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1. Search for charged Higgs bosons in e+e− collisions at $\sqrt{s}=189\mbox{--}209\ \mbox{GeV}$

Author

The OPAL Collaboration, G. Abbiendi, C. Ainsley, P. F. Åkesson, G. Alexander, G. Anagnostou, K. J. Anderson, S. Asai, D. Axen, I. Bailey, E. Barberio, T. Barillari, R. J. Barlow, R. J. Batley, P. Bechtle, T. Behnke, K. W. Bell, P. J. Bell, G. Bella, A. Bellerive, G. Benelli, S. Bethke, O. Biebel, O. Boeriu, P. Bock, M. Boutemeur, S. Braibant, R. M. Brown, H. J. Burckhart, S. Campana, P. Capiluppi, R. K. Carnegie, A. A. Carter, J. R. Carter, C. Y. Chang, D. G. Charlton, C. Ciocca, A. Csilling, M. Cuffiani, S. Dado, M. Dallavalle, A. De Roeck, E. A. De Wolf, K. Desch, B. Dienes, J. Dubbert, E. Duchovni, G. Duckeck, I. P. Duerdoth, E. Etzion, F. Fabbri, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, P. Gagnon, J. W. Gary, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, M. Giunta, J. Goldberg, E. Gross, J. Grunhaus, M. Gruwé, A. Gupta, C. Hajdu, M. Hamann, G. G. Hanson, A. Harel, M. Hauschild, C. M. Hawkes, R. Hawkings, G. Herten, R. D. Heuer, J. C. Hill, K. Hoffman, D. Horváth, P. Igo-Kemenes, K. Ishii, H. Jeremie, P. Jovanovic, T. R. Junk, J. Kanzaki, D. Karlen, K. Kawagoe, T. Kawamoto, R. K. Keeler, R. G. Kellogg, B. W. Kennedy, S. Kluth, T. Kobayashi, M. Kobel, S. Komamiya, T. Krämer, A. Krasznahorkay, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, G. D. Lafferty, H. Landsman, D. Lanske, D. Lellouch, J. Letts, L. Levinson, J. Lillich, S. L. Lloyd, F. K. Loebinger, J. Lu, A. Ludwig, J. Ludwig, W. Mader, S. Marcellini, T. E. Marchant, A. J. Martin, T. Mashimo, P. Mättig, J. McKenna, R. A. McPherson, F. Meijers, W. Menges, F. S. Merritt, H. Mes, N. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D. J. Miller, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H. Nanjo, H. A. Neal, S. W. O’Neale, A. Oh, A. Okpara, M. J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J. R. Pater, J. E. Pilcher, J. Pinfold, D. E. Plane, O. Pooth, M. Przybycień, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, J. M. Roney, A. M. Rossi, Y. Rozen, K. Runge, K. Sachs, T. Saeki, E. K. G. Sarkisyan, A. D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, T. Schörner-Sadenius, M. Schröder, M. Schumacher, R. Seuster, T. G. Shears, B. C. Shen, P. Sherwood, A. Skuja, A. M. Smith, R. Sobie, S. Söldner-Rembold, F. Spano, A. Stahl, D. Strom, R. Ströhmer, S. Tarem, M. Tasevsky, R. Teuscher, M. A. Thomson, E. Torrence, D. Toya, I. Trigger, Z. Trócsányi, E. Tsur, M. F. Turner-Watson, I. Ueda, B. Ujvári, C. F. Vollmer, P. Vannerem, R. Vértesi, M. Verzocchi, H. Voss, J. Vossebeld, C. P. Ward, D. R. Ward, P. M. Watkins, A. T. Watson, N. K. Watson, P. S. Wells, T. Wengler, N. Wermes, G. W. Wilson, J. A. Wilson, G. Wolf, T. R. Wyatt, S. Yamashita, D. Zer-Zion, and L. Zivkovic

Subjects
Higgs Boson, Systematic Uncertainty, Test Mass, Charged Higgs Boson, Likelihood Selection, Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at $\sqrt{s}=189\mbox{--}209\ \mbox{GeV}$ , corresponding to an integrated luminosity of approximately 600 pb−1. Charged Higgs bosons are assumed to be pair-produced and to decay into $\mathrm{q} \bar{\mathrm{q}}$ , τν τ or AW±. No signal is observed. Model-independent limits on the charged Higgs-boson production cross section are derived by combining these results with previous searches at lower energies. Under the assumption $\mathrm{BR} (\mathrm{H}^{\pm} \to \tau\nu_{\tau}) + \mathrm{BR} (\mathrm{H}^{\pm} \to \mathrm{q} \bar{\mathrm{q}}) = 1$ , motivated by general 2HDM type II models, excluded areas on the $[m_{\mathrm{H}^{\pm}} , \mathrm{BR} (\mathrm {H}^{\pm} \to \tau\nu_{\tau})]$ plane are presented and charged Higgs bosons are excluded up to a mass of 76.3 GeV at 95 % confidence level, independent of the branching ratio BR(H±→τν τ). A scan of the 2HDM type I model parameter space is performed and limits on the Higgs-boson masses $m_{\mathrm{H}^{\pm}}$ and m A are presented for different choices of tanβ.

Published
2012
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4. Validation and clinical implementation of an accurate Monte Carlo code for pencil beam scanning proton therapy

Author

C. Ainsley, Kevin Souris, Timothy D. Solberg, James McDonough, Sheng Huang, Charles B. Simone, Minglei Kang, Liyong Lin, and UCL - SSS/IREC/MIRO - Pôle d'imagerie moléculaire, radiothérapie et oncologie

Subjects
Monte Carlo method, Radiotherapy Planning, Clinical Sciences, Medical Physiology, Bioengineering, quality assurance, Imaging phantom, Phantoms, 030218 nuclear medicine & medical imaging, Imaging, 03 medical and health sciences, 0302 clinical medicine, Optics, Computer-Assisted, Range (statistics), Proton Therapy, Radiation Oncology Physics, Radiology, Nuclear Medicine and imaging, commissioning, range shifter, Pencil-beam scanning, Instrumentation, Proton therapy, Monte Carlo, Physics, Scintillation, Radiation, business.industry, Phantoms, Imaging, Radiotherapy Planning, Computer-Assisted, Detector, 87.55.k, pencil beam scanning, Radiotherapy Dosage, Other Physical Sciences, Nuclear Medicine & Medical Imaging, Radiology Nuclear Medicine and imaging, 030220 oncology & carcinogenesis, business, Monte Carlo Method, Energy (signal processing), Algorithms
Abstract

Monte Carlo (MC)-based dose calculations are generally superior to analytical dose calculations (ADC) in modeling the dose distribution for proton pencil beam scanning (PBS) treatments. The purpose of this paper is to present a methodology for commissioning and validating an accurate MC code for PBS utilizing a parameterized source model, including an implementation of a range shifter, that can independently check the ADC in commercial treatment planning system (TPS) and fast Monte Carlo dose calculation in opensource platform (MCsquare). The source model parameters (including beam size, angular divergence and energy spread) and protons per MU were extracted and tuned at the nozzle exit by comparing Tool for Particle Simulation (TOPAS) simulations with a series of commissioning measurements using scintillation screen/CCD camera detector and ionization chambers. The range shifter was simulated as an independent object with geometric and material information. The MC calculation platform was validated through comprehensive measurements of single spots, field size factors (FSF) and three-dimensional dose distributions of spread-out Bragg peaks (SOBPs), both without and with the range shifter. Differences in field size factors and absolute output at various depths of SOBPs between measurement and simulation were within 2.2%, with and without a range shifter, indicating an accurate source model. TOPAS was also validated against anthropomorphic lung phantom measurements. Comparison of dose distributions and DVHs for representative liver and lung cases between independent MC and analytical dose calculations from a commercial TPS further highlights the limitations of the ADC in situations of highly heterogeneous geometries. The fast MC platform has been implemented within our clinical practice to provide additional independent dose validation/QA of the commercial ADC for patient plans. Using the independent MC, we can more efficiently commission ADC by reducing the amount of measured data required for low dose “halo” modeling, especially when a range shifter is employed. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine

Published
2018

5. Cytochrome b(sub 5) reductase: Role of the si-face residues, proline 92 and tyrosine 93, in structure and catalysis

Author

Marohnic, Christoper C., Crowley, Louis J., Davis, C. Ainsley, Smith, Eugene T., and Barber, Michael J.

Subjects
Tyrosine -- Research, Proline -- Research, Cytochrome b -- Research, Biological sciences, Chemistry
Abstract

The roles of Y93 are investigated with the third and only aromatic residue of the 'RxY(super T)(sub x)x(super S)(sub N)' motif, that stacks against the si-face of the flavin isoalloxazine ring, and proline 92 (P92), the second residue in the motif, a series of rat cb5r variants were produced with substitutions at either P92 or Y93, respectively. The results indicated that neither P92 nor Y93 are critical for flavin incorporation in cb(sub 5)r and that an aromatic side chain is not essential at position 93.

Published
2005

6. PART 2: EXPANDING SALES TO WOMEN: HUNTERS

Author

Beeman, C. Ainsley

Subjects
Weatherby Inc., Hunters, Women consumers, Retail trade, Shopping, Marketing, Catering, Business, Sports, sporting goods and toys industry
Abstract

Successful hunters learn to focus on key elements when afield, especially the variables when things don't go as planned--otherwise, they'll join the ranks of the less fortunate. Those who show [...]

Published
2019

7. The Double-Edged Sword

Author

Beeman, C. Ainsley

Subjects
Marketing industry, Social networks, Marketing, Criminal investigation, Company marketing practices, Business, Sports, sporting goods and toys industry
Abstract

As a consumer, have you ever missed out on a great deal simply because you were unaware there was a sale going on in the first place? Perhaps the promotion [...]

Published
2019

8. Pick And Choose ... And Carry

Author

Beeman, C. Ainsley

Subjects
Firearms industry and trade, Women consumers, Firearms, Retail trade, Business, Sports, sporting goods and toys industry
Abstract

Most retailers continuously strive to improve their bottom line by implementing a variety of tactics to increase sales volume. Many are apt to tweak 'a little of this, a little [...]

Published
2019

9. AAPM task group 224: Comprehensive proton therapy machine quality assurance

Author

Ellen Yorke, Mark Pankuch, Sung-Yong Park, Sairos Safai, J Flanz, C. Ainsley, Jonathan B. Farr, David S Followill, Paige A. Taylor, Narayan Sahoo, B. Arjomandy, Eric E. Klein, and Yuki Kase

Subjects
medicine.medical_specialty, Quality Assurance, Health Care, Proton, Computer science, medicine.medical_treatment, Dose distribution, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Beam delivery, Proton Therapy, medicine, Humans, Medical physics, Radiometry, Radionuclide Imaging, Pencil-beam scanning, Proton therapy, Task group, business.industry, Radiotherapy Planning, Computer-Assisted, Radiotherapy Dosage, General Medicine, Radiation therapy, 030220 oncology & carcinogenesis, Safety, business, Quality assurance
Abstract

Purpose Task Group (TG) 224 was established by the American Association of Physicists in Medicine's Science Council under the Radiation Therapy Committee and Work Group on Particle Beams. The group was charged with developing comprehensive quality assurance (QA) guidelines and recommendations for the three commonly employed proton therapy techniques for beam delivery: scattering, uniform scanning, and pencil beam scanning. This report supplements established QA guidelines for therapy machine performance for other widely used modalities, such as photons and electrons (TG 142, TG 40, TG 24, TG 22, TG 179, and Medical Physics Practice Guideline 2a) and shares their aims of ensuring the safe, accurate, and consistent delivery of radiation therapy dose distributions to patients. Methods To provide a basis from which machine-specific QA procedures can be developed, the report first describes the different delivery techniques and highlights the salient components of the related machine hardware. Depending on the particular machine hardware, certain procedures may be more or less important, and each institution should investigate its own situation. Results In lieu of such investigations, this report identifies common beam parameters that are typically checked, along with the typical frequencies of those checks (daily, weekly, monthly, or annually). The rationale for choosing these checks and their frequencies is briefly described. Short descriptions of suggested tools and procedures for completing some of the periodic QA checks are also presented. Conclusion Recommended tolerance limits for each of the recommended QA checks are tabulated, and are based on the literature and on consensus data from the clinical proton experience of the task group members. We hope that this and other reports will serve as a reference for clinical physicists wishing either to establish a proton therapy QA program or to evaluate an existing one.

Published
2019
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10. Monte Carlo simulations of a novel Micromegas 2D array for proton dosimetry

Author

Robert J. Hollebeek, C. Ainsley, Richard L. Maughan, and Derek Dolney

Subjects
Physics, Radiological and Ultrasound Technology, Proton, Physics::Instrumentation and Detectors, Physics::Medical Physics, Monte Carlo method, Detector, Dose profile, MicroMegas detector, 030218 nuclear medicine & medical imaging, Nuclear physics, 03 medical and health sciences, 0302 clinical medicine, 030220 oncology & carcinogenesis, Ionization, Calibration, Proton Therapy, Dosimetry, Radiology, Nuclear Medicine and imaging, Protons, Radiometry, Monte Carlo Method, Proton therapy
Abstract

Modern proton therapy affords control of the delivery of radiotherapeutic dose on fine length and temporal scales. The authors have developed a novel detector technology based on Micromesh Gaseous Structure (Micromegas) that is uniquely tailored for applications using therapeutic proton beams. An implementation of a prototype Micromegas detector for Monte Carlo using Geant4 is presented here. Comparison of simulation results with measurements demonstrates agreement in relative dose along the proton longitudinal dose profile to be 1%. The effect of a radioactive calibration source embedded in the chamber gas is demonstrated by measurements and reproduced by simulations, also at the 1% level. Our Monte Carlo simulations are shown to reproduce the time structure of ionization pulses produced by a double-scattering delivery system.

Published
2016
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11. Ex vivo validation of a stoichiometric dual energy CT proton stopping power ratio calibration

Author

Timothy D. Solberg, C. Ainsley, James McDonough, Alexander Lin, Boon-Keng Kevin Teo, Lingshu Yin, Yunhe Xie, and Wei Zou

Subjects
Materials science, Swine, Analytical chemistry, Kidney, Imaging phantom, Bone and Bones, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Hounsfield scale, Calibration, Dosimetry, Animals, Radiology, Nuclear Medicine and imaging, Muscle, Skeletal, Proton therapy, Radiological and Ultrasound Technology, Phantoms, Imaging, Brain, 030220 oncology & carcinogenesis, Ionization chamber, Measuring instrument, Cattle, Protons, Tomography, X-Ray Computed, Effective atomic number
Abstract

A major source of uncertainty in proton therapy is the conversion of Hounsfield unit (HU) to proton stopping power ratio relative to water (SPR). In this study, we measured and quantified the accuracy of a stoichiometric dual energy CT (DECT) SPR calibration. We applied a stoichiometric DECT calibration method to derive the SPR using CT images acquired sequentially at and . The dual energy index was derived based on the HUs of the paired spectral images and used to calculate the effective atomic number (Z eff), relative electron density (), and SPRs of phantom and biological materials. Two methods were used to verify the derived SPRs. The first method measured the sample's water equivalent thicknesses to deduce the SPRs using a multi-layer ion chamber (MLIC) device. The second method utilized Gafchromic EBT3 film to directly compare relative ranges between sample and water after proton pencil beam irradiation. Ex vivo validation was performed using five different types of frozen animal tissues with the MLIC and three types of fresh animal tissues using film. In addition, the residual ranges recorded on the film were used to compare with those from the treatment planning system using both DECT and SECT derived SPRs. Bland–Altman analysis indicates that the differences between DECT and SPR measurement of tissue surrogates, frozen and fresh animal tissues has a mean of 0.07% and standard deviation of 0.58% compared to 0.55% and 1.94% respectively for single energy CT (SECT) and SPR measurement. Our ex vivo study indicates that the stoichiometric DECT SPR calibration method has the potential to be more accurate than SECT calibration under ideal conditions although beam hardening effects and other image artifacts may increase this uncertainty.

