ 6µm) to a precision of 30 ppm and to deduce the root mean square (rms) proton charge radius with 10 −3 relative accuracy, 20 times more precise than presently known. An important prerequisite to this experiment is the availability of long-lived µp2S -atoms. A 2S- lifetime of ∼1 µs - sufficiently long to perform the laser experiment - at H2 gas pressures of 1-2 hPa was deduced from recent measurements of the collisional 2S-quenching rate. A new low-energy negative muon beam yields an order of magnitude more muon stops in a small low-density gas volume than a conventional cloud muon beam. A stack of ultra-thin carbon foils is the key element of a fast detector for keV-muons. The development of a 2 keV X-ray detector and a 3-stage laser system providing 0.5 mJ laser pulses at 6 µ mi s on the way.
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- 2001
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- View/download PDF
31. Observation of the φ→η′γ decay with four charged particles and photons in the final state
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A.S. Popov, A.V. Otboev, K.Yu. Mikhailov, Igor Nesterenko, V.S. Okhapkin, A.V. Bragin, E.A. Perevedentsev, P.Yu. Stepanov, Yu. M. Shatunov, V. W. Hughes, V.Sh. Banzarov, P.M. Ivanov, Ivan Koop, L.M. Barkov, E. P. Solodov, I.G. Snopkov, N.I. Root, Alexander Valishev, R.R. Akhmetshin, A.S. Kuzmin, Vassili Kazanin, N.S. Bashtovoy, D.V. Chernyak, V.M. Aulchenko, A.A. Ruban, F.V. Ignatov, P. Krokovny, S.V. Karpov, S.I. Redin, Yu.V. Yudin, A.L. Sibidanov, N.M. Ryskulov, G.V. Fedotovitch, M. Arpagaus, D.N. Grigoriev, A.A. Grebeniuk, A.G. Shamov, V.P. Smakhtin, J. A. Thompson, A.I. Sukhanov, S.I. Eidelman, D.V. Bondarev, B.A. Shwartz, S.G. Zverev, L.M. Kurdadze, A.N. Skrinsky, P.A. Lukin, M. S. Korostelev, V.A. Sidorov, T.A. Purlatz, N. Gabyshev, I.B. Logashenko, E.V. Anashkin, V.M. Titov, A.E. Bondar, and B.I. Khazin
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Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Photon ,Branching fraction ,Electron–positron annihilation ,State (functional analysis) ,Decay chain ,Atomic physics ,Charged particle - Abstract
Using 11.6 pb −1 of data collected in the energy range 0.864-1.06 GeV by CMD-2 at VEPP-2M, the rare decay mode φ → η ′ γ was observed via the decay chain η ′→ π + π − η , η → π + π − π 0 or η → π + π − γ . The following branching ratio was obtained: Br(φ→η′γ)= 4.9 +2.2 −1.8 ±0.6 ×10 −5 .
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- 2000
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32. Autoassociative–heteroassociative neural networks
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Claudia V. Kropas-Hughes, Steven K. Rogers, Matthew Kabrisky, and Mark E. Oxley
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Physical neural network ,Quantitative Biology::Neurons and Cognition ,Artificial neural network ,Computer science ,business.industry ,Time delay neural network ,Computer Science::Neural and Evolutionary Computation ,Autoassociative memory ,Probabilistic neural network ,Artificial Intelligence ,Control and Systems Engineering ,Metric (mathematics) ,Artificial intelligence ,Electrical and Electronic Engineering ,Stochastic neural network ,business ,Nervous system network models - Abstract
An efficient neural network computing technique capable of synthesizing two sets of output signal data from a single input signal data set. The method and device of the invention involves a unique integration of autoassociative and heteroassociative neural network mappings, the autoassociative neural network mapping enabling a quality metric for assessing the generalization or prediction accuracy of the heteroassociative neural network mapping.
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- 2000
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33. Observation of the decay
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Alexander Valishev, I.G. Snopkov, N.I. Root, P.Yu. Stepanov, P.M. Ivanov, A.V. Bragin, V.Sh. Banzarov, Yu. M. Shatunov, N.M. Ryskulov, E. P. Solodov, Yu.V. Yudin, A.I. Sukhanov, B.I. Khazin, E.A. Perevedentsev, R.R. Akhmetshin, D.N. Grigoriev, Vassili Kazanin, S.V. Karpov, D.V. Chernyak, L.M. Barkov, A.L. Sibidanov, M. Arpagaus, F.V. Ignatov, V.P. Smakhtin, N.S. Bashtovoy, J. A. Thompson, A.V. Otboev, A.S. Popov, A.S. Kuzmin, I.B. Logashenko, G.V. Fedotovitch, V.S. Okhapkin, E.V Anashkin, V. W. Hughes, B.A. Shwartz, K.Yu. Mikhailov, M. S. Korostelev, A.A Ruban, A.N. Skrinsky, S.I. Eidelman, P.A. Lukin, P. Krokovny, A.E. Bondar, S.G. Zverev, Igor Nesterenko, V.A. Sidorov, T.A. Purlatz, L.M. Kurdadze, N. Gabyshev, I. A. Koop, S.I. Redin, A. I. Milstein, V.M. Titov, D.V. Bondarev, V.M. Aulchenko, A.A. Grebeniuk, and A.G. Shamov
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Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Crystallography ,Annihilation ,Pion ,Meson ,OZI rule ,Branching fraction ,Atomic physics - Abstract
Using 11.6 pb −1 of data collected in the energy range 0.984–1.06GeV by CMD-2 at VEPP-2M, the cross section of the reaction e + e − →π + π − π + π − hasbeen studied. For the firsttime an interference patternwas observed in the energy dependence of the cross section near theφ meson. The branching ratio of the φ → π + π − π + π − decay doublesuppressed by the G-parity and OZI rule is measuredBr(φ → π + π − π + π − ) = (3.93 ±1.74 ±2.14) ·10 −6 .The upper limits have been placed for the decays φ → π + π − π + π − π 0 and φ → ηπ + π − Br(φ → π + π − π + π − π 0 ) < 4.6 ·10 −6 90%CL,Br(φ → ηπ + π − ) < 1.8 ·10 −5 90%CL. 1 Introduction Production of four pions in e + e − annihilation is now well studied in the c.m.energy range 1.05 to 2.5 GeV (see [ 1] and references therein). Results onthe measurements of the cross section of the reaction e + e − → π + π − π + π − in the energy range from 0.60 to 0.97 GeV as well as the probability of theρ 0 meson decay into the π + π − π + π −
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- 2000
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34. A quad 500 MHz waveform digitizer with differential trigger for use in the muon g-2 experiment
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D. Kawall, J. Pretz, Wen Liu, V. W. Hughes, Satish Dhawan, and R Sumner
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Physics ,Nuclear and High Energy Physics ,Muon ,business.industry ,Feature (computer vision) ,8-bit ,Waveform ,Differential (infinitesimal) ,business ,Instrumentation ,Sample (graphics) ,Computer hardware ,Communication channel - Abstract
We have developed and tested a 4 channel, 500 MHz, 512 k sample, 8 bit waveform digitizer in a FASTCAMAC module. A novel feature is the implementation of a sparse scan during readout with a programmable differential trigger to reduce the data to a manageable level. The differential trigger allows reliable detection of pulses with low threshold in the presence of a variable baseline.
