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Sample records for tevatron electron lenses

  1. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  2. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  3. Generation and diagnostics of uncaptured beam in the Fermilab Tevatron and its control by electron lenses

    Directory of Open Access Journals (Sweden)

    Xiao-Long Zhang

    2008-05-01

    Full Text Available In the collider run II, the Tevatron operates with 36 high intensity bunches of 980 GeV protons and antiprotons. Particles not captured by the Tevatron rf system pose a threat since they can quench the superconducting magnets during acceleration or at beam abort. We describe the main mechanisms for the origination of this uncaptured beam, and present measurements of its main parameters by means of a newly developed diagnostics system. The Tevatron electron lens is effectively used in the collider run II operation to remove uncaptured beam and keep its intensity in the abort gaps at a safe level.

  4. Guide for 3D WARP simulations of hollow electron beam lenses. Practical explanation on basis of Tevatron electron lens test stand

    Energy Technology Data Exchange (ETDEWEB)

    Moens, Vince [Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland)

    2014-06-08

    The purpose of this guide is to help successive students handle WARP. It outlines the installation of WARP on personal computers as well as super-computers and clusters. It furthermore teaches the reader how to handle the WARP environment and run basic scripts. Lastly it outlines how to execute the current Hollow Electron Beam Lens scripts.

  5. Weakly oval electron lense

    International Nuclear Information System (INIS)

    Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.

    2001-01-01

    The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system

  6. RHIC electron lenses upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Binello, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Costanzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Pikin, A. I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Shrey, T. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tan, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  7. Tevatron

    International Nuclear Information System (INIS)

    Yamada, R.

    1978-01-01

    The main ongoing project at Fermilab is called the Tevatron, meaning 1,000 GeV in beam energy. The following is a list of major constituents for this project: Super Ring; upgrading external beam lines for experimental areas; electron cooling and antiproton acceleration; and colliding beam facility and its detectors. At present the Super Ring is being build and installed in the Main Ring tunnel. Its injection line is completed and under test. Modification of the tunnel for the Switchyard beam lines is finished. All magnets for the Electron Cooling Ring are installed. Protons are being injected into the cooling ring for study. The designs for the colliding beam facility and its detectors will be finalized shortly. These facilities and their development are described

  8. Electron Lenses for the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermilab; Valishev, Alexander [Fermilab; Bruce, Roderik [CERN; Redaelli, Stefano [CERN; Rossi, Adriana [CERN; Salvachua, Belen [CERN

    2014-07-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.

  9. Electron lenses for the large hadron collider

    CERN Document Server

    Stancari†, G; Bruce, R; Redaelli, S; Rossi, A; Salvachua Ferrando, B

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beamswhose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-bybunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beamcompensation, and for the demonstration of halo scrapingwith hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. A conceptual design was recently completed, and the project is moving towards a technical design in 2014–2015 for construction in 2015–2017, if needed, after resuming LHC operations and re-assessing collimation needs and requirements at 6.5 TeV. Because of the...

  10. Magnetic electron lenses

    CERN Document Server

    1982-01-01

    No single volume has been entirely devoted to the properties of magnetic lenses, so far as I am aware, although of course all the numerous textbooks on electron optics devote space to them. The absence of such a volume, bringing together in­ formation about the theory and practical design of these lenses, is surprising, for their introduction some fifty years ago has created an entirely new family of commercial instruments, ranging from the now traditional transmission electron microscope, through the reflection and transmission scanning microscopes, to co­ lumns for micromachining and microlithography, not to mention the host of experi­ mental devices not available commercially. It therefore seemed useful to prepare an account of the various aspects of mag­ netic lens studies. These divide naturally into the five chapters of this book: the theoretical background, in which the optical behaviour is described and formu­ lae given for the various aberration coefficients; numerical methods for calculat­ ing...

  11. 'Electron compression' of beam-beam footprint in the Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.; Finley, D.A.

    1997-08-01

    The beam-beam interaction in the Tevatron collider sets some limits on bunch intensity and luminosity. These limits are caused by a tune spread in each bunch which is mostly due to head-on collisions, but there is also a bunch-to-bunch tune spread due to parasitic collisions in multibunch operation. We describe a counter-traveling electron beam which can be used to eliminate these effects, and present general considerations and physics limitations of such a device which provides 'electron compression' of the beam-beam footprint in the Tevatron

  12. Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Previtali, Valentina [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Valishev, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Bruce, Roderik [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Redaelli, Stefano [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Rossi, Adriana [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Salvachua Ferrando, Belen [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

    2014-06-26

    Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. We are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.

  13. Plasma lenses for focusing relativistic electron beams

    International Nuclear Information System (INIS)

    Govil, R.; Wheeler, S.; Leemans, W.

    1997-01-01

    The next generation of colliders require tightly focused beams with high luminosity. To focus charged particle beams for such applications, a plasma focusing scheme has been proposed. Plasma lenses can be overdense (plasma density, n p much greater than electron beam density, n b ) or underdense (n p less than 2 n b ). In overdense lenses the space-charge force of the electron beam is canceled by the plasma and the remaining magnetic force causes the electron beam to self-pinch. The focusing gradient is nonlinear, resulting in spherical aberrations. In underdense lenses, the self-forces of the electron beam cancel, allowing the plasma ions to focus the beam. Although for a given beam density, a uniform underdense lens produces smaller focusing gradients than an overdense lens, it produces better beam quality since the focusing is done by plasma ions. The underdense lens can be improved by tapering the density of the plasma for optimal focusing. The underdense lens performance can be enhanced further by producing adiabatic plasma lenses to avoid the Oide limit on spot size due to synchrotron radiation by the electron beam. The plasma lens experiment at the Beam Test Facility (BTF) is designed to study the properties of plasma lenses in both overdense and underdense regimes. In particular, important issues such as electron beam matching, time response of the lens, lens aberrations and shot-to-shot reproducibility are being investigated

  14. Electron beams, lenses, and optics. Volume 2

    International Nuclear Information System (INIS)

    El-Kareh, A.B.; El-Kareh, J.C.J.

    1970-01-01

    This volume presents a systematic coverage of aberrations. It analyzes the geometrical aberrations and treats the spherical and chromatic aberrations in great detail. The coefficients of spherical and chromatic aberration have been computed for a series of electrostatic and magnetic lenses and are listed in table form. The book also covers space charge and its effect on highly focused electron beams

  15. Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

    CERN Document Server

    Stancari, Giulio; Valishev, Alexander; Bruce, Roderik; Redaelli, Stefano; Rossi, Adriana; Salvachua Ferrando, Belen

    2014-01-01

    Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. Within the US LHC Accelerator Research Program (LARP) and the European FP7 HiLumi LHC Design Study, we are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were check...

  16. Plans for Deployment of Hollow Electron Lenses at the LHC for Enhanced Beam Collimation

    Energy Technology Data Exchange (ETDEWEB)

    Redaelli, S. [CERN; Bertarelli, A. [CERN; Bruce, R. [CERN; Perini, D. [CERN; Rossi, A. [CERN; Salvachua, B. [CERN; Stancari, G. [Fermilab; Valishev, A. [Fermilab

    2015-06-01

    Hollow electron lenses are considered as a possible means to improve the LHC beam collimation system, providing active control of halo diffusion rates and suppressing the population of transverse halos. After a very successful experience at the Tevatron, a conceptual design of a hollow e-lens optimized for the LHC was produced. Recent further studies have led to a mature preliminary technical design. In this paper, possible scenarios for the deployment of this technology at the LHC are elaborated in the context of the scheduled LHC long shutdowns until the full implementation of the HL-LHC upgrade in 2023. Possible setups of electron beam test stands at CERN and synergies with other relevant electron beam programmes are also discussed.

  17. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-09-11

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles. At Fermilab, we are planning to install an electron lens in the Integrable Optics Test Accelerator (IOTA, a 40-m ring for 150-MeV electrons) as one of the proof-of-principle implementations of nonlinear integrable optics to achieve large tune spreads and more stable beams without loss of dynamic aperture.

  18. Electron beams, lenses, and optics. Volume 1

    International Nuclear Information System (INIS)

    El-Kareh, A.B.; El-Kareh, J.C.J.

    1970-01-01

    This book treats the ideal case where all lenses are assumed to be free from errors. It presents a thorough mathematical analysis of the electrostatic immersion lens, both symmetrical and asymetrical, and covers the einzel lens and the symmetrical magnetic lens in detail. The authors have obtained data on these lenses by means of a digital computer and present them in tabular form

  19. Measurements of a Newly Designed BPM for the Tevatron Electron Lens 2

    Science.gov (United States)

    Scarpine, V. E.; Kamerdzhiev, V.; Fellenz, B.; Olson, M.; Kuznetsov, G.; Kamerdzhiev, V.; Shiltsev, V. D.; Zhang, X. L.

    2006-11-01

    Fermilab has developed a second electron lens (TEL-2) for beam-beam compensation in the Tevatron as part of its Run II upgrade program. Operation of the beam position monitors (BPMs) in the first electron lens (TEL-1) showed a systematic transverse position difference between short proton bunches (2 ns sigma) and long electron pulses (˜1 us) of up to ˜1.5 mm. This difference was attributed to frequency dependence in the BPM system. The TEL-2 BPMs utilize a new, compact four-plate design with grounding strips between plates to minimize crosstalk. In-situ measurements of these new BPMs are made using a stretched wire pulsed with both proton and electron beam formats. In addition, longitudinal impedance measurements of the TEL-2 are presented. Signal processing algorithm studies indicate that the frequency-dependent transverse position offset may be reduced to ˜0.1 mm for the beam structures of interest.

  20. Experimental studies of stable confined electron clouds using Gabor lenses

    CERN Document Server

    Meusel, O.; Glaeser, B.; Schulte, K.

    2013-04-22

    Based on the idea of D. Gabor [1] space charge lenses are under investigation to be a powerful focussing device for intense ion beams. A stable confined electron column is used to provide strong radially symmetric electrostatic focussing, e.g. for positively charged ion beams. The advantages of Gabor lenses are a mass independent focussing strength, space charge compensation of the ion beam and reduced magnetic or electric fields compared to conventional focussing devices. Collective phenomena of the electron cloud result in aberrations and emittance growth of the ion beam. The knowledge of the behaviour of the electron cloud prevents a decrease of the beam brilliance. Numerical models developed to describe the electron confinement and dynamics within a Gabor lens help to understand the interaction of the ion beam with the electron column and show the causes of non-neutral plasma instabilities. The diagnosis of the electron cloud properties helps to evaluate the numerical models and to investigate the influen...

  1. Applications of Electronstatic Lenses to Electron Gun and Energy Analyzers

    International Nuclear Information System (INIS)

    Sise, O.

    2004-01-01

    Focal properties and geometries are given for several types of electrostatic lens systems commonly needed in electron impact studies. One type is an electron gun which focuses electrons over a wide range of energy onto a fixed point, such as target, and the other type is an analyzer system which focuses scattered electrons of variable energy onto a fixed position, such as the entrance plane of an analyzer. There are many different types and geometries of these lenses for controlling and focusing of the electron beams. In this presentation we discussed the criteria used for the design of the electrostatic lenses associated with the electron gun and energy analyzers and determined the fundamental relationships between the operation and behaviour of multi-element electrostatic lenses, containing five, six and seven elements. The focusing of the electron beam was achieved by applying suitable voltages to the series of these lens elements, Design of the lens system for electron gun was based on our requirements that the beam at the target had a small spot size and zero beam angle, that is, afocal mode. For energy analyzer systems we considered the entrance of the hemispherical analyzer which determines the energy of the electron beam and discussed the focusing condition of this lens systems

  2. UV laser ionization and electron beam diagnostics for plasma lenses

    International Nuclear Information System (INIS)

    Govil, R.; Volfbeyn, P.; Leemans, W.

    1995-04-01

    A comprehensive study of focusing of relativistic electron beams with overdense and underdense plasma lenses requires careful control of plasma density and scale lengths. Plasma lens experiments are planned at the Beam Test Facility of the LBL Center for Beam Physics, using the 50 MeV electron beam delivered by the linac injector from the Advanced Light Source. Here we present results from an interferometric study of plasmas produced in tri-propylamine vapor with a frequency quadrupled Nd:YAG laser at 266 nm. To study temporal dynamics of plasma lenses we have developed an electron beam diagnostic using optical transition radiation to time resolve beam size and divergence. Electron beam ionization of the plasma has also been investigated

  3. Third-rank chromatic aberrations of electron lenses.

    Science.gov (United States)

    Liu, Zhixiong

    2018-02-01

    In this paper the third-rank chromatic aberration coefficients of round electron lenses are analytically derived and numerically calculated by Mathematica. Furthermore, the numerical results are cross-checked by the differential algebraic (DA) method, which verifies that all the formulas for the third-rank chromatic aberration coefficients are completely correct. It is hoped that this work would be helpful for further chromatic aberration correction in electron microscopy. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Upgraded D OE calorimeter electronics for short Tevatron bunch space and the effect of pile-up on the W mass measurement

    International Nuclear Information System (INIS)

    Lokos, S.

    1992-11-01

    The high luminosity and short bunch spacing time of the upgraded Tevatron force the calorimeter to replace a significant part of the present electronics. The W mass measurement was used to study the pile-up effects

  5. Fermilab | Tevatron | Tevatron Symposium | Agenda

    Science.gov (United States)

    Industry Students and teachers Media Tevatron Navbar Toggle About Leadership and Organization Leadership and video archive Resources for Employees Researchers Job seekers Neighbors Industry Students and Haun Music: John Zorn Costumes: Ariane Dolan Dancers: Simone Baechle, Zada Cheeks, Katie Graves, and

  6. Search for electroweak top quark production in the electron + jets channel in the D0 experiment at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Busato, Emmanuel [Paris Univ. (France)

    2005-04-01

    The top quark, whose mass approaches the electroweak symmetry breaking scale, is by far the heaviest known elementary particle. New physics is therefore expected to have its most important effect in the top sector. The Tevatron is, currently, the only collider able to produce the top quark. Among all possible production processes in the standard model, the top-antitop pair production via strong interaction, first observed in 1995, is the one with the largest cross section. The production via electroweak interaction (known as single top production), more difficult to extract from the background because of a lower cross section and of a lower signal to background ratio, has never been observed. In this thesis, we have searched for these processes by studying proton-antiproton collisions at $\\sqrt{s}$ =1.96 TeV produced by the Tevatron and detected with the DØ detector. The experimental study of the top quark is very sensitive to the quality of the data taken by the calorimeter. This detector showed, at the beginning of the Run II, rather important noise problems. Having identified the origin of the noise, new treatments at the offline level were implemented and their effects studied. It has been shown that these treatments reduce very significantly the effect of the noise in the reconstruction of physical quantities without notable degradation of the signal. Within the standard model, the top quark decays into W b with a branching ratio close to 100%. Leptonic decays of the into electron + neutrino have been used to identify the from the top decay. The main backgrounds to the single top signal ( +jets and QCD) are made essentially of light quark jets in the final state. Two ..-tagging algorithms have therefore been applied in order to improve the signal to background ratio. No evidence for electroweak top quark production has been found. Upper limits at the 95 % confidence level on the observed (expected) cross sections have be computed. They are found to be 14

  7. The limits of the electron optical parameters of asymmetric double pipecol magnetic objective lenses

    International Nuclear Information System (INIS)

    Al-khashab, A. M.; Abas, K. A.

    1997-01-01

    The asymmetrical magnetic electron lens is of great importance for the electron microscopes intended for high resolution. Such lenses are determined not only by its geometric structure and shape parameters but also by the gap width to bore diameter (S/D) of its pole pieces. a systematic investigation has been carried out for asymmetric objective lenses having different bore diameters. The results indicate that the op per h ore diameter of pole piece lens has considerable effects on the electron optical properties. The Comparison between the two sets of the family of asymmetric lenses provides good performance, and suggests that the ratio of the lens gap width to the bore diameters of its pole pieces (S/ D 1 /D 2 =3) are favourable. (authors). 9 refs., 9 figs

  8. Using the Tevatron Electron Lens (TEL) as a Wire and other TEL Studies at FNAL

    CERN Document Server

    Zimmermann, Frank; Sen, T; Shiltsev, V D; Zhang, X L; CERN. Geneva. AB Department

    2004-01-01

    During a visit to FNAL, on March 1, 2004, we performed a two-dimensional grid scan - with 1-mm step size - of the TEL transverse position in the vicinity of the proton and pbar beams, while three bunches of either beam were excited by the TEL on every turn. The measured tune shifts of protons and pbars are compatible with expectation. The proton Schottky 'emittance' is strongly dependent on the TEL position, possibly due to a coherent interaction between protons and electrons. The relative position of protons, pbars and TEL can be determined in three different ways: from the TEL BPM readings, from the tune variation with TEL position, and from the loss-rate variation with the TEL position. The results are consistent at least within 1 or 2 mm, possibly better. Tunes and losses do not necessarily yield identical values for the beam position. Significant proton losses occurred when the TEL approached the proton beam. These losses decreased with the third power of the distance. They were the result of a longitudi...

  9. To calculation of electron-optical characteristics of crossed lenses

    International Nuclear Information System (INIS)

    Afanas'ev, V.P.; Gritsyuk, N.P.; Lachashvili, R.A.; Yavor, S.Ya.

    1979-01-01

    Two approaches are used for theoretical study of crossed lenses (CL), which are formed by plates with slits turned by 90 deg: 1) aberration determination according to axial determination of potential and 2) trajectory analysis of CL. While studying CL of definite configuration it is necessary to take into account aberrations of the highest order. The following conclusions are drawn: the classical method is applied for fast determination of the main characteristics, of CL by means of average power computers (the ''M-220'' or the ''Minsk-32'' computers); the trajectory analysis should be performed by means of power computer (the BESM-6) when it is necessary to obtain more detailed information of the CL, including the trajectory deflection along the system axis, the dimensions of the point source image taking into account the aberrations of the highest order

  10. Determination of Electron Optical Properties for Aperture Zoom Lenses Using an Artificial Neural Network Method.

    Science.gov (United States)

    Isik, Nimet

    2016-04-01

    Multi-element electrostatic aperture lens systems are widely used to control electron or charged particle beams in many scientific instruments. By means of applied voltages, these lens systems can be operated for different purposes. In this context, numerous methods have been performed to calculate focal properties of these lenses. In this study, an artificial neural network (ANN) classification method is utilized to determine the focused/unfocused charged particle beam in the image point as a function of lens voltages for multi-element electrostatic aperture lenses. A data set for training and testing of ANN is taken from the SIMION 8.1 simulation program, which is a well known and proven accuracy program in charged particle optics. Mean squared error results of this study indicate that the ANN classification method provides notable performance characteristics for electrostatic aperture zoom lenses.

  11. Landau Damping of Beam Instabilities by Electron Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V. [Fermilab; Alexahin, Yuri; Burov, A. [Fermilab; Valishev, A. [Fermilab

    2017-06-26

    Modern and future particle accelerators employ increasingly higher intensity and brighter beams of charged particles and become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, beam feedback dampers and use of chromatic effects, become less effective and insufficient. We show that, in contrast, Lorentz forces of a low-energy, a magnetically stabilized electron beam, or "electron lens", easily introduces transverse nonlinear focusing sufficient for Landau damping of transverse beam instabilities in accelerators. It is also important that, unlike other nonlinear elements, the electron lens provides the frequency spread mainly at the beam core, thus allowing much higher frequency spread without lifetime degradation. For the parameters of the Future Circular Collider, a single conventional electron lens a few meters long would provide stabilization superior to tens of thousands of superconducting octupole magnets.

  12. Research for the boson of Higgs and for couplings of capacity quartic abnormal in the channel WW in electrons in the experiment D0 in Tevatron

    International Nuclear Information System (INIS)

    Chapon, Emilien

    2013-01-01

    Two physics analyzes are presented in this thesis, both probing the electroweak sector of the Standard Model using events with two oppositely charged electrons and missing transverse energy. The events are selected from the full Run II data sample of 9.7 fb -1 of proton-antiproton collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s=1.96 TeV. The first analysis is a search for the Higgs boson in H → WW → evev decays. To validate the search methodology, the non-resonant WW production cross section is measured. In the Higgs boson search, no significant excess above the background expectation is observed. Upper limits on the Higgs boson production cross section are therefore derived, within the Standard Model, but also within a theoretical framework with a fourth generation of fermions, and in the context of fermiophobic Higgs boson couplings. A search for anomalous quartic gauge couplings between the photon and the W boson is then presented, using exclusive W boson pair production, allowing to probe new physics effects. The selection of the events and the analysis techniques used are mostly identical to those used in the first analysis, the search for the Higgs boson. The limits set on this type of anomalous couplings are the first ones from the Tevatron and the most stringent ones at the time of the publication. (author) [fr

  13. Coupling in the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1994-12-01

    The performance of the Fermilab Tevatron Collider at the commencement of run Ib was far below expectations. After a frustrating period of several months, a low-β quad downstream of the interaction point at B0 was found to be rolled. This rolled quadrupole coupled the horizontal and vertical motion of the Tevatron beams. It also made matching the beam from the Main Ring to the Tevatron impossible, resulting in emittance blow up on injection. The net result of the roll was a significant reduction in the Tevatron luminosity. When the roll in the quadrupole was corrected the performance of the Tevatron improved dramatically. This note will discuss the experimental data indicating the presence of coupling and subsequent calculations which show how coupling an affect the luminosity. It is not intended to exhaust a discussion of coupling, which hopefully will be understood well enough to be discussed in a subsequent note

  14. Celebrating the Tevatron legacy

    CERN Multimedia

    2012-01-01

    Fermilab hosted an exceptional event on 11 June: the Tevatron Impact symposium. More than 800 people attended to hear how the Tevatron advanced our understanding of fundamental physics.   A version of this "Director's Corner" by Pier Oddone first appeared in Fermilab Today on 12 June.   The development of accelerator technology for the Tevatron has influenced every subsequent major hadron accelerator. We heard reviews on the detector technologies and trigger systems developed with the Tevatron that are essential today for high-luminosity machines like the LHC. There were also talks on the superconducting-wire industry that made MRI magnets ubiquitous, and we discussed the major computational systems that use large farms of Linux-based commodity processors. Researchers who worked on the Tevatron also established multivariate analysis techniques that now allow us to squeeze the maximum information from complex data sets. One focus of the symposium was the ...