Published
2018

12. Validation and application of a fast Monte Carlo algorithm for assessing the clinical impact of approximations in analytical dose calculations for pencil beam scanning proton therapy

Author

Sheng Huang, Minglei Kang, C. Ainsley, Siyang Li, Elizabeth Garver, Paige A. Taylor, Ana Maria Barragan Montero, Alexander Lin, Kevin Souris, Liyong Lin, Ying Xiao, Guillaume Janssens, and UCL - SSS/IREC/MIRO - Pôle d'imagerie moléculaire, radiothérapie et oncologie

Subjects
Time Factors, Dose calculation, Monte Carlo method, computer.software_genre, Radiation Dosage, Imaging phantom, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Voxel, Proton Therapy, Humans, Pencil-beam scanning, Proton therapy, Lung, Monte Carlo algorithm, Mathematics, business.industry, Phantoms, Imaging, Radiotherapy Dosage, General Medicine, General purpose, 030220 oncology & carcinogenesis, Nuclear medicine, business, computer, Monte Carlo Method, Algorithms
Abstract

Purpose: Monte Carlo (MC) dose calculation is generally superior to analytical dose calculation (ADC) used in commercial TPS to model the dose distribution especially for heterogeneous sites, such as lung and head/neck patients. The purpose of this study was to provide a validated, fast, and open-source MC code, MCsquare, to assess the impact of approximations in ADC on clinical pencil beam scanning (PBS) plans covering various sites. Methods: First, MCsquare was validated using tissue-mimicking IROC lung phantom measurements as well as benchmarked with the general purpose Monte Carlo TOPAS for patient dose calculation. Then a comparative analysis between MCsquare and ADC was performed for a total of 50 patients with 10 patients per site (including liver, pelvis, brain, head-and-neck, and lung). Differences among TOPAS, MCsquare, and ADC were evaluated using four dosimetric indices based on the dose-volume histogram (target Dmean, D95, homogeneity index, V95), a 3D gamma index analysis (using 3%/3 mm criteria), and estimations of tumor control probability (TCP). Results: Comparison between MCsquare and TOPAS showed less than 1.8% difference for all of the dosimetric indices/TCP values and resulted in a 3D gamma index passing rate for voxels within the target in excess of 99%. When comparing ADC and MCsquare, the variances of all the indices were found to increase as the degree of tissue heterogeneity increased. In the case of lung, the D95s for ADC were found to differ by as much as 6.5% from the corresponding MCsquare statistic. The median gamma index passing rate for voxels within the target volume decreased from 99.3% for liver to 75.8% for lung. Resulting TCP differences can be large for lung (≤10.5%) and head-and-neck (≤6.2%), while smaller for brain, pelvis and liver (≤1.5%). Conclusions: Given the differences found in the analysis, accurate dose calculation algorithms such as Monte Carlo simulations are needed for proton therapy, especially for disease sites with high heterogeneity, such as head-and-neck and lung. The establishment of MCsquare can facilitate patient plan reviews at any institution and can potentially provide unbiased comparison in clinical trials given its accuracy, speed and open-source availability. © 2018 American Association of Physicists in Medicine

Published
2018

13. Lean In, Listen & Learn

Author

Beeman, C. Ainsley

Subjects
Incorporation, Business, Sports, sporting goods and toys industry
Abstract

Lean in and Listen--sound advice I've found to be most beneficial in life, but especially as a woman adept in the great outdoors. If I could have your ear for [...]

Published
2018

14. Women In The Great Outdoors--Oh My!

Author

Beeman, C. Ainsley

Subjects
Business, Sports, sporting goods and toys industry
Abstract

A quick social media search will reveal the great outdoors is no longer off limits to the ladies. The 'men only' sign has long since been tossed into the campfire, [...]

Published
2018

15. Technical Note: Validation of halo modeling for proton pencil beam spot scanning using a quality assurance test pattern

Author

Minglei Kang, Timothy D. Solberg, Sheng Huang, James McDonough, Liyong Lin, and C. Ainsley

Subjects
Physics, Optics, Proton, business.industry, Isocenter, Dosimetry, General Medicine, Halo, business, Pencil-beam scanning, Proton therapy, Particle detector, Beam (structure)
Abstract

Purpose: The purpose of this paper is to demonstrate the utility of a comprehensive test pattern in validating calculation models that include the halo component (low-dose tails) of proton pencil beam scanning (PBS) spots. Such a pattern has been used previously for quality assurance purposes to assess spot shape, position, and dose. Methods: In this study, a scintillation detector was used to measure the test pattern in air at isocenter for two proton beam energies (115 and 225 MeV) of two IBA universal nozzles (UN #1 and UN #2). Planar measurements were compared with calculated dose distributions based on the weighted superposition of location-independent (UN #1) or location-dependent (UN #2) spot profiles, previously measured using a pair-magnification method and between two nozzles. Results: Including the halo component below 1% of the central dose is shown to improve the gamma-map comparison between calculation and measurement from 94.9% to 98.4% using 2 mm/2% criteria for the 115 MeV proton beam of UN #1. In contrast, including the halo component below 1% of the central dose does not improve the gamma agreement for the 115 MeV proton beam of UN #2, due to the cutoff of the halo component at off-axis locations. When location-dependent spot profiles are used for calculation instead of spot profiles at central axis, the gamma agreement is improved from 98.0% to 99.5% using 2 mm/2% criteria. The two nozzles clearly have different characteristics, as a direct comparison of measured data shows a passing rate of 89.7% for the 115 MeV proton beam. At 225 MeV, the corresponding gamma comparisons agree better between measurement and calculation, and between measurements in the two nozzles. Conclusions: In addition to confirming the primary component of individual PBS spot profiles, a comprehensive test pattern is useful for the validation of the halo component at off-axis locations, especially for low energy protons.

Published
2015
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16. Use of a novel two-dimensional ionization chamber array for pencil beam scanning proton therapy beam quality assurance

Author

Minglei Kang, C. Ainsley, Christian Baeumer, Liyong Lin, Timothy D. Solberg, Thierry Mertens, and James McDonough

Subjects
Materials science, Quality Assurance, Health Care, Medizin, quality assurance, Sensitivity and Specificity, Imaging phantom, Radiotherapy, High-Energy, Optics, Ionization, Proton Therapy, Radiation Oncology Physics, Radiology, Nuclear Medicine and imaging, PBS, Radiometry, Pencil-beam scanning, Instrumentation, Proton therapy, Radiation, business.industry, Detector, Australia, Reproducibility of Results, Radiotherapy Dosage, Equipment Design, recombination, Equipment Failure Analysis, Ionization chamber, Laser beam quality, business, Beam (structure)
Abstract

The need to accurately and efficiently verify both output and dose profiles creates significant challenges in quality assurance of pencil beam scanning (PBS) proton delivery. A system for PBS QA has been developed that combines a new two-dimensional ionization chamber array in a waterproof housing that is scanned in a water phantom. The MatriXX PT has the same detector array arrangement as the standard math formula but utilizes a smaller 2 mm plate spacing instead of 5 mm. Because the bias voltage of the MatriXX PT and Evolution cannot be changed, PPC40 and FC65-G ionization chambers were used to assess recombination effects. The PPC40 is a parallel plate chamber with an electrode spacing of 2 mm, while the FC65-G is a Farmer chamber FC65-G with an electrode spacing of 2.8 mm. Three bias voltages (500, 200, and 100 V) were used for both detectors to determine which radiation type (continuous, pulse or pulse-scanned beam) could closely estimate math formula from the ratios of charges collected. In comparison with the math formula, a significant improvement in measurement of absolute dose with the MatriXX PT was observed. While dose uncertainty of the math formula can be up to 4%, it is math formula for the MatriXX PT. Therefore the math formula should not be used for QA of PBS for conditions in which ion recombination is not negligible. Farmer chambers should be used with caution for measuring the absolute dose of PBS beams, as the uncertainty of math formula can be math formula; chambers with an electrode spacing of 2 mm or smaller are recommended. PACS number: 87.53.Qc OA gold

Published
2015
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17. A comparison of the dose distributions from three proton treatment planning systems in the planning of meningioma patients with single‐field uniform dose pencil beam scanning

Author

I. Rosenberg, El Hassane Bentefour, Gary Royle, P Doolan, Jailan Alshaikhi, C. Ainsley, Adam Gibson, and Derek D'Souza

Subjects
Adult, treatment planning, Field (physics), Proton, planning comparison, medicine.medical_treatment, Dose distribution, Young Adult, Meningeal Neoplasms, Proton Therapy, Medicine, Radiation Oncology Physics, Humans, Radiology, Nuclear Medicine and imaging, Pencil-beam scanning, Radiation treatment planning, Instrumentation, Proton therapy, Aged, Radiation, Particle therapy, business.industry, Radiotherapy Planning, Computer-Assisted, Radiotherapy Dosage, Middle Aged, particle therapy, Radiotherapy, Intensity-Modulated, Neoplasm Grading, business, Nuclear medicine, Meningioma, Beam (structure), Algorithms, Synchrotrons
Abstract

With the number of new proton centers increasing rapidly, there is a need for an assessment of the available proton treatment planning systems (TPSs). This study compares the dose distributions of complex meningioma plans produced by three proton TPSs: Eclipse, Pinnacle3, and XiO. All three systems were commissioned with the same beam data and, as best as possible, matched configuration settings. Proton treatment plans for ten patients were produced on each system with a pencil beam scanning, single‐field uniform dose approach, using a fixed horizontal beamline. All 30 plans were subjected to identical dose constraints, both for the target coverage and organ at risk (OAR) sparing, with a consistent order of priority. Beam geometry, lateral field margins, and lateral spot resolutions were made consistent across all systems. Few statistically significant differences were found between the target coverage and OAR sparing of each system, with all optimizers managing to produce plans within clinical tolerances (D295%, D99>90%, and OAR maximum doses) despite strict constraints and overlapping structures. PACS number: 87.55.D‐

Published
2015

18. The Promise of Proton Therapy for Central Nervous System Malignancies

Author

Jennifer Vogel, C. Ainsley, Robert A. Lustig, and Ruben Carmona

Subjects
Adult, medicine.medical_specialty, medicine.medical_treatment, Central nervous system, Bragg peak, Malignancy, Meningioma, Central Nervous System Neoplasms, 03 medical and health sciences, 0302 clinical medicine, medicine, Proton Therapy, Humans, Proton therapy, business.industry, Clinical literature, medicine.disease, Acute toxicity, Radiation therapy, medicine.anatomical_structure, 030220 oncology & carcinogenesis, Surgery, Neurology (clinical), Radiology, business, 030217 neurology & neurosurgery
Abstract

Radiation therapy plays a significant role in management of benign and malignant diseases of the central nervous system. Patients may be at risk of acute and late toxicity from radiation therapy due to dose deposition in critical normal structures. In contrast to conventional photon delivery techniques, proton therapy is characterized by Bragg peak dose deposition which results in decreased exit dose beyond the target and greater sparing of normal structure which may reduce the rate of late toxicities from treatment. Dosimetric studies have demonstrated reduced dose to normal structures using proton therapy as compared to photon therapy. In addition, clinical studies are being reported demonstrating safety, feasibility, and low rates of acute toxicity. Technical challenges in proton therapy remain, including full understanding of depth of proton penetration and the biological activity in the distal Bragg peak. In addition, longer clinical follow-up is required to demonstrate reduction in late toxicities as compared to conventional photon-based radiation techniques. In this review, we summarize the current clinical literature and areas of active investigation in proton therapy for adult central nervous system malignancies.

Published
2017

19. Study of the Angular Dependence of a Prompt Gamma Detector Response during Proton Radiation Therapy

Author

C. Ainsley, Derek Dolney, E. Lee, Jerimy C. Polf, Sam Beddar, Stephen Avery, Dennis Stephen Mackin, and A Kassaee

Subjects
Physics, Range (particle radiation), Proton, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Detector, Atomic and Molecular Physics, and Optics, Imaging phantom, Optics, Nuclear magnetic resonance, Physics::Accelerator Physics, Radiology, Nuclear Medicine and imaging, Angular dependence, business, Proton therapy, Beam (structure)
Abstract

Purpose: Several studies have recently shown that the characteristics of prompt gamma (PG) rays emitted during proton radiation therapy are beneficial for verifying proton beam range during treatment delivery. Since PG rays are produced instantaneously upon the proton beam delivery, the viability of in vivo beam range verification using PG rays depends greatly on the design optimization of not only intrinsically highly efficient detectors, but also detector location around the beam to maximize detection efficiency. The purpose of this study is to characterize angular dependence of the PG detection rates as a function of proton beam energy to help develop the design of clinically feasible detectors. Materials and Methods: In this study as a part of the long-term goal of developing a clinically feasible multistage Compton camera, we performed a Monte Carlo–based study of the detector response in a water phantom over the clinical range of beam energies, 50 to 200 MeV, and characterized PG emission s...

Published
2014
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20. Experimentally validated pencil beam scanning source model in TOPAS

Author

James McDonough, Timothy D. Solberg, Minglei Kang, C. Ainsley, and Liyong Lin

Subjects
Physics, Quality Assurance, Health Care, Radiological and Ultrasound Technology, Phantoms, Imaging, business.industry, Monte Carlo method, Water, Radiotherapy Dosage, Radius, Models, Theoretical, Imaging phantom, Optics, Mockup, Proton Therapy, Fiber Optic Technology, Humans, Dosimetry, Radiology, Nuclear Medicine and imaging, Halo, business, Pencil-beam scanning, Monte Carlo Method, Proton therapy, Algorithms
Abstract

The presence of a low-dose envelope, or 'halo', in the fluence profile of a proton spot can increase the output of a pencil beam scanning field by over 10%. This study evaluated whether the Monte Carlo simulation code, TOPAS 1.0-beta 8, based on Geant4.9.6 with its default physics list, can predict the spot halo at depth in phantom by incorporating a halo model within the proton source distribution. Proton sources were modelled using three 2D Gaussian functions, and optimized until simulated spot profiles matched measurements at the phantom surface out to a radius of 100 mm. Simulations were subsequently compared with profiles measured using EBT3 film in Solidwater® phantoms at various depths for 100, 115, 150, 180, 210 and 225 MeV proton beams. Simulations predict measured profiles within a 1 mm distance to agreement for 2D profiles extending to the 0.1% isodose, and within 1 mm/1% Gamma criteria over the integrated curve of spot profile as a function of radius. For isodose lines beyond 0.1% of the central spot dose, the simulated primary spot sigma is smaller than the measurement by up to 15%, and can differ by over 1 mm. The choice of particle interaction algorithm and phantom material were found to cause ~1 mm range uncertainty, a maximal 5% (0.3 mm) difference in spot sigma, and maximal 1 mm and ~2 mm distance to agreement in isodoses above and below the 0.1% level, respectively. Based on these observations, therefore, the selection of physics model and the application of Solidwater® as water replacement material in simulation and measurement should be used with caution.

Published
2014
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21. Implementation of an improved dose-per-MU model for double-scattered proton beams to address interbeamline modulation width variability

Author

Liyong Lin, James McDonough, Timothy D. Solberg, JiaJien Shen, and C. Ainsley

Subjects
Models, Biological, Sensitivity and Specificity, Radiotherapy, High-Energy, double scattering, Optics, Proton Therapy, Calibration, Range (statistics), Humans, Computer Simulation, Radiology, Nuclear Medicine and imaging, Operations management, Radiometry, Instrumentation, Proton therapy, Physics, Radiation, business.industry, Radiotherapy Planning, Computer-Assisted, Reproducibility of Results, Radiotherapy Dosage, Function (mathematics), Radiation Measurements, output model, Transformation (function), Beamline, Modulation, business, Algorithms, Beam (structure)
Abstract

Because treatment planning systems (TPSs) generally do not provide monitor units (MUs) for double‐scattered proton plans, models to predict MUs as a function of the range and the nominal modulation width requested of the beam delivery system, such as the one developed by the MGH group, have been proposed. For a given nominal modulation width, however, the measured modulation width depends on the accuracy of the vendor's calibration process and may differ from this nominal value, and also from one beamline to the next. Although such a difference can be replicated in our TPS, the output dependence on range and modulation width for each beam option or suboption has to be modeled separately for each beamline in order to achieve maximal 3% inaccuracy. As a consequence, the MGH output model may not be directly transferable. This work, therefore, serves to extend the model to more general clinic situations. In this paper, a parameterized linear‐quadratic transformation is introduced to convert the nominal modulation width to the measured modulation width for each beam option or suboption on a per‐beamline basis. Fit parameters are derived for each beamline from measurements of 60 reference beams spanning the minimum and maximum ranges, and modulation widths from 2 cm to full range per option or suboption. Using the modeled modulation width, we extract the MGH parameters for the output dependence on range and modulation width. Our method has been tested with 1784 patient‐specific fields delivered across three different beamlines at our facility. For these fields, all measured outputs fall within 3%, and 64.4% fall within 1%, of our model. Using a parameterized linear‐quadratic modulation width, MU calculation models can be established on a per‐beamline basis for each double scattering beam option or suboption. PACS number: 87.53.Qc

Published
2014
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22. Assessment of Clinical Impact of Analytical Dose Calculation in TPS for Proton PBS Treatment Using Fast Monte Carlo Simulation

Author

Minglei Kang, Kevin Souris, Guillaume Janssens, Alexander Lin, L.L. Lin, Sheng Huang, Y. Xiao, S. Li, C. Ainsley, and E.H. Garver

Subjects
Cancer Research, Radiation, Oncology, Dose calculation, Proton, business.industry, Monte Carlo method, Medicine, Radiology, Nuclear Medicine and imaging, business, Computational physics
Published
2018
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23. 5 Storefront Necessities: A Woman's Perspective

Author

Beeman, C. Ainsley

Subjects
Business, Sports, sporting goods and toys industry
Abstract

Recently, I spoke with an acquaintance who has worked in outdoor retail sales for some time. After recapping the previous hunting season, our discussion shifted to industry trends and statistics. [...]

Published
2017

24. Experimental characterization of two-dimensional spot profiles for two proton pencil beam scanning nozzles

Author

C. Ainsley, Timothy D. Solberg, James McDonough, and Liyong Lin

Subjects
Range (particle radiation), Materials science, Radiological and Ultrasound Technology, Field (physics), Spots, Proton, Phantoms, Imaging, business.industry, Radiotherapy Planning, Computer-Assisted, Magnification, Radiotherapy Dosage, Radius, Optics, Proton Therapy, Radiology, Nuclear Medicine and imaging, business, Pencil-beam scanning, Proton therapy
Abstract

Dose calculation for pencil beam scanning proton therapy requires accurate measurement of the broad tails of the proton spot profiles for every nozzle in clinical use. By applying a pair/magnification method and merging film data, 200 mm × 240 mm dose kernels extending to 10(-4) of the central spot dose are generated for six selected energies of the IBA dedicated and universal nozzles (DN and UN). One-dimensional, circular profiles up to 100 mm in radius are generated from the asymmetric profiles to facilitate spot profile comparison. For the highest energy, 225 MeV, the output of both the DN and the UN for field sizes from 40 to 200 mm increases in parallel, slowest at the surface (∼1%) and fastest at a depth of 150 mm (∼9%). In contrast, at the lowest energy, 100 MeV, the output of the DN across the same range of field sizes increases 3-4% versus 6-7% for the UN throughout all the depths. The charge deficits in the measured depth-dose of Bragg peaks are similar between the UN and the DN. At 100 MeV, the field size factor difference at the surface between two orientations of a rectangular 40 mm × 200 mm field is 1.4% at isocentre for the DN versus 2% for the UN. Though the one-dimensional distributions are similar for the primary and tail components at different positions, the primary components of the DN spots are more elliptical 270 mm upstream than at isocentre.