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- 2000
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- View/download PDF
35. Measurement of the1s−2sEnergy Interval in Muonium
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A. Breitrück, J. Merkel, Robin Santra, W. T. Toner, Simon L. Cornish, S. Reinhard, G. H. Eaton, Y Matyugin, Yakhontov, Klaus-Peter Jungmann, Yi-Wei Liu, GZ Putlitz, B Meyer, Christopher A. Scott, P E G Baird, D Hubl, A. Grossmann, SN Bagayev, P. Bakule, Lorenz Willmann, I. C. Lane, V. W. Hughes, S Dychkov, M. G. Boshier, D Lucas, P.G.H. Sandars, K. Träger, M. Towrie, and P. V. Schmidt
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Physics ,Muon ,Deuterium ,Frequency separation ,Muonium ,Atom ,Energy interval ,General Physics and Astronomy ,High Energy Physics::Experiment ,Charge (physics) ,Physics::Atomic Physics ,Atomic physics ,Spectroscopy - Abstract
The 1s-2s interval has been measured in the muonium (;mgr;(+)e(-)) atom by Doppler-free two-photon pulsed laser spectroscopy. The frequency separation of the states was determined to be 2 455 528 941.0(9.8) MHz, in good agreement with quantum electrodynamics. The result may be interpreted as a measurement of the muon-electron charge ratio as -1-1.1(2.1)x10(-9). We expect significantly higher accuracy at future high flux muon sources and from cw laser technology.
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- 2000
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36. New measurement of the rare decay φ→η′γ with CMD-2
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N.M. Ryskulov, A.I. Shekhtman, A.A. Grebeniuk, D.V. Bondarev, Alexander Valishev, A.G. Shamov, Igor Nesterenko, P.A. Lukin, A.S. Popov, V.A. Sidorov, L.M. Kurdadze, T.A. Purlatz, S.V. Karpov, A.S. Kuzmin, K.Yu. Mikhailov, E. P. Solodov, V.P. Smakhtin, N. Gabyshev, P. Krokovny, A.E. Bondar, A. P. Lysenko, V.Sh. Banzarov, J. A. Thompson, Yu. M. Shatunov, B.I. Khazin, D.N. Grigoriev, A.I. Sukhanov, Ivan Koop, M. Arpagaus, A.L. Sibidanov, I.G. Snopkov, V.M. Aulchenko, G.V. Fedotovitch, E.V. Anashkin, A.N. Skrinsky, M. S. Korostelev, A.A. Ruban, P.Yu. Stepanov, V.M. Titov, I.B. Logashenko, V. W. Hughes, B.A. Shwartz, N.I. Root, S.G. Zverev, N.S. Bashtovoy, Vassili Kazanin, A.V. Otboev, V.S. Okhapkin, A.V. Bragin, P.M. Ivanov, R.R. Akhmetshin, D.V. Chernyak, A.A. Polunin, Yu.V. Yudin, S.I. Eidelman, E.A. Perevedentsev, and L.M. Barkov
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Luminosity (scattering theory) ,law ,Branching fraction ,Electron–positron annihilation ,Detector ,Collider ,law.invention - Abstract
A new measurement of the rare decay φ → η ′ γ performed with the CMD-2 detector at the VEPP-2M collider in Novosibirsk is described. Of the data sample corresponding to the integrated luminosity of 14.5 pb −1 , twenty one events have been selected in the mode η ′→ π + π − η , η → γγ . The following branching ratio was obtained: B( φ → η ′ γ )=(8.2 +2.1 −1.9 ±1.1)·10 −5 .