  15. Atomic force microscopy and scanning electron microscopy analysis of daily disposable limbal ring contact lenses.

    Science.gov (United States)

    Lorenz, Kathrine Osborn; Kakkassery, Joseph; Boree, Danielle; Pinto, David

    2014-09-01

    Limbal ring (also known as 'circle') contact lenses are becoming increasingly popular, especially in Asian markets because of their eye-enhancing effects. The pigment particles that give the eye-enhancing effects of these lenses can be found on the front or back surface of the contact lens or 'enclosed' within the lens matrix. The purpose of this research was to evaluate the pigment location and surface roughness of seven types of 'circle' contact lenses. Scanning electron microscopic (SEM) analysis was performed using a variable pressure Hitachi S3400N instrument to discern the placement of lens pigments. Atomic force microscopy (Dimension Icon AFM from Bruker Nano) was used to determine the surface roughness of the pigmented regions of the contact lenses. Atomic force microscopic analysis was performed in fluid phase under contact mode using a Sharp Nitride Lever probe (SNL-10) with a spring constant of 0.06 N/m. Root mean square (RMS) roughness values were analysed using a generalised linear mixed model with a log-normal distribution. Least square means and their corresponding 95% confidence intervals were estimated for each brand, location and pigment combination. SEM cross-sectional images at 500× and 2,000× magnification showed pigment on the surface of six of the seven lens types tested. The mean depth of pigment for 1-DAY ACUVUE DEFINE (1DAD) lenses was 8.1 μm below the surface of the lens, while the remaining lens types tested had pigment particles on the front or back surface. Results of the atomic force microscopic analysis indicated that 1DAD lenses had significantly lower root mean square roughness values in the pigmented area of the lens than the other lens types tested. SEM and AFM analysis revealed pigment on the surface of the lens for all types tested with the exception of 1DAD. Further research is required to determine if the difference in pigment location influences on-eye performance. © 2014 The Authors. Clinical and Experimental

  16. Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1994-07-01

    This year saw the completion of three accelerator improvement projects (AIP) and two capital equipment projects pertaining to the Tevatron cryogenic system. The projects result in the ability to operate the Tevatron at lower temperature, and thus higher energy. Each project improves a subsystem by expanding capabilities (refrigerator controls), ensuring reliability (valve box, subatmospheric hardware, and compressor D), or enhancing performance (cold compressors and coldbox II). In January of 1994, the Tevatron operated at an energy of 975 GeV for the first time. This was the culmination, of many years of R ampersand D, power testing in a sector (one sixth) of the Tevatron, and final system installation during the summer of 1993. Although this is a modest increase in energy, the discovery potential for the Top quark is considerably improved

  17. Physics at the Tevatron

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Physics Results from the Tevatron : The Tevatron proton-antiproton collider at Fermilab in the US is currently the world's highest energy collider. At the experiments CDF and D0 a broad physics programme is being pursued, ranging from flavour physics via electroweak precision measurements to searches for the Higgs boson and new particles beyond the Standard Model. In my lecture I will describe some of the highlight measurements in the flavour, electroweak and searches sectors, and the experimental techniques that are used.

  18. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

    Stancari, G; Kuznetsov, G; Shiltsev, V; Still, D A; Valishev, A; Vorobiev, L G; Assmann, R; Kabantsev, A

    2012-01-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  19. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

    Stancari, G.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; Assmann, R.; Kabantsev, A.

    2010-01-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams

  20. Physics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Field, Rick; /Florida U.

    2006-04-01

    The theme of the XXXIV International Meeting on Fundamental Physics held in El Escorial, Spain on April 2-7, 2006 was ''From HERA and the TEVATRON to the LHC''. This is a summary of the four lectures I presented on ''Physics at the Tevatron''. Heavy quark production and the production of photons, bosons, and jets at the Tevatron are discussed. Also, a detailed study at the ''underlying event'' at CDF is presented together with a discussion of PYTHIA 6.2 tunes. A look back at the ''old days'' of Feynman-Field collider phenomenology is included.

  1. Tevatron physics results

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    I will summarize the physics results from the Tevatron experiments with particular emphasis on the experimental methods used in different kinds of analysis. In particular, the Tevatron is a proton-antiproton collider that has now accumulated more than 2 fb^-1 of luminosity in the two experiments, called CDF and D0. In this lecture I will review the results on inclusive productions of jets, W- and Z-bosons, the results in the flavor sector, the measurements of top production, searches for Higgs boson production and searches for physics beyond the Standard Model. In each case I will explain the basic experimental concepts and methods needed for making the measurement.

  2. Tevatron Collider physics

    International Nuclear Information System (INIS)

    Eichten, E.J.

    1990-02-01

    The physics of hadron colliders is briefly reviewed. Issues for further study are presented. Particular attention is given to the physics opportunities for a high luminosity (≥ 100 pb -1 /experiment/run) Upgrade of the Tevatron Collider. 25 refs., 10 figs., 2 tabs

  3. Consumer electronic optics: how small can a lens be: the case of panomorph lenses

    Science.gov (United States)

    Thibault, Simon; Parent, Jocelyn; Zhang, Hu; Du, Xiaojun; Roulet, Patrice

    2014-09-01

    In 2014, miniature camera modules are applied to a variety of applications such as webcam, mobile phone, automotive, endoscope, tablets, portable computers and many other products. Mobile phone cameras are probably one of the most challenging parts due to the need for smaller and smaller total track length (TTL) and optimized embedded image processing algorithms. As the technology is developing, higher resolution and higher image quality, new capabilities are required to fulfil the market needs. Consequently, the lens system becomes more complex and requires more optical elements and/or new optical elements. What is the limit? How small an injection molded lens can be? We will discuss those questions by comparing two wide angle lenses for consumer electronic market. The first lens is a 6.56 mm (TTL) panoramic (180° FOV) lens built in 2012. The second is a more recent (2014) panoramic lens (180° FOV) with a TTL of 3.80 mm for mobile phone camera. Both optics are panomorph lenses used with megapixel sensors. Between 2012 and 2014, the development in design and plastic injection molding allowed a reduction of the TTL by more than 40%. This TTL reduction has been achieved by pushing the lens design to the extreme (edge/central air and material thicknesses as well as lens shape). This was also possible due to a better control of the injection molding process and material (low birefringence, haze and thermal stability). These aspects will be presented and discussed. During the next few years, we don't know if new material will come or new process but we will still need innovative people and industries to push again the limits.

  4. Supersymmetry at the Tevatron?

    International Nuclear Information System (INIS)

    Lammel, S.

    1998-02-01

    These lectures contain an introduction to the search for supersymmetry at hadron colliders. The Tevatron is one of high-energy physics most sophisticated tools. The high center-of-mass energy of its proton-antiproton collisions makes it an ideal place to search for physics beyond the Standard Model, such as supersymmetry. Two experiments, CDF and D0, completed a long data taking period in summer of 1995, yielding over 100 pb -1 of proton-antiproton interactions. The data recorded by the experiments are still being analyzed. The lectures outline the strategies in the search for supersymmetry at the Tevatron and examine the major analyses in detail. Results obtained by the two experiments are included where available

  5. Gas chromatographic determination with electron capture detection of residual ethylene oxide in intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, H.; Nakamura, A.; Tsuji, K.

    1988-01-01

    A sensitive method is described to determine trace quantities of ethylene oxide (EO) in EO-sterilized intraocular lenses (IOLs). An IOL is dipped in ethanol containing 0.25 ppm propylene oxide (PO) in a 4 mL vial, 2 drops of freshly distilled hydrobromic acid is added through a septum, and the mixture is warmed at 50/sup 0/C for 24 h. It is then neutralized by vigorous shaking with sodium bicarbonate, dehydrated with anhydrous sodium sulfate, and filtered. The filtrate is injected into a gas chromatograph with electron-capture detection, and the peak height ratio of ethylene bromohydrin/propylene bromohydrin is measured. EO residue is calculated from the calibration curve obtained through a similar procedure with the standard EO/PO solutions. The limit of determination is 0.04 ..mu..g/lens (ca 2.0 ppm). When EO residue levels were determined for IOLs sampled at 3 different aeration periods after stabilization, the authors found that 9 days of aeration was necessary to meet the US Food and Drug Administration proposed limit for EO residue in IOLs.

  6. Beam Dynamics in an Electron Lens with the Warp Particle-in-cell Code

    CERN Document Server

    Stancari, Giulio; Redaelli, Stefano

    2014-01-01

    Electron lenses are a mature technique for beam manipulation in colliders and storage rings. In an electron lens, a pulsed, magnetically confined electron beam with a given current-density profile interacts with the circulating beam to obtain the desired effect. Electron lenses were used in the Fermilab Tevatron collider for beam-beam compensation, for abort-gap clearing, and for halo scraping. They will be used in RHIC at BNL for head-on beam-beam compensation, and their application to the Large Hadron Collider for halo control is under development. At Fermilab, electron lenses will be implemented as lattice elements for nonlinear integrable optics. The design of electron lenses requires tools to calculate the kicks and wakefields experienced by the circulating beam. We use the Warp particle-in-cell code to study generation, transport, and evolution of the electron beam. For the first time, a fully 3-dimensional code is used for this purpose.

  7. Tevatron operational experiences

    International Nuclear Information System (INIS)

    Norris, B.L.; Theilacker, J.C.

    1989-02-01

    Fermilabs superconducting accelerator, the Tevatron has been operational for nearly six years. The history of its operation is presented. Several long shutdowns for superconducting dipole repairs are discussed. The dominant factor influencing the repair was conductor motion which fatigued the cable in the magnet ends. Borescoping and x-raying techniques were used to determine which magnet ends required repair. Detailed downtime logs were kept for each of the running periods. A discussion of the sources of downtime and a comparison for different operating modes is presented

  8. Tevatron extraction microcomputer

    International Nuclear Information System (INIS)

    Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.; Batavia, IL)

    1985-01-01

    Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper (1) summarizes performance

  9. Tevatron extraction microcomputer

    International Nuclear Information System (INIS)

    Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.

    1985-06-01

    Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper summarizes performance

  10. Reduction of radiation damage on organic material at very low object temperatures in an electron microscope with supraconductive lenses

    International Nuclear Information System (INIS)

    Knapek, E.

    1981-01-01

    As a result of this study, the increase in structure conservation by cooling the object to very low temperatures (cryoprotection) as compared with the conditions at room temperature was higher than the values at low temperatures reached so far by one to two orders of magnitude. The experiments carried out with an electron microscope with supraconductive lenses (SLEM) showed, depending of the organic substance, that in tests with an electron diffraction of about 4.2 K the reduction of radiation damage as compared with room temperature was by a factor between 30 and 350. (orig./PW) [de

  11. Recent results from the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Vellidis, Costas; Bravina, L.; Foka, Y.; Kabana, S.

    2015-01-01

    The Tevatron p$\\bar{p}$ collider was shut down in 2011, after 10 years of high performance operation at a center-of-mass energy √s = 1.96 TeV in Run II. The two experiments, CDF and DZero, continue to analyze the collected data, aiming to extract all possible information regarding studies of the standard model and searches for new physics. A short review of some of the recent measurements at the Tevatron, and of the impact of the Tevatron program to high energy physics, is presented.

  12. Tevatron instrumentation: boosting collider performance

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; Jansson, Andreas; Moore, Ronald; /Fermilab

    2006-05-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for the next big machines--LHC and ILC.

  13. B physics at the tevatron

    International Nuclear Information System (INIS)

    1998-07-01

    Precision B-physics results from the CDF and D0 Collaborations based on data collected during the Tevatron 1992-96 run are presented. In particular we discuss the measurement of the B s meson lifetime, B c meson observation, and B 0 - anti B 0 mixing results obtained using time-evolution analyses. Prospects for the next Tevatron run, starting in 1999, are also reported

  14. Calculations of time-of-flight aberrations in practical electrostatic electron lenses using the differential algebraic method

    International Nuclear Information System (INIS)

    Kang, Yongfeng; Zhao, Jingyi; Tang, Tiantong

    2013-01-01

    The high order time-of-flight (TOF) aberrations in a practical electrostatic electron lens are calculated using the differential algebraic (DA) method. The electrostatic fields of the electrostatic lens, which are calculated by the FEM methods, are in the form of discrete arrays. Thus, the proposed DA method is applicable for engineering designs, and programs are written to compute up to fifth order TOF aberrations of practical electrostatic electron lenses. An example is given, and TOF aberrations up to the fifth order are calculated. It is proven that the numerical results for the electrostatic fields in the form of discrete arrays have a good accuracy compared with the theoretical solutions. The accuracy is limited only by the accuracy of the numerical computation of the fields and the numerical computation algorithms for interpolation and integration. Finally, a practical electrostatic electron lens is analysed and discussed as an example.

  15. Electroweak physics at the Tevatron collider

    International Nuclear Information System (INIS)

    Aihara, H.

    1993-08-01

    Preliminary results on electroweak physics from the 1992--1993 run with the CDF and D0 detectors at the Tevatron collider are presented. New measurements of the ratio of the W and Z production cross sections times the branching fractions for subsequent decay into leptons are shown. The W width, Γ(W), and a limit on the top-quark mass independent of decay mode are extracted. The status of a measurement of the charge asymmetry of electrons from W decay is given. Also shown are a study of diboson (Wγ, Zγ and WZ) production and a search for a new neutral gauge boson (Z')

  16. Squark production at the Tevatron

    International Nuclear Information System (INIS)

    Beenakker, W.; Hoepker, R.; Spira, M.; Zerwas, P.M.

    1994-11-01

    We have determined the QCD corrections to the production of squark-antisquark pairs in p anti p collisions at the Tevatron. If the next-to-leading order corrections are taken into account, the renormalization/factorization scale dependence of the theoretical prediction for the cross section is reduced considerably. The higher order corrections increase the production cross section at the Tevatron by about a factor two if we compare the next-to-leading order prediction at a scale near the sqaurk mass with the lowest order prediction for which, in the experimental analyses, the scale was identified with the invariant energy of the parton subprocess. This results in a rise of the experimental lower bound on the squark mass from the Tevatron by about 20 GeV. (orig.)

  17. TEVATRON Searches for Large Extra Dimensions and Leptoquarks

    International Nuclear Information System (INIS)

    Mattingly, S.

    2002-01-01

    This paper presents searches for large extra dimensions and leptoquarks in p(anti)p collisions from Run 1 at the Tevatron. Large extra dimensions are searched for in real graviton production with a monojet or monophoton and in virtual graviton exchange processes with electron or photon pairs. Results from leptoquark searches are presented for three generations of leptoquarks. No evidence of signal is found in any searches for large extra dimensions or leptoquarks and limits are placed. Perceptivities for these searches in the Tevatron's Run 2 are discussed and initial Run 2 data is presented. (author)

  18. Recent Results from the Tevatron

    International Nuclear Information System (INIS)

    Demorden, L.

    1998-06-01

    We review recent results from fixed-target and collider experiments at the Fermilab Tevatron. Among the topics discussed are jet production rates, α S measurements, the anti d/anti u ratio in the proton sea, diffraction, heavy quark physics and leptoquark searches

  19. Tau identification at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Stephen; /Chicago U., EFI

    2005-07-01

    Methods for reconstructing and identifying the hadronic decays of tau leptons with the CDF and D0 detectors at the Fermilab Tevatron collider in Run II are described. Precision electroweak measurements of W and Z gauge boson cross sections are presented as well as results of searches for physics beyond the Standard Model with hadronically decaying tau leptons in the final state.

  20. Achievements and Lessons from Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.

    2011-01-01

    For almost a quarter of a century, the Tevatron proton-antiproton collider was the centerpiece of the world's high energy physics program - beginning operation in December of 1985 until it was overtaken by LHC in 2011. The aim of the this unique scientific instrument was to explore the elementary particle physics reactions with center of mass collision energies of up to 1.96 TeV. The initial design luminosity of the Tevatron was 10 30 cm -2 s -1 , however as a result of two decades of upgrades, the accelerator has been able to deliver 430 times higher luminosities to each of two high luminosity experiments, CDF and D0. Tevatron will be shut off September 30, 2011. The collider was arguably one of the most complex research instruments ever to reach the operation stage and is widely recognized for many technological breakthroughs and numerous physics discoveries. Below we briefly present the history of the Tevatron, major advances in accelerator physics, and technology implemented during the long quest for better and better performance. We also discuss some lessons learned from our experience.

  1. Neural networks at the Tevatron

    International Nuclear Information System (INIS)

    Badgett, W.; Burkett, K.; Campbell, M.K.; Wu, D.Y.; Bianchin, S.; DeNardi, M.; Pauletta, G.; Santi, L.; Caner, A.; Denby, B.; Haggerty, H.; Lindsey, C.S.; Wainer, N.; Dall'Agata, M.; Johns, K.; Dickson, M.; Stanco, L.; Wyss, J.L.

    1992-10-01

    This paper summarizes neural network applications at the Fermilab Tevatron, including the first online hardware application in high energy physics (muon tracking): the CDF and DO neural network triggers; offline quark/gluon discrimination at CDF; ND a new tool for top to multijets recognition at CDF

  2. Comparative study of active plasma lenses in high-quality electron accelerator transport lines

    Science.gov (United States)

    van Tilborg, J.; Barber, S. K.; Benedetti, C.; Schroeder, C. B.; Isono, F.; Tsai, H.-E.; Geddes, C. G. R.; Leemans, W. P.

    2018-05-01

    Electrically discharged active plasma lenses (APLs) are actively pursued in compact high-brightness plasma-based accelerators due to their high-gradient, tunable, and radially symmetric focusing properties. In this manuscript, the APL is experimentally compared with a conventional quadrupole triplet, highlighting the favorable reduction in the energy dependence (chromaticity) in the transport line. Through transport simulations, it is explored how the non-uniform radial discharge current distribution leads to beam-integrated emittance degradation and a charge density reduction at focus. However, positioning an aperture at the APL entrance will significantly reduce emittance degradation without additional loss of charge in the high-quality core of the beam. An analytical model is presented that estimates the emittance degradation from a short beam driving a longitudinally varying wakefield in the APL. Optimizing laser plasma accelerator operation is discussed where emittance degradation from the non-uniform discharge current (favoring small beams inside the APL) and wakefield effects (favoring larger beam sizes) is minimized.

  3. An Ionization Profile Monitor for the Tevatron

    CERN Document Server

    Jansson, Andreas; Bowie, Kwame; Bross, Alan; Dysert, Robert; Fitzpatrick, Thomas; Kwarciany, Richard; Lundberg, Carl; Nguyen, Hogan; Rivetta, Claudio H; Slimmer, David; Valerio, Linda; Zagel, James

    2005-01-01

    Primarily to study emittance blowup during injection and ramping, an ionization profile monitor has been developed for the Tevatron. It is based on a prototype installed in the Main Injector, although with extensive modifications. In particular, the electromagnetic shielding has been improved, the signal path has been cleaned up, and provisions have been made for an internal electron source. Due to the good Tevatron vacuum, a local pressure bump is introduced to increase the primary signal, which is then amplified by a microchannel plate and detected on anode strips. For the DAQ, a custom ASIC developed for the CMS experiment is used. It is a combined charge integrator and digitizer, with a sensitivity of a few fC, and a time-resolution that allows single bunch measurement. Digitization is done in the tunnel to reduce noise. Preparations for detector installation were made during the long 2004 shutdown, with the installation of magnets, vacuum chambers, vacuum pumps and cabling. The actual detector will be in...

  4. Tevatron serial data repeater system

    International Nuclear Information System (INIS)

    Ducar, R.J.

    1981-01-01

    A ten megabit per second serial data repeater system has been developed for the 6.28km Tevatron accelerator. The repeaters are positioned at each of the thirty service buildings and accommodate control and abort system communications as well as distribution of the Tevatron time and energy clocks. The repeaters are transparent to the particular protocol of the transmissions. Serial data are encoded locally as unipolar two volt signals employing the self-clocking Manchester Bi-Phase code. The repeaters modulate the local signals to low-power bursts of 50 MHz rf carrier for the 260m transmission between service buildings. The repeaters also demodulate the transmission and restructure the data for local utilization. The employment of frequency discrimination techniques yields high immunity to the characteristic noise spectrum

  5. Luminosity lifetime in the Tevatron

    International Nuclear Information System (INIS)

    Jackson, G.; Finley, D.; Johnson, R.P.; Kerns, Q.; McCarthy, J.; Siemann, R.; Zhang, P.

    1988-01-01

    Since the inauguration of colliding proton-antiproton operations in 1987, the Tevatron has exhibited luminosity lifetimes shorter than expected. During a typical colliding beam storage period, called a store, luminosity is calculated periodically by measuring the charge and emittances of each bunch. The growth of the transverse bunch emittances is the dominant cause of luminosity deterioration. Throughout, this period, the position spectrum of the bunches exhibited betatron signals larger than expected from Schottky noise. A model assuming externally driven betatron oscillations explains both the betatron signals and the emittance growth. A program is underway to improve the Tevatron luminosity lifetime. The abort kickers have been identified as sources of emittance growth, and some quadrupole power supplies are further candidates. Because the horizontal dispersion through the RF cavities is nonzero, RF phase noise has been investigated. Noise in the main dipole regulation circuit has also been studied. 13 refs., 4 figs

  6. Accelerating polarized beams in Tevatron

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-02-01

    In this paper, we will examine the totality of equipment, manpower and cost necessary to obtain a polarized proton beam in the Tevatron. We will not, however, be concerned with the acquisition and acceleration of polarized /bar p/ beams. Furthermore we will consider only a planar main ring without overpass, although it is expected that Siberian snake schemes could be made to apply equally well to non-planar machines. In addition to not wanting to tackle here the task of reformulating the theory for a non-planar closed orbit, we also anticipate that as part of the Tevatron upgrade the main ring will in the not too distant future, be replaced by a planar main injector situated in a separate tunnel. 4 refs., 11 figs., 1 tab

  7. Electroweak results from the tevatron

    International Nuclear Information System (INIS)

    Wood, D.