Published
2013
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25. Experimental characterization of two-dimensional pencil beam scanning proton spot profiles

Author

James McDonough, C. Ainsley, and Liyong Lin

Subjects
Film Dosimetry, Materials science, Radiological and Ultrasound Technology, Dose calculation, business.industry, Radiotherapy Planning, Computer-Assisted, Magnification, Radiotherapy Dosage, Bragg peak, Optics, Proton Therapy, Field size, Primary component, Radiology, Nuclear Medicine and imaging, business, Pencil-beam scanning, Saturation (magnetic)
Abstract

Dose calculations of pencil beam scanning treatment plans rely on the accuracy of proton spot profiles; not only the primary component but also the broad tail components. Four films are placed at several locations in air and multiple depths in Solidwater® for six selected energies. The films used for the primary components are exposed to 50–200 MU to avoid saturation; the films used for the tail components are exposed to 800, 8000 and 80 000 MU. By applying a pair/magnification method and merging these data, dose kernels down to 10−4 of the central spot dose can be generated. From these kernels one can calculate the dose-per-MU for different field sizes and shapes. Measurements agree within 1% of dose-kernel-based calculations for output versus field size comparisons. Asymmetric, comet-shaped profile tails have a bigger impact at superficial depths and low energies: the output difference between two orientations at the surface of a rectangular field of 40 mm×200 mm is about 2% at the isocentre at 100 MeV. Integration of these dose kernels from 0 to 40 mm radius shows that the charge deficit in the Bragg peak chamber varies

Published
2013
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26. Optimization of the modelling of longitudinal dose distributions for double-scattered proton beams in a commercially-available treatment planning system

Author

Liyong Lin, C. Ainsley, and James McDonough

Subjects
Radiological and Ultrasound Technology, Proton, Computer science, Radiotherapy Planning, Computer-Assisted, Process (computing), Radiotherapy Dosage, Dose distribution, Radiation Dosage, Models, Biological, Proton (rocket family), Beam delivery, Proton Therapy, Range (statistics), Scattering, Radiation, Radiology, Nuclear Medicine and imaging, Radiation treatment planning, Proton therapy, Simulation
Abstract

The configuration of a treatment planning system (TPS) for double-scattering-based proton therapy requires many user inputs. Most of these are either gathered during the routine collection of commissioning data, or can be supplied by the equipment vendor; however, this is not true of all. In this study we developed a technique both to (a) expedite the extraction of those undetermined TPS parameters related to the range modulator wheels that can only otherwise be obtained by the time-consuming process of trial-and-error, and (b) demonstrate how, for a commonly-employed, commercially-available TPS, the judicious determination of such parameters can be used to optimize the resultant modelling of longitudinal dose distributions delivered by a double scattering proton therapy system. Our technique is simple to implement, robust in nature and also provides insight allowing parameters that must be contrived in that model to be related directly to physical aspects of the beam delivery system.

Published
2013
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27. A benchmarking method to evaluate the accuracy of a commercial proton monte carlo pencil beam scanning treatment planning system

Author

Jari Lindberg, Sami Siljamaki, Ian Davis, Sheng Huang, Todd A. Wareing, Charles B. Simone, Minglei Kang, Hiltunen Petri, Reynald Vanderstraeten, Timothy D. Solberg, Liyong Lin, C. Ainsley, John McGhee, James McDonough, and A Barnett

Subjects
Gaussian, Monte Carlo method, Imaging phantom, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, symbols.namesake, 0302 clinical medicine, Optics, Neoplasms, proton therapy, Humans, Radiation Oncology Physics, AcurosPT, Radiology, Nuclear Medicine and imaging, commissioning, Pencil-beam scanning, Radiometry, Instrumentation, Proton therapy, Monte Carlo algorithm, Physics, Radiation, business.industry, Phantoms, Imaging, Radiotherapy Planning, Computer-Assisted, Monte Carlo dose calculation, Radiotherapy Dosage, pencil beam scanning, Benchmarking, 030220 oncology & carcinogenesis, symbols, Halo, Radiotherapy, Intensity-Modulated, business, MCS algorithm, Monte Carlo Method, Algorithms
Abstract

AcurosPT is a Monte Carlo algorithm in the Eclipse 13.7 treatment planning system, which is designed to provide rapid and accurate dose calculations for proton therapy. Computational run‐time in minimized by simplifying or eliminating less significant physics processes. In this article, the accuracy of AcurosPT was benchmarked against both measurement and an independent MC calculation, TOPAS. Such a method can be applied to any new MC calculation for the detection of potential inaccuracies. To validate multiple Coulomb scattering (MCS) which affects primary beam broadening, single spot profiles in a Solidwater® phantom were compared for beams of five selected proton energies between AcurosPT, measurement and TOPAS. The spot Gaussian sigma in AcurosPT was found to increase faster with depth than both measurement and TOPAS, suggesting that the MCS algorithm in AcurosPT overestimates the scattering effect. To validate AcurosPT modeling of the halo component beyond primary beam broadening, field size factors (FSF) were compared for multi‐spot profiles measured in a water phantom. The FSF for small field sizes were found to disagree with measurement, with the disagreement increasing with depth. Conversely, TOPAS simulations of the same FSF consistently agreed with measurement to within 1.5%. The disagreement in absolute dose between AcurosPT and measurement was smaller than 2% at the mid‐range depth of multi‐energy beams. While AcurosPT calculates acceptable dose distributions for typical clinical beams, users are cautioned of potentially larger errors at distal depths due to overestimated MCS and halo implementation.

Published
2016

28. PO-0931: Onset and recovery of neuronal injury following proton radiotherapy

Author

R. Wolf, M. Alonson-Basanta, W. Sumei, C. Hill-Keyser, Ching-Ling Teng, C. Ainsley, N. Thorne, Stephen Avery, L. Sloan, S. Mohan, H. Poptani, Zelig Tochner, B.K.K. Kevin, T. Brown, M. Mix, Timothy D. Solberg, C. Armstrong, and K. Manoj

Subjects
Radiation therapy, Proton, Oncology, business.industry, Radiology Nuclear Medicine and imaging, medicine.medical_treatment, Medicine, food and beverages, Radiology, Nuclear Medicine and imaging, Hematology, business, Nuclear medicine
Published
2016
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29. Angular analysis of the muon pair asymmetry at LEP 1

Author

G. Abbiendi, C. Ainsley, P.F. Åkesson, G. Alexander, J. Allison, G. Anagnostou, K.J. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, I. Bailey, E. Barberio, R.J. Barlow, R.J. Batley, T. Behnke, K.W. Bell, P.J. Bell, G. Bella, A. Bellerive, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, R.K. Carnegie, B. Caron, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, J. Couchman, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. De Roeck, E.A. De Wolf, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, A. Gupta, C. Hajdu, M. Hamann, G.G. Hanson, K. Harder, A. Harel, M. Harin-Dirac, M. Hauschild, J. Hauschildt, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, K. Hoffman, R.J. Homer, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, R.V. Kowalewski, T. Krämer, T. Kress, P. Krieger, J. von Krogh, D. Krop, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, C. Littlewood, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, G. Masetti, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, S. Moed, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J.R. Pater, G.N. Patrick, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, Y. Rozen, K. Runge, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, M. Sproston, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, L. Stumpf, B. Surrow, S. Tarem, M. Tasevsky, R.J. Taylor, R. Teuscher, J. Thomas, M.A. Thomson, E. Torrence, D. Toya, T. Trefzger, A. Tricoli, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Ujvári, B. Vachon, C.F. Vollmer, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, D. Zer-Zion, G., Abbiendi, C., Ainsley, P. F., Akesson, G., Alexander, J., Allison, G., Anagnostou, K. J., Anderson, S., Arcelli, S., Asai, D., Axen, G., Azuelo, I., Bailey, E., Barberio, R. J., Barlow, R. J., Batley, T., Behnke, K. W., Bell, P. J., Bell, G., Bella, A., Bellerive, S., Bethke, O., Biebel, I. J., Bloodworth, O., Boeriu, P., Bock, J., Bohme, D., Bonacorsi, M., Boutemeur, S., Braibant, L., Brigliador, R. M., Brown, H. J., Burckhart, J., Cammin, R. K., Carnegie, B., Caron, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, P. E., L., E., Clay, I., Cohen, J., Couchman, A., Csilling, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, A., De Roeck, E. A., De, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, E., Etzion, F., Fabbri, L., Feld, P., Ferrari, F., Fiedler, I., Fleck, M., Ford, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, D., Glenzinski, J., Goldberg, K., Graham, E., Gro, J., Grunhau, M., Gruwe, P. O., Gunther, A., Gupta, C., Hajdu, M., Hamann, G. G., Hanson, K., Harder, A., Harel, M., Harin Dirac, M., Hauschild, J., Hauschildt, C. M., Hawke, R., Hawking, R. J., Hemingway, C., Hensel, G., Herten, R. D., Heuer, J. C., Hill, K., Hoffman, R. J., Homer, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, K., Ishii, A., Jawahery, H., Jeremie, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, G., Karapetian, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, K., Klein, A., Klier, S., Kluth, T., Kobayashi, M., Kobel, T. P., Kokott, S., Komamiya, R. V., Kowalewski, T., Kramer, T., Kre, P., Krieger, J., van Krogh, D., Krop, T., Kuhl, M., Kupper, P., Kyberd, G. D., Lafferty, H., Landsman, D., Lanske, I., Lawson, J. G., Layter, A., Lein, D., Lellouch, J., Lett, L., Levinson, J., Lillich, C., Littlewood, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, A., Macchiolo, A., Macpherson, W., Mader, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, G., Masetti, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, W., Menge, F. S., Merritt, H., Me, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, S., Moed, W., Mohr, T., Mori, A., Mutter, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, A., Oh, A., Okpara, M. J., Oreglia, S., Orito, C., Pahl, G., Pasztor, J. R., Pater, G. N., Patrick, J. E., Pilcher, J., Pinfold, D. E., Plane, B., Poli, J., Polok, O., Pooth, A., Quadt, K., Rabbertz, C., Rembser, P., Renkel, H., Rick, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, Y., Rozen, K., Runge, D. R., Rust, K., Sach, T., Saeki, O., Sahr, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, F., Spano, M., Sproston, A., Stahl, K., Stephen, D., Strom, R., Strohmer, L., Stumpf, B., Surrow, S., Tarem, M., Tasevsky, R. J., Taylor, R., Teuscher, J., Thoma, M. A., Thomson, E., Torrence, D., Toya, T., Trefzger, A., Tricoli, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, B., Ujvari, B., Vachon, C. F., Vollmer, P., Vannerem, M., Verzocchi, H., Vo, J., Vossebeld, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, T., Wengler, N., Werme, D., Wetterling, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, D., Zer Zion, and OPAL Collaboration

Subjects
Physics, Particle physics, Nuclear and High Energy Physics, Muon, 010308 nuclear & particles physics, media_common.quotation_subject, Photon radiation, FOS: Physical sciences, Radiation, Interference (wave propagation), 01 natural sciences, Asymmetry, Standard Model, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Pair production, 0103 physical sciences, Invariant mass, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, media_common
Abstract

Data on muon pair production obtained by the OPAL collaboration at centre of mass energies near the Z peak are analysed. Small angular mismatches between the directions of the two muons are used to assess the effects of initial state photon radiation and initial-final-state radiation interference on the forward-backward asymmetry of muon pairs. The dependence of the asymmetry on the invariant mass of the pair is measured in a model-independent way. Effective vector and axial-vector couplings of the Z boson are determined and compared to the Standard Model expectations., 31 pages, 8 figures, Accepted by Physics Letters B

Published
2001
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30. Reply to 'Comment on ‘Comparison of secondary neutron dose in proton therapy resulting from the use of a tungsten alloy MLC or a brass collimator system’' [Med. Phys. 38(11), 6248-6256 (2011)]

Author

Maura Kirk, Eric S. Diffenderfer, Richard L. Maughan, James McDonough, and C. Ainsley

Subjects
Materials science, business.industry, chemistry.chemical_element, Collimator, General Medicine, Tungsten, Collimated light, law.invention, Neutron spectroscopy, Brass, Nuclear physics, chemistry, law, visual_art, visual_art.visual_art_medium, Dosimetry, Neutron, Nuclear medicine, business, Proton therapy
Published
2012
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31. Searching for DNA Lesions: Structural Evidence for Lower- and Higher-Affinity DNA Binding Conformations of Human Alkyladenine DNA Glycosylase

Author

Jeremy W. Setser, Catherine L. Drennan, Gondichatnahalli M. Lingaraju, Leona D. Samson, and C. Ainsley Davis

Subjects
DNA Repair, HMG-box, Protein Conformation, Base pair, Biology, Crystallography, X-Ray, Biochemistry, Article, Catalysis, DNA Glycosylases, DNA Adducts, 03 medical and health sciences, 0302 clinical medicine, DNA adduct, polycyclic compounds, Humans, Protein–DNA interaction, Replication protein A, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, DNA ligase, DNA clamp, Genome, Human, Nucleic Acid Heteroduplexes, female genital diseases and pregnancy complications, DNA-Binding Proteins, chemistry, Mutagenesis, DNA supercoil, 030217 neurology & neurosurgery, DNA Damage, Plasmids
Abstract

To efficiently repair DNA, human alkyladenine DNA glycosylase (AAG) must search the million-fold excess of unmodified DNA bases to find a handful of DNA lesions. Such a search can be facilitated by the ability of glycosylases, like AAG, to interact with DNA using two affinities: a lower-affinity interaction in a searching process and a higher-affinity interaction for catalytic repair. Here, we present crystal structures of AAG trapped in two DNA-bound states. The lower-affinity depiction allows us to investigate, for the first time, the conformation of this protein in the absence of a tightly bound DNA adduct. We find that active site residues of AAG involved in binding lesion bases are in a disordered state. Furthermore, two loops that contribute significantly to the positive electrostatic surface of AAG are disordered. Additionally, a higher-affinity state of AAG captured here provides a fortuitous snapshot of how this enzyme interacts with a DNA adduct that resembles a one-base loop.

Published
2011
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32. Comparison of secondary neutron dose in proton therapy resulting from the use of a tungsten alloy MLC or a brass collimator system

Author

Eric S. Diffenderfer, James McDonough, Maura Kirk, C. Ainsley, and Richard L. Maughan

Subjects
Materials science, Proton, business.industry, Analytical chemistry, Collimator, General Medicine, law.invention, Multileaf collimator, law, Ionization chamber, Neutron source, Dosimetry, Neutron, Cobalt-60, Nuclear medicine, business
Abstract

Purpose: To apply the dual ionization chamber method for mixed radiation fields to an accurate comparison of the secondary neutron dose arising from the use of a tungsten alloy multileaf collimator (MLC) as opposed to a brass collimator system for defining the shape of a therapeutic proton field. Methods: Hydrogenous and nonhydrogenous ionization chambers were constructed with large volumes to enable measurements of absorbed doses below 10{sup -4} Gy in mixed radiation fields using the dual ionization chamber method for mixed-field dosimetry. Neutron dose measurements were made with a nominal 230 MeV proton beam incident on a closed tungsten alloy MLC and a solid brass block. The chambers were cross-calibrated against a {sup 60}Co-calibrated Farmer chamber in water using a 6 MV x-ray beam and Monte Carlo simulations were performed to account for variations in ionization chamber response due to differences in secondary neutron energy spectra. Results: The neutron and combined proton plus {gamma}-ray absorbed doses are shown to be nearly equivalent downstream from either a closed tungsten alloy MLC or a solid brass block. At 10 cm downstream from the distal edge of the collimating material the neutron dose from the closed MLC was (5.3 {+-} 0.4) x 10{supmore » -5} Gy/Gy. The neutron dose with brass was (6.4 {+-} 0.7) x 10{sup -5} Gy/Gy. Further from the secondary neutron source, at 50 cm, the neutron doses remain close for both the MLC and brass block at (6.9 {+-} 0.6) x 10{sup -6} Gy/Gy and (6.3 {+-} 0.7) x 10{sup -6} Gy/Gy, respectively. Conclusions: The dual ionization chamber method is suitable for measuring secondary neutron doses resulting from proton irradiation. The results of measurements downstream from a closed tungsten alloy MLC and a brass block indicate that, even in an overly pessimistic worst-case scenario, secondary neutron production in a tungsten alloy MLC leads to absorbed doses that are nearly equivalent to those seen from brass collimators. Therefore, the choice of tungsten alloy in constructing the leaves of a proton MLC is appropriate, and does not lead to a substantial increase in the secondary neutron dose to the patient compared to that generated in a brass collimator.« less

Published
2011
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33. Structural Basis for the Inhibition of Human Alkyladenine DNA Glycosylase (AAG) by 3,N4-Ethenocytosine-containing DNA

Author

Leona D. Samson, C. Ainsley Davis, Jeremy W. Setser, Catherine L. Drennan, and Gondichatnahalli M. Lingaraju

Subjects
DNA Repair, DNA damage, DNA repair, Cancer Treatment, Deoxyribozyme, Enzyme Mechanisms, Biology, Biochemistry, DNA Enzymes, DNA Glycosylases, Cytosine, Structure-Activity Relationship, 03 medical and health sciences, chemistry.chemical_compound, X-ray Crystallography, Catalytic Domain, Neoplasms, Humans, Molecular Biology, 030304 developmental biology, 0303 health sciences, Cancer Etiology, Enzyme Inhibitor Design, 030302 biochemistry & molecular biology, Genome Stability, Hydrogen Bonding, Environmental Exposure, DNA, Neoplasm, Cell Biology, Environmental exposure, Molecular biology, Enzyme structure, Neoplasm Proteins, 3. Good health, chemistry, DNA glycosylase, Enzyme Structure, Enzymology, DNA, DNA Damage
Abstract

Reactive oxygen and nitrogen species, generated by neutrophils and macrophages in chronically inflamed tissues, readily damage DNA, producing a variety of potentially genotoxic etheno base lesions; such inflammation-related DNA damage is now known to contribute to carcinogenesis. Although the human alkyladenine DNA glycosylase (AAG) can specifically bind DNA containing either 1,N(6)-ethenoadenine (εA) lesions or 3,N(4)-ethenocytosine (εC) lesions, it can only excise εA lesions. AAG binds very tightly to DNA containing εC lesions, forming an abortive protein-DNA complex; such binding not only shields εC from repair by other enzymes but also inhibits AAG from acting on other DNA lesions. To understand the structural basis for inhibition, we have characterized the binding of AAG to DNA containing εC lesions and have solved a crystal structure of AAG bound to a DNA duplex containing the εC lesion. This study provides the first structure of a DNA glycosylase in complex with an inhibitory base lesion that is induced endogenously and that is also induced upon exposure to environmental agents such as vinyl chloride. We identify the primary cause of inhibition as a failure to activate the nucleotide base as an efficient leaving group and demonstrate that the higher binding affinity of AAG for εC versus εA is achieved through formation of an additional hydrogen bond between Asn-169 in the active site pocket and the O(2) of εC. This structure provides the basis for the design of AAG inhibitors currently being sought as an adjuvant for cancer chemotherapy.