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- 2000
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37. Cross section of the reaction e+e−→π+π−π+π− below 1 GeV at CMD-2
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A.A. Polunin, A.V. Bragin, Igor Nesterenko, Alexander Valishev, S.V. Karpov, A.I. Sukhanov, A.E. Bondar, A. I. Milstein, E. P. Solodov, S.I. Eidelman, A.A. Grebeniuk, M. Arpagaus, N.M. Ryskulov, V.Sh. Banzarov, E.V. Anashkin, A.G. Shamov, A.L. Sibidanov, I.G. Snopkov, A.N. Skrinsky, A.S. Kuzmin, J. A. Thompson, M. S. Korostelev, I.B. Logashenko, Vassili Kazanin, V.A. Sidorov, R.R. Akhmetshin, B.A. Shwartz, V.M. Aulchenko, G.V. Fedotovitch, B.I. Khazin, V.M. Titov, S.G. Zverev, P.Yu. Stepanov, L.M. Kurdadze, N.I. Root, D.V. Bondarev, A.V. Otboev, P.A. Lukin, D.V. Chernyak, V.S. Okhapkin, T.A. Purlatz, N.S. Bashtovoy, N. Gabyshev, V. W. Hughes, Yu. M. Shatunov, Ivan Koop, A.S. Popov, K.Yu. Mikhailov, Yu.V. Yudin, L.M. Barkov, A.A. Ruban, P. Krokovny, V.P. Smakhtin, and D.N. Grigoriev
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Physics ,Nuclear and High Energy Physics ,Cross section (physics) ,Range (particle radiation) ,Meson ,Branching fraction ,Electron–positron annihilation ,Intermediate state ,Atomic physics - Abstract
Using 3.07 pb −1 of data collected in the energy range 0.60–0.97 GeV by CMD-2, about 150 events of the process e + e − → π + π − π + π − have been selected. The energy dependence of the cross section agrees with the assumption of the a 1 (1260) π intermediate state which is dominant above 1 GeV. For the first time π + π − π + π − events are observed at the ρ meson energy. Under the assumption that all these events come from the ρ meson decay, the value of the cross section at the ρ meson peak corresponds to the following decay width: Γ(ρ 0 →π + π − π + π − )=(2.8±1.4±0.5) keV or to the branching ratio B(ρ 0 →π + π − π + π − )=(1.8±0.9±0.3)·10 −5 .
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- 2000
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38. [Untitled]
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P E G Baird, J. Merkel, Yi-Wei Liu, S Dychkov, WT Toner, Lorenz Willmann, D Hubl, Michael Towrie, Simon L. Cornish, I. C. Lane, P. V. Schmidt, V. W. Hughes, SN Bagayev, P. Bakule, S. Reinhard, A. Grossmann, K. Träger, D Lucas, Klaus-Peter Jungmann, Robin Santra, G. H. Eaton, M. G. Boshier, P.G.H. Sandars, Y Matyugin, Christopher A. Scott, B Meyer, G. zu Putlitz, A. Breitrück, and Yakhontov
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Hydrogen ,Chemistry ,Muonium ,chemistry.chemical_element ,Mass ratio ,Lamb shift ,symbols.namesake ,Deuterium ,Atom ,symbols ,High Energy Physics::Experiment ,Physics::Atomic Physics ,Atomic physics ,Spectroscopy ,Doppler effect - Abstract
The 1s–2s energy interval in the muonium (μ+e−) atom has been measured by Doppler free two photon laser spectroscopy. A value of 2455528941.0(9.8) MHz has been obtained in good agreement with quantum electrodynamics (QED). The muon-electron mass ratio can be extracted and is found to be 206.76838(17). The measurement may also be interpreted as a determination of the muon-electron charge ratio as -1- 1.1(2.1)· 10−9. Corresponding measurements in deuterium using the same experimental setup confirmed the validity of the applied analysis procedure.
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- 2000
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39. [Untitled]
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Randolf Pohl, F. Trehin, Wolfgang Schott, O. Huot, Yi-Wei Liu, C. Petitjean, Paul E. Knowles, J.M.F. dos Santos, F. J. Hartmann, Hubert Schneuwly, L. M. Simons, C.A.N. Conde, V. W. Hughes, P. Hauser, David Taqqu, Françoise Mulhauser, Franz Kottmann, Theodor W. Hänsch, François Biraben, Paul Rabinowitz, J.F.C.A. Veloso, F. Nez, Paul Indelicato, and Lukas A. Schaller
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Physics ,Muon ,Proton ,Physics::Instrumentation and Detectors ,chemistry.chemical_element ,Laser ,law.invention ,Lamb shift ,Root mean square ,Laser linewidth ,Xenon ,chemistry ,law ,Charge radius ,Atomic physics - Abstract
The contribution of the root mean square (RMS) proton charge radius to the Lamb shift (2S–2P energy difference) in muonic hydrogen (μp) amounts to 2%. Apart from the uncertainty on this charge radius, theory predicts the Lamb shift with a precision on the ppm level. We are going to measure ΔE (2 S1/2(F=1)–2 P3/2(F=2)) in a laser resonance experiment to a precision of 30 ppm (i.e., 10% of the natural linewidth) and to deduce the RMS proton charge radius with 10−3 relative accuracy, 20 times more precise than presently known. The most important requirement for the feasibility of such an experiment, namely the availability of a sufficient amount of long lived metastable μp atoms in the 2S state, has been investigated in a recent experiment at PSI. Our analysis shows that in the order of one percent of all muons stopped in low pressure hydrogen gas form a long lived μp(2S) with a lifetime of the order of 1 μs. The technical realization of our experiment involves a new high intensity low energy muon beam, an efficient low energy muon entrance detector, a randomly triggered 3 stage laser system providing the 0.5 mJ, 7 ns laser pulses at 6.02 μm wavelength, and a combination of a xenon gas proportional scintillation chamber (GPSC) and a microstrip gas chamber (MSGC) with a CsI coated surface to detect the 2 keV X rays from theμp(2P → 1S) transition.