    1997-01-01

    Electroweak results are presented from the CDF and DO experiments based on data collected in recent runs of the Fermilab Tevatron Collider. The measurements include the mass and width of the W boson, the production cross sections of the W and Z bosons, and the W charge asymmetry. Additional results come from studies of events with pairs of electroweak gauge bosons and include limits on anomalous couplings

  8. Electroweak results from the tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Wood, D. [Fermi National Accelerator Laboratory, Batavia, IL (United States)

    1997-01-01

    Electroweak results are presented from the CDF and DO experiments based on data collected in recent runs of the Fermilab Tevatron Collider. The measurements include the mass and width of the W boson, the production cross sections of the W and Z bosons, and the W charge asymmetry. Additional results come from studies of events with pairs of electroweak gauge bosons and include limits on anomalous couplings.

  9. B physics at the Tevatron

    International Nuclear Information System (INIS)

    Morello, M.J.

    2011-01-01

    The CDF and DO experiments at the Tevatron pp collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e + e - colliders. This provides a rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in B 0 s s mixing, b→s penguin decays, and charm physics.

  10. Tevatron in the 1990s

    International Nuclear Information System (INIS)

    Lederman, L.M.

    1989-01-01

    This paper reports that in 1978, Fermilab set out a goal of building a superconducting accelerator (Energy Saver) which would raise the proton energy to close to 1000 GeV for operation in two modes. Tevatron I would provide proton-antiproton collisions at a total CM energy of near 2.0 TeV to study the particle mass domain beyond 100 GeV. Tevatron II would provide extensive facilities for the programmatic study of Standard Model physics in an upgraded fixed-target program. There was of course the realization that with the right mixture of precision and imagination, the collider could add significantly to Standard Model physics (e.g. W and Z physics, W, Z pairs, B-physics) and that the fixed-target program could explore beyond the Standard Model (e.g., rare K-decays, CP violation). In 1988, we are engaged in setting out the future program of the Laboratory based upon the success of the Energy Saver, TeV I and TeV II construction programs. This future program assures the operation of the TEVATRON facility for physics is the overriding priority between now and perhaps 1993 and it also assumes that the Superconducting Super Collider (SSC) will be funded for construction in 1990 and will begin producing physics by 1999. A brief history of upgrades is presented in section XI

  11. A realtime feedback microprocessor for the TEVATRON

    International Nuclear Information System (INIS)

    Herrup, D.A.; Chapman, L.; Franck, A.; Groves, T.; Lublinsky, B.

    1993-01-01

    A feedback microprocessor has been built for the TEVATRON. Its inputs are realtime accelerator measurements, data describing the state of the TEVATRON, and ramp tables. The microprocessor includes a finite state machine. Each state corresponds to a specific TEVATRON operation. Transitions between states are initiated by the global TEVATRON clock. Each state includes a cyclic routine which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast TEVATRON-wide link from which the power supplies will read the realtime correction. The authors also store all of the input data and output corrections in a set of buffers which can easily be retrieved for diagnostic analysis. This talk will describe use of this device to control the TEVATRON tunes and discuss other uses

  12. Magnifying Lenses with Weak Achromatic Bends for High-Energy Electron Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Walstrom, Peter Lowell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-27

    This memo briefly describes bremsstrahlung background effects in GeV-range electron radiography systems and the use of weak bending magnets to deflect the image to the side of the forward bremsstrahlung spot to reduce background. The image deflection introduces first-order chromatic image blur due to dispersion. Two approaches to eliminating the dispersion effect to first order by use of magnifying lens with achromatic bends are described. Also, higher-order image blur terms caused by weak bends are also discussed, and shown to be negligibly small in most cases of interest.

  13. BFKL Tests at the Tevatron

    International Nuclear Information System (INIS)

    Goussiou, A.

    1997-06-01

    The azimuthal decorrelation of jets as a function of their rapidity separation and the dependence of the fraction of jet events with central rapidity gaps on the center of mass energy are studied in p anti p collisions at the Tevatron. The preliminary results on jet decorrelation are in disagreement with calculations based on the Leading Logarithmic Approximation for BFKL resummation. The preliminary results on the √s--dependence of the central rapidity gap events are in disagreement with the two-gluon model for color-singlet exchange

  14. Parton distribution and Tevatron jet data

    International Nuclear Information System (INIS)

    Alekhin, S.; Bluemlein, J.; Moch, S.

    2011-05-01

    We study the impact of Tevatron jet data on a global fit of parton distribution functions and on the determination of the value of the strong coupling constant α s (M Z ). The consequences are illustrated for cross sections of Higgs boson production at Tevatron and the LHC. (orig.)

  15. Gravitational lensing

    CERN Document Server

    Dodelson, Scott

    2017-01-01

    Gravitational lensing is a consequence of general relativity, where the gravitational force due to a massive object bends the paths of light originating from distant objects lying behind it. Using very little general relativity and no higher level mathematics, this text presents the basics of gravitational lensing, focusing on the equations needed to understand the phenomena. It then applies them to a diverse set of topics, including multiply imaged objects, time delays, extrasolar planets, microlensing, cluster masses, galaxy shape measurements, cosmic shear, and lensing of the cosmic microwave background. This approach allows undergraduate students and others to get quickly up to speed on the basics and the important issues. The text will be especially relevant as large surveys such as LSST and Euclid begin to dominate the astronomical landscape. Designed for a one semester course, it is accessible to anyone with two years of undergraduate physics background.

  16. Gabor lenses

    International Nuclear Information System (INIS)

    Mobley, R.M.; Gamml, G.; Maschke, A.W.

    1979-01-01

    Stable operation of Gabor lenses has been reported by at least three experimental groups. At Brookhaven, several lens designs have been tried since February, 1978 with very good results. The lens concept is simple, operation is less complicated than anticipated, and the focussing strengths attainable make them very attractive alternatives to magnetic focussing for heavy ion beams at low energies. Results obtained with five different configurations are presented. The lenses work well, concern is now with fine details of their beam-optical performance

  17. Gravitational lenses

    International Nuclear Information System (INIS)

    Turner, E.L.

    1989-01-01

    The author discusses how gravitational lens studies is becoming a major focus of extragalactic astronomy and cosmology. This review is organized into five parts: an overview of the observational situation, a look at the state of theoretical work on lenses, a detailed look at three recently discovered types of lensing phenomena (luminous arcs, radio rings, quasar-galaxy associations), a review of progress on two old problems in lens studies (deriving unique lens mass distribution models, measurements of differential time delays), and an attempt to look into the future of lens studies

  18. Acoustic lenses

    International Nuclear Information System (INIS)

    Kittmer, C.A.

    1983-03-01

    Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

  19. Beam instrumentation for the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  20. Measurements of Top Properties at the Tevatron

    International Nuclear Information System (INIS)

    Husemann, Ulrich; Yale U.

    2007-01-01

    The large data samples of thousands of top events collected at the Tevatron experiments CDF and D(O) allow for a variety of measurements to analyze the properties of the top quark. Guided by the question ''Is the top quark observed at the Tevatron really the top quark of the standard model,'' we present Tevatron analyses studying the top production mechanism including resonant t(bar t) production, the V -A structure of the t → Wb decay vertex, the charge of the top quark, and single-top production via flavor-changing neutral currents

  1. Academic Training - Tevatron: studying pp collisions at the highest energy

    CERN Multimedia

    2006-01-01

    ACADEMIC TRAINING LECTURE SERIES 15, 16, 17, 18 May Main Auditorium, bldg. 500 on 15, 16, 17 May - Council Chamber on 18 May Physics at the Tevatron B. HEINEMANN, Univ. of Liverpool, FERMILAB Physics Results from the Tevatron The Tevatron proton-antiproton collider at Fermilab in the US is currently the world's highest energy collider. At the experiments CDF and D0 a broad physics programme is being pursued, ranging from flavour physics via electroweak precision measurements to searches for the Higgs boson and new particles beyond the Standard Model. In my lecture I will describe some of the highlight measurements in the flavour, electroweak and searches sectors, and the experimental techniques that are used. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www.cern.ch/...

  2. Fermilab Tevatron and Pbar source status report

    International Nuclear Information System (INIS)

    Edwards, H.

    1986-08-01

    The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently under evaluation to accomplish these goals: luminosity increase to 5 x 10 31 cm -2 sec -1 , production rates up to 4 x 10 11 antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade

  3. Precision electroweak physics at the Tevatron

    International Nuclear Information System (INIS)

    James, Eric B.

    2006-01-01

    An overview of Tevatron electroweak measurements performed by the CDF and Dφ experiments is presented. The current status and future prospects for high precision measurements of electroweak parameters and detailed studies of boson production are highlighted. (author)

  4. Tevatron alignment issues 2003-2004

    International Nuclear Information System (INIS)

    Volk, J.T.; Annala, J.; Elementi, L.; Gelfand, N.; Gollwitzer, K.E.; Greenwood, J.; Martens, M.; Moore, C.; Nobrega, A.; Russell, A.D.; Shiltsev, V.; Stefanski, R.; Sager, T.; Syphers, M.J.; Wojcik, G.

    2005-01-01

    It was observed during the early part of Run II that dipole corrector currents in the Tevatron were changing over time. Measurement of the roll for dipoles and quadrupoles confirmed that there was a slow and systematic movement of the magnets from their ideal position. A simple system using a digital protractor and laptop computer was developed to allow roll measurements of all dipoles and quadrupoles. These measurements showed that many magnets in the Tevatron had rolled more than 1 milliradian. To aid in magnet alignment a new survey network was built in the Tevatron tunnel. This network is based on the use of free centering laser tracker. During the measurement of the network coordinates for all dipole, quadrupole and corrector magnets were obtained. This paper discusses roll measurement techniques and data, the old and new Tevatron alignment network

  5. Estimates of Fermilab Tevatron collider performance

    International Nuclear Information System (INIS)

    Dugan, G.

    1991-09-01

    This paper describes a model which has been used to estimate the average luminosity performance of the Tevatron collider. In the model, the average luminosity is related quantitatively to various performance parameters of the Fermilab Tevatron collider complex. The model is useful in allowing estimates to be developed for the improvements in average collider luminosity to be expected from changes in the fundamental performance parameters as a result of upgrades to various parts of the accelerator complex

  6. Digital signal processing the Tevatron BPM signals

    International Nuclear Information System (INIS)

    Cancelo, G.; James, E.; Wolbers, S.

    2005-01-01

    The Beam Position Monitor (TeV BPM) readout system at Fermilab's Tevatron has been updated and is currently being commissioned. The new BPMs use new analog and digital hardware to achieve better beam position measurement resolution. The new system reads signals from both ends of the existing directional stripline pickups to provide simultaneous proton and antiproton measurements. The signals provided by the two ends of the BPM pickups are processed by analog band-pass filters and sampled by 14-bit ADCs at 74.3MHz. A crucial part of this work has been the design of digital filters that process the signal. This paper describes the digital processing and estimation techniques used to optimize the beam position measurement. The BPM electronics must operate in narrow-band and wide-band modes to enable measurements of closed-orbit and turn-by-turn positions. The filtering and timing conditions of the signals are tuned accordingly for the operational modes. The analysis and the optimized result for each mode are presented

  7. Tevatron HTS power lead test

    International Nuclear Information System (INIS)

    Feher, S.; Carcagno, R.; Orris, D.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.; Tompkins, J.C.

    2004-01-01

    Two pairs of ASC 6 kA power leads developed for the Tevatron were successfully tested at Fermilab at over-current conditions. Stable operation was achieved while operating at a current of 9.56 kA for five hours and while continuously ramping between 0-9.56 kA at a ramp rate of 200 A/s for one hour. The minimum required liquid nitrogen flow rate was measured to be 1.5 g/s at 10 kA. After ramping up to 10 kA at 200A/s, it took only 15 minutes to stabilize the upper copper section of the lead with a flow of 1.8 g/s of liquid nitrogen vapor. Testing under extreme operating conditions--270-370 kPa liquid nitrogen vapor pressure and over 0.1 T external magnetic field--demonstrated that the HTS part of the lead can safely operate in the current sharing mode and that this design has large operating margin

  8. Managing discovery risks--A Tevatron case study

    International Nuclear Information System (INIS)

    Bakul Banerjee

    2004-01-01

    To meet the increasing need for higher performance, Management of Fermi National Accelerator Laboratory has undertaken various projects to improve systems associated with the Tevatron high-energy particle collider located at Batavia, Illinois. One of the larger projects is the Tevatron Beam Position Monitor (BPM) system. The objective of this project is to replace the existing BPM electronics and software system that was originally installed during early 1980s, along with the original construction of the Tevatron.The original system consists of 236 beam position monitors located around the underground tunnel of the accelerator. Above ground control systems are attached to these monitors using pickup cables. When the Tevatron collider is operational, signals received from the BPMs are used to perform a number of control and diagnostic tasks. The original system can only capture the proton signals from the collider. The new system, when fully operational, will be able to capture combined proton and antiproton signals and will be able to separate the antiproton signal from the combined signal at high resolution. This significant enhancement was beyond the range of technical capabilities when the Tevatron was constructed about two decades ago. To take advantage of exceptional progress made in the hardware and software area in past two decades, Department of Energy approved funding of the BPM electronics and software replacement project. The approximate length of the project is sixteen months with a budget of four million dollars not including overhead, escalation, and contingencies. Apart from cost and schedule risks, there are two major risks associated with this research and development project. The primary risk is the risk of discovery. Since the Tevatron beam path is highly complex, BPMs have to acquire and process a large amount of data. In this environment, analysis of data to separate antiproton signals is even more complex. Finding an optimum algorithm that can

  9. Applying EVM principles to Tevatron Beam Position Monitor Project

    International Nuclear Information System (INIS)

    Banerjee, Bakul

    2005-01-01

    At Fermi National Accelerator Laboratory (Fermilab), the Tevatron high energy particle collider must meet the increasing scientific demand of higher beam luminosity. To achieve this higher luminosity goal, U. S. Department of Energy (DOE) sponsored a major upgrade of capabilities of Fermilab's accelerator complex that spans five years and costs over fifty million dollars. Tevatron Beam Position Monitor (BPM) system upgrade is a part of this project, generally called RunII upgrade project. Since the purpose of the Tevatron collider is to detect the smashing of proton and anti-protons orbiting the circular accelerator in opposite directions, capability to detect positions of both protons and antiprotons at a high resolution level is a desirable functionality of the monitoring system. The original system was installed during early 1980s, along with the original construction of the Tevatron. However, electronic technology available in 1980s did not allow for the detection of significantly smaller resolution of antiprotons. The objective of the upgrade project is to replace the existing BPM system with a new system utilizing capabilities of modern electronics enhanced by a front-end software driven by a real-time operating software. The new BPM system is designed to detect both protons and antiprotons with increased resolution of up to an order of magnitude. The new system is capable of maintaining a very high-level of data integrity and system reliability. The system consists of 27 VME crates installed at 27 service buildings around the Tevatron ring servicing 236 beam position monitors placed underground, inside the accelerator tunnel. Each crate consists of a single Timing Generator Fanout module, custom made by Fermilab staff, one MVME processor card running VxWorks 5.5, multiple Echotek Digital Receiver boards complimented by custom made Filter Board. The VxWorks based front-end software communicates with the Main Accelerator Control software via a special

  10. Multiplicities and minijets at Tevatron Collider energies

    International Nuclear Information System (INIS)

    Sarcevic, I.

    1989-01-01

    We show that in the parton branching model, the probability distribution does not obey KNO scaling. As energy increases, gluon contribution to multiplicities increases, resulting in the widening of the probability distribution, in agreement with experimental data. We predict that the widening of the distribution will stop at Tevatron Collider energies due to the dominant role of gluons at these energies. We also find that the gluon contribution to the 'minijet' cross section increases with energy and becomes dominant at the Tevatron Collider. We calculate QCD minijet cross sections for a variety of structure functions, QCD scales and p T min . We compare our theoretical results with the experimental data and find that some of the structure functions and choices of scale are preferred by the experimental data. We give theoretical predictions for the minijet cross section at the Tevatron Collider, indicating the possibility of distinguishing between different sets of structure functions and choices of scale. (orig.)

  11. Multibunch operation in the Tevatron Collider

    International Nuclear Information System (INIS)

    Holt, J.A.; Finley, D.A.; Bharadwaj, V.

    1993-05-01

    The Tevatron Collider at Fermilab is the world's highest energy hadron collider, colliding protons with antiprotons at a center of mass energy of 1800 GeV. At present six proton bunches collide with six antiproton bunches to generate luminosities of up to 9 x 10 30 cm -2 s -1 . It is estimated that to reach luminosities significantly greater than 10 31 cm -2 s -1 while minimizing the number of interactions per crossing, the number of bunches will have to be increased. Thirty-six bunch operation looks like the most promising plan. This paper looks at the strategies for increasing the number of particle bunches, the new hardware that needs to be designed and changes to the operating mode in filling the Tevatron. An interactive program which simulates the filling of the Tevatron collider is also presented. The time scale for multibunch operation and progress towards running greater than six bunches is given in this paper

  12. From the Tevatron to Project X

    CERN Multimedia

    Pier Oddone, Fermilab director (from CERN Courier)

    2011-01-01

    In the October issue of the CERN Courier, Fermilab Director Pier Oddone will present the past, present and future of the US laboratory after the Tevatron. The Bulletin presents some early extracts from his article…   Fermilab Director, Pier Oddone. The end of September marks the end of an era at Fermilab, with the shutdown of the Tevatron after 28 years of operation at the frontiers of particle physics. The Tevatron’s far-reaching legacy spans particle physics, accelerator science and industry. The collider established Fermilab as a world leader in particle physics research, a role that will be strengthened with a new set of facilities, programmes and projects in neutrino and rare-process physics, astroparticle physics, and accelerator and detector technologies. The Tevatron exceeded every expectation ever set for it. This remarkable machine achieved luminosities with antiprotons once considered impossible, reaching more than 4x1032 cm-2s-1 instantaneous luminosity and...

  13. Beta measurements and modeling the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1993-06-01

    The Tevatron collider is now able with two low-β (β*=0.25--0.5m) interaction regions denoted as B0 and D0. This lattice allows independent operation of the interaction regions which required that the previous collider lattice, used in 1988--89, had to be modified. In order to see how well the lattice conforms to the design, measurements of the β function have been carried out at 15 locations in the new Tevatron collider lattice. Agreement can be obtained between the measurements and a computer model for the Tevatron, based on the design, only if the strengths of the gradients in the quadrupoles in the low-β triplet are allowed to differ from their design values. It is also observed that the lattice is very sensitive to the precise values of the gradients in these magnets

  14. Top quark mass measurement at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes da Costa, Joao; /Harvard U.

    2004-12-01

    The authors report on the latest experimental measurements of the top quark mass by the CDF and D0 Collaborations at the Fermilab Tevatron. They present a new top mass measurement using the t{bar t} events collected by the D0 Collaboration in Run I between 1994 and 1996. This result is combined with previous measurements to yield a new world top mass average. They also describe several preliminary results using up to 193 pb{sup -1} of t{bar t} events produced in {bar p}p collisions at {radical}s = 1.96 TeV during the Run II of the Tevatron.

  15. Hard diffraction at HERA and Tevatron

    International Nuclear Information System (INIS)

    Kaidalov, A.B.

    2001-01-01

    A relation between hard diffraction at HERA and Tevatron is discussed. A model, which takes into account unitarity effects is developed for interaction of high-energy virtual photons with nucleons. It is shown that this model gives a good description of HERA data on both total γ* p total cross section and diffractive dissociation of virtual photons in a broad region of Q 2 . It is shown how to describe the CDF data on diffractive jet production at Tevatron using an information on distribution of partons in the Pomeron from HERA experiments

  16. Top and Electroweak Measurements at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Bartos, P. [Comenius U.

    2016-01-01

    In this report, we summarize the latest results of the top-quark mass and electroweak measurements from the Tevatron. Since the world combination of top-quark mass measurements was done, CDF and D0 experiments improved the precision of several results. Some of them reach the relative precition below 1% for a single measurement. From the electroweak results, we report on the WW and WZ production cross section, measurements of the weak mixing angle and indirect measurements of W boson mass. The Tevatron results of the weak mixing angle are still the most precise ones of hadron colliders.

  17. Are PDFs still consistent with Tevatron data?

    Directory of Open Access Journals (Sweden)

    Sullivan Zack

    2018-01-01

    Full Text Available As active data taking has moved to the LHC at CERN, more and more LHC data have been included into fits of parton distribution functions. An anomaly has arisen where formerly excellent agreement between theoretical predictions and experiment in single-top-quark production at the Tevatron is no longer quite as good. Is this indicative of a deeper issue?

  18. Photon final states at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Campanelli, Mario; /University Coll. London

    2008-04-01

    The authors present here several recent measurements involving associate production of photons and jets at the Tevatron. In particular, inclusive photon + met from D0, and photon + b-jets and photon + b-jet + leptons + MET from CDF are described in some detail. These measurements offer a good test of QCD predictions in rather complex final states.

  19. Tevatron targets three-year extension

    CERN Multimedia

    Harris, Margaret

    2010-01-01

    "Fermilab's Tevatron collider could get a new lease on life following a campaign to keep the facility running beyond the end of 2011, when the rival Large Hadron Collider (LHC) at Cern is scheduled to shut down for 15 months of repairs" (0.75 page)

  20. Fundamentally new physics at the Tevatron Collider?

    International Nuclear Information System (INIS)

    Chan Hongmo; Nellen, L.; Tsou Sheungtsun

    1989-02-01

    A new dispersion relation analysis of present pp-bar scattering data suggests the existence by Tevatron Collider energies of a threshold, of such nature, as is unlikely to be explainable in terms of known physics or any of its standard projections. (author)

  1. Initial operation of the Tevatron collider

    International Nuclear Information System (INIS)

    Johnson, R.