Published
2011
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35. Search for invisibly decaying Higgs bosons in e+e−→Z0h0 production at s=183–209 GeV

Author

A. J. Martin, M. Ford, M. Boutemeur, F. S. Merritt, D. E. Plane, P. Scharff-Hansen, J. von Krogh, W. Mader, R. J. Hawkings, A. Harel, Ikuo Ueda, D. M. Strom, J. Lu, Ehud Duchovni, A. M. Smith, J. A. McKenna, Kiyotomo Kawagoe, Daniel Lellouch, Tara Shears, A. Michelini, J. Dubbert, Robert Vertesi, R. K. Carnegie, J. A. Wilson, Takehiko Mori, M. Schumacher, Gideon Bella, Andris Skuja, Robert McPherson, T. Kobayashi, M. Przybycień, A. Ludwig, A. D. Schaile, Gabriella Pasztor, D. Axen, A. A. Carter, Richard Teuscher, Oana Elena Vickey Boeriu, M. Verzocchi, P. F. Åkesson, Giovanni Abbiendi, P. J. Bell, H. J. Burckhart, R. M. Brown, T. R. Junk, Tetsuro Mashimo, M. F. Turner-Watson, P. Vannerem, Fabrizio Fabbri, A. Frey, E. A. De Wolf, F. Spano, P. S. Wells, Lorne Levinson, Peter Sherwood, Terry Richard Wyatt, A. T. Watson, J. Lillich, Matthias Schröder, B. W. Kennedy, C. P. Ward, G. W. Wilson, I. R. Bailey, P. Jovanovic, Christoph Geich-Gimbel, J. Ludwig, M. Hauschild, M. Hamann, N. Meyer, Klaus Rabbertz, L. Zivkovic, K. Runge, P. Bock, Peter Krieger, J. M. Roney, S. Söldner-Rembold, S. W. O'Neale, W. Menges, Otmar Biebel, M. Kupper, H. Nanjo, R. J. Sobie, Stephen Lloyd, Joost Vossebeld, Oliver Pooth, Klaus Desch, T. Schörner-Sadenius, Koichi Nagai, C. F. Vollmer, Attila Krasznahorkay, E. Torrence, A. Gupta, Yoram Rozen, W. Mohr, H. Mes, I. P. Duerdoth, Shlomo Dado, Jochen Schieck, K. J. Anderson, Thorsten Wengler, T. Behnke, D. J. Miller, G. Mikenberg, Norbert Wermes, Junichi Kanzaki, James Pinfold, A. Quadt, R. Seuster, M. A. Thomson, Marco Cuffiani, Gideon Alexander, Paolo Capiluppi, T. Kawamoto, E. K. U. Gross, R. J. Batley, Dave Charlton, H. Voss, R. J. Barlow, S. Orito, H. Landsman, C. Y. Chang, Teresa Barillari, Satoru Yamashita, Gabriele Benelli, P. Gagnon, A. Csilling, R. D. Heuer, M. J. Oreglia, E. L. Barberio, S. Braibant, E. Tsur, C. M. Hawkes, Zoltan Laszlo Trocsanyi, Isabel Marian Trigger, K. W. Bell, P. Mättig, Shoji Asai, Gregor Herten, J. C. Hill, Balazs Ujvari, Tobias Kramer, J. E. Pilcher, B. C. Shen, Siegfried Bethke, I. Nakamura, J. W. Gary, Raimund Ströhmer, Marek Tasevsky, Dezso Horvath, R. G. Kellogg, Beatrix Dienes, Alexander Oh, D. Lanske, Csaba Hajdu, J. Goldberg, Stefano Marcellini, Christoph Rembser, Gunter Wolf, James Letts, D. Karlen, D. Zer-Zion, F. K. Loebinger, Erez Etzion, Ivor Fleck, Stefan Kluth, Shlomit Tarem, Joleen Pater, M. Giunta, Edward K. G. Sarkisyan, D. Toya, H. A. Neal, Sachio Komamiya, M. Gruwe, T. Saeki, A. Mutter, J. Grunhaus, Gordon H. Hanson, G. Giacomelli, A. De Roeck, M. Kobel, Frans Meijers, Alain Bellerive, P. Igo-Kemenes, K. Ishii, H. Jeremie, G. Anagnostou, O. Schaile, T. Kuhl, Pamela Ferrari, Paolo Giacomelli, Claudia Ciocca, K. Sachs, J. R. Carter, Philip Bechtle, N. K. Watson, Achim Stahl, C. Ainsley, C. Pahl, A. M. Rossi, G. D. Lafferty, R. K. Keeler, P. M. Watkins, P. Renkel, S. Campana, Guenter Duckeck, Satoshi Mihara, Frank Fiedler, and D. R. Ward

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Electron–positron annihilation, High Energy Physics::Phenomenology, Elementary particle, 01 natural sciences, Standard Model, Vector boson, Nuclear physics, 0103 physical sciences, Neutralino, Higgs boson, High Energy Physics::Experiment, 010306 general physics, Minimal Supersymmetric Standard Model, Boson
Abstract

A search is performed for Higgs bosons decaying into invisible final states, produced in association with a Z(0) boson in e(+)e(-) collisions at energies between 183 and 209 GeV. The search is based on data samples collected by the OPAL detector at LEP corresponding to an integrated luminosity of about 660 pb(-1). The analysis aims to select events containing the hadronic decay products of the Z(0) boson and large missing momentum, as expected from Higgs boson decay into a pair of stable weakly interacting neutral particles, such as the lightest neutralino in the Minimal Supersymmetric Standard Model. The same analysis is applied to a search for nearly invisible Higgs boson cascade decays into stable weakly interacting neutral particles. No excess over the expected background from Standard Model processes is observed. Limits on the production of invisibly decaying Higgs bosons produced in association with a Z(0) boson are derived. Assuming a branching ratio BR(h(0) -> invisible) = 1, a lower limit of 108.2 GeV is placed on the Higgs boson mass at the 95% confidence level. Limits on the production of nearly invisibly decaying Higgs bosons are also obtained. (C) 2009 Elsevier B.V. All rights reserved.

Published
2010
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36. Mutagenesis of glycine 179 modulates both catalytic efficiency and reduced pyridine nucleotide specificity in cytochrome b5 reductase

Author

Roma, Glenn W., Crowley, Louis J., Davis, C. Ainsley, and Barber, Michael J.

Subjects
Mutagenesis -- Research, Cytochrome b -- Research, Escherichia coli -- Genetic aspects, Bacterial proteins -- Research, Biological sciences, Chemistry
Abstract

A series of rat cytochrome b5 reductase (cb5r) variants are generated, corresponding to G179A, G179P, G179T, and G179V, recombinantly expressed in Escherichia coli and purified to homogeneity to investigate the role of G179 in NADH complex formation and NAD(P)H specificity. Each mutant protein is found to incorporate FAD in a 1:1 cofactor/protein stoichiometry and exhibited absorption and CD spectra that are identical to those of wild-type cb5r, indicating both correct protein folding and similar flavin environments.

Published
2005

37. Search for Dirac magnetic monopoles in e+e− collisions with the OPAL detector at LEP2

Author

M. Ford, P. Igo-Kemenes, W. Menges, Otmar Biebel, Achim Stahl, J. von Krogh, K. Ishii, H. Jeremie, Kiyotomo Kawagoe, Yoram Rozen, David J. Miller, M. Boutemeur, F. S. Merritt, S. Campana, Sachio Komamiya, R. J. Hawkings, B. C. Shen, H. Landsman, M. Gruwe, O. Schaile, Norbert Wermes, J. A. McKenna, T. Kawamoto, Oliver Pooth, D. Zer-Zion, F. K. Loebinger, Junichi Kanzaki, Ivor Fleck, Joleen Pater, Edward K. G. Sarkisyan, D. Toya, H. A. Neal, Andris Skuja, R. G. Kellogg, Csaba Hajdu, Stefano Marcellini, T. Kuhl, Siegfried Bethke, Alain Bellerive, S. W. O'Neale, Gordon H. Hanson, Gideon Bella, S. Orito, Daniel Lellouch, H. Mes, E. L. Barberio, Paolo Giacomelli, Takehiko Mori, T. Saeki, H. J. Burckhart, Christoph Geich-Gimbel, I. Nakamura, I. P. Duerdoth, Gideon Alexander, A. D. Schaile, D. Axen, J. Dubbert, Robert Vertesi, R. K. Carnegie, A. J. Martin, Paolo Capiluppi, Tetsuro Mashimo, M. F. Turner-Watson, J. W. Gary, Oana Elena Vickey Boeriu, Gabriella Pasztor, P. Vannerem, J. A. Wilson, A. Krasznahorkay, F. Spano, G. Mikenberg, Guenter Duckeck, K. J. Anderson, Peter Sherwood, Lorne Levinson, D. R. Ward, Thorsten Wengler, Raimund Ströhmer, J. Lillich, Richard Teuscher, N. Meyer, P. Mättig, Teresa Barillari, B. W. Kennedy, I. R. Bailey, Marek Tasevsky, A. Csilling, M. J. Oreglia, J. Letts, J. Ludwig, K. Runge, P. Jovanovic, R. J. Batley, M. Kupper, P. Bock, T. R. Wyatt, S. Braibant, C. P. Ward, N. K. Watson, C. Pahl, Dezso Horvath, J. Grunhaus, Gunter Wolf, Peter Krieger, D. E. Plane, Shoji Asai, W. Mader, M. Schumacher, S. Söldner-Rembold, M. Przybycień, Klaus Rabbertz, T. R. Junk, A. A. Carter, G. M. Dallavalle, D. Karlen, J. M. Roney, E. A. De Wolf, Stephen Lloyd, C. Ainsley, P. S. Wells, Tara Shears, M. Verzocchi, G. Giacomelli, A. M. Rossi, P. F. Åkesson, Giovanni Abbiendi, A. T. Watson, P. Scharff-Hansen, L. Zivkovic, Dave Charlton, P. Gagnon, A. De Roeck, M. Kobel, Gabriele Benelli, Koichi Nagai, Shlomo Dado, W. Mohr, A. Mutter, Ehud Duchovni, Robert McPherson, R. M. Brown, P. M. Watkins, Zoltan Laszlo Trocsanyi, Frans Meijers, A. Harel, Fabrizio Fabbri, A. Frey, George Lafferty, A. M. Smith, Satoshi Mihara, A. Michelini, Ikuo Ueda, D. M. Strom, E. Torrence, A. Gupta, P. Renkel, R. D. Heuer, T. Kobayashi, J. Lu, M. Cozzi, Gregor Herten, A. Ludwig, John Hill, James Pinfold, A. Quadt, R. Seuster, Claudia Ciocca, Beatrix Dienes, K. Sachs, J. R. Carter, J. Goldberg, Philip Bechtle, Frank Fiedler, M. Hamann, G. Anagnostou, Balazs Ujvari, J. E. Pilcher, Richard Keeler, Pamela Ferrari, G. W. Wilson, R. J. Sobie, M. Hauschild, C. Y. Chang, Joost Vossebeld, M. A. Thomson, E. K. U. Gross, H. Voss, Klaus Desch, Satoru Yamashita, Matthias Schröder, E. Tsur, C. M. Hawkes, Christoph Rembser, T. Behnke, Isabel Marian Trigger, K. W. Bell, Erez Etzion, T. Schörner-Sadenius, Stefan Kluth, Shlomit Tarem, Tobias Kramer, M. Giunta, P. J. Bell, M. Cuffiani, H. Nanjo, C. F. Vollmer, Jochen Schieck, R. J. Barlow, Alexander Oh, and D. Lanske

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), 010308 nuclear & particles physics, Dirac (video compression format), Electron–positron annihilation, Magnetic monopole, Tracking (particle physics), 01 natural sciences, Charged particle, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Ionization energy, 010306 general physics, Event generator
Abstract

This Letter describes a direct search for pair produced magnetic monopoles in e(+)e(-) collisions. The analysis is based on 62.7 pb(-1) of data collected with the OPAL detector at an average centre-of-mass energy of root S = 206.3 GeV. The monopole signal was assumed to be characterized by two back-to-back particles with an anomalously high ionization energy loss dE/dx in the tracking chambers. No evidence for production of monopoles was observed. Upper limits were obtained on the magnetic monopole pair-production cross-section (sigma) in the mass range 45 GeV/c(2) < m(M) < 102 GeV/c(2). The average limit is sigma < 0.05 pb and is essentially independent of the magnetic monopole mass. The cross-section limit is derived at the 95% confidence level and is valid for spin-1/2 magnetic monopoles. (C) 2008 Published by Elsevier B.V.

Published
2008
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38. Inclusive jet production in photon–photon collisions at see from 189 to 209 GeV

Author

George Lafferty, Erez Etzion, Satoshi Mihara, Thorsten Wengler, Stefan Kluth, Shlomit Tarem, Klaus Rabbertz, Frank Fiedler, Dave Charlton, M. Ford, Stephen Lloyd, A. Harel, J. Lillich, Kiyotomo Kawagoe, Ikuo Ueda, D. M. Strom, S. Campana, B. W. Kennedy, M. Giunta, P. Jovanovic, C. Y. Chang, J. Lu, Peter Krieger, D. R. Ward, J. von Krogh, M. Schumacher, P. J. Bell, Shlomo Dado, Ehud Duchovni, D. Zer-Zion, D. E. Plane, Christoph Geich-Gimbel, R. D. Heuer, Gabriele Benelli, F. K. Loebinger, A. Michelini, P. Scharff-Hansen, R. J. Hawkings, T. Schörner-Sadenius, E. A. De Wolf, Gideon Bella, Ivor Fleck, E. Tsur, Gunter Wolf, Joleen Pater, Sachio Komamiya, C. M. Hawkes, H. J. Burckhart, Edward K. G. Sarkisyan, D. Toya, T. Kobayashi, A. Ludwig, Isabel Marian Trigger, K. W. Bell, D. Karlen, H. A. Neal, L. Zivkovic, Pamela Ferrari, H. Nanjo, A. M. Smith, D. J. Miller, A. D. Schaile, Gabriella Pasztor, P. Igo-Kemenes, M. Przybycień, P. Vannerem, J. C. Hill, Tara Shears, Gregor Herten, Richard Teuscher, Tobias Kramer, B. C. Shen, T. R. Junk, A. A. Carter, K. Ishii, H. Jeremie, C. P. Ward, M. Gruwe, Andris Skuja, S. W. O'Neale, E. Torrence, A. Gupta, Siegfried Bethke, H. Mes, P. S. Wells, A. Csilling, S. Söldner-Rembold, Oliver Pooth, C. F. Vollmer, M. Boutemeur, F. S. Merritt, Jochen Schieck, J. M. Roney, Gideon Alexander, Tetsuro Mashimo, M. F. Turner-Watson, Balazs Ujvari, J. Goldberg, J. E. Pilcher, R. K. Keeler, N. K. Watson, Koichi Nagai, H. Landsman, T. R. Wyatt, I. P. Duerdoth, K. J. Anderson, A. T. Watson, M. Verzocchi, P. F. Åkesson, Giovanni Abbiendi, I. Nakamura, J. W. Gary, W. Mohr, O. Schaile, N. Meyer, R. J. Barlow, Paolo Capiluppi, Paolo Giacomelli, M. Kupper, M. Hamann, Raimund Ströhmer, G. Mikenberg, G. W. Wilson, M. Hauschild, T. Behnke, P. Mättig, Marek Tasevsky, P. M. Watkins, T. Kuhl, E. L. Barberio, J. A. McKenna, Dezso Horvath, M. A. Thomson, J. Dubbert, Robert Vertesi, R. K. Carnegie, Robert McPherson, R. M. Brown, Lorne Levinson, Christoph Rembser, E. K. U. Gross, H. Voss, Daniel Lellouch, Marco Cuffiani, Takehiko Mori, P. Renkel, R. J. Batley, R. J. Sobie, J. A. Wilson, I. R. Bailey, R. G. Kellogg, Satoru Yamashita, James Pinfold, Joost Vossebeld, A. Quadt, R. Seuster, C. Ainsley, Fabrizio Fabbri, Klaus Desch, A. Frey, Guenter Duckeck, A. M. Rossi, A. J. Martin, Csaba Hajdu, Stefano Marcellini, Alain Bellerive, A. Krasznahorkay, W. Mader, J. Letts, C. Pahl, T. Saeki, Alexander Oh, G. Anagnostou, D. Lanske, Gordon H. Hanson, Claudia Ciocca, Achim Stahl, K. Sachs, J. R. Carter, Philip Bechtle, G. Giacomelli, A. Mutter, A. De Roeck, M. Kobel, Frans Meijers, Yoram Rozen, J. Grunhaus, Junichi Kanzaki, Teresa Barillari, B. Dienes, Shoji Asai, D. Axen, Oana Elena Vickey Boeriu, F. Spano, Peter Sherwood, J. Ludwig, K. Runge, P. Bock, P. Gagnon, Zoltan Laszlo Trocsanyi, W. Menges, Otmar Biebel, Norbert Wermes, T. Kawamoto, S. Orito, M. J. Oreglia, S. Braibant, and Matthias Schröder

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), Jet (fluid), Photon, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Perturbative QCD, 01 natural sciences, Nuclear physics, Pair production, 0103 physical sciences, Strong coupling, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, 010306 general physics, Event generator
Abstract

Inclusive jet production (e(+)e(-) -> e(+)e(-) + jet + X) is studied in collisions of quasi-real photons radiated by the LEP beams at e(+)e(-) centre-of-mass energies root s(ee) from 189 to 209 GeV. Jets are reconstructed using the k(perpendicular to) jet algorithm. The inclusive differential cross-section is measured as a function of the jet transverse momentum, p(T)(jet), in the range 5 < p(T)(jet) < 40 GeV for pseudo-rapidities, eta(jet), in the range - 1.5 < eta(jet) < 1.5. The results are compared to predictions of perturbative QCD in next-to-leading order in the strong coupling constant. (c) 2007 Elsevier B.V. All rights reserved.