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- 2000
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40. Study of the radiative decay φ→ηγ with CMD-2 detector
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P.A. Lukin, V.P. Smakhtin, N. Gabyshev, J. A. Thompson, P.Yu. Stepanov, I.B. Logashenko, S.I. Eidelman, D.V. Bondarev, A.A. Ruban, T.A. Purlatz, L.M. Kurdadze, I.G. Snopkov, N.I. Root, N.S. Bashtovoy, G.V. Fedotovich, A.I. Sukhanov, D.N. Grigoriev, B.A. Shwartz, Yu.V. Yudin, V. W. Hughes, S.G. Zverev, V. S. Banzarov, A. Bondar, A. P. Lysenko, L.M. Barkov, R.R. Akhmetshin, D.V. Chernyak, A.A. Grebeniuk, B.I. Khazin, A.G. Shamov, E.V. Anashkin, B. L. Roberts, A.N. Skrinsky, A.S. Kuzmin, Yu. M. Shatunov, P.M. Ivanov, Ivan Koop, P. Krokovny, K.Yu. Mikhailov, V.A. Sidorov, N.M. Ryskulov, V.S. Okhapkin, E. P. Solodov, and Vassili Kazanin
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Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Branching fraction ,Detector ,Mode (statistics) ,Radiative decay - Abstract
Using the 1.9 pb −1 of data collected with the CMD-2 detector at VEPP-2M the decay mode φ→ηγ, η→π+π−π0 has been studied. The obtained branching ratio is B(φ→ηγ)=(1.18±0.03±0.06)%.
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- 1999
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41. Status of the g-2 experiment at BNL
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D. Kawall, V. B. Golubev, S. Kurokawa, E. P. Solodov, B. J. Hughes, G. Bunce, P. Cushman, P. von Walter, R. M. Carey, A. Stillman, P. T. Debevec, Y.Y. Lee, J. W. Jackson, G.V. Fedotovich, Louis Snydstrup, F. Toldo, A.G. Chertovskikh, Rasmus Larsen, H. Hirabayashi, J. Cullen, M. F. Hare, O. Rind, H. Deng, D. von Lintig, E. Benedict, D. Urner, David Miller, Alexei Trofimov, X. Fei, J. Benante, A. Disco, D. Winn, A. Soukas, E. Efstathiadis, F. J. M. Farley, Yannis K. Semertzidis, R. Prigl, H. N. Brown, R. McNabb, O. N. Ryskulov, Yuri Shatunov, C. Timmermans, Jinsong Ouyang, J. Geller, William Deninger, G. zu Putlitz, S. I. Redin, M. Tanaka, K. Woodle, C. Poly, E. Hazen, B. Bunker, C. Pearson, Y. Mizumachi, M. Grosse Perdekamp, H. E. Ahn, Ulrich Haeberlen, J. Pretz, K. Endo, D. Zimmerman, V. Monich, L. Jia, G. T. Danby, R. P. Shutt, J. Kindem, William Morse, T. D. Jones, A. Maskimov, L. Duong, H. Hseuh, V. P. Druzhinin, S. I. Serednyakov, F. Krienen, Wuzheng Meng, B.I. Khazin, C. Pai, Yuri F. Orlov, Michael A. Green, W. Earle, M. Mapes, A. Grossmann, V. W. Hughes, D. Warbuton, Yu Merzliakov, I. Polk, Satish Dhawan, J. Gerhaeuser, W. A. Worstell, S. Kochis, J. P. Miller, B. L. Roberts, Klaus-Peter Jungmann, Masahiko Iwasaki, J. Sandberg, S. Sedykh, S. Rankowitz, D.H Brown, D. N. Grigorev, I. Logashenko, G. S. Varner, D. W. Hertzog, A. Yamamoto, T. Tallerico, S. Giron, L. R. Sulak, and Precision Frontier
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Physics ,Nuclear and High Energy Physics ,Particle physics ,Large Hadron Collider ,Muon ,Meson ,Anomalous magnetic dipole moment ,Physics::Instrumentation and Detectors ,MUON ,Atomic and Molecular Physics, and Optics ,Nuclear physics ,Pion ,DIPOLE-MOMENT ,Antimatter ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,ANOMALOUS MAGNETIC-MOMENT ,Storage ring ,Lepton - Abstract
The muon g-2 experiment at Brookhaven has successfully completed two exploratory runs using pion injection and direct muon injection for checkout and initial data taking. The main components of the experiment, which include the pion beam line, the superconducting storage ring and inflector magnets, the muon kicker and the lead-scintillating fiber calorimeters have been satisfactorily commissioned. First results on the anomalous magnetic moment of the positive muon from pion injection are in good agreement with previous experimental results for a(mu+) and a(mu-) from CERN and of comparable accuracy (13 ppm). Analysis of the 1998 muon injection run is in progress and expected to improve the precision to about 4 ppm. A first production run is scheduled for January 1999 with the goal of reaching the 1 ppm error level.
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- 1999
- Full Text
- View/download PDF
42. Anomalousgvalues of the electron and muon
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V. W. Hughes and T. Kinoshita
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Physics ,Muon ,Quantum electrodynamics ,General Physics and Astronomy ,Electron ,Atomic physics ,Spectroscopy ,Spin (physics) ,Electron magnetic dipole moment ,Hyperfine structure ,Lamb shift ,Spin magnetic moment - Abstract
Historically, the spin magnetic moment of the electron µ e or its gvalue g e has played a central role in modern physics, dating from its discovery in atomic optical spectroscopy and its subsequent incorporation in the Dirac theory of the electron, which predicted the value g e = 2 The experimental discovery in atomic microwave spectroscopy that g e was larger than 2 by a multiplicative factor of about 1 part in 103, g e =2.00238(10), together with the discovery of the Lamb shift in hydrogen (S=22 S 1/2 − 22 P 1/2), led to the development of modern quantum electrodynamics with its renormalization procedure. The theory enables us to calculate these effects precisely as finite radiative corrections. By now the experimental value of g e -2has been measured to about 4 ppb, and the theoretical value, which is expressed as a power series in the fine-structure constant a, has been evaluated to better than 1 ppb, assuming the value of α is known.