    1987-03-01

    The Tevatron is now the highest energy proton synchrotron and the only accelerator made with superconducting magnets. Operating since 1983 as a fixed-target machine at energies up to 800 GeV, it has now been modified to operate as a 900 GeV antiproton-proton collider. This paper describes the initial operation of the machine in this mode. The new features of the Fermilab complex, including the antiproton source and the Main Ring injector with its two overpasses and new rf requirements, are discussed. Beam characteristics in the Tevatron (including lifetimes, emittances, luminosity, beam-beam tune shifts, backgrounds, and low beta complications), the coordination of the steps in the accelerator chain, and the commissioning history are also discussed. Finally, some plans for the improvement of the collider are presented

  2. The Tevatron Hadron Collider: A short history

    International Nuclear Information System (INIS)

    Tollestrup, A.V.

    1994-11-01

    The subject of this presentation was intended to cover the history of hadron colliders. However this broad topic is probably better left to historians. I will cover a much smaller portion of this subject and specialize my subject to the history of the Tevatron. As we will see, the Tevatron project is tightly entwined with the progress in collider technology. It occupies a unique place among accelerators in that it was the first to make use of superconducting magnets and indeed the basic design now forms a template for all machines using this technology. It was spawned in an incredibly productive era when new ideas were being generated almost monthly and it has matured into our highest energy collider complete with two large detectors that provide the major facility in the US for probing high Pt physics for the coming decade

  3. Tevatron B0 low beta tuning report

    International Nuclear Information System (INIS)

    Johnson, D.E.

    1982-01-01

    A detailed study of the low beta insertion for the B0 experimental area has been carried out and is described below. This insertion is similar to the Type C low beta previously report, anti p Note 169, although some changes have been made to the quadrupole lengths and positions. This insertion is designated Type E. The purpose of the study was to see if it is possible to turn the insertion on in a smooth and continuous manner and tune the insertion to a value of β* of less than one meter while maintaining the overall tune of the j Tevatron to a constant value. This was found to be possible. An examination of chromaticity corrections for the Tevatron with the low beta insertion on in various configurations was also undertaken

  4. Longitudinal damping in the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs.

  5. Recent QCD Studies at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Group, Robert Craig

    2008-04-01

    Since the beginning of Run II at the Fermilab Tevatron the QCD physics groups of the CDF and D0 experiments have worked to reach unprecedented levels of precision for many QCD observables. Thanks to the large dataset--over 3 fb{sup -1} of integrated luminosity recorded by each experiment--important new measurements have recently been made public and will be summarized in this paper.

  6. Top quark production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Varnes, Erich W.; /Arizona U.

    2010-09-01

    The Fermilab Tevatron has, until recently, been the only accelerator with sufficient energy to produce top quarks. The CDF and D0 experiments have collected large samples of top quarks. We report on recent top quark production measurements of the single top and t{bar t} production cross sections, as well as studies of the t{bar t} invariant mass distribution and a search for highly boosted top quarks.

  7. Photons and diphotons from the Tevatron

    International Nuclear Information System (INIS)

    Blair, R.

    1997-08-01

    Photon measurements from the CDF and D0 collaboration are described. The subjects touched on are loosely organized around the fact that they all have some bearing on the structure functions and pQCD. The methodology of collider measurements is briefly reviewed, and the results for single photons, photons plus jets, photons plus charm and diphotons are discussed. Finally there is a very brief indication of what is expected from the Tevatron based experiments in the future

  8. Searches for new physics at the Tevatron

    International Nuclear Information System (INIS)

    Merritt, K. Wyatt

    1997-01-01

    This paper summarizes searches at the Fermilab Tevatron for a wide variety of signatures for physics beyond the Standard Model. These include searches for supersymmetric particles, in the two collider detectors and in one fixed target experiment. Also covered are searches for leptoquarks, dijet resonances, heavy gauge bosons, and particles from a fourth generation, as well as searches for deviations from the Standard Model predictions in dijet angular distributions, dilepton mass distributions, and trilinear gauge boson couplings

  9. Longitudinal damping in the Tevatron collider

    International Nuclear Information System (INIS)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs

  10. Higgs boson studies at the Tevatron

    Czech Academy of Sciences Publication Activity Database

    Aaltonen, L.; Abbott, B.; Abazov, V. M.; Kupčo, Alexander; Lokajíček, Miloš; Lysák, Roman

    2013-01-01

    Roč. 88, č. 5 (2013), "052014-1"-"052014-29" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : Higgs particle * mass * vector boson * gluon * fusion * Batavia TEVATRON Coll * CDF * DZERO * anti-p p * interaction Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.864, year: 2013

  11. Twenty years of diffraction at the Tevatron

    International Nuclear Information System (INIS)

    Goulianos, K.; Rockefeller U.

    2005-01-01

    Results on diffractive particle interactions from the Fermilab Tevatron (bar p)p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held

  12. Fermilab tevatron five refrigerator system tests

    International Nuclear Information System (INIS)

    Rode, C.; Ferry, R.; Leiniger, M.; Makara, J.; Misek, J.; Mizicko, D.; Richied, D.; Theilacker, J.

    1982-01-01

    The Fermilab Tevatron refrigeration system is described with the layout illustrated. The compressor control loops, the refrigerator control loops, and magnet control loops (two per refrigerator) are described and each illustrated. The mobile purifier is described. A five refrigerator test is presented, using two compressor buildings, satellite refrigerator concept test and the test current to the writing. The configuration of the five refrigerator test is diagramed

  13. Increasing the energy of the Fermilab Tevatron accelerator

    International Nuclear Information System (INIS)

    Fuerst, J.D.; Theilacker, J.C.

    1994-07-01

    The superconducting Tevatron accelerator at Fermilab has reached its eleventh year of operation since being commissioned in 1983. Last summer, four significant upgrades to the cryogenic system became operational which allow Tevatron operation at higher energy. This came after many years of R ampersand D, power testing in sectors (one sixth) of the Tevatron, and final system installation. The improvements include the addition of cold helium vapor compressors, supporting hardware for subatmospheric operation, a new satellite refrigerator control system, and a higher capacity central helium liquefier. A description of each cryogenic upgrade, commissioning experience, and attempts to increase the energy of the Tevatron are presented

  14. Beyond the standard model at Tevatron

    International Nuclear Information System (INIS)

    Pagliarone, C.

    2000-01-01

    Tevatron experiments performed extensive searches for physics beyond the Standard Model. No positive results have been found so far showing that the data are consistent with the SM expectations. CDF and D0 continue the analysis of Run I data placing limits on new physics, including Supersymmetry, large space time dimensions and leptoquark models. With the Run II upgrades, providing an higher acceptance and higher luminosity, it will be possible to make important progresses in the search for new phenomena as well as in setting limits on a larger variety of theoretical models

  15. Present state of Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Norris, B.L.

    1996-09-01

    Fermilab continues to work on raising the particle energy of the Tevatron by lowering magnet temperatures using cold vapor compressors. In 1995, another two rounds of power tests were completed. These power tests, although showing significant improvement over the initial tests of 1993-94, have led to the conclusion that 1000 GeV operation cannot be attained without replacing/rearranging magnets with lower quench currents before the next Collider Run in 1999. Development of more cold compressor control strategies also continues

  16. Standard Model Higgs Searches at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Knoepfel, Kyle J.

    2012-06-01

    We present results from the search for a standard model Higgs boson using data corresponding up to 10 fb{sup -1} of proton-antiproton collision data produced by the Fermilab Tevatron at a center-of-mass energy of 1.96 TeV. The data were recorded by the CDF and D0 detectors between March 2001 and September of 2011. A broad excess is observed between 105 < m{sub H} < 145 GeV/c{sup 2} with a global significance of 2.2 standard deviations relative to the background-only hypothesis.

  17. Calculating luminosity for a coupled Tevatron lattice

    International Nuclear Information System (INIS)

    Holt, J.A.; Martens, M.A.; Michelotti, L.; Goderre, G.

    1995-05-01

    The traditional formula for calculating luminosity assumes an uncoupled lattice and makes use of one-degree-of-freedom lattice functions, β H and β v , for relating transverse beam widths to emittances. Strong coupling requires changing this approach. It is simplest to employ directly the linear normal form coordinates of the one turn map. An equilibrium distribution in phase space is expressed as a function of the Jacobian's eigenvectors and beam size parameters or emittances. Using the equilibrium distributions an expression for the luminosity was derived and applied to the Tevatron lattice, which was coupled due to a quadrupole roll

  18. New diffractive results from the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Gallinaro, Michele; /Rockefeller U.

    2005-05-01

    Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.

  19. Gluino-pair production at the Tevatron

    International Nuclear Information System (INIS)

    Beenakker, W.; Spira, M.; Zerwas, P.M.

    1995-05-01

    The next-to-leading order QCD corrections to the production of gluino pairs at the Tevatron are presented in this paper. Similar to the production of squark-antisquark pairs, the dependence of the cross section on the renormalization/factorization scale is reduced considerably by including the higher-order corrections. The cross section increases with respect to the lowest-order calculation which, in previous experimental analyses, had been evaluated at the scale of the invariant energy of the partonic subprocesses. (orig.)

  20. Electroweak, top and bottom physics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Ukegawa, Fumihiko; /Tsukuba U.

    2004-10-01

    The Tevatron Run-II program has been in progress since 2001, and the CDF and D0 experiments have been operational with upgraded detectors. Coupled with recent improvements in the Tevatron accelerator performance, the experiments have started producing important physics results and measurements. They report these measurements as well as prospects in the near future.

  1. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  2. Sonic Helium Detectors in the Fermilab Tevatron

    Science.gov (United States)

    Bossert, R. J.

    2006-04-01

    In the Fermilab Tevatron cryogenic system there are many remotely located low-pressure plate relief valves that must vent large volumes of cold helium gas when magnet quenches occur. These valves can occasionally stick open or not reseat completely, resulting in a large helium loss. As such, the need exists for a detector to monitor the relief valve's discharge area for the presence of helium. Due to the quantity needed, cost is an important factor. A unit has been developed and built for this purpose that is quite inexpensive. Its operating principle is based on the speed of sound, where two closely matched tubes operate at their acoustic resonant frequency. When helium is introduced into one of these tubes, the resulting difference in acoustic time of flight is used to trigger an alarm. At present, there are 39 of these units installed and operating in the Tevatron. They have detected many minor and major helium leaks, and have also been found useful in detecting a rise in the helium background in the enclosed refrigerator buildings. This paper covers the construction, usage and operational experience gained with these units over the last several years.

  3. Sonic helium detectors in the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Bossert, R.J.; Fermilab

    2006-01-01

    In the Fermilab Tevatron cryogenic system there are many remotely located low-pressure plate relief valves that must vent large volumes of cold helium gas when magnet quenches occur. These valves can occasionally stick open or not reseat completely, resulting in a large helium loss. As such, the need exists for a detector to monitor the relief valve's discharge area for the presence of helium. Due to the quantity needed, cost is an important factor. A unit has been developed and built for this purpose that is quite inexpensive. Its operating principle is based on the speed of sound, where two closely matched tubes operate at their acoustic resonant frequency. When helium is introduced into one of these tubes, the resulting difference in acoustic time of flight is used to trigger an alarm. At present, there are 39 of these units installed and operating in the Tevatron. They have detected many minor and major helium leaks, and have also been found useful in detecting a rise in the helium background in the enclosed refrigerator buildings. This paper covers the construction, usage and operational experience gained with these units over the last several years

  4. Non-SUSY Searches at the Tevatron

    International Nuclear Information System (INIS)

    Strologas, John

    2011-01-01

    We present recent results from searches for new physics beyond supersymmetry performed at the Tevatron accelerator at Fermilab. The CDF and D0 analyses presented here utilized data of integrated luminosity up to 6 fb -1 . We cover leptonic and bosonic resonances interpreted in the Randall-Sundrum graviton and new-boson models, rare final states, and the search for vector-like quarks. The search for new phenomena beyond the weak-scale supersymmetry is a vital part of the Fermilab program. Both CDF and D0 experiments at the Tevatron collider actively look for signals not expected by the standard model (SM) or minimal supersymmetric models. The searches can be sorted in three categories: (a) searches for generic resonances that can be interpreted in several new-physics models; (b) searches for exotic combinations of final-state objects or abnormal kinematics (not necessarily predicted by current theories); and (c) model-dependent searches that test a particular theory. We present here latest results from all these categories: searches for new dilepton and diboson resonances (interpreted as gravitons and new gauge bosons), searches for anomalous γ + E T + X production, and searches for vector-like quarks.

  5. One Episode, Two Lenses

    Science.gov (United States)

    Drijvers, Paul; Godino, Juan D.; Font, Vicenc; Trouche, Luc

    2013-01-01

    A deep understanding of students' learning processes is one of the core challenges of research in mathematics education. To achieve this, different theoretical lenses are available. The question is how these different lenses compare and contrast, and how they can be coordinated and combined to provide a more comprehensive view on the topic of…

  6. Diagnostics of the Fermilab Tevatron using an AC dipole

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Ryoichi [Univ. of Texas, Austin, TX (United States)

    2008-08-01

    The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

  7. Nonlinear dynamics experiment in the Tevatron

    International Nuclear Information System (INIS)

    Merminga, N.; Edwards, D.; Finley, D.

    1989-01-01

    Results of the continuing analysis of the nonlinear dynamics experiment E778 are presented. Sixteen special sextupoles introduced nonlinearities in the Tevatron. 'Smear,' which is one of the parameters used to quantify the degree of nonlinearity, was extracted from the data and compared with calculation. Injection efficiency in the presence of nonlinearities was studied. Measurements of the dynamic aperture were performed. The final results in one degree of freedom of the smear, the injection efficiency and the dynamic aperture are presented. Particles captured on nonlinear resonance islands were directly observed and measurements were performed. The capture efficiency was extracted from the data and compared with prediction. The influence of tune modulation on the stability of these islands was investigated. Plans for future measurements are discussed. 4 refs., 6 figs

  8. Neutrino results from the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Shaevitz, M.H.; Arroyo, C.; Bachmann, K.T.; Bazarko, A.O.; Blair, R.E.; Bolton, T.A.; Foudas, C.; King, B.J.; Lefmann, W.C.; Leung, W.C.; Mishra, S.R.; Oltman, E.; Quintas, P.Z.; Rabinowitz, S.A.; Sciulli, F.; Seligman, W.G.; Merritt, F.S.; Oreglia, M.J.; Schumm, B.A.; Bernstein, R.H.; Borcherding, F.; Fisk, H.E.; Lamm, M.J.; Marsh, W.; Merritt, K.W.B.; Schellman, H.; Yovanovitch, D.D.; Bodek, A.; Budd, H.S.; De Barbaro, P.; Salcumoto, W.K.; Kinnel, T.S.; Sandler, P.H.; Smith, W.H.

    1995-01-01

    Results from the high-energy, high-statistics studies of neutrino nucleon interactions by the CCFR collaboration at the Fermilab Tevatron are described. Using a data sample of over 3.7million events with energies up to 600GeV, precision measurements are presented for the weak mixing angle, sin 2 θ w , the structure functions, F 2 (x,Q 2 ) and xF 3 (x,Q 2 ), aud the strange quark distribution, xs(x,Q 2 ). Comparisons of these measurements to those obtained in other processes are made in the context of global electroweak and QCD tests. Prospects for the next generation measurements by the NuTeV collaboration at Fermilab are also presented. ((orig.))

  9. Recent heavy flavor results from the Tevatron

    International Nuclear Information System (INIS)

    Dorigo, Mirco

    2012-01-01

    The CDF and D0 experiments at the Tevatron p(bar p) collider have pioneered and established the role of flavor physics in hadron collisions. A broad program is now at its full maturity. We report on three new results sensitive to physics beyond the standard model, obtained using the whole CDF dataset: a measurement of the difference of CP asymmetries in K + K - and π + π - decays of D 0 mesons, new bounds on the B s 0 mixing phase and on the decay width difference of B s 0 mass-eigenstates, and an update of the summer 2011 search for B (s) 0 mesons decaying into pairs of muons. Finally, the D0 confirmation of the observation of a new hadron, the χ b (3P) state, is briefly mentioned.

  10. Scientific Opportunity: the Tevatron and the LHC

    CERN Multimedia

    2010-01-01

    The press makes much of the competition between CERN’s LHC and Fermilab’s Tevatron in the search for the Higgs boson. This competitive aspect is real, and probably adds spice to the scientific exploration, but for us such reporting often feels like spilling the entire pepper shaker over a fine meal. The media’s emphasis on competition obscures the more important substance of our long-standing collaboration in scientific discovery.   Our laboratories and our communities have worked together for decades. Europeans have contributed greatly to the Tevatron’s many successes, including the discovery of the top quark, the discovery of fast oscillations in the decay of strange B mesons and the many searches for new phenomena. Americans have contributed to many programs at CERN, notably the extraordinary precision measurements of LEP, and more recently construction of the LHC accelerator and detectors. Fermilab scientists played a vital role throughout 2009 in...

  11. Initial performance of upgraded Tevatron cryogenic systems

    International Nuclear Information System (INIS)

    Norris, B.L.

    1996-09-01

    Fermilab began operating a re-designed satellite refrigerator systems in November 1993. Upgrades were installed to operate the Tevatron at a magnet temperature of 3.5 K, approximately 1K lower than the original design. Refrigerator upgrades included new valve boxes, larger reciprocating expanders, the installation of cold vapor compressors, new sub-atmospheric instrumentation and an entirely new distributed controls system. Cryogenic system reliability data for Colliding Physics Run 1B is presented emphasizing a failure analysis for each aspect of the upgrade. Comparison to data for Colliding Physics Run 1A (previous to upgrade) is presented to show the impact of a major system overhaul. New operational problems and their solutions are presented in detail

  12. Plasma surface modification of rigid contact lenses decreases bacterial adhesion.

    Science.gov (United States)

    Wang, Yingming; Qian, Xuefeng; Zhang, Xiaofeng; Xia, Wei; Zhong, Lei; Sun, Zhengtai; Xia, Jing

    2013-11-01

    Contact lens safety is an important topic in clinical studies. Corneal infections usually occur because of the use of bacteria-carrying contact lenses. The current study investigated the impact of plasma surface modification on bacterial adherence to rigid contact lenses made of fluorosilicone acrylate materials. Boston XO and XO2 contact lenses were modified using plasma technology (XO-P and XO2-P groups). Untreated lenses were used as controls. Plasma-treated and control lenses were incubated in solutions containing Staphylococcus aureus or Pseudomonas aeruginosa. MTT colorimetry, colony-forming unit counting method, and scanning electron microscopy were used to measure bacterial adhesion. MTT colorimetry measurements showed that the optical density (OD) values of XO-P and XO2-P were significantly lower than those of XO and XO2, respectively, after incubation with S. aureus (P lenses and to the XO2-P versus XO2 lenses incubated with S. aureus (P lenses incubated with P. aeruginosa (P lenses. Plasma surface modification can significantly decrease bacterial adhesion to fluorosilicone acrylate contact lenses. This study provides important evidence of a unique benefit of plasma technology in contact lens surface modification.

  13. Tevatron The Cinderella story or the art of collider

    CERN Document Server

    CERN. Geneva

    2007-01-01

    The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world's highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world's High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we'll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing" Issues; Beam Physics Issues; Luminosity Progress; Organization of Troops and Lessons for LHC.

  14. Effects of Resonant and Random Excitations on the Proton Beam in the Large Hadron Collider, with Applications to the Design of Pulsed Hollow Electron Lenses for Active Halo Control

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, Miriam; Stancari, Giulio; Valishev, Alexander; Redaelli, Stefano; Valuch, Daniel

    2018-04-19

    We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses (HEL) for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies.

  15. Gravitational lensing of quasars

    CERN Document Server

    Eigenbrod, Alexander

    2013-01-01

    The universe, in all its richness, diversity and complexity, is populated by a myriad of intriguing celestial objects. Among the most exotic of them are gravitationally lensed quasars. A quasar is an extremely bright nucleus of a galaxy, and when such an object is gravitationally lensed, multiple images of the quasar are produced – this phenomenon of cosmic mirage can provide invaluable insights on burning questions, such as the nature of dark matter and dark energy. After presenting the basics of modern cosmology, the book describes active galactic nuclei, the theory of gravitational lensing, and presents a particular numerical technique to improve the resolution of astronomical data. The book then enters the heart of the subject with the description of important applications of gravitational lensing of quasars, such as the measurement of the famous Hubble constant, the determination of the dark matter distribution in galaxies, and the observation of the mysterious inner parts of quasars with much higher r...

  16. W mass and Triple Gauge Couplings at Tevatron

    Directory of Open Access Journals (Sweden)

    Pétroff Pierre

    2013-05-01

    Full Text Available The W mass is a crucial parameter in the Standard Model (SM of particle physics, providing constraints on the mass of the Higgs boson as well as on new physics models via quantum loop corrections. On the other hand, any deviation of the triple gauge boson couplings (TGC from their values predicted by the SM would be also an indication for new physics. We present recent measurements on W boson mass and searches for anomalous TGC (aTGC in Wγ, Zγ, WW, WZ and ZZ at Fermilab Tevatron both by CDF and DØ Collaborations. The CDF Collaboration has measured the W boson mass using data corresponding to 2.2 fb−1 of integrated luminosity. The measurement, performed using electron and muon decays of W boson, yields a mass of MW = 80387 ± 19 MeV. The DØ Collaboration has measured MW = 80367 ± 26 MeV with data corresponding to 4.3 fb−1 of integrated luminosity in the channel W → ev. The combination with an earlier DØ result, using independant data sample at 1 fb−1 of integrated luminosity, yields MW = 80375 ± 23 MeV. The limits on anomalous TGCs parameters are consistent with the SM expectations.