Published
2008
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39. The structure of the S127P mutant of cytochrome b(sub)5 reductase that causes methemoglobinemia shows the AMP moiety of the flavin occupying the substrate binding site

Author

Bewley, Maria C., Davis, C. Ainsley, Marohnic, Christopher C., Taormina, David, and Barber, Michael J.

Subjects
Cytochrome b, Biological sciences, Chemistry
Abstract

The X-ray structure of the recombinant rat cytochrome b(sub)5 reductase mutant at 1.8 angstrom resolution suggests that proline substitution at residue 127 leads to an altered FAD conformation. In this state, the flavin ADP moiety shares part of the substrate binding site, decreasing enzyme efficiency.

Published
2003

40. QCD coherence and correlations of particles with restricted momenta in hadronic Z decays

Author

G. ABBIENDI, C. AINSLEY, P. F. AKESSON, G. ALEXANDER, G. ANAGNOSTOU, K. J. ANDERSON, S. ASAI, D. AXEN, I. BAILEY, E. BARBERIO, T. BARILLARI, R. J. BARLOW, R. J. BATLEY, P. BECHTLE, T. BEHNKE, K. W. BELL, P. J. BELL, G. BELLA, A. BELLERIVE, G. BENELLI, S. BETHKE, O. BIEBEL, O. BOERIU, P. BOCK, M. BOUTEMEUR, R. M. BROWN, H. J. BURCKHART, S. CAMPANA, R. K. CARNEGIE, A. A. CARTER, J. R. CARTER, C. Y. CHANG, D. G. CHARLTON, A. CSILLING, S. DADO, A. DE ROECK, E. A. DE WOLF, S, K. DESCH, B. DIENES, J. DUBBERT, E. DUCHOVNI, G. DUCKECK, I. P. DUERDOTH, E. ETZION, F. FABBRI, P. FERRARI, F. FIEDLER, I. FLECK, M. FORD, A. FREY, P. GAGNON, J. W. GARY, C. GEICH GIMBEL, P. GIACOMELLI, M. GIUNTA, J. GOLDBERG, E. GROSS, J. GRUNHAUS, M. GRUW, P. O. GUNTHER, A. GUPTA, C. HAJDU, M. HAMANN, G. G. HANSON, A. HAREL, M. HAUSCHILD, C. M. HAWKES, R. HAWKINGS, R. J. HEMINGWAY, G. HERTEN, R. D. HEUER, J. C. HILL, D. HORVATH, P. IGO KEMENES, K. ISHII, H. JEREMIE, P. JOVANOVIC, T. R. JUNK, J. KANZAKI, D. KARLEN, K. KAWAGOE, T. KAWAMOTO, R. K. KEELER, R. G. KELLOGG, B. W. KENNEDY, S. KLUTH, T. KOBAYASHI, M. KOBEL, S. KOMAMIYA, T. KRAMER, A. KRASZNAHORKAY, P. KRIEGER, J. VON KROGH, T. KUHL, M. KUPPER, G. D. LAFFERTY, H. LANDSMAN, D. LANSKE, D. LELLOUCH, J. LETTSO, L. LEVINSON, J. LILLICH, S. L. LLOYD, F. K. LOEBINGER, J. LU27, A. LUDWIG, J. LUDWIG, W. MADER, S. MARCELLINI, A. J. MARTIN, T. MASHIMO, P. MATTIGM, J. MCKENNA, R. A. MCPHERSON, F. MEIJERS, W. MENGES, F. S. MERRITT, H. MES, N. MEYER, A. MICHELINI, S. MIHARA, G. MIKENBERG, D. J. MILLER, W. MOHR, T. MORI, A. MUTTER, K. NAGAI, I. NAKAMURA, H. NANJO, H. A. NEAL, R. NISIUS, S. W. O’NEALE, A. OH, M. J. OREGLIA, S. ORITO, C. PAHL, G. PASZTOR, J. R. PATER, J. E. PILCHER, J. PINFOLD, D. E. PLANE, O. POOTH, M. PRZYBYCIEN, A. QUADT, K. RABBERTZ, C. REMBSER, P. RENKEL, J. M. RONEY, Y. ROZEN, K. RUNGE, K. SACHS, T. SAEKI, E. K. G. SARKISYAN, A. D. SCHAILE, O. SCHAILE, P. SCHARFF HANSEN, J. SCHIECK, T. SCHORNER SADENIUS, M. SCHRODER, M. SCHUMACHER, R. SEUSTER, T. G. SHEARS, B. C. SHEN, P. SHERWOOD, A. SKUJA, A. M. SMITH, R. SOBIE, S. SOLDNER REMBOLD, F. SPANO, A. STAHL, D. STROM, R. STROHMER, S. TAREM, M. TASEVSKY, R. TEUSCHER, M. A. THOMSON, E. TORRENCE, D. TOYA, P. TRAN, I. TRIGGER, Z. TROCSANYI, E. TSUR, M. F. TURNER WATSON, I. UEDA, B. UJVARI, C. F. VOLLMER, P. VANNEREM, R. VERTESI, M. VERZOCCHI, H. VOSS, J. VOSSEBELD, C. P. WARD, D. R. WARD, P. M. WATKINS, A. T. WATSON, N. K. WATSON, P. S. WELLS, T. WENGLER, N. WERMES, G. W. WILSON1, J. A. WILSON, G. WOLF, T. R. WYATT, S. YAMASHITA, D. ZER ZION, L. ZIVKOVIC, BRAIBANT, SYLVIE, CAPILUPPI, PAOLO, CIOCCA, CLAUDIA, CUFFIANI, MARCO, GIACOMELLI, GIORGIO MARIA, ROSSI, ANTONIO MARIA, G.ABBIENDI, C.AINSLEY, P.F.AKESSON, G.ALEXANDER, G.ANAGNOSTOU, K.J.ANDERSON, S.ASAI, D.AXEN, I.BAILEY, E.BARBERIO, T.BARILLARI, R.J.BARLOW, R.J.BATLEY, P.BECHTLE, T.BEHNKE, K.W.BELL, P.J.BELL, G.BELLA, A.BELLERIVE, G.BENELLI, S.BETHKE, O.BIEBEL, O.BOERIU, P.BOCK, M.BOUTEMEUR, S.BRAIBANT, R.M.BROWN, H.J.BURCKHART, S.CAMPANA, P.CAPILUPPI, R.K.CARNEGIE, A.A.CARTER, J.R.CARTER, C.Y.CHANG, D.G.CHARLTON, C.CIOCCA, A.CSILLING, M.CUFFIANI, S.DADO, A.DE ROECK, E.A.DE WOLF, K.DESCH, B.DIENES, J.DUBBERT, E.DUCHOVNI, G.DUCKECK, I.P.DUERDOTH, E.ETZION, F.FABBRI, P.FERRARI, F.FIEDLER, I.FLECK, M.FORD, A.FREY, P.GAGNON, J.W.GARY, C.GEICH-GIMBEL, G.GIACOMELLI, P.GIACOMELLI, M.GIUNTA, J.GOLDBERG, E.GROSS, J.GRUNHAUS, M.GRUW, P.O.GUNTHER, A.GUPTA, C.HAJDU, M.HAMANN, G.G.HANSON, A.HAREL, M.HAUSCHILD, C.M.HAWKES, R.HAWKINGS, R.J.HEMINGWAY, G.HERTEN, R.D.HEUER, J.C.HILL, D.HORVATH, P. IGO-KEMENES, K. ISHII, H. JEREMIE, P. JOVANOVIC, T.R. JUNK, J.KANZAKI, D.KARLEN, K.KAWAGOE, T.KAWAMOTO, R.K.KEELER, R.G.KELLOGG, B.W.KENNEDY, S.KLUTH, T.KOBAYASHI, M.KOBEL, S.KOMAMIYA, T.KRAMER, A.KRASZNAHORKAY, P.KRIEGER, J. VON KROGH, T.KUHL, M.KUPPER, G.D. LAFFERTY, H. LANDSMAN, D. LANSKE, D. LELLOUCH, J. LETTSO, L. LEVINSON, J. LILLICH, S.L. LLOYD, F.K. LOEBINGER, J. LU27, A. LUDWIG, J. LUDWIG, W.MADER, S.MARCELLINI, A.J.MARTIN, T.MASHIMO, P.MATTIGM, J.MCKENNA, R.A.MCPHERSON, F.MEIJERS, W.MENGES, F.S.MERRITT, H.MES, N.MEYER, A.MICHELINI, S.MIHARA, G.MIKENBERG, D.J.MILLER, W.MOHR, T.MORI, A.MUTTER, K.NAGAI, I.NAKAMURA, H.NANJO, H.A.NEAL, R.NISIUS, S.W.O’NEALE, A.OH, M.J.OREGLIA, S.ORITO, C.PAHL, G.PASZTOR, J.R.PATER, J.E.PILCHER, J.PINFOLD, D.E.PLANE, O.POOTH, M.PRZYBYCIEN, A.QUADT, K.RABBERTZ, C.REMBSER, P.RENKEL, J.M.RONEY, A.M.ROSSI, Y.ROZEN, K.RUNGE, K. SACHS, T. SAEKI, E.K.G. SARKISYAN, A.D. SCHAILE, O. SCHAILE, P. SCHARFF-HANSEN, J. SCHIECK, T. SCHORNER-SADENIUS, M. SCHRODER, M. SCHUMACHER, R. SEUSTER, T.G. SHEARS, B.C. SHEN, P. SHERWOOD, A. SKUJA, A.M. SMITH, R. SOBIE, S. SOLDNER-REMBOLD, F. SPANO, A. STAHL, D. STROM, R. STROHMER, S.TAREM, M.TASEVSKY, R.TEUSCHER, M.A.THOMSON, E.TORRENCE, D.TOYA, P.TRAN, I.TRIGGER, Z.TROCSANYI, E.TSUR, M.F.TURNER-WATSON, I.UEDA, B.UJVARI, C.F.VOLLMER, P.VANNEREM, R.VERTESI, M.VERZOCCHI, H.VOSS, J.VOSSEBELD, C.P.WARD, D.R.WARD, P.M.WATKINS, A.T.WATSON, N.K.WATSON, P.S.WELLS, T.WENGLER, N.WERMES, G.W.WILSON1, J.A.WILSON, G.WOLF, T.R.WYATT, S.YAMASHITA, D. ZER-ZION, and L. ZIVKOVIC

Subjects
Quantum chromodynamics, Physics, Particle physics, Nuclear and High Energy Physics, Annihilation, 010308 nuclear & particles physics, Electron–positron annihilation, High Energy Physics::Lattice, Hadron, High Energy Physics::Phenomenology, Perturbative QCD, FOS: Physical sciences, Bose–Einstein correlations, HERA, Deep inelastic scattering, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, ddc:530, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Particle Physics - Experiment
Abstract

QCD coherence effects are studied based on measurements of correlations of particles with either restricted transverse momenta, pT, Comment: 17 pages, 4 figures, Submitted to Phys. Letts. B

Published
2006
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41. Search for radions at LEP2