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- 1999
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43. Cepheus A East: Unraveling the Mysteries
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Matthew A. Greenhouse, Jennifer A. Goetz, Dan M. Watson, William J. Forrest, V. A. Hughes, Jacqueline Fischer, S. N. Raines, Howard A. Smith, Charles E. Woodward, and Judy Pipher
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Physics ,Space and Planetary Science ,Infrared ,Coincident ,Molecular cloud ,Artillery shell ,Astronomy ,Astronomy and Astrophysics ,Outflow ,Astrophysics ,Emission spectrum ,Spectral line - Abstract
New infrared images of Cep A East are presented that show two regions of shock-excited line emission from separate bipolar flows. We identify the dominant sources powering the outflows and argue that the results support a multiple outflow model (Narayanan & Walker) as opposed to a quadrupolar outflow scenario. The images include near-infrared broadband ( [2.158 μm], L'' [3.81 μm], and M' [4.67 μm]) and spectral line ([Fe II] emission line at 1.644 μm and H2 1-0 S[1] line at 2.122 μm) observations, as well as continuum emission, at 1.644 μm and 2.122 μm. Considering our data and other results, we present a unified, self-consistent picture of the disk and shock structure. The northern emission region appears to be the result of the ablation of a dense molecular clump (coincident with HW 6) in the path of a diverting jet from YSO HW 2 and subsequent multiple bow shocks with prompt entrainment arising from the interaction of the jet with the molecular cloud Cep A-2. The southern line emission region near HW 7 resembles the artillery shell bow shocks found in Orion and is most likely a J-type shock caused by a jet from another YSO, possibly HW 3(d)ii.
- Published
- 1998
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44. Study of dynamics of φ→π+π−π0 decay with CMD-2 detector
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V.A. Sidorov, A.I. Sukhanov, V.I Ptitzyn, D.N. Grigoriev, P.M. Ivanov, B.I. Khazin, V. W. Hughes, Yu. M. Shatunov, D.H Brown, N.I. Root, S.G. Zverev, N.M. Ryskulov, T.A. Purlatz, Ivan Koop, G.V. Fedotovich, S. Eidelman, Igor Nesterenko, B. L. Roberts, A.A. Polunin, L.M. Kurdadze, V.S. Okhapkin, I.G. Snopkov, B.O Baibusinov, J. A. Thompson, A.S. Dvoretsky, Yu.I Merzlyakov, E.V. Anashkin, I.B. Logashenko, G.A Aksenov, A.N. Skrinsky, M. Arpagaus, P.Yu. Stepanov, R.R. Akhmetshin, P.A. Lukin, N. Gabyshev, V.M. Titov, B. Shwartz, V.P. Smakhtin, A.A. Ruban, Yu.V. Yudin, A. Bondar, L.M. Barkov, V. S. Banzarov, V.V Danilov, E. P. Solodov, A.A. Grebeniuk, A.S. Kuzmin, D.V. Chernyak, and A.G. Shamov
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Amplitude ,Meson ,law ,Electron–positron annihilation ,Detector ,Dalitz plot ,Atomic physics ,Collider ,law.invention - Abstract
A study of the φ → π + π − π 0 decay mode has been performed using a data sample of about 2.0 million φ decays collected by the CMD-2 detector at VEPP-2M collider in Novosibirsk. The following parameters of the φ -meson have been measured: Br ( φ → π + π − π 0 )=0.145±0.009±0.003 and δ φ − ω =162±17°. The analysis of the Dalitz plot showed the dominance of the φ → ρπ intermediate mechanism, the limits for the ratio of the direct amplitude of φ →3 π to that of φ → ρπ are −0.16 a 1 φ → π + π − η and direct φ → ργγ have been found for the first time: Br ( φ → π + π − η ) −4 and Br ( φ → ργγ ) −4 at 90% C.L.
- Published
- 1998
- Full Text
- View/download PDF
45. Polarised quark distributions in the nucleon from semi-inclusive spin asymmetries
- Author
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F. Tessarotto, F. Perrot-Kunne, W. Kröger, E. Burtin, K. Zaremba, Jay Roberts, J. Cranshaw, T. Matsuda, M. Plo, I. Sabo, M. Grosse Perdekamp, A. Karev, K. Haft, V. G. Krivokhijine, S. K. Dhawan, J. Lichtenstadt, S. Platchkov, N. de Botton, Victor Kukhtin, H. Gilly, M. Lamanna, J. H. Moromisato, Clemens A. Heusch, J. S. McCarthy, G. Igo, A. Steinmetz, Patrick Hautle, S. Bültmann, R. Birsa, F. Feinstein, D. von Harrach, J. E.J. Oberski, Takahiro Iwata, A. Ogawa, A. Schiller, D. Thers, Yu. Kisselev, G. Reicherz, D. Crabb, J. A. Garzon, C. Dulya, Naoaki Horikawa, Franco Bradamante, T. Akdogan, B. Roscherr, S. Dalla Torre, H. J. Kessler, G. Bardin, L. Betev, Roland Windmolders, J. Martino, Abhay Deshpande, C. S. Özben, M. Velasco, A. Arvidson, Rudiger Voss, J. Nassalski, M. Giorgi, U. Stiegler, T. Hasegawa, I.A. Savin, D. J. Miller, P. Schiavon, Andrea Bressan, Michal Szleper, A. Gallas, G. K. Mallot, J. Vogt, E. Arik, B. W. Mayes, T. O. Niinikoski, S. Ishimoto, Lawrence Pinsky, A. Witzmann, Y. Miyachi, St. Goertz, F. Lehar, G. Unel, B. Frois, H. Postma, R. van