  17. Updated overview of the Tevatron control system

    International Nuclear Information System (INIS)

    Lucas, P.

    1987-10-01

    A single unified control system is used for all of the Fermilab accelerators and storage rings, from the LINAC to the Tevatron and antiproton source. A review of the general features is given - these include a 'host' system consisting of a number of minicomputers integrated with many distributed microprocessors in a variety of subsystems, usage of an in-house developed protocol, GAS, for communication between the two classes of machines, and a Parameter Page program, designed in conjunction with the system database, which allows a wide variety of quantities to be read and set in a coherent fashion. Recent developments include the implementation of a block transfer and 'fast time plot' facility through CAMAC, inclusion of several new computers in the host, a better understanding of system throughput, greatly improved reliability, advent of programs which sequence a large number of independent operations, and the construction of new hardware subsystems. Possible future system upgrades will be briefly presented. A summary of the utilization of a quite large software staff, at a time when the system is no longer under construction, will be discussed

  18. Aberration characteristics of immersion lenses for LVSEM

    International Nuclear Information System (INIS)

    Khursheed, Anjam

    2002-01-01

    This paper investigates the on-axis aberration characteristics of various immersion objective lenses for low voltage scanning electron microscopy (LVSEM). A simple aperture lens model is used to generate smooth axial field distributions. The simulation results show that mixed field electric-magnetic immersion lenses are predicted to have between 1.5 and 2 times smaller aberration limited probe diameters than their pure-field counterparts. At a landing energy of 1 keV, mixed field immersion lenses operating at the vacuum electrical field breakdown limit are predicted to have on-axis aberration coefficients between 50 and 60 μm, yielding an ultimate image resolution of below 1 nm. These aberrations lie in the same range as those for LVSEM systems that employ aberration correctors

  19. Coherent betatron instability in the Tevatron

    International Nuclear Information System (INIS)

    Bogacz, S.A.; Harrison, M.; Ng, K.Y.

    1988-01-01

    The coherent betatron instability was first observed during the recent 1987-88 Tevatron fixed target run. In this operating mode 1000 consecutive bunches are loaded into the machine at 150 GeV with a bunch spacing of 18.8 /times/ 10 -9 sec (53 MHz). The normalized transverse emittance is typically 15 π /times/ 10 -6 m rad in each plane with a longitudinal emittance of about 1.5 eV-sec. The beam is accelerated to 800 GeV in 13 sec. and then it is resonantly extracted during a 23 sec flat top. As the run progressed the bunch intensities were increased until at about 1.4 /times/ 10 10 ppb (protons per bunch) we experienced the onset of a coherent horizontal oscillation taking place in the later stages of the acceleration cycle (>600 GeV). This rapidly developing coherent instability results in a significant emittance growth, which limits machine performance and in a catastrophic scenario it even prevents extraction of the beam. In this paper we will present a simple analytic description of the observed instability. We will show that a combination of a resistive wall coupled bunch effect and a single bunch slow head-tail instability is consistent with the above observations. Finally, a systematic numerical analysis of our model (growth-time vs chromaticity plots) points to the existence of the ≥1 slow head-tail modes as a plausible mechanism for the observed coherent instability. This last claim, as mentioned before, does not have conclusive experimental evidence, although it is based on a very good agreement between the measured values of the instability growth-time and the ones calculated on the basis of our model. 4 refs., 3 figs

  20. Tevatron energy and luminosity upgrades beyond the Main Injector

    International Nuclear Information System (INIS)

    Amidei, D.; Kamon, T.; Lopez, J.; McIntyre, P.; White, J.

    1994-08-01

    The Fermilab Tevatron will be the world's highest energy hadron collider until the LHC is commissioned, it has the world's highest energy fixed target beams, and Fermilab will be the leading high energy physics laboratory in the US for the foreseeable future. Following the demise of the SSC, a number of possible upgrades to the Tevatron complex, beyond construction of the Main Injector, are being discussed. Using existing technology, it appears possible to increase the luminosity of the bar pp Collider to at least 10 33 cm -2 sec -1 (Tevatron-Star) and to increase the beam energy to 2 TeV (DiTevatron). Fixed target beam of energy about 1.5 TeV could also be delivered. Leaving the existing Tevatron in the tunnel and constructing bypasses around the collider halls would allow simultaneous 800 GeV fixed target and √s = 4 TeV collider operation. These upgrades would give Fermilab an exciting physics program which would be complementary to the LHC, and they would lay the groundwork for the construction of a possible post-LHC ultra-high energy hadron collider

  1. Constraints on unparticles from top properties measured at Tevatron

    International Nuclear Information System (INIS)

    Islam, Rashidul; Dahiya, Mamta; Dutta, Sukanta

    2013-01-01

    We discuss the recent observations of the top pair production at Tevatron through flavor conserving and flavor violating channels via vector and tensor unparticles. The unparticle sector is considered to be a color singlet or octet. We have used the unparticle propagators modified for full conformal invariance to investigate the contribution of these unparticles to the observed forward backward asymmetry and the spin correlation in top pair production at Tevatron. We also discuss the impact of the flavor violating couplings of unparticles to the third generation quarks on (a) pair production of same sign tops/antitops at TeVatron and (b) the partial top decay width for Γ u (t → uU V )

  2. Tevatron-for-LHC Report of the QCD Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Albrow, Michael G.; Begel, M.; Bourilkov, D.; Campanelli, M.; Chlebana, F.; De Roeck, A.; Dittmann, J.R.; Ellis, S.D.; Field, B.; Field, R.; Gallinaro, M.; /Fermilab

    2006-10-01

    The experiments at Run 2 of the Tevatron have each accumulated over 1 fb{sup -1} of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focused on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.

  3. Simulation of beam-beam effects in tevatron

    International Nuclear Information System (INIS)

    Mishra, C.S.; Assadi, S.; Talman, R.

    1995-08-01

    The Fermilab accelerator complex is in the middle of an upgrade plan Fermilab III. In the last phase of this upgrade the luminosity of the Tevatron will increase by at least one order of magnitude. In order to keep the number of interactions per crossing manageable for experiments, the number of bunches will be increased from 6 x 6 to 36 x 36 and finally to ∼100 x 100 bunches. The beam dynamics of the Tevatron has been studied from Beam-Beam effect point of view in a ''Strong-Weak'' representation with a single particle being tracked in presence of other beam. This paper describes the beam-beam effect in 6 x 6 operation of Tevatron

  4. Detector implications for eletroweak physics at the Tevatron

    International Nuclear Information System (INIS)

    Madaras, R.J.

    1996-12-01

    D0 and CDF are two large, powerful, multipurpose detectors with outstanding tracking, calorimeter and muon systems that have done an excellent job in exploiting the Top Quark, b Quark, QCD, New Phenomena/Exotics and Electroweak Physics at the Fermilab Tevatron Collider. The upgrades of the D0 and CDF detectors will further enhance their capabilities for physics at the Tevatron. The addition of a magnetic field and silicon vertex chamber will open up new physical opportunities for D0, and the replacement of the plug and forward gas calorimeters with new scintillator based calorimeters will give CDF uniform calorimetry over all η

  5. Signal processing for longitudinal parameters of the Tevatron beam

    International Nuclear Information System (INIS)

    Pordes, S.; Crisp, J.; Fellenz, B.; Flora, R.; Para, A.; Tollestrup, A.V.

    2005-01-01

    We describe the system known as the Tevatron SBD [1] which is used to provide information on the longitudinal parameters of coalesced beam bunches in the Tevatron. The system has been upgraded over the past year with a new digitizer and improved software. The quantities provided for each proton and antiproton bunch include the intensity, the longitudinal bunch profile, the timing of the bunch with respect to the low-level RF, the momentum spread and the longitudinal emittance. The system is capable of 2 Hz operation and is run at 1 Hz

  6. Fresnel's Lighthouse Lenses

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2007-01-01

    One of the rewards of walking up the scores of steps winding around the inside of the shaft of a lighthouse is turning inward and examining the glass optical system. This arrangement of prisms, lenses, and reflectors is used to project the light from a relatively small source in a beam that can be seen far at sea.

  7. Tevatron-for-LHC Report: Preparations for Discoveries

    CERN Document Server

    Abdullin, Salavat; Asai, Shoji; Atramentov, Oleksiy Vladimirovich; Baer, Howard; Balazs, Csaba; Bartalini, Paolo; Belyaev, Alexander; Bernhard, Ralf Patrick; Birkedal, Andreas; Buescher, Volker; Cavanaugh, Richard; Chen, Mu-Chun; Clement, Christophe; Datta, AseshKrishna; de Boer, Ytsen R.; De Roeck, Albert; Dobrescu, Bogdan A.; Drozdetskiy, Alexey; Gershtein, Yuri S.; Glenzinski, Douglas A.; Group, Robert Craig; Heinemeyer, Sven; Heldmann, Michael; Hubisz, Jay; Karlsson, Martin; Kong, Kyoungchul; Korytov, Andrey; Kraml, Sabine; Krupovnickas, Tadas; Lafaye, Remi; Lane, Kenneth; Ledroit, Fabienne; Lehner, Frank; Lin, Cheng-Ju; Macesanu, Cosmin; Matchev, Konstantin T.; Menon, Arjun; Milstead, David; Mitselmakher, Guenakh; Morel, Julien; Morrissey, David; Mrenna, Steve; O'Farrill, Jorge; Pakhotin, Yu.; Perelstein, Maxim; Plehn, Tilman; Rainwater, David; Raklev, Are; Schmitt, Michael; Scurlock, Bobby; Sherstnev, Alexander; Skands, Peter Z.; Sullivan, Zack; Tait, Timothy M.P.; Tata, Xerxes; Torchiani, Ingo; Trocme, Benjamin; Wagner, Carlos; Weiglein, Georg; Zerwas, Dirk

    2006-01-01

    This is the "TeV4LHC" report of the "Physics Landscapes" Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

  8. Tests of QCD in W and Z production at Tevatron

    International Nuclear Information System (INIS)

    Abachi, S.

    1995-01-01

    We present measurements of the production cross sections times leptonic branching fractions and the transverse momentum distributions of W and Z bosons in p bar p collisions at √s = 1.8 TeV using data collected with the DO detector at the Fermilab Tevatron p bar p collider. A preliminary measurement of the W charge asymmetry is also presented

  9. Experience with the new reverse injection scheme in the Tevatron

    International Nuclear Information System (INIS)

    Saritepe, S.; Goderre, G.; Annala, G.; Hanna, B.; Braun, A.

    1993-01-01

    In the new injection scenario the antiproton beam is injected onto a helical Tevatron orbit to avoid the detrimental effects of the beam-beam interaction at 150 GeV. The new scenario required changes in the tuning procedures. Antiprotons are too precious to be used for tuning, therefore the antiproton injection line has to be tuned with protons by reverse injecting them from the Tevatron into the Main Ring. Previously, the reverse injection was performed in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. The orbit closure was performed in the Main Ring. In the new scheme the lambertson magnets have to be moved, separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS (Tevatron Beam Synchronized Clock) event $D8 as MRBS (Main Ring Beam Synchronized Clock) $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the Main Ring

  10. On Self-Similarity of Top Production at Tevatron

    Czech Academy of Sciences Publication Activity Database

    Tokarev, M. V.; Zborovský, Imrich

    2012-01-01

    Roč. 3, č. 8 (2012), s. 815-820 ISSN 2153-120X R&D Projects: GA MŠk LA08002; GA MŠk LA08015 Institutional research plan: CEZ:AV0Z10480505 Keywords : top quark * Tevatron Subject RIV: BE - Theoretical Physics http://www.scirp.org/journal/PaperInformation.aspx?paperID=21690

  11. Race for the Higgs hots up as Tevatron seeks extension

    CERN Multimedia

    Banks, Michael

    2009-01-01

    "With researchers at Cern's Large Hadron Collider (LHC) having circulated protons for the first time since last year's accident, the US Department of Energy (DOE) is requesting $25m so that the Tevatron collider at the Fermi National Accelerator Laboratory in Illinois can run for an extra year until 2011" (0.25 page)

  12. Antiproton acceleration in the Fermilab Main Ring and Tevatron

    International Nuclear Information System (INIS)

    Martin, P.; Dinkel, J.; Ducar, R.

    1987-01-01

    The operation of the Fermilab Main Ring and Tevatron rf systems for colliding beams physics is discussed. The changes in the rf feedback system required for acceleration of antiprotons, and the methods for achieving proper transfer of both protons and antiprotons are described. Data on acceleration and transfer efficiencies are presented

  13. Searches for New Phenomena at the Tevatron and at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Arnd

    2006-10-01

    Recent results on searches for new physics at Run II of the Tevatron and highlights from HERA are reported. The searches cover many different final states and a wide range of models. All analyses have at this point led to negative results, but some interesting anomalies have been found.

  14. Surge recovery techniques for the Tevatron cold compressors

    International Nuclear Information System (INIS)

    Martinez, A.; Klebaner, A.L.; Makara, J.N.; Theilacker, J.C.; Fermilab

    2006-01-01

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, made by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/s of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/s and operating speeds between 40 and 95 krpm. Since initial commissioning in 1993, Tevatron transient conditions such as quench recovery have led to multiple-location machine trips as a result of the cold compressors entering the surge regime. Historically, compressors operating at lower inlet pressures and higher speeds have been especially susceptible to these machine trips and it was not uncommon to have multiple compressor trips during large multiple-house quenches. In order to cope with these events and limit accelerator down time, surge recovery techniques have been implemented in an attempt to prevent the compressors from tripping once the machine entered this surge regime. This paper discusses the different methods of surge recovery that have been employed. Data from tests performed at the Cryogenic Test Facility at Fermilab as well as actual Tevatron operational data were utilized. In order to aid in the determination of the surge region, a full mapping study was undertaken to characterize the entire pressure field of the cold compressor. These techniques were then implemented and tested at several locations in the Tevatron with some success

  15. Tevatron: recent results and prospects at the upgrade

    International Nuclear Information System (INIS)

    Mondal, Naba K.

    1998-01-01

    In this article, we review some of the recent results from CDF and DΦ experiments at the Tevatron and their prospects at the upgrade. Among the topics discussed are top quark physics, electroweak physics, QCD physics and new physics beyond standard model. (author)

  16. Explaining Tevatron leptons photons missing- T events with ...

    Indian Academy of Sciences (India)

    Abstract. The CDF experiment reported a lepton photon missing transverse energy. (/ET) signal 3σ in excess of the standard model prediction in Tevatron Run I data. The excess can be explained by the resonant production of a smuon, which subsequently decays to a muon, a photon and a gravitino. Here, we perform ...

  17. Measurements of beam halo diffusion and population density in the Tevatron and in the Large Hadron Collider

    CERN Document Server

    Stancari, Giulio

    Halo dynamics influences global accelerator performance: beam lifetimes, emittance growth, dynamic aperture, and collimation efficiency. Halo monitoring and control are also critical for the operation of high-power machines. For instance, in the high-luminosity upgrade of the LHC, the energy stored in the beam tails may reach several megajoules. Fast losses can result in superconducting magnet quenches, magnet damage, or even collimator deformation. The need arises to measure the beam halo and to remove it at controllable rates. In the Tevatron and in the LHC, halo population densities and diffusivities were measured with collimator scans by observing the time evolution of losses following small inward or outward collimator steps, under different experimental conditions: with single beams and in collision, and, in the case of the Tevatron, with a hollow electron lens acting on a subset of bunches. After the LHC resumes operations, it is planned to compare measured diffusivities with the known strength of tran...

  18. Observations of gravitational lenses

    International Nuclear Information System (INIS)

    Fort, B.

    1990-01-01

    During the last tow years a burst of results has come from radio and optical surveys of ''galaxy lenses'' (where the main deflector is a galaxy). These are reviewed. On the other hand, in September 1985 we pointed out a very strange blue ring-like structure on a Charge-Coupled Device image of the cluster of galaxies Abell 370. This turned out to be Einstein arcs discovery. Following this discovery, new observational results have shown that many rich clusters of galaxies can produce numerous arclets: tangentially distorted images of an extremely faint galaxy population probably located at redshift larger than 1. This new class of gravitational lenses proves to be an important observational topic and this will be discussed in the second part of the paper. (author)

  19. The search for the Higgs at the Tevatron; La recherche du Higgs au Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Lucotte, A

    2004-07-01

    The Tevatron has undergone an impressive technical renovation program whose final aim is to reach an integrated luminosity of 15 fb{sup -1} per experiment. Both CDF and DO detectors have been upgraded in the fields of detection, triggering, track reconstruction and particle identification. In the framework of the standard model, theoretical studies show that for a luminosity of only 2 fb{sup -1} (that is the first step of the renovation program) CDF and DO could barely extend the domain already excluded by LEP for the existence of the Higgs boson. On the other hand for a luminosity of 15 fb{sup -1}, a standard Higgs boson could be excluded up to 180 GeV/c{sup 2} and discovered up to 125 GeV/c{sup 2}. Moreover, a 3*{sigma} result could be obtained in the decay channels H {yields} bb-bar and H {yields} W{sup +}W{sup -} up to 180 GeV/c{sup 2}. In the framework of the minimal supersymmetric standard model (MSSM), at least 20 fb{sup -1} are required for the discovery of the Higgs boson in the energy range: 80 {<=} m{sub A} {<=} 380 GeV/c{sup 2}. (A.C.)

  20. Additive manufacturing of tunable lenses

    Science.gov (United States)

    Schlichting, Katja; Novak, Tobias; Heinrich, Andreas

    2017-02-01

    Individual additive manufacturing of optical systems based on 3D Printing offers varied possibilities in design and usage. In addition to the additive manufacturing procedure, the usage of tunable lenses allows further advantages for intelligent optical systems. Our goal is to bring the advantages of additive manufacturing together with the huge potential of tunable lenses. We produced tunable lenses as a bundle without any further processing steps, like polishing. The lenses were designed and directly printed with a 3D Printer as a package. The design contains the membrane as an optical part as well as the mechanical parts of the lens, like the attachments for the sleeves which contain the oil. The dynamic optical lenses were filled with an oil. The focal length of the lenses changes due to a change of the radius of curvature. This change is caused by changing the pressure in the inside of the lens. In addition to that, we designed lenses with special structures to obtain different areas with an individual optical power. We want to discuss the huge potential of this technology for several applications. Further, an appropriate controlling system is needed. Wéll show the possibilities to control and regulate the optical power of the lenses. The lenses could be used for illumination tasks, and in the future, for individual measurement tasks. The main advantage is the individuality and the possibility to create an individual design which completely fulfills the requirements for any specific application.

  1. FERMILAB: Tevatron upgrade; Magnetic precession in bent crystals

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-01-15

    The Fermilab accelerator complex is in the middle of a major upgrade to increase the luminosity beyond the original design goal. During Phase I of this upgrade, there have been major modifications to the Tevatron. These modifications were commissioned at the start of the latest collider run and include the installation of electrostatic separators to separate the orbits of the stored beams and new low beta insertions to squeeze the colliding proton and antiproton beams at both experiment interaction regions. These modifications have already enabled the Tevatron to achieve a record peak luminosity of 6.93 x 10{sup 30} per sq cm per s and a record weekly integrated luminosity of 10{sup 60} inverse nanobarns. The peak goal for the present run of 5.0 x 10{sup 30} has already been exceeded.

  2. The A0 abort system for the Tevatron upgrade

    International Nuclear Information System (INIS)

    Crawford, C.

    1989-01-01

    The installation of electrostatic separator modules at B48 and C17 in the Tevatron necessitates changes to the Tevatron abort system. There will no longer be room for either the proton or antiproton kicker magnets used in the present system. The kickers at C17 will be permanently removed. The kickers at B48 will be temporarily removed for collider operation and will be replaced for fixed target operation. The existing proton abort system will remain unchanged during fixed target operation. This note describes a proposed abort system for operation in the collider mode for 22 on 22 bunches and provides details of specifications for the required components. In certain cases, for example in the case of the pulsers for the magnets and the absorber assembly, system components are designed with the option of upgrading to 44 on 44 bunch operation in mind. 8 refs., 14 figs

  3. FERMILAB: Tevatron upgrade; Magnetic precession in bent crystals

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The Fermilab accelerator complex is in the middle of a major upgrade to increase the luminosity beyond the original design goal. During Phase I of this upgrade, there have been major modifications to the Tevatron. These modifications were commissioned at the start of the latest collider run and include the installation of electrostatic separators to separate the orbits of the stored beams and new low beta insertions to squeeze the colliding proton and antiproton beams at both experiment interaction regions. These modifications have already enabled the Tevatron to achieve a record peak luminosity of 6.93 x 10 30 per sq cm per s and a record weekly integrated luminosity of 10 60 inverse nanobarns. The peak goal for the present run of 5.0 x 10 30 has already been exceeded

  4. Higgs decay to bottom quarks at the Tevatron

    International Nuclear Information System (INIS)

    Stange, A.; Marciano, W.; Willenbrock, S.

    1993-10-01

    We study the production and detection of the standard-model Higgs boson at the Fermilab Tevatron. The most promising mode is WH and ZH associated production followed by leptonic decay of the weak vector bosons and H → b bar b. It may be possible to detect a Higgs boson of mass m H = 60--80 GeV with 1000 pb -1 of integrated luminosity

  5. Physics at the Fermilab Tevatron Proton-Antiproton Collider

    International Nuclear Information System (INIS)

    Geer, S.

    1994-08-01

    These lectures discuss a selection of QCD and Electroweak results from the CDF and D0 experiments at the Fermilab Tevatron Proton-Antiproton Collider. Results are presently based on data samples of about 20 pb -1 at a center-of-mass energy of 1.8 TeV. Results discussed include jet production, direct photon production, W mass and width measurements, the triboson coupling, and most exciting of all, evidence for top quark production

  6. Review of Physics Results from the Tevatron: Top Quark Physics

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Cecilia E.; Vellidis, Costas

    2014-09-17

    We present results on top quark physics from the CDF and D0 collaborations at the Fermilab Tevatron proton anti-proton collider. These include legacy results from Run II that were published or submitted for publication before mid-2014, as well as a summary of Run I results. The historical perspective of the discovery of the top quark in Run I is also described.