Author

S. Yamashita, P. Igo-Kemenes, A. D. Schaile, K. Ishii, H. Jeremie, Gabriella Pasztor, P. Vannerem, H. Voss, D. E. Plane, O. Schaile, T. Kuhl, G. Giacomelli, Pamela Ferrari, P. Scharff-Hansen, C. P. Ward, S. Söldner-Rembold, P. Tran, Yoram Rozen, Matthias Schröder, D. Axen, R. M. Brown, A. De Roeck, M. Kobel, Lorne Levinson, I. R. Bailey, Ehud Duchovni, Oana Elena Vickey Boeriu, F. Spano, Kiyotomo Kawagoe, A. Gupta, A. Csilling, Frans Meijers, Junichi Kanzaki, Graham Wilson, J. Ludwig, T. Schörner-Sadenius, K. Runge, D. J. Miller, P. Bock, T. Kobayashi, A. Ludwig, J. Goldberg, C. Y. Chang, John Hill, Achim Stahl, B. C. Shen, Alain Bellerive, Daniel Lellouch, Shlomo Dado, D. R. Ward, A. M. Smith, Takehiko Mori, M. Donkers, Arnulf Quadt, P. M. Watkins, Siegfried Bethke, M. Przybycień, S. Campana, G. Anagnostou, N. K. Watson, A. A. Carter, George Lafferty, T. Behnke, A. J. Martin, Christoph Rembser, Satoshi Mihara, J. W. Gary, Klaus Rabbertz, Teresa Barillari, H. Landsman, P. Renkel, Gunter Wolf, M. Verzocchi, Stephen Lloyd, Andris Skuja, P. F. Åkesson, Giovanni Abbiendi, C. Ainsley, A. M. Rossi, Raimund Ströhmer, D. Karlen, Marek Tasevsky, Frank Fiedler, B. Dienes, Dezso Horvath, M. J. Oreglia, A. Michelini, P. Mättig, E. L. Barberio, Shoji Asai, P. Gagnon, Gianni Masetti, R. J. Hemingway, S. Braibant, J. Dubbert, R. K. Carnegie, J. Allison, Tetsuro Mashimo, M. F. Turner-Watson, J. Lillich, B. W. Kennedy, Tara Shears, Zoltan Laszlo Trocsanyi, P. Jovanovic, Claudia Ciocca, J. A. Wilson, K. Sachs, L. Zivkovic, C. Pahl, Peter Krieger, Dave Charlton, Philip Bechtle, C. F. Vollmer, Erez Etzion, Jochen Schieck, N. Meyer, Guenter Duckeck, Stefan Kluth, Shlomit Tarem, Paolo Giacomelli, R. J. Barlow, A. Mutter, J. R. Carter, M. Kupper, Richard Teuscher, Gideon Alexander, Paolo Capiluppi, M. Giunta, E. Tsur, C. M. Hawkes, W. Menges, Otmar Biebel, Isabel Marian Trigger, K. W. Bell, J. von Krogh, T. R. Wyatt, R. J. Hawkings, Tobias Kramer, James Pinfold, Alexander Oh, I. Nakamura, D. Lanske, S. W. O'Neale, Sachio Komamiya, R. D. Heuer, P. O. Günther, Gideon Bella, H. J. Burckhart, T. Saeki, K. J. Anderson, Norbert Wermes, T. Kawamoto, S. Orito, J. Grunhaus, J. M. Roney, M. Schumacher, Koichi Nagai, W. Mohr, E. A. De Wolf, P. Amaral, M. A. Thomson, E. K. U. Gross, H. Mes, I. P. Duerdoth, Eric Torrence, G. Mikenberg, R. J. Batley, P. J. Bell, H. Nanjo, M. Gruwé, Richard Nisius, Marco Cuffiani, M. Ford, A. Harel, Robert McPherson, K. D. Hoffman, Ikuo Ueda, D. M. Strom, Fabrizio Fabbri, A. Frey, J. Lu, W. F. Mader, P. S. Wells, A. T. Watson, M. Hamann, Richard Keeler, R. J. Sobie, Joost Vossebeld, Klaus Desch, T. R. Junk, M. Boutemeur, F. S. Merritt, Gregor Herten, J. A. McKenna, Christoph Geich-Gimbel, J. E. Pilcher, Thorsten Wengler, Gabriele Benelli, M. Hauschild, R. Vértesi, Gordon H. Hanson, Rolf Seuster, P. Sherwood, Oliver Pooth, R. G. Kellogg, Csaba Hajdu, Stefano Marcellini, James Letts, D. Zer-Zion, F. K. Loebinger, Ivor Fleck, Joleen Pater, Edward K. G. Sarkisyan, D. Toya, Balazs Ujvari, H. A. Neal, G.ABBIENDI, C.AINSLEY, P.F.°AKESSON, G.ALEXANDER, J.ALLISON, P.AMARAL, G.ANAGNOSTOU, K.J.ANDERSON, S.ASAI, D.AXEN, G.AZUELOS, I.BAILEY, E.BARBERIO, T.BARILLARI, R.J.BARLOW, R.J.BATLEY, P.BECHTLE, T.BEHNKE, K.W.BELL, P.J.BELL, G.BELLA, A.BELLERIVE, G.BENELLI, S.BETHKE, O.BIEBEL, O.BOERIU, P.BOCK, M.BOUTEMEUR, S.BRAIBANT, R.M.BROWN, K.BUESSER, H.J.BURCKHART, S.CAMPANA, P.CAPILUPPI, R.K.CARNEGIE, A.A.CARTER, J.R.CARTER, C.Y.CHANG, D.G.CHARLTON, C.CIOCCA, A.CSILLING, M.CUFFIANI, S.DADO, A.DE ROECK, E.A.DE WOLF, K.DESCH, B.DIENES, M.DONKERS, J.DUBBERT, E.DUCHOVNI, G.DUCKECK, I.P.DUERDOTH, E.ETZION, F.FABBRI, L.FELD, P.FERRARI, F.FIEDLER, I.FLECK, M.FORD, A.FREY, P.GAGNON, J.W.GARY, G.GAYCKEN, C.GEICH-GIMBEL, G.GIACOMELLI, P.GIACOMELLI, M.GIUNTA, J.GOLDBERG, E.GROSS, J.GRUNHAUS, M.GRUW´E, P.O.G¨UNTHER, A.GUPTA, C.HAJDU, M.HAMANN, G.G.HANSON, A.HAREL, M.HAUSCHILD, C.M.HAWKES, R.HAWKINGS, R.J.HEMINGWAY, G.HERTEN, R.D.HEUER, J.C.HILL, K.HOFFMAN, D.HORV´ATH, P. IGO-KEMENES, K. ISHII, H. JEREMIE, P. JOVANOVIC, T.R. JUNK, N.KANAYA, J.KANZAKI, D.KARLEN, K.KAWAGOE, T.KAWAMOTO, R.K.KEELER, R.G.KELLOGG, B.W.KENNEDY, S.KLUTH, T.KOBAYASHI, M.KOBEL, S.KOMAMIYA, T.KR¨AMER, P.KRIEGER, J. VON KROGH, K.KRUGER, T.KUHL, M.KUPPER, G.D. LAFFERTY, H. LANDSMAN, D. LANSKE, J.G. LAYTER, D. LELLOUCH, J. LETTSO, L. LEVINSON, J. LILLICH, S.L. LLOYD, F.K. LOEBINGER, J. LU, A. LUDWIG, J. LUDWIG, W.MADER, S.MARCELLINI, A.J.MARTIN, G.MASETTI, T.MASHIMO, P.M¨ATTIGM, J.MCKENNA, R.A.MCPHERSON, F.MEIJERS, W.MENGES, F.S.MERRITT, H.MES, N.MEYER, A.MICHELINI, S.MIHARA, G.MIKENBERG, D.J.MILLER, S.MOED, W.MOHR, T.MORI, A.MUTTER, K.NAGAI, I.NAKAMURA, H.NANJO, H.A.NEAL, R.NISIUS, S.W.O’NEALE, A.OH, M.J.OREGLIA, S.ORITO, C.PAHL, G.P´ASZTOR, J.R.PATER, J.E.PILCHER, J.PINFOLD, D.E.PLANE, O.POOTH, M.PRZYBYCIE´N, A.QUADT, K.RABBERTZ, C.REMBSER, P.RENKEL, J.M.RONEY, A.M.ROSSI, Y.ROZEN, K.RUNGE, K. SACHS, T. SAEKI, E.K.G. SARKISYAN, A.D. SCHAILE, O. SCHAILE, P. SCHARFF-HANSEN, J. SCHIECK, T. SCH¨ORNER-SADENIUS, M. SCHR¨ODER, M. SCHUMACHER, W.G. SCOTT, R. SEUSTER, T.G. SHEARS, B.C. SHEN, P. SHERWOOD, A. SKUJA, A.M. SMITH, R. SOBIE, S. S¨OLDNER-REMBOLD, F. SPANO, A. STAHL, D. STROM, R. STR¨OHMER, S.TAREM, M.TASEVSKY, R.TEUSCHER, M.A.THOMSON, E.TORRENCE, D.TOYA, P.TRAN, I.TRIGGER, Z.TR´OCS´ANYI, E.TSUR, M.F.TURNER-WATSON, I.UEDA, B.UJV´ARI, C.F.VOLLMER, P.VANNEREM, R.V´ERTESI, M.VERZOCCHI, H.VOSS, J.VOSSEBELD, C.P.WARD, D.R.WARD, P.M.WATKINS, A.T.WATSON, N.K.WATSON, P.S.WELLS, T.WENGLER, N.WERMES, G.W.WILSON, J.A.WILSON, G.WOLF, T.R.WYATT, S.YAMASHITA, D. ZER-ZION, L. ZIVKOVIC, and OPAL Collaboration

Subjects
Particle physics, Nuclear and High Energy Physics, High Energy Physics::Lattice, FOS: Physical sciences, Elementary particle, 01 natural sciences, 7. Clean energy, Standard Model, High Energy Physics - Experiment, symbols.namesake, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, 010306 general physics, Boson, Physics, Condensed Matter::Quantum Gases, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Hierarchy problem, Scalar boson, Higgs field, Higgs boson, symbols, High Energy Physics::Experiment, Higgs mechanism, Particle Physics - Experiment
Abstract

A new scalar resonance, called the radion, with couplings to fermions and bosons similar to those of the Higgs boson, is predicted in the framework of Randall-Sundrum models, proposed solutions to the hierarchy problem with one extra dimension. An important distinction between the radion and the Higgs boson is that the radion would couple directly to gluon pairs, and in particular its decay products would include a significant fraction of gluon jets. The radion had the same quantum numbers as the Standard Model (SM) Higgs boson, and therefore they can mix, with the resulting mass eigenstates having properties different from those of the SM Higgs boson. Existing searches for the Higgs boson are sensitive to the possible production and decay of radions and Higgs bosons in these models. For the first time, searches for the SM Higgs boson and flavour-independent and decay-mode independent searches for a neutral Higgs boson are used in combination to explore the parameter space of the Randall-Sundrum model. In the dataset recorded by the OPAL experiment at LEP, no evidence for radion or Higgs particle production was observed in any of those searches. The results are used to set limits on the radion and Higgs boson masses., Comment: 18 pages, 6 figures, Submitted to Phys. Lett. B

Published
2005
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42. Measurements of Rb in e+e− collisions at s between 182 and 209 GeV

Author

A. Csilling, P. Mättig, Shoji Asai, Daniel Lellouch, Takehiko Mori, W. F. Mader, E. Torrence, A. Gupta, Dave Charlton, O. Schaile, Yoram Rozen, Junichi Kanzaki, Paolo Giacomelli, J. Goldberg, J. M. Roney, M. Schumacher, Andris Skuja, Christoph Geich-Gimbel, R. Nisius, R. Vértesi, George Lafferty, Graham Wilson, P. S. Wells, Matthias Schröder, Tetsuro Mashimo, M. F. Turner-Watson, Satoshi Mihara, P. Gagnon, Gianni Masetti, R. D. Heuer, Koichi Nagai, A. T. Watson, Shlomo Dado, E. A. De Wolf, D. E. Plane, C. F. Vollmer, Achim Stahl, Gideon Bella, S. Yamashita, P. Igo-Kemenes, Gordon H. Hanson, Klaus Rabbertz, Stephen Lloyd, Zoltan Laszlo Trocsanyi, M. Hauschild, H. J. Burckhart, W. Mohr, N. Meyer, M. Kupper, P. Tran, F. S. Merritt, A. Harel, N. K. Watson, Alain Bellerive, M. A. Thomson, K. Ishii, R. K. Carnegie, T. Schörner-Sadenius, Ikuo Ueda, D. M. Strom, J. A. Wilson, P. Amaral, Oliver Pooth, H. Jeremie, E. K. U. Gross, J. Lu, Tara Shears, D. Axen, John Allison, S. Campana, D. J. Miller, Kiyotomo Kawagoe, M. Gruwé, Oana Elena Vickey Boeriu, F. Spano, C. Ainsley, Gabriella Pasztor, J. A. McKenna, Peter Sherwood, Gideon Alexander, T. Barillari, P. Vannerem, J. Ludwig, K. Runge, P. Bock, M. Hamann, R. J. Hemingway, James Pinfold, R. G. Kellogg, C. P. Ward, G. Anagnostou, R. Seuster, A. Michelini, H. Mes, J. Lillich, M. Boutemeur, A. D. Schaile, Marco Cuffiani, Csaba Hajdu, S. Söldner-Rembold, Thorsten Wengler, B. W. Kennedy, Ehud Duchovni, R. K. Keeler, I. P. Duerdoth, P. Jovanovic, R. M. Brown, Lorne Levinson, Stefano Marcellini, R. J. Sobie, A. J. Martin, Peter Krieger, T. Kuhl, Christoph Rembser, James Letts, Arnulf Quadt, Joost Vossebeld, I. R. Bailey, F. Fiedler, O. Biebel, Klaus Desch, S. Bethke, P. M. Watkins, Alessandro Montanari, D. Zer-Zion, P. J. Bell, G. Mikenberg, Claudia Ciocca, Richard Teuscher, T. Behnke, F. K. Loebinger, Gabriele Benelli, K. Sachs, Philip Bechtle, M. Ford, H. Landsman, P. Renkel, Ivor Fleck, T. Kobayashi, Pamela Ferrari, A. Ludwig, R. J. Batley, Joleen Pater, Erez Etzion, D. R. Ward, P. Scharff-Hansen, S. Kluth, Edward K. G. Sarkisyan, D. Toya, T. R. Junk, Balazs Ujvari, H. A. Neal, E. L. Barberio, T. R. Wyatt, A. M. Smith, Robert McPherson, Gregor Herten, H. Nanjo, Shlomit Tarem, K. D. Hoffman, Fabrizio Fabbri, A. Frey, J. von Krogh, H. Voss, J. Dubbert, M. Giunta, G. Giacomelli, A. De Roeck, M. Kobel, R. J. Hawkings, Gunter Wolf, J. E. Pilcher, Frans Meijers, D. Karlen, G. Duckeck, M. Przybycień, A. A. Carter, M. Verzocchi, P. F. Åkesson, Giovanni Abbiendi, B. C. Shen, M. Donkers, J. W. Gary, Marek Tasevsky, Dezso Horvath, W. Menges, Norbert Wermes, T. Kawamoto, S. Orito, E. Tsur, C. M. Hawkes, M. J. Oreglia, S. Braibant, Isabel Marian Trigger, K. W. Bell, L. Zivkovic, J. R. Carter, J. C. Hill, Tobias Kramer, Jochen Schieck, R. J. Barlow, R. Ströhmer, Alexander Oh, I. Nakamura, D. Lanske, J. Grunhaus, Sachio Komamiya, T. Saeki, Alessandra Fanfani, Beatrix Dienes, C. Y. Chang, A. Mutter, S. W. O'Neale, C. Pahl, P. O. Günther, and K. J. Anderson

Subjects
Nuclear physics, Physics, Quark, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Electron–positron annihilation, 0103 physical sciences, Charm (quantum number), 010306 general physics, 01 natural sciences, Standard Model, Lepton
Abstract

Measurements of R b , the ratio of the b b ¯ cross-section to the q q ¯ cross-section in e + e − collisions, are presented. The data were collected by the OPAL experiment at LEP at centre-of-mass energies between 182 and 209 GeV. Lepton, lifetime and event-shape information is used to tag events containing b quarks with high efficiency. The data are compatible with the Standard Model expectation. The mean ratio of the eight measurements reported here to the Standard Model prediction is 1.055 ± 0.031 ± 0.037 , where the first error is statistical and the second systematic.

Published
2005
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43. Determination of the LEP beam energy using radiative fermion-pair events

Author

Siegfried Bethke, J. W. Gary, Dezso Horvath, W. Menges, Otmar Biebel, G. W. Wilson, M. Hamann, M. Hauschild, Richard Keeler, J. Goldberg, R. J. Sobie, Joost Vossebeld, George Lafferty, Klaus Desch, Christoph Rembser, H. Landsman, W. F. Mader, Gunter Wolf, Erez Etzion, S. W. O'Neale, Stefan Kluth, Shlomit Tarem, P. O. Günther, Norbert Wermes, T. Kawamoto, M. Giunta, D. Karlen, Satoshi Mihara, P. S. Wells, P. Sherwood, Oliver Pooth, S. Orito, A. T. Watson, Alain Bellerive, E. Tsur, C. M. Hawkes, E. L. Barberio, Isabel Marian Trigger, K. W. Bell, K. J. Anderson, H. Mes, Kiyotomo Kawagoe, John Allison, A. Harel, Ikuo Ueda, D. M. Strom, J. C. Hill, J. Lu, I. P. Duerdoth, Tobias Kramer, R. J. Hemingway, Gianni Masetti, M. J. Oreglia, C. Y. Chang, Shlomo Dado, J. Lillich, Achim Stahl, S. Braibant, N. K. Watson, Sachio Komamiya, Dave Charlton, L. Zivkovic, Frank Fiedler, Thorsten Wengler, B. W. Kennedy, P. Jovanovic, J. R. Carter, D. Toya, Tara Shears, M. Przybycień, Peter Krieger, C. Ainsley, A. M. Rossi, Raimund Ströhmer, Christoph Geich-Gimbel, Giora Mikenberg, R. G. Kellogg, R. J. Batley, Gideon Alexander, J. M. Roney, A. A. Carter, Csaba Hajdu, R. D. Heuer, P. J. Bell, Stefano Marcellini, S. Yamashita, M. Schumacher, A. D. Schaile, Gabriella Pasztor, T. Saeki, James Letts, P. Vannerem, M. Verzocchi, Gideon Bella, Gabriele Benelli, P. F. Åkesson, Giovanni Abbiendi, Beatrix Dienes, Klaus Rabbertz, P. Igo-Kemenes, Stephen Lloyd, M. Tasevsky, R. Vértesi, Yoram Rozen, E. A. De Wolf, R. M. Brown, Lorne Levinson, Claudia Ciocca, T. Behnke, K. Sachs, C. P. Ward, Philip Bechtle, H. J. Burckhart, S. Söldner-Rembold, Ehud Duchovni, Alexander Oh, P. Amaral, I. R. Bailey, J. Dubbert, R. K. Carnegie, K. Ishii, H. Jeremie, A. Michelini, Arnulf Quadt, Matthias Schröder, Koichi Nagai, D. J. Miller, T. R. Junk, T. Kobayashi, K. Hoffman, A. Ludwig, Gregor Herten, W. Mohr, J. A. Wilson, Junichi Kanzaki, M. Boutemeur, F. S. Merritt, P. Gagnon, I. Nakamura, D. Lanske, D. E. Plane, P. M. Watkins, A. Mutter, Robert McPherson, D. R. Ward, Zoltan Laszlo Trocsanyi, O. Schaile, Paolo Giacomelli, Gordon H. Hanson, J. A. McKenna, T. Schörner-Sadenius, J. E. Pilcher, P. Renkel, Daniel Lellouch, T. Kuhl, P. Tran, Fabrizio Fabbri, A. Frey, Takehiko Mori, H. Nanjo, D. Zer-Zion, A. J. Martin, D. Axen, F. K. Loebinger, M. Ford, Oana Elena Vickey Boeriu, F. Spano, Ivor Fleck, P. Capiluppi, Joleen Pater, Edward K. G. Sarkisyan, J. Ludwig, K. Runge, P. Bock, M. A. Thomson, Balazs Ujvari, H. A. Neal, C. F. Vollmer, J. von Krogh, A. Gupta, Jochen Schieck, R. J. Hawkings, E. K. U. Gross, J. Grunhaus, C. Pahl, Teresa Barillari, R. J. Barlow, A. Csilling, M. Gruwé, Eric Torrence, Richard Nisius, P. Mättig, Shoji Asai, Marco Cuffiani, H. Voss, Andris Skuja, G. Giacomelli, Pamela Ferrari, A. De Roeck, M. Kobel, Tetsuro Mashimo, M. F. Turner-Watson, Frans Meijers, N. Meyer, M. Kupper, G. Anagnostou, James Pinfold, R. Seuster, P. Scharff-Hansen, Guenter Duckeck, A. M. Smith, S. Campana, Richard Teuscher, T. R. Wyatt, B. C. Shen, M. Donkers, G.ABBIENDI, C.AINSLEY, P.F.°AKESSON, G.ALEXANDER, J.ALLISON, P.AMARAL, G.ANAGNOSTOU, K.J.ANDERSON, S.ASAI, D.AXEN, G.AZUELOS, I.BAILEY, E.BARBERIO, T.BARILLARI, R.J.BARLOW, R.J.BATLEY, P.BECHTLE, T.BEHNKE, K.W.BELL, P.J.BELL, G.BELLA, A.BELLERIVE, G.BENELLI, S.BETHKE, O.BIEBEL, O.BOERIU, P.BOCK, M.BOUTEMEUR, S.BRAIBANT, R.M.BROWN, K.BUESSER, H.J.BURCKHART, S.CAMPANA, P.CAPILUPPI, R.K.CARNEGIE, A.A.CARTER, J.R.CARTER, C.Y.CHANG, D.G.CHARLTON, C.CIOCCA, A.CSILLING, M.CUFFIANI, S.DADO, A.DE ROECK, E.A.DE WOLF, K.DESCH, B.DIENES, M.DONKERS, J.DUBBERT, E.DUCHOVNI, G.DUCKECK, I.P.DUERDOTH, E.ETZION, F.FABBRI, L.FELD, P.FERRARI, F.FIEDLER, I.FLECK, M.FORD, A.FREY, P.GAGNON, J.W.GARY, G.GAYCKEN, C.GEICH-GIMBEL, G.GIACOMELLI, P.GIACOMELLI, M.GIUNTA, J.GOLDBERG, E.GROSS, J.GRUNHAUS, M.GRUW´E, P.O.G¨UNTHER, A.GUPTA, C.HAJDU, M.HAMANN, G.G.HANSON, A.HAREL, M.HAUSCHILD, C.M.HAWKES, R.HAWKINGS, R.J.HEMINGWAY, G.HERTEN, R.D.HEUER, J.C.HILL, K.HOFFMAN, D.HORV´ATH, P. IGO-KEMENES, K. ISHII, H. JEREMIE, P. JOVANOVIC, T.R. JUNK, N.KANAYA, J.KANZAKI, D.KARLEN, K.KAWAGOE, T.KAWAMOTO, R.K.KEELER, R.G.KELLOGG, B.W.KENNEDY, S.KLUTH, T.KOBAYASHI, M.KOBEL, S.KOMAMIYA, T.KR¨AMER, P.KRIEGER, J. VON KROGH, K.KRUGER, T.KUHL, M.KUPPER, G.D. LAFFERTY, H. LANDSMAN, D. LANSKE, J.G. LAYTER, D. LELLOUCH, J. LETTSO, L. LEVINSON, J. LILLICH, S.L. LLOYD, F.K. LOEBINGER, J. LU, A. LUDWIG, J. LUDWIG, W.MADER, S.MARCELLINI, A.J.MARTIN, G.MASETTI, T.MASHIMO, P.M¨ATTIGM, J.MCKENNA, R.A.MCPHERSON, F.MEIJERS, W.MENGES, F.S.MERRITT, H.MES, N.MEYER, A.MICHELINI, S.MIHARA, G.MIKENBERG, D.J.MILLER, S.MOED, W.MOHR, T.MORI, A.MUTTER, K.NAGAI, I.NAKAMURA, H.NANJO, H.A.NEAL, R.NISIUS, S.W.O’NEALE, A.OH, M.J.OREGLIA, S.ORITO, C.PAHL, G.P´ASZTOR, J.R.PATER, J.E.PILCHER, J.PINFOLD, D.E.PLANE, O.POOTH, M.PRZYBYCIE´N, A.QUADT, K.RABBERTZ, C.REMBSER, P.RENKEL, J.M.RONEY, A.M.ROSSI, Y.ROZEN, K.RUNGE, K. SACHS, T. SAEKI, E.K.G. SARKISYAN, A.D. SCHAILE, O. SCHAILE, P. SCHARFF-HANSEN, J. SCHIECK, T. SCH¨ORNER-SADENIUS, M. SCHR¨ODER, M. SCHUMACHER, W.G. SCOTT, R. SEUSTER, T.G. SHEARS, B.C. SHEN, P. SHERWOOD, A. SKUJA, A.M. SMITH, R. SOBIE, S. S¨OLDNER-REMBOLD, F. SPANO, A. STAHL, D. STROM, R. STR¨OHMER, S.TAREM, M.TASEVSKY, R.TEUSCHER, M.A.THOMSON, E.TORRENCE, D.TOYA, P.TRAN, I.TRIGGER, Z.TR´OCS´ANYI, E.TSUR, M.F.TURNER-WATSON, I.UEDA, B.UJV´ARI, C.F.VOLLMER, P.VANNEREM, R.V´ERTESI, M.VERZOCCHI, H.VOSS, J.VOSSEBELD, C.P.WARD, D.R.WARD, P.M.WATKINS, A.T.WATSON, N.K.WATSON, P.S.WELLS, T.WENGLER, N.WERMES, G.W.WILSON, J.A.WILSON, G.WOLF, T.R.WYATT, S.YAMASHITA, D. ZER-ZION, L. ZIVKOVIC, and OPAL Collaboration