Dantzig, Matias Rodriguez, E. P. Sichtermann, F. Simeoni, G.I. Smirnov, J. Saborido, R. Puntaferro, D. Fasching, G. van Middelkoop, Jinkui Zhao, D. Pose, W. Meyer, Kunikazu Mori, C. A. Whitten, J. Kyynäräinen, A. de Lesquen, J. Pretz, K. Medved, Regine Willumeit, H. Pereira, W. Tlaczala, A. Tripet, G. Gracia, A. Sandacz, N. De Groot, K. Kurek, Anna Zanetti, F. Marie, T. Kageya, A. Rijllart, Bernardo Adeva, E. Rondio, T. Çuhadar, J. M. Le Goff, Heinrich B. Stuhrmann, A. Magnon, J. Ylöstalo, L. Naumann, M. Litmaath, Günter Baum, P. Berglund, B. Derro, E. von Goeler, D. Krämer, W. Wislicki, G. Rädel, S. Eichblatt, Alan D. Martin, B. Badelek, C. Fernandez, N. Hayashi, D. Peshekhonov, A. Bravar, V. W. Hughes, Ulrich Landgraf, A. Staude, T. J. Ketel, S. Forthmann, J. Kiryluk, E. M. Kabuß, (Astro)-Particles Physics, B., Adeva, T., Akdogan, E., Arik, A., Arvidson, B., Badelek, G., Bardin, G., Baum, P., Berglund, L., Betev, R., Birsa, N., de Botton, Bradamante, Franco, A., Bravar, Bressan, Andrea, S., Bültmann, E., Burtin, D., Crabb, J., Cranshaw, T., Çuhadar, DALLA TORRE, Silvia, R., van Dantzig, B., Derro, A., Deshpande, S., Dhawan, C., Dulya, S., Eichblatt, D., Fasching, F., Feinstein, C., Fernandez, S., Forthmann, B., Froi, A., Galla, J. A., Garzon, H., Gilly, Giorgi, Marcello, E., von Goeler, S., Goertz, G., Gracia, N., de Groot, M., Grosse Perdekamp, K., Haft, D., von Harrach, T., Hasegawa, P., Hautle, N., Hayashi, C. A., Heusch, N., Horikawa, V. W., Hughe, G., Igo, S., Ishimoto, T., Iwata, E. M., Kabuß, T., Kageya, A., Karev, H. J., Kessler, T. J., Ketel, J., Kiryluk, Kisselev, Y. u., D., Krämer, V., Krivokhijine, W., Kröger, V., Kukhtin, K., Kurek, J., Kyynäräinen, M., Lamanna, U., Landgraf, J. M., Le Goff, F., Lehar, A., de Lesquen, J., Lichtenstadt, M., Litmaath, A., Magnon, G. K., Mallot, F., Marie, Martin, Anna, J., Martino, T., Matsuda, B., Maye, J. S., Mccarthy, K., Medved, W., Meyer, G., van Middelkoop, D., Miller, Y., Miyachi, K., Mori, J., Moromisato, J., Nassalski, L., Naumann, T. O., Niinikoski, J. E. J., Oberski, A., Ogawa, C., Ozben, H., Pereira, F., Perrot Kunne, D., Peshekhonov, L., Pinsky, S., Platchkov, M., Plo, D., Pose, H., Postma, J., Pretz, R., Puntaferro, G., Rädel, A., Rijllart, G., Reicherz, J., Robert, M., Rodriguez, E., Rondio, B., Roscherr, I., Sabo, J., Saborido, A., Sandacz, I., Savin, Schiavon, Paolo, A., Schiller, E. P., Sichtermann, F., Simeoni, G. I., Smirnov, A., Staude, A., Steinmetz, U., Stiegler, H., Stuhrmann, M., Szleper, F., Tessarotto, D., Ther, W., Tlaczala, A., Tripet, G., Unel, M., Velasco, J., Vogt, R., Vo, C., Whitten, R., Windmolder, R., Willumeit, W., Wislicki, A., Witzmann, J., Ylöstalo, Zanetti, ANNA MARIA, K., Zaremba, and J., Zhao
- Subjects
Quark ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Muon ,Valence (chemistry) ,SMC ,Hadron ,FOS: Physical sciences ,SIDIS ,Polarized quark distributions ,Deep inelastic scattering ,High Energy Physics - Experiment ,Nuclear physics ,High Energy Physics - Experiment (hep-ex) ,Deuterium ,High Energy Physics::Experiment ,Nucleon ,Particle Physics - Experiment - Abstract
We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$., Comment: 17 pages
- Published
- 1998
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46. First observation of the decay φ→η′(958)γ
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E.V Popkov, E.V Anashkin, B.I. Khazin, P.Yu. Stepanov, D.H Brown, M.A Shubin, V.V Danilov, Yu. M. Shatunov, N.M. Ryskulov, V.P. Smakhtin, A.I. Sukhanov, A.I. Shekhtman, A.P. Lysenko, V.I Ptitzyn, S.I. Eidelman, B.A. Shwartz, M. Arpagaus, T.A. Purlatz, A.A. Grebeniuk, A. V. Klimenkov, P.M. Ivanov, S.G. Zverev, N.I. Root, A.A. Polunin, G.V. Fedotovich, A.G. Shamov, V. W. Hughes, A.A. Ruban, S.E Baru, E. P. Solodov, D.N. Grigoriev, I.B. Logashenko, J. A. Thompson, P.A. Lukin, E.A. Perevedentsev, A.S. Kuzmin, A.G. Chertovskikh, A. Bondar, L.M. Barkov, Yu.V. Yudin, R.R. Akhmetshin, V.A. Sidorov, Vassili Kazanin, V. S. Banzarov, D.V. Chernyak, V.M Aulchenko, Alexander Skrinsky, I. A. Koop, A.V Maksimov, V.S. Okhapkin, B.L. Roberts, N. Gabyshev, L.M. Kurdadze, I.G. Snopkov, and A.S. Dvoretsky
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Particle physics ,law ,Branching fraction ,Radiative decay ,Collider ,Event (particle physics) ,law.invention - Abstract
The decay φ → η ′ γ has been observed by the CMD-2 detector at the e + e − collider VEPP-2M at Novosibirsk. Of 5.5 million produced φ 's, six events of the φ → η ′ γ decay were selected with the expected background less than one event. The corresponding branching ratio is B( φ → η ′ γ )=1.2 +0.7 −0.5 ·10 −4 . It is the first observation of this radiative decay.