  7. Tests of QCD in W and Z production at Tevatron

    International Nuclear Information System (INIS)

    Alitti, J.; Chevalier, L.; Ducros, Y.; Lebrat, J.F.; Mangeot, P.

    1995-01-01

    We present measurements of the production cross sections times leptonic branching fractions and the transverse momentum distributions of W and Z bosons in pp-bar collisions at √ s = 1.8 TeV using data collected with the DΦ detector at the Fermilab Tevatron pp-bar collider. A preliminary measurement of the W charge asymmetry is also presented. (authors). 27 refs., 9 figs., 3 tabs

  8. Programmable high power beam damper for the Tevatron

    International Nuclear Information System (INIS)

    Crisp, J.; Goodwin, R.; Gerig, R.

    1985-06-01

    A bunch-by-bunch beam damper has been developed for the Fermilab Tevatron. The system reduces betatron oscillation amplitudes and incorporates some useful machine diagnostics. The device is programmable via look-up tables so the output is an arbitrary function, on a bunch-by-bunch basis, of the beam displacement. We are presently using this feature to measure the betatron tune throughout the acceleration cycle. 4 refs

  9. Tevatron-for-LHC Report: Preparations for Discoveries

    Energy Technology Data Exchange (ETDEWEB)

    Buescher, V.; Carena, Marcela S.; Dobrescu, Bogdan A.; Mrenna, S.; Rainwater, D.; Schmitt, M.

    2006-08-01

    This is the ''TeV4LHC'' report of the ''Physics Landscapes'' Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

  10. Status of the Tevatron CDF and D0 experiments

    International Nuclear Information System (INIS)

    Rolli, Simona

    2010-01-01

    The status of the Tevatron Collider is reviewed and highlights of the rich physics program carried out by the CDF and D0 experiments are presented. The Tevatron Collider has been performing remarkably well in the past few years and it is continuing to deliver record luminosity. The machine collides proton and anti-proton beams at an energy in the center of mass of 1.96 TeV, with average peak luminosity of 300E30 cm -2 s -1 . The total delivered luminosity is slightly above 9 fb -1 . The CDF and D0 experiments have been collecting data with an average efficiency of 90%, while the experiments have enjoyed an annual doubling of the integrated luminosity delivered and recorded. This has led to an avalanche of new results from areas as diverse as QCD, top, searches for new physics and the area of electroweak symmetry breaking with particular focus on direct searches for the Higgs boson. The physics reach of the Tevatron is built on a mountain of measurements that confirm the ability of the Tevatron collaborations to use their detectors to discover new particles. Each measurement is of itself a significant result. Measurements begin with the largest cross section processes, those of B physics, but move on to processes with small branching ratios and backgrounds that are hard to distinguish from the signal. The measurement of Bs oscillations demonstrates the performance of the silicon tracking and vertexing. Discovery of single top production, WZ production, and evidence for the ZZ production in both leptonic and now hadronic modes provide the final base camp from which the Higgs summit is in sight. Processes such as single top and ZZ act as important messengers heralding the impending arrival of the Higgs. This journey through lower and lower cross section processes represents our approach to provide convincing evidence of these processes, first as discovery then as measurements that constrain the Standard Model.

  11. Searching for directly decaying gluinos at the Tevatron

    International Nuclear Information System (INIS)

    Alwall, Johan; Le, My-Phuong; Lisanti, Mariangela; Wacker, Jay G.

    2008-01-01

    This Letter describes how to perform searches over the complete kinematically-allowed parameter space for new pair-produced color octet particles that each subsequently decay into two jets plus missing energy at the Tevatron. This Letter shows that current searches can miss otherwise discoverable spectra of particles due to CMSSM-motivated cuts. Optimizing the H T and E/ T cuts expands the sensitivity of these searches

  12. Present searches for Higgs signatures at the Tevatron

    International Nuclear Information System (INIS)

    Groer, L.

    1997-08-01

    We present results for various searches for signatures of standard and non-standard model Higgs boson decays conducted at the collider detectors CDF and D0 using ∼100 pb -1 of integrated luminosity each from the Tevatron collider Run 1 (1992-96) at √s=1.8 TeV. No evidence for a Higgs boson decay is found and various limits are set

  13. Search for new fermions ('Quirks') at the Fermilab Tevatron Collider

    Czech Academy of Sciences Publication Activity Database

    Abazov, V. M.; Abbott, B.; Abolins, M.; Kupčo, Alexander; Lokajíček, Miloš

    2010-01-01

    Roč. 105, č. 21 (2010), "211803-1"-"211803-6" ISSN 0031-9007 R&D Projects: GA MŠk LA08047; GA MŠk LC527 Institutional research plan: CEZ:AV0Z10100502 Keywords : missing-energy * transverse energy * D0 * Batavia TEVATRON Coll * interaction Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 7.621, year: 2010 http://arxiv.org/abs/arXiv:1008.3547

  14. Cryogenic testing and analysis associated with Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1996-01-01

    An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation of the Fermilab superconducting Tevatron accelerator is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics run at the previous energy of 900 GeV. This has allowed the author to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which have taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, the new satellite refrigerator controls system is capable of the expansion necessary to reach this goal. New features are being added to the controls systems which will allow for more intelligent control and better diagnostics for component monitoring and trending

  15. Pressure field study of the Tevatron cold compressors

    International Nuclear Information System (INIS)

    Klebaner, A.L.; Martinez, A.; Soyars, W.M.; Theilacker, J.C.; Fermilab

    2003-01-01

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40 and 95 krpm, with a speed of 80 krpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper

  16. Pressure Field Study of the Tevatron Cold Compressors

    International Nuclear Information System (INIS)

    Klebaner, A.L.; Martinez, A.; Soyars, W.M.; Theilacker, J.C.

    2004-01-01

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40,000 and 95,000 rpm, with a speed of 80,000 rpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper

  17. Gravitational lenses and cosmological evolution

    International Nuclear Information System (INIS)

    Peacock, J.A.

    1982-01-01

    The effect of gravitational lensing on the apparent cosmological evolution of extragalactic radio sources is investigated. Models for a lens population consisting of galaxies and clusters of galaxies are constructed and used to calculate the distribution of amplification factors caused by lensing. Although many objects at high redshifts are predicted to have flux densities altered by 10 to 20 per cent relative to a homogeneous universe, flux conservation implies that de-amplification is as common as amplification. The effects on cosmological evolution as inferred from source counts and redshift data are thus relatively small; the slope of the counts is not large enough for intrinsically rare lensing events of high amplitude to corrupt observed samples. Lensing effects may be of greater importance for optically selected quasars, where lenses of mass as low as approximately 10 -4 solar mass can cause large amplifications. (author)

  18. Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal; Koester, Benjamin P.; Sharon, Keren; Bayliss, Matthew

    2009-01-29

    We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model of the lensing cluster Abell 1703 with constraints from multiple image families, and find the dark matter inner density profile to be cuspy with the slope consistent with -1, in agreement with expectations.

  19. Bacterial adherence to extended wear soft contact lenses

    International Nuclear Information System (INIS)

    Aswad, M.I.; John, T.; Barza, M.; Kenyon, K.; Baum, J.

    1990-01-01

    The authors studied the adherence of Pseudomonas aeruginosa and Staphylococcus aureus to extended wear soft contact lenses (EWSCLs) with and without focal deposits using both a radiolabeling technique and electron microscopy. P. aeruginosa showed significant adherence to contact lenses in vitro. In contrast, S. aureus failed to show significant adherence to contact lenses in vitro (i.e., the radioactive uptake was not significantly above background). The extent of adherence of Pseudomonas was proportional to the number of focal deposits on the lenses. Results of electron microscopic examination showed the bacteria to be adherent primarily to large focal deposits (greater than or equal to 150 microns). There was no pseudomonal adherence to the small focal deposits (less than or equal to 50 microns) and little adherence to the areas in between the focal deposits. The authors hypothesize that worn lenses, especially those with large focal deposits, serve as a vehicle for the transport of P. aeruginosa to the cornea. This hypothesis could be a partial explanation for the high incidence of keratitis caused by P. aeruginosa in EWSCL patients

  20. Resonant second generation slepton production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Autermann, Christian Tobias [RWTH Aachen Univ. (Germany)

    2006-12-01

    A search for R-parity violating supersymmetry with the D0 detector at the Fermilab Tevatron p$\\bar{p}$-collider is presented. Assuming a non-zero LQ$\\bar{d}$ coupling λ$'\\atop{2jk}$ leads to final state with two muons and jets. A total integrated luminosity of 375 pb-1 collected between April 2002 and August 2004 is utilized. The observed number of events is in agreement with the Standard Model expectation, and limits on Rp supersymmetry are derived.

  1. Spectroscopy and Decay of $B$ Hadrons at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Paulini, Manfred

    2007-02-01

    The authors review recent results on heavy quark physics focusing on Run II measurements of B hadron spectroscopy and decay at the Tevatron. A wealth of new B physics measurements from CDF and D0 has been available. These include the spectroscopy of excited B states (B**, B**{sub s}) and the observation of the {Sigma}{sub b} baryon. The discussion of the decays of B hadrons and measurements of branching fractions focuses on charmless two-body decays of B {yields} h{sup +}h{sup -}. They report several new B{sub s}{sup 0} and {Lambda}{sub b}{sup 0} decay channels.

  2. The dijet invariant mass at the Tevatron Collider

    International Nuclear Information System (INIS)

    Giannetti, P.

    1990-01-01

    The differential cross section of the process p + pbar → jet + jet + X as a function of the dijet invariant mass has been measured with the CDF detector at a center of mass energy of 1.8 TeV at the Tevatron Collider in Fermilab. The present analysis is based on the sample of events collected in the 1988/89 run, amounting to a total integrated luminosity of 4.2 pb -1 . A comparison to leading order QCD and quark compositeness predictions is presented as well as a study of the sensitivity of the mass spectrum to the gluon radiation. 10 refs., 6 figs

  3. $B$ physics at the Tevatron: Run II and beyond

    CERN Document Server

    Anikeev, K; Azfar, F.; Bailey, S.; Bauer, C.W.; Bell, W.; Bodwin, G.; Braaten, E.; Burdman, G.; Butler, J.N.; Byrum, K.; Cason, N.; Cerri, A.; Cheung, H.W.K.; Dighe, A.; Donati, S.; Ellis, R.K.; Falk, A.; Feild, G.; Fleming, S.; Furic, I.; Gardner, S.; Grossman, Y.; Gutierrez, G.; Hao, W; Harris, B.W.; Hewett, J.; Hiller, G.; Jesik, R.; Jones, M.; Kasper, P.A.; El-Khadra, A.; Kirk, M.; Kiselev, V.V.; Kroll, J.; Kronfeld, A.S.; Kutschke, R.; Kuznetsov, V.E.; Laenen, E.; Lee, J.; Leibovich, A.K.; Lewis, J.D.; Ligeti, Z.; Likhoded, A.K.; Logan, H.E.; Luke, M.; Maciel, A.; Majumder, G.; Maksimovic, P.; Martin, M.; Menary, S.; Nason, P.; Nierste, U.; Nir, Y.; Nogach, L.; Norrbin, E.; Oleari, C.; Papadimitriou, V.; Paulini, M.; Paus, C.; Petteni, M.; Poling, R.; Procario, M.; Punzi, G.; Quinn, H.; Rakitine, A.; Ridolfi, G.; Shestermanov, K.; Signorelli, G.; Silva, J.P.; Skwarnicki, T.; Smith, A.; Speakman, B.; Stenson, K.; Stichelbaut, F.; Stone, S.; Sumorok, K.; Tanaka, M.; Taylor, W.; Trischuk, W.; Tseng, J.; Van Kooten, R.; Vasiliev, A.; Voloshin, M.; Wang, J.C.; Wicklund, A.B.; Wurthwein, F.; Xuan, N.; Yarba, J.; Yip, K.; Zieminski, A.

    2002-01-01

    This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.

  4. High intensity beam dump for the Tevatron beam abort system

    International Nuclear Information System (INIS)

    Kidd, J.; Mokhov, N.; Murphy, T.; Palmer, M.; Toohig, T.; Turkot, F.; VanGinneken, A.

    1981-01-01

    The beam abort system proposed for the Fermilab Tevatron Accelerator will extract the proton beam from the ring in a single turn (approximately 20/mu/s) and direct it to an external beam dump. It is the function of the beam dump to absorb the unwanted beam and limit the escaping radiation to levels that are acceptable to the surrounding populace and apparatus. A beam dump that is expected to meet these requirements has been designed and constructed. Detailed design of the dump, including considerations leading to the choice of materials, are given. 6 refs

  5. Online calculation of the Tevatron collider luminosity using accelerator instrumentation

    International Nuclear Information System (INIS)

    Hahn, A.A.

    1997-07-01

    The luminosity of a collision region may be calculated if one understands the lattice parameters and measures the beam intensities, the transverse and longitudinal emittances, and the individual proton and antiproton beam trajectories (space and time) through the collision region. This paper explores an attempt to make this calculation using beam instrumentation during Run 1b of the Tevatron. The instrumentation used is briefly described. The calculations and their uncertainties are compared to luminosities calculated independently by the Collider Experiments (CDF and D0)

  6. Minimax: Multiparticle physics at the TeVatron collider

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1994-01-01

    The author and two dozen others are engaged in a small test/experiment in the Fermilab Tevatron collider. It is called Minimax, and its purpose is to explore large-cross-section physics in the forward direction. The primary goal of Minimax is search for events containing the residue of disoriented chiral condensate (dcc) produced in the primary collision. The theoretical ideas are very speculative. But if they are right, they could provide an interpretation of the Centauro/anti-Centauro anomalies claimed to have been seen in cosmic-ray events. In this paper, the history and status of Minimax is described

  7. Top Production at the Tevatron: The Antiproton Awakens

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Kenneth [Nebraska U.

    2017-07-01

    A long time ago, at a laboratory far, far away, the Fermilab Tevatron collided protons and antiprotons at $\\sqrt{s} = 1.96$ TeV. The CDF and D0 experiments each recorded datasets of about 10 fb$^{-1}$. As such experiments may never be repeated, these are unique datasets that allow for unique measurements. This presentation describes recent results from the two experiments on top-quark production rates, spin orientations, and production asymmetries, which are all probes of the $p\\bar{p}$ initial state.

  8. Tevatron as an SSC prototype; experience versus predictions

    International Nuclear Information System (INIS)

    Johnson, R.P.

    1984-01-01

    Early machine experiments on the Tevatron which are relevant to the SSC are discussed. Despite the preliminary nature of the data, there have been some interesting observations which may influence the design of the SSC. In particular, comparisons of measured betatron tunes, chromaticities, and resonance line widths with those predicted from computer simulations using magnetic field measurements have been made; the predictability for low order phenomena seems acceptable. Coasting beam studies indicate long lifetime and lack of strong resonance driving terms. Low energy studies of beam behavior indicate that a dynamic range of a factor of 15 from injection to operation energy should be possible

  9. Tests of high gradient superconducting quadrupole magnets for the Tevatron

    International Nuclear Information System (INIS)

    Lamm, M.J.; Carson, J.; Gourlay, S.; Hanft, R.; Koepke, K.; Mantsch, P.; McInturff, A.D.; Riddiford, A.; Strait, J.

    1989-09-01

    Tests have been completed on three prototype magnets and two production magnets to be used for the Tevatron Dφ/Bφ low- β insertion. These cold iron, two shell quadrupoles are made of 36 strand Rutherford type NbTi superconducting cable. Magnet field gradients well in excess of the design 1.41 T/cm have been achieved at a transfer function of 0.291 T/cm/kA. Quench performance at 4.2 K and 3.7 K and magnetic multipole measurement data are presented and discussed. 9 refs., 4 figs., 4 tabs

  10. First results from bent crystal extraction at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    1996-07-01

    First results from Fermilab Experiment 953 are presented. E853 is an experiment to test the feasibility and efficiency of extracting a low intensity beam from the halo of the Tevatron using channeling in a bent silicon crystal. The motivation for the experiment is to apply crystal extraction to trans-TeV accelerators like the LHC. Extensive simulation work has been carried out. Two accelerator operating modes have been developed for crystal studies, ''kick'' mode and diffusion mode. Results from the first successful extraction in kick mode are presented

  11. J/ψ production: Tevatron and fixed-target collisions

    International Nuclear Information System (INIS)

    Petrelli, A.

    1999-01-01

    In this talk the author shows the results of a fit of the NRQCD matrix elements to the CDF data for direct J/ψ production, by including the radiative corrections to the g g > 3 S 1 [1] channel and the effect of the k T -smearing. Furthermore he performs the NLO NRQCD analysis of J/ψ production in fixed-target proton-nucleon collisions and he fits the colour-octet matrix elements to the available experimental data. The results are compared to the Tevatron ones

  12. High Mass Standard Model Higgs searches at the Tevatron

    Directory of Open Access Journals (Sweden)

    Petridis Konstantinos A.

    2012-06-01

    Full Text Available We present the results of searches for the Standard Model Higgs boson decaying predominantly to W+W− pairs, at a center-of-mass energy of √s = 1.96 TeV, using up to 8.2 fb−1 of data collected with the CDF and D0 detectors at the Fermilab Tevatron collider. The analysis techniques and the various channels considered are discussed. These searches result in exclusions across the Higgs mass range of 156.5< mH <173.7 GeV for CDF and 161< mH <170 GeV for D0.

  13. Electroweak and b-physics at the Tevatron collider

    International Nuclear Information System (INIS)

    Hara, K.

    1994-04-01

    The CDF and D0 experiments have collected integrated luminosities of 21 pb -1 and 16 pb -1 , respectively, in the 1992--1993 run (Run Ia) at the Fermilab Tevatron. Preliminary results on electroweak physics are reported from both experiments: the W mass, the leptonic branching ratios Τ(W → ell ν), the total W width, gauge boson couplings, W decay asymmetry and W'/Z' search. Preliminary new results on b physics are presented: B o - bar B o mixing from D0, and masses and lifetimes of B-mesons from CDF

  14. The CDF SVX II upgrade for the Tevatron Run II

    International Nuclear Information System (INIS)

    Bortoletto, Daniela

    1997-01-01

    A microstrip silicon detector SVX II has been proposed for the upgrade of CDF to be installed in 1999 for Run II of the Tevatron. Three barrels of five layers of double-sided silicon microstrip detectors will cover the interaction region. A description of the project status will be presented. Emphasis will be given to the R and D program for silicon sensors which includes capacitance minimization, the study of coupling capacitor integrity, the operation of the detectors in conjunction with the SVXH and SVX2 readout chips in two beam tests and the determination of the detectors performance deterioration due to radiation damage

  15. Top and Higgs at the Tevatron: Measurements, searches, prospects

    International Nuclear Information System (INIS)

    Konigsberg, J.

    2000-01-01

    In this paper we summarize the status of Top Quark Physics and of searches for the Standard Model Higgs at the Tevatron. Results from both the CDF and D0 experiments are discussed and the prospects for the upcoming Run 2, in the year 2001, are outlined. Much work has been performed on these topics and due to the nature of these proceedings only a brief explanation can be offered here. For more details the reader should turn to the excellent sources listed in the reference section

  16. Review of physics results from the Tevatron: QCD physics

    Energy Technology Data Exchange (ETDEWEB)

    Mesropian, Christina [Rockefeller U.; Bandurin, Dmitry [Virginia U.

    2015-02-17

    We present a summary of results from studies of quantum chromodynamics at the Fermilab Tevatron collider by the CDF and the D0 experiments. These include Run II results for the time period up to the end of Summer 2014. A brief description of Run I results is also given. This review covers a wide spectrum of topics, and includes measurements with jet and vector boson final states in the hard (perturbative) energy regime, as well as studies of soft physics such as diffractive and elastic scatterings, underlying and minimum bias events, hadron fragmentation, and multiple parton interactions.

  17. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  18. KINOFORM LENSES - TOWARD NANOMETER RESOLUTION.

    Energy Technology Data Exchange (ETDEWEB)

    STEIN, A.; EVANS-LUTTERODT, K.; TAYLOR, A.

    2004-10-23

    While hard x-rays have wavelengths in the nanometer and sub-nanometer range, the ability to focus them is limited by the quality of sources and optics, and not by the wavelength. A few options, including reflective (mirrors), diffractive (zone plates) and refractive (CRL's) are available, each with their own limitations. Here we present our work with kinoform lenses which are refractive lenses with all material causing redundant 2{pi} phase shifts removed to reduce the absorption problems inherently limiting the resolution of refractive lenses. By stacking kinoform lenses together, the effective numerical aperture, and thus the focusing resolution, can be increased. The present status of kinoform lens fabrication and testing at Brookhaven is presented as well as future plans toward achieving nanometer resolution.

  19. Astrophysical Applications of Gravitational Lensing

    Science.gov (United States)

    Mediavilla, Evencio; Muñoz, Jose A.; Garzón, Francisco; Mahoney, Terence J.

    2016-10-01

    Contributors; Participants; Preface; Acknowledgements; 1. Lensing basics Sherry H. Suyu; 2. Exoplanet microlensing Andrew Gould; 3. Case studies of microlensing Veronica Motta and Emilio Falco; 4. Microlensing of quasars and AGN Joachim Wambsganss; 5. DM in clusters and large-scale structure Peter Schneider; 6. The future of strong lensing Chris Fassnacht; 7. Methods for strong lens modelling Charles Keeton; 8. Tutorial on inverse ray shooting Jorge Jimenez-Vicente.