Subjects
Physics, Particle physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, FOS: Physical sciences, Fermion, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Calibration, Radiative transfer, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Beam energy
Abstract

We present a determination of the LEP beam energy using "radiative return" fermion-pair events recorded at centre-of-mass energies from 183 GeV to 209 GeV. We find no evidence of a disagreement between the OPAL data and the LEP Energy Workings Group's standard calibration. Including the energy- averaged 11 MeV uncertainty in the standard determination, the beam energy we obtain from the OPAL data is higher than that obtained from the LEP calibration by 0+-34(stat.)+-27(syst.)MeV, Comment: 24 pages, 5 figures, Submitted to Phys. Letts. B

Published
2004
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45. Multi-photon events with large missing energy in e+e− collisions at s=192–209 GeV

Author

James Pinfold, R. Seuster, P. Scharff-Hansen, A. M. Smith, Andris Skuja, Tetsuro Mashimo, M. F. Turner-Watson, N. Meyer, M. Kupper, Daniel Lellouch, Takehiko Mori, L. Brigliadori, T. Behnke, S. W. O'Neale, P. O. Günther, J. Goldberg, M. Boutemeur, F. S. Merritt, K. J. Anderson, Thorsten Wengler, B. C. Shen, M. Donkers, Yoram Rozen, Siegfried Bethke, J. A. McKenna, Tara Shears, W. G. Scott, S. Yamashita, Junichi Kanzaki, Silvia Arcelli, J. W. Gary, P. Igo-Kemenes, K. Buesser, M. Gruwé, K. Ishii, H. Jeremie, Gideon Bella, Gianni Masetti, C. Y. Chang, R. M. Brown, Lorne Levinson, Christoph Rembser, Christoph Geich-Gimbel, Teresa Barillari, H. J. Burckhart, A. Csilling, S. Moed, Gabriele Benelli, Guenter Duckeck, D. Axen, Dezso Horvath, Erez Etzion, Richard Nisius, Graham Wilson, I. R. Bailey, O. Schaile, Oana Elena Vickey Boeriu, Raimund Ströhmer, Stefan Kluth, T. Kuhl, Shlomit Tarem, P. Mättig, Shoji Asai, Marco Cuffiani, Shlomo Dado, Richard Teuscher, A. J. Martin, F. Spano, M. J. Oreglia, M. Hauschild, M. Giunta, D. Zer-Zion, Robert McPherson, L. Zivkovic, Lutz Feld, D. Toya, P. J. Bell, G. Gaycken, W. Mader, Beatrix Dienes, F. K. Loebinger, C. Pahl, Giora Mikenberg, M. Schumacher, Matthias Schröder, Alexander Oh, J. R. Carter, W. Menges, Otmar Biebel, Paolo Giacomelli, Ivor Fleck, J. Ludwig, K. Runge, P. Bock, Georges Azuelos, T. R. Wyatt, I. Nakamura, D. Lanske, T. R. Junk, A. D. Schaile, Joleen Pater, Edward K. G. Sarkisyan, Gabriella Pasztor, K. Hoffman, E. Tsur, Gregor Herten, C. M. Hawkes, E. A. De Wolf, P. Vannerem, H. Nanjo, T. Schörner-Sadenius, Fabrizio Fabbri, A. Frey, Balazs Ujvari, H. A. Neal, Isabel Marian Trigger, K. W. Bell, A. Gupta, C. F. Vollmer, C. P. Ward, P. Gagnon, A. Harel, J. E. Pilcher, J. C. Hill, George Lafferty, Norbert Wermes, T. Kawamoto, Jochen Schieck, Ikuo Ueda, D. M. Strom, R. J. Barlow, J. Lu, Tobias Kramer, P. Amaral, Satoshi Mihara, S. Söldner-Rembold, Gunter Wolf, S. Orito, Zoltan Laszlo Trocsanyi, Kiyotomo Kawagoe, Gideon Alexander, D. Karlen, Frank Fiedler, B. Poli, R. K. Keeler, Dave Charlton, P. S. Wells, Arnulf Quadt, H. Mes, P. M. Watkins, A. T. Watson, Klaus Rabbertz, I. P. Duerdoth, S. Braibant, P. Renkel, Stephen Lloyd, P. Sherwood, Achim Stahl, Oliver Pooth, Ehud Duchovni, John Allison, D. E. Plane, N. Kanaya, A. Michelini, R. G. Kellogg, M. Hamann, R. D. Heuer, Csaba Hajdu, T. Kobayashi, A. Ludwig, Stefano Marcellini, Claudia Ciocca, James Letts, R. Vértesi, R. J. Sobie, Joost Vossebeld, Klaus Desch, P. Tran, K. Sachs, Philip Bechtle, Gordon H. Hanson, D. R. Ward, M. Ford, N. K. Watson, R. J. Batley, S. Campana, C. Ainsley, J. von Krogh, R. J. Hawkings, J. Dubbert, R. K. Carnegie, J. A. Wilson, M. A. Thomson, E. K. U. Gross, Eric Torrence, D. J. Miller, R. J. Hemingway, J. Lillich, B. W. Kennedy, P. Jovanovic, Peter Krieger, M. Przybycień, H. Landsman, A. A. Carter, E. L. Barberio, M. Verzocchi, P. F. Åkesson, Giovanni Abbiendi, J. M. Roney, M. Tasevsky, Koichi Nagai, W. Mohr, J. Grunhaus, A. Mutter, Sachio Komamiya, K. Kruger, T. Saeki, J. G. Layter, Alain Bellerive, G. Anagnostou, H. Voss, G. Giacomelli, Pamela Ferrari, A. De Roeck, M. Kobel, and Frans Meijers

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Missing energy, 010308 nuclear & particles physics, Electron–positron annihilation, 01 natural sciences, 7. Clean energy, Nuclear physics, Massless particle, Pair production, Excited state, 0103 physical sciences, Neutralino, Gravitino, 010306 general physics, Bhabha scattering
Abstract

Events with a final state consisting of two or more photons and large missing transverse energy have been observed in e + e − collisions at centre-of-mass energies in the range 192–209 GeV using the OPAL detector at LEP. Cross-section measurements are performed within the kinematic acceptance of the selection and compared with the expectations from the Standard Model process e + e − → ν ν ¯ γ γ ( γ ) . No evidence for new physics contributions to this final state is observed. Upper limits on σ ( e + e − → X X ) ⋅ BR 2 ( X → Y γ ) are derived for the case of stable and invisible Y. In the case of massive Y the combined limits obtained from all the data range from 10 to 60 fb, while for the special case of massless Y the range is 20 to 40 fb. The limits apply to pair production of excited neutrinos ( X = ν * , Y = ν ), to neutralino production ( X = χ ˜ 2 0 , Y = χ ˜ 1 0 ) and to supersymmetric models in which X = χ ˜ 1 0 and Y = G ˜ is a light gravitino.

Published
2004
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47. Flavour independent search for Higgs bosons decaying into hadronic final states in e+e− collisions at LEP

Author

Silvia Arcelli, N. Kanaya, Daniel Lellouch, Erez Etzion, Gordon H. Hanson, M. Ford, Takehiko Mori, A. Okpara, Stefan Kluth, Shlomit Tarem, T. R. Junk, Christoph Geich-Gimbel, Gregor Herten, R. M. Brown, Lorne Levinson, J. Böhme, M. Giunta, Gianni Masetti, C. Y. Chang, Alexander Oh, C. Pahl, T. Behnke, A. J. Martin, Georges Azuelos, E. Tsur, C. M. Hawkes, J. Goldberg, A. Hocker, S. Moed, G. D. Lafferty, S. Yamashita, E. K. U. Gross, I. R. Bailey, Gideon Bella, H. J. Burckhart, I. Nakamura, D. Lanske, D. R. Ward, K. Hoffman, H. Mes, P. Igo-Kemenes, A. Mutter, J. E. Pilcher, A. D. Schaile, Isabel Marian Trigger, K. W. Bell, M. A. Thomson, Robert McPherson, Gabriella Pasztor, P. Vannerem, Fabrizio Fabbri, A. Frey, Raimund Ströhmer, R. J. Hemingway, I. P. Duerdoth, M. Gruwé, K. Ishii, H. Jeremie, P. Gagnon, S. Braibant, James Pinfold, D. Zer-Zion, W. Mader, J. C. Hill, Lutz Feld, B. W. Kennedy, F. K. Loebinger, J. Lillich, A. Harel, Thorsten Wengler, R. Seuster, Tobias Kramer, Ikuo Ueda, D. M. Strom, D. E. Plane, Klaus Rabbertz, Ivor Fleck, Yoram Rozen, R. K. Keeler, Christoph Rembser, J. M. Roney, M. Boutemeur, F. S. Merritt, J. Lu, Joleen Pater, Edward K. G. Sarkisyan, C. P. Ward, Zoltan Laszlo Trocsanyi, B. Poli, Richard Teuscher, Stephen Lloyd, B. C. Shen, P. Jovanovic, Tara Shears, M. Tasevsky, Beatrix Dienes, Richard Nisius, M. Donkers, P. Tran, O. Schaile, M. Przybycień, A. Klier, R. J. Batley, Balazs Ujvari, H. A. Neal, Arnulf Quadt, Koichi Nagai, W. Mohr, Marco Cuffiani, S. Söldner-Rembold, Gabriele Benelli, Siegfried Bethke, W. G. Scott, Peter Krieger, Junichi Kanzaki, J. W. Gary, P. M. Watkins, T. Kuhl, Paolo Giacomelli, A. A. Carter, Gunter Wolf, N. K. Watson, G. Gaycken, J. A. McKenna, J. Grunhaus, L. Brigliadori, M. Hamann, K. Buesser, M. Schumacher, M. Hauschild, D. Karlen, P. Renkel, Oliver Pooth, C. F. Vollmer, E. A. De Wolf, John Allison, Teresa Barillari, M. Verzocchi, S. W. O'Neale, P. O. Günther, A. Csilling, C. Ainsley, M. J. Oreglia, Dezso Horvath, Stefano Rosati, Jochen Schieck, R. J. Sobie, R. J. Barlow, P. Scharff-Hansen, E. Torrence, A. Gupta, Dave Charlton, P. F. Åkesson, Giovanni Abbiendi, D. Axen, Oana Elena Vickey Boeriu, P. Amaral, Gideon Alexander, K. J. Anderson, F. Spano, R. G. Kellogg, Joost Vossebeld, Sachio Komamiya, Graham Wilson, Matthias Schröder, Klaus Desch, P. J. Bell, Peter Sherwood, Csaba Hajdu, L. Zivkovic, D. J. Miller, Stefano Marcellini, J. Ludwig, P. Mättig, Shoji Asai, Satoshi Mihara, Shlomo Dado, Ehud Duchovni, A. M. Smith, J. R. Carter, Katja Klein, K. Runge, P. Bock, Achim Stahl, James Letts, W. Menges, Otmar Biebel, D. Waller, K. Kruger, T. Saeki, R. D. Heuer, A. Michelini, Andris Skuja, T. Schörner-Sadenius, J. von Krogh, H. Landsman, Guenter Duckeck, Kiyotomo Kawagoe, P. S. Wells, Frank Fiedler, D. Toya, T. Kobayashi, Tetsuro Mashimo, M. F. Turner-Watson, A. Ludwig, Claudia Ciocca, K. Sachs, H. Nanjo, Terry Richard Wyatt, A. T. Watson, S. Campana, Giora Mikenberg, Philip Bechtle, M. Kupper, E. L. Barberio, R. J. Hawkings, Norbert Wermes, T. Kawamoto, D. Wetterling, S. Orito, J. Dubbert, R. K. Carnegie, J. A. Wilson, H. Voss, G. Giacomelli, A. De Roeck, M. Kobel, Frans Meijers, Alain Bellerive, G. Anagnostou, Pamela Ferrari, J. G. Layter, and R. Vértesi

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Branching fraction, High Energy Physics::Phenomenology, Hadron, Scalar boson, 01 natural sciences, Standard Model, Nuclear physics, Pair production, 0103 physical sciences, Higgs boson, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Boson, Event generator
Abstract

A search for the Higgsstrahlung process e + e − → hZ is described, where the neutral Higgs boson h is assumed to decay into hadronic final states. In order to be sensitive to a broad range of models, the search is performed independent of the flavour content of the Higgs boson decay. The analysis is based on e + e − collision data collected by the OPAL detector at energies between 192 and 209 GeV. The search does not reveal any significant excess over the Standard Model background prediction. Results are combined with previous searches at energies around 91 and at 189 GeV. A limit is set on the product of the cross-section and the hadronic branching ratio of the Higgs boson, as a function of the Higgs boson mass. Assuming the hZ coupling predicted by the Standard Model, and a Higgs boson decaying only into hadronic final states, a lower bound of 104 GeV / c 2 is set on the mass at the 95% confidence level.