- Published
- 1997
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47. Search for rare φ decays in π+π−γ final state
- Author
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D.H Brown, M.A Shubin, S.I. Eidelman, Igor Nesterenko, P.M. Ivanov, B.O Baibusinov, V.A. Sidorov, N.I. Root, E.V Popkov, L.M. Kurdadze, I.G. Snopkov, G.V. Fedotovich, V. S. Banzarov, I.B. Logashenko, V.P. Smakhtin, E. P. Solodov, B.I. Khazin, A. Bondar, L.M. Barkov, B.A. Shwartz, B.L. Roberts, C.M Valine, Yu.V. Yudin, R.R. Akhmetshin, M. Arpagaus, A.V Maksimov, I. A. Koop, G.A Aksenov, V. W. Hughes, T.A. Purlatz, Yu.I Merzlyakov, N.M. Ryskulov, V.M. Titov, Alexander Skrinsky, V.S. Okhapkin, E.A. Perevedentsev, A.A. Ruban, J. A. Thompson, E.V Anashkin, V. A. Astakhov, A.A. Grebeniuk, P.A. Lukin, D.N. Grigoriev, N. Gabyshev, A.I. Sukhanov, A.S. Kuzmin, A.P. Lysenko, and D.V. Chernyak
- Subjects
Physics ,Nuclear and High Energy Physics ,Crystallography ,Bremsstrahlung ,State (functional analysis) ,Atomic physics - Abstract
A search for φ radiative decays has been performed using a data sample of about 2.0 million φ decays collected by the CMD-2 detector at VEPP-2M collider in Novosibirsk. From the selected e + e − → π + π − γ events the following results were obtained: B( φ → f 0 (980) γ ) −4 for destructive and B( φ → f 0 (980) γ ) −4 for constructive interference with the Bremsstrahlung process respectively, B( φ → γ → π + π − γ ) −5 for E γ >20 MeV, B( φ → ργ ) −4 . From the selected e + e − → μ + μ − γ events B( φ → μ + μ − γ )=(2.3±1.0)×10 −5 has been obtained for E γ >20 MeV. The upper limit on the P,CP-violating decay η → π + π − has also been placed: B( η → π + π − ) −4 . All upper limits are at 90% C.L.
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- 1997
- Full Text
- View/download PDF
48. The spin-dependent structure function g1(x) of the proton from polarized deep-inelastic muon scattering
- Author
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Michal Szleper, D. Crabb, Heinrich B. Stuhrmann, A. Schiller, Naoaki Horikawa, J. Pretz, A. Rijllart, Bernardo Adeva, T. Kageya, J. Ylöstalo, A. Ogawa, L. Naumann, C. Dulya, I. Sabo, C. A. Whitten, J. Kyynäräinen, A. Tripet, D. Peshekhonov, F. Lehar, V. W. Hughes, G. Gracia, P. Schiavon, A. Sandacz, M. Giorgi, V. G. Krivokhijine, B. Mayes, Rudiger Voss, Yu. Kisselev, S. K. Dhawan, B. Derro, J. S. McCarthy, S. Bültmann, T. O. Niinikoski, Ulrich Landgraf, E. Arik, Alan D. Martin, F. Marie, A. Staude, M. Litmaath, Etienne Burtin, David Miller, Matias Rodriguez, Kunikazu Mori, J. Moromisato, A. Magnon, D. Thers, E. P. Sichtermann, K. Kurek, E. M. Kabuß, E. Rondio, D. Pose, Abhay Deshpande, K. Zaremba, I.A. Savin, T. J. Ketel, M. Plo, F. Feinstein, A. Karev, Matthias Grosse Perdekamp, G. Bardin, A. Witzmann, Patrick Hautle, J. M. Le Goff, G. Igo, J. Kiryluk, Clemens A. Heusch, T. Çuhadar, S. Platchkov, J. Lichtenstadt, R. Birsa, J. A. Garzon, Franco Bradamante, W. Wislicki, A. Steinmetz, P. Berglund, K. Medved, N. De Groot, Anna Zanetti, H. Postma, B. Frois, J. Saborido, W. Tlaczala, B. Roscherr, Lawrence Pinsky, T. Matsuda, S. Ishimoto, U. Stiegler, H. Gilly, G. Unel, F. Simeoni, G.I. Smirnov, R. van Dantzig, R. Puntaferro, J. E.J. Oberski, J. Nassalski, G. van Middelkoop, G. Rädel, W. Meyer, B. Badelek, C. Fernandez, Mayda Velasco, N. Hayashi, L. Betev, F. Perrot-Kunne, S. Eichblatt, A. Bravar, V. Kuktin, J. Cranshaw, D. Fasching, J. Vogt, G. Baum, Takahiro Iwata, G. Reicherz, Roland Windmolders, S. Dalla Torre, A. Arvidson, H. Pereira, A. de Lesquen, St. Goertz, N. de Botton, Andrea Bressan, J. Martino, A. Gallas, G. K. Mallot, Y. Miyachi, M. Lamanna, S. Forthmann, K. Haft, F. Tessarotto, W. Kröger, B., Adeva, E., Arik, A., Arvidson, B., Badelek, G., Bardin, G., Baum, P., Berglund, L., Betev, Birsa, Renato, N., de Botton, Bradamante, Franco, A., Bravar, Bressan, Andrea, S., Bültmann, E., Burtin, D., Crabb, J., Cranshaw, T., Çuhadar, DALLA TORRE, Silvia, R., van Dantzig, B., Derro, A., Deshpande, S., Dhawan, C., Dulya, S., Eichblatt, D., Fasching, F., Feinstein, C., Fernandez, S., Forthmann, B., Froi, A., Galla, J. A., Garzon, H., Gilly, Giorgi, Marcello, S., Goertz, G., Gracia, N., de Groot, K., Haft, D., von Harrach, T., Hasegawa, P., Hautle, N., Hayashi, C. A., Heusch, N., Horikawa, V. W., Hughe, G., Igo, S., Ishimoto, T., Iwata, E. M., Kabuß, T., Kageya, A., Karev, T. J., Ketel, J., Kiryluk, Kisselev, Y. u., V., Krivokhijine, W., Kröger, V., Kuktin, K., Kurek, J., Kyynäräinen, M., Lamanna, U., Landgraf, J. M., Le Goff, F., Lehar, A., de Lesquen, J., Lichtenstadt, M., Litmaath, A., Magnon, G. K., Mallot, F., Marie, Martin, Anna, J., Martino, T., Matsuda, B., Maye, J. S., Mccarthy, K., Medved, W., Meyer, G., van Middelkoop, D., Miller, Y., Miyachi, K., Mori, J., Moromisato, J., Nassalski, L., Naumann, T. O., Niinikoski, J. E. J., Oberski, A., Ogawa, M., Perdekamp, H., Pereira, F., Perrot Kunne, D., Peshekhonov, L., Pinsky, S., Platchkov, M., Plo, D., Pose, H., Postma, J., Pretz, R., Puntaferro, G., Rädel, A., Rijllart, G., Reicherz, M., Rodriguez, E., Rondio, B., Roscherr, I., Sabo, J., Saborido, A., Sandacz, I., Savin, Schiavon, Paolo, A., Schiller, E. P., Sichtermann, F., Simeoni, G. I., Smirnov, A., Staude, A., Steinmetz, U., Stiegler, H., Stuhrmann, M., Szleper, F., Tessarotto, D., Ther, W., Tlaczala, A., Tripet, G., Unel, M., Velasco, J., Vogt, R., Vo, C., Whitten, R., Windmolder, W., Wislicki, A., Witzmann, J., Ylöstalo, Zanetti, ANNA MARIA, K., Zaremba, and (Astro)-Particles Physics