  20. Breaking Symmetry in Viral Icosahedral Capsids as Seen through the Lenses of X-ray Crystallography and Cryo-Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Kristin N. Parent

    2018-02-01

    Full Text Available The majority of viruses on Earth form capsids built by multiple copies of one or more types of a coat protein arranged with 532 symmetry, generating an icosahedral shell. This highly repetitive structure is ideal to closely pack identical protein subunits and to enclose the nucleic acid genomes. However, the icosahedral capsid is not merely a passive cage but undergoes dynamic events to promote packaging, maturation and the transfer of the viral genome into the host. These essential processes are often mediated by proteinaceous complexes that interrupt the shell’s icosahedral symmetry, providing a gateway through the capsid. In this review, we take an inventory of molecular structures observed either internally, or at the 5-fold vertices of icosahedral DNA viruses that infect bacteria, archea and eukaryotes. Taking advantage of the recent revolution in cryo-electron microscopy (cryo-EM and building upon a wealth of crystallographic structures of individual components, we review the design principles of non-icosahedral structural components that interrupt icosahedral symmetry and discuss how these macromolecules play vital roles in genome packaging, ejection and host receptor-binding.

  1. The experience in production of composite refraction lenses from beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, A. A.; Zabrodin, A. V.; Gorlevskiy, V. V.; Sheverdyaev, M. S.; Lizunov, A. V.; Brylev, D. A.; Anikin, A. S.; Klykov, S. S.; Kozlova, E. V.; Lesina, I. G.; Nebera, A. L.; Morozov, I. A.; Demin, A. V. [Bochvar High-Technology Research Institute of Inorganic Materials (Russian Federation); Buzmakov, A. V.; Dymshicz, Yu. M.; Volkov, V. V.; Zhigalina, O. M.; Konarev, P. V.; Khmelenin, D. N.; Seregin, A. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation); and others

    2017-01-15

    The choice of beryllium-based material for the use in X-ray optics has been substantiated based on electron microscopy and X-ray diffraction data. The first results of applying refraction lenses made of this material are reported.

  2. In celebration of the fixed target program with the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey A. Appel et al.

    2001-12-28

    The Tevatron is the world's first large superconducting accelerator. With its construction, we gained the dual opportunities to advance the state of the art in accelerator technology with the machine itself and in particle physics with the experiments that became possible in a higher energy regime. There have been 43 experiments in the Tevatron fixed target program. Many of these are better described as experimental programs, each with a broad range of physics goals and results, and more than 100 collaborating physicists and engineers. The results of this program are three-fold: (1) new technologies in accelerators, beams and detectors which advanced the state of the art; (2) new experimental results published in the refereed physics journals; and (3) newly trained scientists who are both the next generation of particle physicists and an important part of the scientific, technical and educational backbone of the country as a whole. In this book they compile these results. There are sections from each experiment including what their physics goals and results were, what papers were published, and which students have received degrees. Summaries of these results from the program as a whole are quite interesting, but the physics results from this program are too broad to summarize globally. The most important of the results appear in later sections of this booklet.

  3. A disoriented chiral condensate search at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Convery, M.E.

    1997-05-01

    MiniMax (Fermilab T-864) was a small test/experiment at the Tevatron designed to search for disoriented chiral condensates (DCC) in the forward direction. Relativistic quantum field theory treats the vacuum as a medium, with bulk properties characterized by long-range order parameters. This has led to suggestions that regions of open-quotes disoriented vacuumclose quotes might be formed in high-energy collision processes. In particular, the approximate chiral symmetry of QCD could lead to regions of vacuum which have chiral order parameters disoriented to directions which have non-zero isospin, i.e. disoriented chiral condensates. A signature of DCC is the resulting distribution of the fraction of produced pions which are neutral. The MiniMax detector at the C0 collision region of the Tevatron was a telescope of 24 multi-wire proportional chambers (MWPC's) with a lead converter behind the eighth MWPC, allowing the detection of charged particles and photon conversions in an acceptance approximately a circle of radius 0.6 in pseudorapidity-azimuthal-angle space, centered on pseudorapidity η ∼ 4. An electromagnetic calorimeter was located behind the MWPC telescope, and hadronic calorimeters and scintillator were located in the upstream anti-proton direction to tag diffractive events

  4. Review of Physics Results from the Tevatron: Higgs Boson Physics

    International Nuclear Information System (INIS)

    Junk, Thomas R.; Juste, Aurelio

    2015-01-01

    We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DO. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeVTevatron: gluon-gluon fusion, WH and ZH associated production, vector boson fusion, and tt ¯ H production, and in five main decay modes: H→bb ¯ , H→τ + τ − , H→WW (∗) , H→ZZ (∗) , and H→γγ . An excess of events was seen in the H→bb ¯ searches consistent with a Standard Model Higgs boson with a mass in the range 115 GeV

  5. Successful observation of Schottky signals at the Tevatron collider

    International Nuclear Information System (INIS)

    Goldberg, D.A.; Lambertson, G.R.

    1989-08-01

    We have constructed a Schottky detector for the Tevatron collider in the form of a high-Q (∼5000) cavity which operates at roughly 2 GHz, well above the frequency at which the Tevatron's single-bunch frequency spectrum begins to roll off. Initial spectra obtained from the detector show clearly observable Schottky betatron lines, free of coherent contaminants; also seen are the ''common-mode'' longitudinal signals due to the offset of the beam from the detector center. The latter signals indicate that at 2 GHz, the coherent single-bunch spectrum from the detector is reduced by >80 dB; therefore, in normal collider operation, the Schottky betatron lines are >40 dB greater than their coherent counterparts. We describe how the data we have obtained give information on transverse and longitudinal emittances, synchrotron frequency, and betatron tunes, as well as reveal what may be previously unobserved phenomena. Space limitations restrict us to presenting only as much data as should be necessary to convince even the skeptical reader of the validity of the claim made in the paper's title. 3 refs., 2 figs

  6. Cryogenic testing and analysis associated with Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1996-09-01

    An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics at the previous energy of 900 GeV. This has allowed us to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which has taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, our new satellite refrigerator controls system is capable of the expansion necessary to reach our goal. New features are being added to the control system which will allow for more intelligent control and better diagnostics for component monitoring and trending

  7. Cosmology with weak lensing surveys

    International Nuclear Information System (INIS)

    Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan

    2008-01-01

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  8. Cosmology with weak lensing surveys

    Energy Technology Data Exchange (ETDEWEB)

    Munshi, Dipak [Institute of Astronomy, Madingley Road, Cambridge, CB3 OHA (United Kingdom); Astrophysics Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE (United Kingdom)], E-mail: munshi@ast.cam.ac.uk; Valageas, Patrick [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France); Waerbeke, Ludovic van [University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Heavens, Alan [SUPA - Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

    2008-06-15

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  9. Parabolic crossed planar polymeric x-ray lenses

    Science.gov (United States)

    Nazmov, V.; Reznikova, E.; Mohr, J.; Saile, V.; Vincze, L.; Vekemans, B.; Bohic, S.; Somogyi, A.

    2011-01-01

    The principles of design and manufacturing of the polymer planar x-ray lenses focusing in one and two directions, as well as the peculiarities of optical behaviors and the results of the lens test are reported in this paper. The methods of electron and deep x-ray lithography used in lens manufacturing allow the manufacture of ten or more x-ray lenses on one substrate; the lenses show focal lengths down to several centimeters for photon energies between 5 and 40 keV. The measured focus size was 105 nm for a linear lens with an intensity gain of about 407, and 300 × 770 nm for a crossed lens with an intensity gain of 6470.

  10. Statistics of gravitational lenses. III. Astrophysical consequences of quasar lensing

    International Nuclear Information System (INIS)

    Ostriker, J.P.; Vietri, M.

    1986-01-01

    The method of Schmidt and Green (1983) for calculating the luminosity function of quasars is combined with gravitational-lensing theory to compute expected properties of lensed systems. Multiple quasar images produced by galaxies are of order 0.001 of the observed quasars, with the numbers over the whole sky calculated to be (0.86, 120, 1600) to limiting B magnitudes of (16, 19, 22). The amount of false evolution is small except for an interesting subset of apparently bright, large-redshift objects for which minilensing by starlike objects may be important. Some of the BL Lac objects may be in this category, with the galaxy identified as the parent object really a foreground object within which stars have lensed a background optically violent variable quasar. 24 references

  11. Program package for the computation of lenses and deflectors

    International Nuclear Information System (INIS)

    Lencova, B.; Wisselink, G.

    1990-01-01

    In this paper a set of computer programs for the design of electrostatic and magnetic electron lenses and for the design of multipoles for electron microscopy and lithography is described. The two-dimensional field computation is performed by the finite-element method. In order to meet the high demands on accuracy, the programs include the use of a variable step in the fine mesh made with an automeshing procedure, improved methods for coefficient evaluation, a fast solution procedure for the linear equations, and modified algorithms for computation of multipoles and electrostatic lenses. They allow for a fast and accurate computation of electron optical elements. For the input and modification of data, and for presentation of results, graphical menu driven programs written for personal computers are used. For the computation of electron optical properties axial fields are used. (orig.)

  12. Contact Lenses for Color Blindness.

    Science.gov (United States)

    Badawy, Abdel-Rahman; Hassan, Muhammad Umair; Elsherif, Mohamed; Ahmed, Zubair; Yetisen, Ali K; Butt, Haider

    2018-06-01

    Color vision deficiency (color blindness) is an inherited genetic ocular disorder. While no cure for this disorder currently exists, several methods can be used to increase the color perception of those affected. One such method is the use of color filtering glasses which are based on Bragg filters. While these glasses are effective, they are high cost, bulky, and incompatible with other vision correction eyeglasses. In this work, a rhodamine derivative is incorporated in commercial contact lenses to filter out the specific wavelength bands (≈545-575 nm) to correct color vision blindness. The biocompatibility assessment of the dyed contact lenses in human corneal fibroblasts and human corneal epithelial cells shows no toxicity and cell viability remains at 99% after 72 h. This study demonstrates the potential of the dyed contact lenses in wavelength filtering and color vision deficiency management. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Lensing smoothing of BAO wiggles

    Energy Technology Data Exchange (ETDEWEB)

    Dio, Enea Di, E-mail: enea.didio@oats.inaf.it [INAF—Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34143 Trieste (Italy)

    2017-03-01

    We study non-perturbatively the effect of the deflection angle on the BAO wiggles of the matter power spectrum in real space. We show that from redshift z ∼2 this introduces a dispersion of roughly 1 Mpc at BAO scale, which corresponds approximately to a 1% effect. The lensing effect induced by the deflection angle, which is completely geometrical and survey independent, smears out the BAO wiggles. The effect on the power spectrum amplitude at BAO scale is about 0.1 % for z ∼2 and 0.2 % for z ∼4. We compare the smoothing effects induced by the lensing potential and non-linear structure formation, showing that the two effects become comparable at z ∼ 4, while the lensing effect dominates for sources at higher redshifts. We note that this effect is not accounted through BAO reconstruction techniques.

  14. Top-quark mass measurements: Alternative techniques (LHC + Tevatron)

    CERN Document Server

    Adomeit, Stefanie; The ATLAS collaboration

    2014-01-01

    Measurements of the top-quark mass employing alternative techniques are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at the LHC. The alternative methods presented include measurements using the lifetime of $B$-hadrons, the transverse momentum of charged leptons and the endpoints of kinematic distributions in top quark anti-quark pair ($t\\bar{t}$) final states. The extraction of the top-quark pole mass from the $t\\bar{t}$ production cross-section and the normalized differential $t\\bar{t}$ + 1-jet cross-section are discussed as well as the top-quark mass extraction using fixed-order QCD predictions at detector level. Finally, a measurement of the top-quark mass using events enhanced in single top t-channel production is presented.

  15. Searches for Long-lived Particles at the Tevatron Collider

    International Nuclear Information System (INIS)

    Adams, T.; Florida State U.

    2008-01-01

    Several searches for long-lived particles have been performed using data from p(bar p) collisions from Run II at the Tevatron. In most cases, new analysis techniques have been developed to carry out each search and/or estimate the backgrounds. These searches expand the discovery potential of the CDF and D0 experiments to new physics that may have been missed by traditional search techniques. This review discusses searches for (1) neutral, long-lived particles decaying to muons, (2) massive, neutral, long-lived particles decaying to a photon and missing energy, (3) stopped gluinos, and (4) charged massive stable particles. It summarizes some of the theoretical and experimental motivations for such searches

  16. Position sensitive silicon detectors inside the Tevatron collider

    International Nuclear Information System (INIS)

    Apollinari, G.; Bedeschi, F.; Bellettini, G.; Bosi, F.; Bosisio, L.; Cervelli, F.; Del Fabbro, R.; Dell'Orso, M.; Di Virgilio, A.; Focardi, E.; Giannetti, P.; Giorgi, M.; Menzione, A.; Ristori, L.; Scribano, A.; Sestini, P.; Stefanini, A.; Tonelli, G.; Zetti, F.; Bertolucci, S.; Cordelli, M.; Curatolo, M.; Dulach, B.; Esposito, B.; Giromini, P.; Miscetti, S.; Sansoni, A.

    1986-01-01

    Four position sensitive silicon detectors have been tested inside the Tevatron beam pipe at Fermilab. The system is the prototype of the small angle silicon spectrometer designed to study primarily p-anti p elastic and diffractive cross-sections at the Collider of Fermilab (CDF). Particles in the beam halo during p-anti p storage tests were used to study the performance of the detectors. Efficiency, linearity of response and spatial resolution are shown. Measurements performed at different distances from the beam axis have shown that the detectors could be operated at 8.5 mm from the beam with low rates and no disturbance to the circulating beams. This distance corresponds to about 11 times the standard half-width of the local beam envelope. The behaviour of the detectors with the radiation dose has also been investigated. (orig.)

  17. New Measurements of Upsilon Spin Alignment at the Tevatron

    Directory of Open Access Journals (Sweden)

    Jones Matthew

    2012-06-01

    Full Text Available We describe a new analysis of γ(nS → μ+μ− decays collected in pp¯ $par p$ collisions with the CDF II detector at the Fermilab Tevatron. This analysis measures the angular distributions of the final state muons in the γ rest frame, providing new information about γ production polarization. We find the angular distributions to be nearly isotropic up to γ pT of 40 GeV/c, consistent with previous measurements by CDF, but inconsistent with results obtained by the D0 experiment. The results are compared with recent NLO calculations based on color-singlet matrix elements and non-relativistic QCD with color-octet matrix elements.

  18. A New Flying Wire System for the Tevatron

    Science.gov (United States)

    Blokland, Willem; Dey, Joseph; Vogel, Greg

    1997-05-01

    A new Flying Wires system replaces the old system to enhance the analysis of the beam emittance, improve the reliability, and handle the upcoming upgrades of the Tevatron. New VME data acquisition modules and timing modules allow for more bunches to be sampled more precisely. The programming language LabVIEW, running on a Macintosh computer, controls the VME modules and the nuLogic motion board that flies the wires. LabVIEW also analyzes and stores the data, and handles local and remote commands. The new system flies three wires and fits profiles of 72 bunches to a gaussian function within two seconds. A new console application operates the flying wires from any control console. This paper discusses the hardware and software setup, the capabilities and measurement results of the new Flying Wires system.

  19. Aspheric lenses for terahertz imaging.

    Science.gov (United States)

    Lo, Yat Hei; Leonhardt, Rainer

    2008-09-29

    We present novel designs for aspheric lenses used in terahertz (THz) imaging. As different surfaces result in different beam shaping properties and in different losses from reflection and absorption, the resultant imaging resolution (i.e. the focal spot size) depends critically on the design approach. We evaluate the different lens designs using Kirchhoff's scalar diffraction theory, and test the predictions experimentally. We also show that our lenses can achieve sub-wavelength resolution. While our lens designs are tested with THz radiation, the design considerations are applicable also to other regions of the electro-magnetic spectrum.

  20. Gravitational lensing by spinning and radially moving lenses

    International Nuclear Information System (INIS)

    Sereno, M.

    2002-01-01

    The effect of currents of mass on bending of light rays is considered in the weak field regime. Following Fermat's principle and the standard theory of gravitational lensing, we derive the gravito-magnetic correction to time delay function and deflection angle caused by a geometrically-thin lens. The cases of both rotating and shifting deflectors are discussed

  1. Experimental and Numerical Studies on the Proposed Application of Hollow Electron Beam Collimation for the LHC at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Moens, Vince [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-01-01

    This thesis work was carried out in the framework of the U.S. LHC Accelerator Research Program (USLARP), a collaboration between the European Organization for Nuclear Research (CERN) and the U.S. Department of Energy. The first half of the work was completed at Fermilab (USA), the location of the Tevatron, a proton-antiproton collider and the second largest particle collider in the world. The second half was completed at CERN (Switzerland), the location of the largest proton collider in the world (Large Hadron Collider (LHC)). This thesis characterizes a Hollow Electron Beam (HEB) for possible usage at the LHC to enhance its collimation through Hollow Electron Beam Lenses (HEBLs). Collimation is a long established principle in high energy particle accelerators. Hollow Electron Beam Collimation (HEBC) aims to enhance current collimation systems by controlling diffusion of primary halo particles into the limiting aperture. It works on the principle of a transverse radial electric field that kicks the primary halo particles outwards upon each pass in a multi-pass system. The transverse field is produced by a HEB that is coaxially aligned with the accelerator beam, producing a negligible electric field in the center and a strong transverse electric field at amplitudes higher than the inner radius of the electron beam. Ideally, halo particles are affected without perturbation of the beam core. One of the main advantages of this system is to decrease the dependence on instantaneous loss spikes and beam jitter. A solid experimental basis of HEBC was accumulated at the Tevatron. The application of this technique at the LHC is now under investigation. The aim of this thesis is to present a preliminary report to support a future optimal conceptual design report. It characterizes the available hardware in order to facilitate the design of a Hollow Electron Gun (HEG) for the LHC, characterizes the effect on beam diffusion by determining the transverse electric fields of the

  2. Measurements of beam halo diffusion and population density in the Tevatron and in the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermilab

    2015-03-01

    Halo dynamics influences global accelerator performance: beam lifetimes, emittance growth, dynamic aperture, and collimation efficiency. Halo monitoring and control are also critical for the operation of high-power machines. For instance, in the high-luminosity upgrade of the LHC, the energy stored in the beam tails may reach several megajoules. Fast losses can result in superconducting magnet quenches, magnet damage, or even collimator deformation. The need arises to measure the beam halo and to remove it at controllable rates. In the Tevatron and in the LHC, halo population densities and diffusivities were measured with collimator scans by observing the time evolution of losses following small inward or outward collimator steps, under different experimental conditions: with single beams and in collision, and, in the case of the Tevatron, with a hollow electron lens acting on a subset of bunches. After the LHC resumes operations, it is planned to compare measured diffusivities with the known strength of transverse damper excitations. New proposals for nondestructive halo population density measurements are also briefly discussed.

  3. DYNAMIC SPECTRAL MAPPING OF INTERSTELLAR PLASMA LENSES

    Energy Technology Data Exchange (ETDEWEB)

    Tuntsov, Artem V.; Walker, Mark A. [Manly Astrophysics, 3/22 Cliff Street, Manly 2095 (Australia); Koopmans, Leon V. E. [Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, NL-9700 AV Groningen (Netherlands); Bannister, Keith W.; Stevens, Jamie; Johnston, Simon [CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW 1710 (Australia); Reynolds, Cormac; Bignall, Hayley E., E-mail: Artem.Tuntsov@manlyastrophysics.org, E-mail: Mark.Walker@manlyastrophysics.org, E-mail: koopmans@astro.rug.nl [International Centre for Radio Astronomy Research—Curtin University, Perth (Australia)

    2016-02-01

    Compact radio sources sometimes exhibit intervals of large, rapid changes in their flux density, due to lensing by interstellar plasma crossing the line of sight. A novel survey program has made it possible to discover these “Extreme Scattering Events” (ESEs) in real time, resulting in a high-quality dynamic spectrum of an ESE observed in PKS 1939–315. Here we present a method for determining the column-density profile of a plasma lens, given only the dynamic radio spectrum of the lensed source, under the assumption that the lens is either axisymmetric or totally anisotropic. Our technique relies on the known, strong frequency dependence of the plasma refractive index in order to determine how points in the dynamic spectrum map to positions on the lens. We apply our method to high-frequency (4.2–10.8 GHz) data from the Australia Telescope Compact Array of the PKS 1939–315 ESE. The derived electron column-density profiles are very similar for the two geometries we consider, and both yield a good visual match to the data. However, the fit residuals are substantially above the noise level, and deficiencies are evident when we compare the predictions of our model to lower-frequency (1.6–3.1 GHz) data on the same ESE, thus motivating future development of more sophisticated inversion techniques.

  4. Probing supervoids with weak lensing

    Science.gov (United States)

    Higuchi, Yuichi; Inoue, Kaiki Taro

    2018-05-01

    The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot, is one of such features. If a large underdense region (supervoid) resides towards the Cold Spot, we would be able to detect a systematic shape distortion in the images of background source galaxies via weak lensing effect. In order to estimate the detectability of such signals, we used the data of N-body simulations to simulate full-sky ray-tracing of source galaxies. We searched for a most prominent underdense region using the simulated convergence maps smoothed at a scale of 20° and obtained tangential shears around it. The lensing signal expected in a concordant Λ cold dark matter model can be detected at a signal-to-noise ratio S/N ˜ 3. If a supervoid with a radius of ˜200 h-1 Mpc and a density contrast δ0 ˜ -0.3 at the centre resides at a redshift z ˜ 0.2, on-going and near-future weak gravitational lensing surveys would detect a lensing signal with S/N ≳ 4 without resorting to stacking. From the tangential shear profile, we can obtain a constraint on the projected mass distribution of the supervoid.

  5. Weak lensing and dark energy

    International Nuclear Information System (INIS)

    Huterer, Dragan

    2002-01-01

    We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy

  6. Optics Demonstrations Using Cylindrical Lenses

    Science.gov (United States)

    Ivanov, Dragia; Nikolov, Stefan

    2015-01-01

    In this paper we consider the main properties of cylindrical lenses and propose several demonstrational experiments that can be performed with them. Specifically we use simple glasses full of water to demonstrate some basic geometrical optics principles and phenomena. We also present some less standard experiments that can be performed with such…

  7. Scientific visualization of gravitational lenses

    International Nuclear Information System (INIS)

    Magallon, M.