Published
2004
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48. Study of Bose-Einstein correlations in ${\rm e}^ + {\rm e}^-\to {\rm W}^ + {\rm W}^-$ events at LEP

Author

N. Kanaya, Christoph Geich-Gimbel, H. Mes, I. P. Duerdoth, M. J. Oreglia, M. A. Thomson, E. K. U. Gross, Shlomo Dado, S. Braibant, Alexander Oh, R. M. Brown, Lorne Levinson, L. Zivkovic, M. Przybycień, Tara Shears, T. Barillari, Guenter Duckeck, M. Hamann, J. Grunhaus, J. R. Carter, A. Csilling, I. Nakamura, D. Lanske, J. M. Roney, A. A. Carter, B. Poli, Ehud Duchovni, M. Tasevsky, Richard Teuscher, D. Toya, D. R. Ward, Koichi Nagai, I. R. Bailey, Lutz Feld, W. Mohr, M. Verzocchi, S. Yamashita, P. F. Åkesson, Giovanni Abbiendi, Thorsten Wengler, K. Hoffman, P. Igo-Kemenes, R. J. Sobie, C. Pahl, A. Michelini, R. J. Batley, Joost Vossebeld, H. Landsman, W. Menges, Otmar Biebel, Satoshi Mihara, K. Ishii, H. Jeremie, Klaus Desch, Georges Azuelos, E. Tsur, C. F. Vollmer, Gideon Bella, T. R. Wyatt, P. Mättig, Shoji Asai, D. Zer-Zion, Giora Mikenberg, M. Boutemeur, F. S. Merritt, Katja Klein, D. E. Plane, C. M. Hawkes, Pamela Ferrari, J. G. Layter, J. von Krogh, H. J. Burckhart, N. K. Watson, Matthias Schröder, James Pinfold, R. Seuster, G. Gaycken, F. K. Loebinger, Isabel Marian Trigger, K. W. Bell, Jochen Schieck, T. Kobayashi, O. Schaile, M. Schumacher, P. Gagnon, R. J. Hawkings, E. L. Barberio, J. A. McKenna, Frank Fiedler, A. Ludwig, R. J. Barlow, Kiyotomo Kawagoe, Ivor Fleck, J. C. Hill, Yoram Rozen, L. Brigliadori, Tobias Kramer, P. Tran, T. Kuhl, B. C. Shen, E. A. De Wolf, S. Campana, Joleen Pater, P. S. Wells, C. Ainsley, T. Schörner-Sadenius, M. Donkers, J. Dubbert, R. K. Carnegie, Siegfried Bethke, Norbert Wermes, Edward K. G. Sarkisyan, A. T. Watson, P. Amaral, S. W. O'Neale, Andris Skuja, W. G. Scott, Junichi Kanzaki, J. A. Wilson, T. Kawamoto, J. Goldberg, K. Buesser, J. W. Gary, A. D. Schaile, Gabriella Pasztor, Gabriele Benelli, Tetsuro Mashimo, M. F. Turner-Watson, Daniel Lellouch, A. J. Martin, P. O. Günther, Balazs Ujvari, A. Mutter, D. J. Miller, Zoltan Laszlo Trocsanyi, Takehiko Mori, P. Vannerem, H. A. Neal, A. Harel, S. Orito, N. Meyer, Dezso Horvath, Ikuo Ueda, D. M. Strom, J. Lu, M. Kupper, K. J. Anderson, Gideon Alexander, C. P. Ward, W. Mader, Robert McPherson, Dave Charlton, S. Söldner-Rembold, Alain Bellerive, Gianni Masetti, C. Y. Chang, Fabrizio Fabbri, A. Frey, P. Scharff-Hansen, E. Torrence, A. Gupta, Sachio Komamiya, S. Moed, R. D. Heuer, T. R. Junk, A. M. Smith, R. J. Hemingway, G. Anagnostou, Klaus Rabbertz, Stephen Lloyd, Oliver Pooth, Gregor Herten, K. Kruger, T. Saeki, H. Voss, John Allison, J. Lillich, B. W. Kennedy, Raimund Ströhmer, G. Giacomelli, P. Jovanovic, A. De Roeck, M. Kobel, Christoph Rembser, Peter Krieger, J. E. Pilcher, R. G. Kellogg, G. W. Wilson, Frans Meijers, M. Hauschild, Beatrix Dienes, Csaba Hajdu, Erez Etzion, Stefano Marcellini, Stefan Kluth, Shlomit Tarem, James Letts, R. Vértesi, M. Giunta, T. Behnke, Gordon H. Hanson, M. Ford, Thomas Kress, Gunter Wolf, D. Karlen, D. Axen, Oana Elena Vickey Boeriu, F. Spano, Peter Sherwood, J. Ludwig, K. Runge, P. Bock, G. D. Lafferty, R. K. Keeler, Arnulf Quadt, P. M. Watkins, P. Renkel, M. Gruwé, Richard Nisius, Marco Cuffiani, P. J. Bell, Achim Stahl, H. Nanjo, Claudia Ciocca, K. Sachs, Philip Bechtle, and Paolo Giacomelli

Subjects
Condensed Matter::Quantum Gases, Nuclear physics, Physics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Hadron, Monte Carlo method, High Energy Physics::Experiment, Bose–Einstein correlations, Engineering (miscellaneous), Bar (unit), Boson
Abstract

Bose-Einstein correlations between like-sign charged-particle pairs in e(+)e(-) --> W+ W- events recorded with the OPAL detector at LEP at centre-of-mass energies between 183 GeV and 209 GeV are studied. Recently proposed methods which allow direct searches for correlations in the data via distributions of test variables are used to investigate the presence of correlations between hadrons originating from different W bosons in W+W- --> q (q) over barq (q) over bar events. Within the statistics of the data sample no evidence for inter - WW Bose-Einstein correlations is obtained. The data are also compared with predictions of a recent implementation of Bose-Einstein correlation effects in the Monte Carlo model PYTHIA.

Published
2004
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49. Cytochrome b5 oxidoreductase: expression and characterization of the original familial ideopathic methemoglobinemia mutations E255- and G291D

Author

Michael J. Barber and C. Ainsley Davis

Subjects
Mutant, Biophysics, Genes, Recessive, Flavin group, Biochemistry, Catalysis, Oxidoreductase, Enzyme Stability, Cytochrome b5, Humans, Molecular Biology, chemistry.chemical_classification, Chemistry, Cytochrome b, Temperature, Molecular biology, Enzyme Activation, Cytochromes b5, Enzyme, Mutation, Congenital Methemoglobinemia, Mutagenesis, Site-Directed, Heterologous expression, Methemoglobinemia, Oxidoreductases, Oxidation-Reduction, Cytochrome-B(5) Reductase
Abstract

NADH:cytochrome b 5 oxidoreductase catalyzes the transfer of reducing equivalents from the physiological electron donor, NADH, to two molecules of cytochrome b 5 . Utilizing a heterologous expression system for the soluble, catalytic domain of the rat microsomal enzyme, we have produced two mutants, corresponding to E255- and G291D. These mutants correspond to the two specific mutations that were identified over a half century later following diagnosis of the original cases of type I recessive congenital methemoglobinemia (RCM). We have purified both the E255- and G291D variants to homogeneity to determine the molecular basis for type I RCM in these individuals. Both the E255- and G291D variants retained a full complement of FAD and exhibited absorption and CD spectroscopic properties comparable to those of the wild-type protein. Oxidation–reduction potentiometric titrations yielded standard midpoint potentials ( E 0′ ) for the FAD/FADH 2 couple of −271 and −273 mV for the E255- and G291D variants, respectively, which were comparable to the value of −268 mV obtained for the wild-type protein and confirmed that the redox potential of the flavin was unaffected by either mutation. Thermal and proteolytic stability studies revealed that while the G291D variant exhibited stability comparable to that of wild-type, the E255- variant was markedly less stable, indicative of an altered conformation. Initial-rate kinetic studies revealed that both mutants had decreased catalytic activity ( k cat ), with the E255- and G291D variants retaining approximately 38 and 58% of wild-type activity, respectively. However, the affinity for NADH ( K m NADH ) was decreased ∼100-fold for E255- compared to only ∼1.3-fold for G291D, results supported by the spectroscopic binding constant ( K s ) obtained for G291D. These results indicate that the properties of both the E255- and G291D cytochrome b 5 oxidoreductase mutants are similar to those of other variants that have been identified as resulting in the type I form of RCM.

Published
2004
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50. Determination of α S using OPAL hadronic event shapes at $\sqrt{s} = 91\mbox{--}209~\mathrm{GeV}$ and resummed NNLO calculations

Author

P. Scharff-Hansen, Siegfried Bethke, C. Y. Chang, I. Nakamura, D. Axen, Oana Elena Vickey Boeriu, A. M. Smith, Gideon Bella, J. W. Gary, H. J. Burckhart, H. Mes, A. J. Martin, I. P. Duerdoth, Peter Sherwood, Marek Tasevsky, Richard Teuscher, Dezso Horvath, J. Ludwig, K. Runge, P. Bock, D. Zer-Zion, James Pinfold, A. Quadt, R. Seuster, Gunter Wolf, Oliver Pooth, F. K. Loebinger, Ivor Fleck, R. G. Kellogg, Csaba Hajdu, Alexander Oh, Stefano Marcellini, James Letts, Joleen Pater, Edward K. G. Sarkisyan, D. Toya, Graham Wilson, Christoph Geich-Gimbel, Balazs Ujvari, H. A. Neal, Yoram Rozen, D. Karlen, W. Mader, P. J. Bell, M. J. Oreglia, S. Braibant, C. Pahl, G. Mikenberg, R. Vértesi, Shlomo Dado, T. R. Wyatt, Gordon H. Hanson, A. Krasznahorkay, D. Lanske, S. W. O'Neale, Junichi Kanzaki, Sachio Komamiya, Matthias Schröder, M. Gruwe, J. M. Roney, Francesco Spanò, Andris Skuja, K. J. Anderson, Dave Charlton, R. J. Batley, P. Igo-Kemenes, W. Menges, Otmar Biebel, R. K. Keeler, J. Lillich, Koichi Nagai, J. Goldberg, E. Tsur, C. M. Hawkes, P. Gagnon, B. W. Kennedy, Raimund Ströhmer, Tetsuro Mashimo, M. F. Turner-Watson, P. Jovanovic, W. Mohr, K. Ishii, H. Jeremie, A. D. Schaile, Gabriella Pasztor, Isabel Marian Trigger, K. W. Bell, Daniel Lellouch, P. Vannerem, Claudia Ciocca, P. M. Watkins, T. Saeki, J. C. Hill, C. F. Vollmer, M. Boutemeur, F. S. Merritt, N. Meyer, M. Kupper, Peter Krieger, T. Schörner-Sadenius, Zoltan Laszlo Trocsanyi, Takehiko Mori, K. Sachs, J. R. Carter, Tobias Kramer, C. P. Ward, H. Nanjo, Philip Bechtle, Steve Lloyd, Tara Shears, P. Renkel, R. M. Brown, Lorne Levinson, Norbert Wermes, Christoph Rembser, S. Söldner-Rembold, Gideon Alexander, M. A. Thomson, Beatrix Dienes, E. K. U. Gross, H. Voss, Jochen Schieck, S. Campana, O. Schaile, Paolo Capiluppi, T. Kawamoto, I. R. Bailey, M. Schumacher, G. Duckeck, J. A. McKenna, S. Orito, J. Dubbert, Erez Etzion, A. Mutter, Teresa Barillari, Stefan Kluth, Satoru Yamashita, A. Csilling, T. Kuhl, R. J. Barlow, R. K. Carnegie, Shlomit Tarem, E. A. De Wolf, Klaus Rabbertz, M. Giunta, D. E. Plane, N. K. Watson, P. Mättig, D. J. Miller, Shoji Asai, T. Behnke, L. Zivkovic, J. A. Wilson, J. Grunhaus, M. Dallavalle, H. Landsman, C. Ainsley, A. M. Rossi, Ehud Duchovni, Marco Cuffiani, A. Michelini, E. L. Barberio, T. Kobayashi, A. Ludwig, E. Torrence, A. Gupta, Paolo Giacomelli, D. R. Ward, Alain Bellerive, George Lafferty, M. Przybycień, G. Anagnostou, A. A. Carter, Satoshi Mihara, Achim Stahl, G. Giacomelli, M. Verzocchi, P. F. Åkesson, Giovanni Abbiendi, Frank Fiedler, A. De Roeck, M. Kobel, Frans Meijers, M. Ford, Pamela Ferrari, J. von Krogh, R. J. Hawkings, Kiyotomo Kawagoe, Robert McPherson, R. D. Heuer, Fabrizio Fabbri, A. Frey, M. Hamann, R. J. Sobie, Joost Vossebeld, Klaus Desch, A. Harel, Ikuo Ueda, D. M. Strom, J. Lu, P. S. Wells, A. T. Watson, M. Hauschild, T. R. Junk, Thorsten Wengler, Gabriele Benelli, Gregor Herten, J. E. Pilcher, B. C. Shen, G. Abbiendi, C. Ainsley, P. F. Åkesson, G. Alexander, G. Anagnostou, K. J. Anderson, S. Asai, D. Axen, I. Bailey, E. Barberio, T. Barillari, R. J. Barlow, R. J. Batley, P. Bechtle, T. Behnke, K. W. Bell, P. J. Bell, G. Bella, A. Bellerive, G. Benelli, S. Bethke, O. Biebel, O. Boeriu, P. Bock, M. Boutemeur, S. Braibant, R. M. Brown, H. J. Burckhart, S. Campana, P. Capiluppi, R. K. Carnegie, A. A. Carter, J. R. Carter, C. Y. Chang, D. G. Charlton, C. Ciocca, A. Csilling, M. Cuffiani, S. Dado, M. Dallavalle, A. Roeck, E. A. Wolf, K. Desch, B. Diene, J. Dubbert, E. Duchovni, G. Duckeck, I. P. Duerdoth, E. Etzion, F. Fabbri, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, P. Gagnon, J. W. Gary, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, M. Giunta, J. Goldberg, E. Gro, J. Grunhau, M. Gruwé, A. Gupta, C. Hajdu, M. Hamann, G. G. Hanson, A. Harel, M. Hauschild, C. M. Hawke, R. Hawking, G. Herten, R. D. Heuer, J. C. Hill, D. Horváth, P. Igo-Kemene, K. Ishii, H. Jeremie, P. Jovanovic, T. R. Junk, J. Kanzaki, D. Karlen, K. Kawagoe, T. Kawamoto, R. K. Keeler, R. G. Kellogg, B. W. Kennedy, S. Kluth, T. Kobayashi, M. Kobel, S. Komamiya, T. Krämer, A. Krasznahorkay, P. Krieger, J. Krogh, T. Kuhl, M. Kupper, G. D. Lafferty, H. Landsman, D. Lanske, D. Lellouch, J. Lett, L. Levinson, J. Lillich, S. L. Lloyd, F. K. Loebinger, J. Lu, A. Ludwig, J. Ludwig, W. Mader, S. Marcellini, A. J. Martin, T. Mashimo, P. Mättig, J. McKenna, R. A. McPherson, F. Meijer, W. Menge, F. S. Merritt, H. Me, N. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D. J. Miller, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H. Nanjo, H. A. Neal, S. W. O’Neale, A. Oh, M. J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J. R. Pater, J. E. Pilcher, J. Pinfold, D. E. Plane, O. Pooth, M. Przybycień, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, J. M. Roney, A. M. Rossi, Y. Rozen, K. Runge, K. Sach, T. Saeki, E. K. G. Sarkisyan, A. D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, T. Schörner-Sadeniu, M. Schröder, M. Schumacher, R. Seuster, T. G. Shear, B. C. Shen, P. Sherwood, A. Skuja, A. M. Smith, R. Sobie, S. Söldner-Rembold, F. Spano, A. Stahl, D. Strom, R. Ströhmer, S. Tarem, M. Tasevsky, R. Teuscher, M. A. Thomson, E. Torrence, D. Toya, I. Trigger, Z. Trócsányi, E. Tsur, M. F. Turner-Watson, I. Ueda, B. Ujvári, C. F. Vollmer, P. Vannerem, R. Vértesi, M. Verzocchi, H. Vo, J. Vossebeld, C. P. Ward, D. R. Ward, P. M. Watkin, A. T. Watson, N. K. Watson, P. S. Well, T. Wengler, N. Werme, G. W. Wilson, J. A. Wilson, G. Wolf, T. R. Wyatt, S. Yamashita, D. Zer-Zion, and L. Zivkovic

Subjects
Quantum chromodynamics, Physics, Particle physics, Annihilation, OPAL, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Electron–positron annihilation, Hadron, Nuclear Theory, LEP, 01 natural sciences, Asymptotic freedom, Nuclear physics, Renormalization, ALFA_S, 0103 physical sciences, High Energy Physics::Experiment, Gauge theory, 010306 general physics, Event (particle physics), Engineering (miscellaneous)
Abstract

Hadronic event shape distributions from e+e− annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used to determine the strong coupling α S. The results are based on QCD predictions complete to the next-to-next-to-leading order (NNLO), and on NNLO calculations matched to the resummed next-to-leading-log-approximation terms (NNLO + NLLA). The combined NNLO result from all variables and centre-of-mass energies is while the combined NNLO + NLLA result is The completeness of the NNLO and NNLO + NLLA results with respect to missing higher order contributions, studied by varying the renormalization scale, is improved compared to previous results based on NLO or NLO + NLLA predictions only. The observed energy dependence of α S agrees with the QCD prediction of asymptotic freedom and excludes the absence of running.

Published
2011

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