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Physics ,Quantum chromodynamics ,DIS ,Nuclear and High Energy Physics ,Particle physics ,Muon ,Proton ,SMC ,Scattering ,g1 structure function ,Perturbative QCD ,Deep inelastic scattering ,Nuclear physics ,Sum rule in quantum mechanics ,Nucleon ,Particle Physics - Experiment - Abstract
We present a new measurement of the virtual photon proton asymmetry $A_1^{\rm p}$ from deep inelastic scattering of polarized muons on polarized protons in the kinematic range $0.0008 < x < 0.7$ and $0.2 < Q^{2} < 100$ GeV$^{2}$. With this, the statistical uncertainty of our measurement has improved by a factor of $2$ compared to our previous measurements. The spin-dependent structure function $g_{1}^{\rm p}$ is determined for the data with $Q^{2} > 1$ GeV$^{2}$. A perturbative QCD evolution in next-to-leading order is used to determine $g_1^{\rm p}(x)$ at a constant $Q^2$. At $Q^{2} = 10$ GeV$^{2}$ we find, in the measured range, $\int_{0.003}^{0.7} g_{1}^{\rm p}(x){\rm d}x = 0.139 \pm 0.006~({\rm stat})\pm 0.008~({\rm syst)} \pm 0.006~({\rm evol})$. The value of the first moment $\Gamma_{1}^{\rm p} = \int_{0}^{1} g_{1}^{\rm p}(x){\rm d}x$ of $g_{1}^{\rm p}$ depends on the approach used to describe the behaviour of $g_{1}^{\rm p}$ at low $x$. We find that the Ellis-Jaffe sum rule is violated. With our published result for $\Gamma_{1}^{\rm d}$ we confirm the Bjorken sum rule with an accuracy of $\approx 15\%$ at the one standard deviation level.
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- 1997
- Full Text
- View/download PDF
49. Precision measurement of the magnetic field in terms of the free-proton NMR frequency
- Author
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V. W. Hughes, Ralf Prigl, and Xiang Fei
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Accuracy and precision ,Range (particle radiation) ,Field (physics) ,Proton NMR ,Experimental methods ,Instrumentation ,Water sample ,Magnetic field ,Computational physics - Abstract
We have developed a NMR standard probe using a spherical pure water sample of 1 cm diameter to determine the absolute magnetic field B in terms of the free-proton NMR frequency fp with an accuracy of 3.4 × 10−8. Our standard probe can be used conveniently to calibrate other probes in the field range from 1.45 to 1.7 T and can readily be employed over a much wider field range. The probe design and the tests carried out to verify its precision and accuracy are presented.
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- 1997
- Full Text
- View/download PDF
50. An Evolving Radio Source in the Young Star‐forming Region Cepheus A
- Author
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V. A. Hughes
- Subjects
Physics ,Jet (fluid) ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,Synchrotron radiation ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Magnetic field ,Relativistic particle ,Transverse plane ,Stars ,Acceleration ,Space and Planetary Science ,Protostar ,Astrophysics::Galaxy Astrophysics - Abstract
Observations of Cepheus A have been carried out since 1981, covering a period of more than 13 years. In this paper we examine in detail the data on source 3(a), which consists of two nonthermal sources that are diverging with a relative transverse speed ~370 km s-1. Source 3(a)(i) is decreasing in flux density and is seen initially at both 1.46 GHz and 4.9 GHz, but in time the 4.9 GHz flux density falls below the noise level; source 3(a)(ii) is increasing in flux density but is seen only at 1.46 GHz. An application of the theory of synchrotron radiation leads to a value for the magnetic field of 3(a)(i) of 0.2 G, a total magnetic field energy of 5.5 × 1044 ergs, and an energy for the relativistic particles of ~1036 ergs. If 3(a)(ii) has a similar magnetic field, then the increase in flux density could be the result of the coupling of magnetic field energy into the acceleration of low-energy relativistic particles. The morphology of the source does not place it in any known category of radio stars, but it is probably associated with a protostar and could be evidence for a jet or the expulsion of part of the star's magnetic field.
- Published
- 1997
- Full Text
- View/download PDF
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