    1999-01-01

    Concepts related to gravitational lenses are discussed and applied to develop an interactive visualization tool that allow us to investigate them. Optimization strategies were performed to elaborate the tool. Some results obtained from the application of the tool are shown [es

  8. Achromatic X-ray lenses

    International Nuclear Information System (INIS)

    Umbach, Marion

    2009-01-01

    This thesis presents first results on the development of achromatic refractive X-ray lenses which can be used for scientific experiments at synchrotron sources. First of all the different requirements for achromatic X-ray lenses have been worked out. There are different types of lenses, one type can be used for monochromatized sources when the energy is scanned while the spot size should be constant. The other type can be used at beamlines providing a broad energy band. By a combination of focusing and defocusing elements we have developed a lens system that strongly reduces the chromatic aberration of a refractive lens in a given energy range. The great challenge in the X-ray case - in contrast to the visible range - the complex refractive index, which is very similar for the possible materials in the X-ray spectrum. For precise studies a numerical code has been developed, which calculates the different rays on their way through the lenses to the detector plane via raytracing. In this numerical code the intensity distribution in the detector plane has been analyzed for a chromatic and the corresponding achromatic system. By optimization routines for the two different fields of applications specific parameter combinations were found. For the experimental verification an achromatic system has been developed, consisting of biconcave SU-8 lenses and biconvex Nickel Fresnel lenses. Their fabrication was based on the LIGA-process, including a further innovative development, namely the fabrication of two different materials on one wafer. In the experiment at the synchrotron source ANKA the energy was varied in a specific energy range in steps of 0.1 keV. The intensity distribution for the different energies was detected at a certain focal length. For the achromatic system a reduction of the chromatic aberration could be clearly shown. Achromatic refractive X-ray lenses, especially for the use at synchrotron sources, have not been developed so far. As a consequence of the

  9. Measurements of field decay and snapback effect on Tevatron dipole and quadrupole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Velev, G.V.; Ambrosio, G.; Annala, G.; Bauer, P.; Carcagno, R.; DiMarco, J.; Glass, H.; Hanft, R.; Kephart, R.; Lamm, M.; Martens, M.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2005-05-01

    Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility (MTF) to understand dynamic effects in Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field ''snapback'' during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 6s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented.

  10. Measurements of field decay and snapback effect on Tevatron dipole and quadrupole magnets

    International Nuclear Information System (INIS)

    Velev, G.V.; Ambrosio, G.; Annala, G.; Bauer, P.; Carcagno, R.; DiMarco, J.; Glass, H.; Hanft, R.; Kephart, R.; Lamm, M.; Martens, M.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.

    2005-01-01

    Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility (MTF) to understand dynamic effects in Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field ''snapback'' during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 6s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented

  11. Measurements of Field Decay and Snapback Effect on Tevatron Dipole and Quadrupole Magnets

    CERN Document Server

    Velev, Gueorgui; Annala, Gerald; Bauer, Pierre; Carcagno, Ruben H; Di Marco, Joseph; Glass, Henry; Hanft, Ray; Kephart, Robert; Lamm, Michael J; Martens, Michael A; Schlabach, Philip; Sylvester, C D; Tartaglia, M; Tompkins, John

    2005-01-01

    Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility to understand dynamic effects in the Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field "snapback" during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 20 s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented.

  12. Measurement of the top quark properties at the Tevatron and the LHC

    CERN Document Server

    INSPIRE-00040958

    2014-01-01

    Almost two decades after its discovery at Fermilab's Tevatron collider experiments, the top quark is still under the spotlight due to its connections to some of the most interesting puzzles in the Standard Model. The Tevatron has been shut down two years ago, yet some interesting results are coming out of the CDF and D0 collaborations. The LHC collider at CERN produced two orders of magnitude more top quarks than Tevatron's, thus giving birth to a new era for top quark physics. While the LHC is also down at the time of this writing, many top quark physics results are being extracted out of the 7\\,TeV and 8\\,TeV proton proton collisions by the ATLAS and CMS collaborations, and many more are expected to appear before the LHC will be turned on again sometime in 2015. These proceedings cover a selection of recent results produced by the Tevatron and LHC experiments.

  13. Electroweak Physics at the Tevatron and LHC: Theoretical Status and Perspectives

    OpenAIRE

    Baur, U.

    2005-01-01

    I review the status of theoretical calculations relevant for electroweak physics at the Tevatron and LHC and discuss future directions. I also give a brief overview of current electroweak data and discuss future expectations.

  14. Upgrading the Tevatron to a 1 TeV on 1 TeV pp collider

    International Nuclear Information System (INIS)

    Teng, L.C.

    1987-01-01

    This report describes the tasks necessary to change the Tevatron into a proton-proton collider. Also included in the discussion is an estimate of the cost to carry out the modification. 4 figs., 3 tabs

  15. Landau Damping of the Weak Head-Tail Instability at Tevatron

    CERN Document Server

    Ivanov, Petr M; Annala, Jerry; Lebedev, Valeri; Shiltsev, Vladimir

    2005-01-01

    Landau damping of the head-tail modes in Tevatron beam with the help of octupole-generated betatron tune spreads permits to reduce chromaticity from 15-20 units to zero thus significantly improving the beam lifetime. The octupole strengths have been experimentally optimized at different stages of the Tevatron operation, from proton injection to collision. Predictions of the analytical Landau damping model are compared with the experimental results.

  16. Present status and future prospects for a Higgs boson discovery at the Tevatron and LHC

    International Nuclear Information System (INIS)

    Haber, Howard E

    2010-01-01

    Discovering the Higgs boson is one of the primary goals of both the Tevatron and the Large Hadron Collider (LHC). The present status of the Higgs search is reviewed and future prospects for discovery at the Tevatron and LHC are considered. This talk focuses primarily on the Higgs boson of the Standard Model and its minimal supersymmetric extension. Theoretical expectations for the Higgs boson and its phenomenological consequences are reviewed.

  17. EDITORIAL: Focus on Gravitational Lensing

    Science.gov (United States)

    Jain, Bhuvnesh

    2007-11-01

    Gravitational lensing emerged as an observational field following the 1979 discovery of a doubly imaged quasar lensed by a foreground galaxy. In the 1980s and '90s dozens of other multiply imaged systems were observed, as well as time delay measurements, weak and strong lensing by galaxies and galaxy clusters, and the discovery of microlensing in our galaxy. The rapid pace of advances has continued into the new century. Lensing is currently one of best techniques for finding and mapping dark matter over a wide range of scales, and also addresses broader cosmological questions such as understanding the nature of dark energy. This focus issue of New Journal of Physics presents a snapshot of current research in some of the exciting areas of lensing. It provides an occasion to look back at the advances of the last decade and ahead to the potential of the coming years. Just about a decade ago, microlensing was discovered through the magnification of stars in our galaxy by invisible objects with masses between that of Jupiter and a tenth the mass of the Sun. Thus a new component of the mass of our galaxy, dubbed MACHOs, was established (though a diffuse, cold dark matter-like component is still needed to make up most of the galaxy mass). More recently, microlensing led to another exciting discovery—of extra-solar planets with masses ranging from about five times that of Earth to that of Neptune. We can expect many more planets to be discovered through ongoing surveys. Microlensing is the best technique for finding Earth mass planets, though it is not as productive overall as other methods and does not allow for follow up observations. Beyond planet hunting, microlensing has enabled us to observe previously inaccessible systems, ranging from the surfaces of other stars to the accretion disks around the black holes powering distant quasars. Galaxies and galaxy clusters at cosmological distances can produce dramatic lensing effects: multiple images of background galaxies

  18. Investigation of hadronic matter at the Fermilab Tevatron Collider: Technical progress report, 1986 October-1987 October

    International Nuclear Information System (INIS)

    Anderson, E.W.

    1987-01-01

    An investigation of hadronic matter at very high energy densities is reported. The present experiment, E-735, is a search for a deconfined quark-gluon plasma phase of matter expected to occur when temperatures of 240 MeV are achieved. Preliminary data have been obtained during the first operation of the Fermilab Tevatron Collider during the period January to May 1987. The collaboration is about to publish first results on the charged particle multiplicity and transverse momentum distributions. In addition, we have data on the particle identification of the produced secondaries. Both measurements are regarded on theoretical grounds to be sensitive indicators of the formation of a high temperature plasma. The capital project funded under this contract was a 240-element trigger hodoscope array, with associated electronics and monitor. The hodoscope was completed and performed to design expectations in the high-rate and high-radiation environment of the Collider. Scientific personnel supported under this contract were also responsible for the implementation of the data acquisition system used for E-735. Although the system underwent several unanticipated modifications in response to changing schedules, the required service was provided. Preparations are currently under way for the principal data acquisition during the spring of 1988. At that time we will have in place the central tracking chamber, and the remainder of the spectrometer chambers. Tests will also be made on backgrounds and detector materials appropriate to our proposal, P-787, to measure leptons and photons in the third Collider running period

  19. B Physics at tevatron and the B Factories

    International Nuclear Information System (INIS)

    Paus, C.

    2004-01-01

    The following contribution is in no way a complete summary of the physics of b hadrons but merely a selection of some key topics which the author considered exemplary to explain the essence of B physics to beginners in the field. The main emphasis has been put on electroweak decays of b hadrons which in one form or another contain information about the Cabibbo-Kobayashi-Maskawa matrix. The elements of this matrix define the coupling strength of the various quark pairs to the W boson. The coupling strengths cannot be predicted but have to be measured and are thus input parameters to the Standard Model of Particle Physics. Furthermore the CKM matrix is the mechanism which implements CP violation in the Standard Model. The phenomenon of CP violation and the CKM matrix are enjoying quite some attention since there are indications that something is not right in the Standard Model. This contribution discusses the most prominent measurements in the field of B physics which are presently performed or prepared at the Tevatron and the B factories. The experimental setup in terms of the accelerators and the experiments is described in the beginning. The differences between e+e- and pp machines and the corresponding detector designs are discussed in detail. In the next step the analysis tools are developed step by step by describing the measurements which make use of them. (Author) 39 refs

  20. Measurements of top-quark properties at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Andreas Werner [Fermilab

    2013-07-30

    Recent measurements of top-quark properties at the Tevatron are presented. CDF uses data corresponding up to 9.0 fb-1 to measure the ratio R of the branching fractions , the branching fraction for top-quarks decaying into τ leptons and the cross section for the production of an additional γ in t production. The results from all these measurements agree well with their respective Standard Model expectation. DØ uses 5.3 fb-1 of data to measure the t cross section as a function of the time. A time dependency would imply Lorentz invariance violation as implemented by the Standard Model extension. No time dependency is observed and DØ sets first limits in the top-quark sector for Lorentz invariance violation. DØ also determines indirectly the top quark width using the results of earlier measurements at DØ. The measured top quark width is in agreement with the SM expectation and does not show any hints for new physics contributions.

  1. A new Tevatron Collider working point near the integer

    International Nuclear Information System (INIS)

    Johnson, R.P.; Zhang, P.

    1989-12-01

    It is well established that in hadron colliders the beam-beam interaction is more harmful in the presence of machine resonances of the form mν x + nν y = p, where |m| + |n| is the order of the resonance. Since the closest a resonance line can be to the integer stopband is 1/order, the closer the working point is to the integer, the fewer lower order resonances there are to enhance the beam-beam effects. A shift of the working point of the Tevatron from 19.4 to values near 19 and 20 has been studied. Problems with closed orbit control, dispersion matching, and matched low β insertions were considered. An excellent solution for the B0 insertion was found which has an improved β*. A new injection optics allows a transition to the low β optics which is much easier than the one now used. Results from the first machine studies demonstrate the ability to control the orbit with tunes of 19.03 horizontal and 20.03 vertical. Further studies require the activation of additional quadrupole compensation circuits. 4 refs. , 2 figs

  2. Proposed Fermilab fixed target experiment: Kaons at the Tevatron

    International Nuclear Information System (INIS)

    1993-12-01

    The US Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-0898, evaluating the impacts associated with the proposed fixed target experiment at the Fermi National Accelerator Laboratory (Femilab) in Batavia, Illinois, known as Kaons at the Tevatron (KTeV). The proposed KTeV project includes reconfiguration of an existing target station, enhancement of an existing beam transport system connected to existing utility facilities, and construction of a new experimental detector hall area. The study of the K meson, a type of subatomic particle, has been going on at Fermilab for 20 years. The proposed KTEV project advances the search for the origins of a violation of a fundamental symmetry of nature called charge parity (CP) violation. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required

  3. Soft color interactions and diffractive hard scattering at the Tevatron

    International Nuclear Information System (INIS)

    Enberg, R.; Timneanu, N.; Ingelman, G.; Uppsala Univ.

    2001-06-01

    An improved understanding of nonperturbative QCD can be obtained by the recently developed soft color interaction models. Their essence is the variation of color string-field topologies, giving a unified description of final states in high energy interactions, e.g., diffractive and nondiffractive events in ep and pp. Here we present a detailed study of such models (the soft color interaction model and the generalized area law model) applied to pp, considering also the general problem of the underlying event including beam particle remnants. With models turned to HERA ep data, we find a good description also of Tevatron data on production of W, bottom and jets in diffractive events defined either by leading antiprotons or by one or two rapidity gaps in the forward or backward regions. We also give predictions for diffractive J/ψ production where the soft exchange mechanism produces both a gap and a color singlet cc state in the same event. This soft color interaction approach is also compared with Pomeron-based models for diffraction, and some possibilities to experimentally discriminate between these different approaches are discussed. (orig.)

  4. Search prospects of light stabilized radions at Tevatron and LHC

    CERN Document Server

    Mahanta, U

    2000-01-01

    In this paper we use the conformal anomaly in QCD to derive the radion coupling to gluons in the Randall-Sundrum model and use it to compute the radion production cross section at hadron colliders by gluon fusion. We find that for the vacuum expectation value of the radion field, =1 TeV the radion production cross section by gluon fusion at LHC would exceed that of the standard model (SM) Higgs boson by a factor that lies between 7 and 8 over most of the mass range. The radion production cross-section decreases as 1/(/sup 2/) and for greater than 3 TeV, the Higgs production cross-section exceeds that of the radion production. The decay modes of the radion are similar to that of the SM Higgs boson. But the striking feature is the enhancement of radion to 2-photon and radion to 2-gluon branching ratio over the SM case. Utilizing this, we then discuss the possible search strategies of such scalars at the Tevatron and LHC. Using the gamma gamma decay mode one can explore /exclude a radion mass up to 1 TeV at the...

  5. The search for the Higgs at the Tevatron

    International Nuclear Information System (INIS)

    Lucotte, A.

    2004-01-01

    The Tevatron has undergone an impressive technical renovation program whose final aim is to reach an integrated luminosity of 15 fb -1 per experiment. Both CDF and DO detectors have been upgraded in the fields of detection, triggering, track reconstruction and particle identification. In the framework of the standard model, theoretical studies show that for a luminosity of only 2 fb -1 (that is the first step of the renovation program) CDF and DO could barely extend the domain already excluded by LEP for the existence of the Higgs boson. On the other hand for a luminosity of 15 fb -1 , a standard Higgs boson could be excluded up to 180 GeV/c 2 and discovered up to 125 GeV/c 2 . Moreover, a 3*σ result could be obtained in the decay channels H → bb-bar and H → W + W - up to 180 GeV/c 2 . In the framework of the minimal supersymmetric standard model (MSSM), at least 20 fb -1 are required for the discovery of the Higgs boson in the energy range: 80 ≤ m A ≤ 380 GeV/c 2 . (A.C.)

  6. New case of gravitational lensing

    Energy Technology Data Exchange (ETDEWEB)

    Surdej, J.; Swings, J.-P.; Magain, P.; Borgeest, U.; Kayser, R.; Refsdal, S.; Courvoisier, T.J.-L.; Kellermann, K.I.; Kuehr, H.

    1987-10-22

    The authors report a brief description of a gravitational lens system UM673 = Q0142 - 100 = PHL3703. It consists of two images, A and B, separated by 2.2 arc s at a redshift zsub(q) = 2.719. The lensing galaxy has also been found. It lies very near the line connecting the two QSO (quasi-stellar objects) images, approx. 0.8 arc s from the fainter one. Application of gravitational optometry to this system leads to a value Msub(o) or approx. = 2.4 x 10/sup 11/ M solar masses for the mass of the lensing galaxy and to ..delta..t approx. 7 weeks for the most likely travel-time difference between the two light paths to the QSO.

  7. Investigation of hadronic matter at the Fermilab Tevatron Collider. Technical progress report

    International Nuclear Information System (INIS)

    Anderson, E.W.

    1985-01-01

    Hadronic matter at very high energy densities is investigated. The present experimental effort is focused on a search for a new quark-gluon plasma phase expected to occur when temperatures of 240 MeV are achieved. Instrumentation for several unique signatures is being developed to exploit the first operation of the Fermilab Tevatron Collider in 1986. The capital projects funded under this contract are a 240-element trigger hodoscope array, and in phase II a segmented photon detector. For these projects $172K are requested for the period 1986 February 1 through 1987 January 31 to complete the trigger hodoscope, and $160K for the period 1987 February 1 through 1988 January 31 to construct a portion of the photon detector. These figures are as presented in the original proposal. Due to budget constraints on the Fermilab experimental support program, we will not be able to receive the full complement of necessary electronics from the Fermilab PREP pool in the required period. Consequently, an additional $35K is requested for the period 1986 February 1 through 1987 January 31 for a portion of the electronics for the 240-channel trigger hodoscope. For the same reasons, Fermilab cannot provide the required magnet on schedule; a one year delay is proposed. As this would seriously impact our physics goals, the collaboration is attempting to fund the magnet without delay through the universities. Efforts to date have concentrated on the design and testing of the hodoscope. Extensive measurements on the radiation levels and effects during the various accelerator cycles have been made. These data are essential to the proper selection of scintillator and design of electronics. These tests are now complete, and final construction is beginning. 11 refs

  8. A system of catoptric lenses

    International Nuclear Information System (INIS)

    McFarland, P.J.; Rambauske, W.R.

    1973-01-01

    Description is given of a system of catoptric lenses for combining energies provided by a certain number of sources, e.g. optical energies provided by a certain number of lasers. This system comprises sets of mirrors the reflecting surfaces of which have their focuses spaced from a common axis. The mirrors of all these sets are arranged on a common frame, which makes aperture-locking impossible. This can be applied to thermonuclear fusion [fr

  9. Gravitational lensing in plasmic medium

    Energy Technology Data Exchange (ETDEWEB)

    Bisnovatyi-Kogan, G. S., E-mail: gkogan@iki.rssi.ru; Tsupko, O. Yu., E-mail: tsupko@iki.rssi.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation)

    2015-07-15

    The influence of plasma on different effects of gravitational lensing is reviewed. Using the Hamiltonian approach for geometrical optics in a medium in the presence of gravity, an exact formula for the photon deflection angle by a black hole (or another body with a Schwarzschild metric) embedded in plasma with a spherically symmetric density distribution is derived. The deflection angle in this case is determined by the mutual combination of different factors: gravity, dispersion, and refraction. While the effects of deflection by the gravity in vacuum and the refractive deflection in a nonhomogeneous medium are well known, the new effect is that, in the case of a homogeneous plasma, in the absence of refractive deflection, the gravitational deflection differs from the vacuum deflection and depends on the photon frequency. In the presence of a plasma nonhomogeneity, the chromatic refractive deflection also occurs, so the presence of plasma always makes gravitational lensing chromatic. In particular, the presence of plasma leads to different angular positions of the same image if it is observed at different wavelengths. It is discussed in detail how to apply the presented formulas for the calculation of the deflection angle in different situations. Gravitational lensing in plasma beyond the weak deflection approximation is also considered.

  10. 30 CFR 18.30 - Windows and lenses.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Windows and lenses. 18.30 Section 18.30 Mineral... § 18.30 Windows and lenses. (a) MSHA may waive testing of materials for windows or lenses except headlight lenses. When tested, material for windows or lenses shall meet the test requirements prescribed in...

  11. Planck 2015 results. XV. Gravitational lensing

    CERN Document Server

    Ade, P.A.R.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J.M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P.B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P.M.; Macías-Pérez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P.G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Nørgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G.W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J.P.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; White, M.; Yvon, D.; Zacchei, A.

    2016-01-01

    We present the most significant measurement of the cosmic microwave background (CMB) lensing potential to date (at a level of 40 sigma), using temperature and polarization data from the Planck 2015 full-mission release. Using a polarization-only estimator we detect lensing at a significance of 5 sigma. We cross-check the accuracy of our measurement using the wide frequency coverage and complementarity of the temperature and polarization measurements. Public products based on this measurement include an estimate of the lensing potential over approximately 70% of the sky, an estimate of the lensing potential power spectrum in bandpowers for the multipole range 40lensing potential power spectrum and that found in the best-fitting LCDM model based on the Planck temperature and polarization power spectra. Using the lensing likelihood alone we obtain a percent-level measurement of ...

  12. Instrumental systematics and weak gravitational lensing

    International Nuclear Information System (INIS)

    Mandelbaum, R.

    2015-01-01

    We present a pedagogical review of the weak gravitational lensing measurement process and its connection to major scientific questions such as dark matter and dark energy. Then we describe common ways of parametrizing systematic errors and understanding how they affect weak lensing measurements. Finally, we discuss several instrumental systematics and how they fit into this context, and conclude with some future perspective on how progress can be made in understanding the impact of instrumental systematics on weak lensing measurements

  13. Factors influencing bacterial adhesion to contact lenses

    OpenAIRE

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The ...

  14. Weak lensing of the Lyman α forest

    Science.gov (United States)

    Croft, Rupert A. C.; Romeo, Alessandro; Metcalf, R. Benton

    2018-06-01

    The angular positions of quasars are deflected by the gravitational lensing effect of foreground matter. The Lyman α (Lyα) forest seen in the spectra of these quasars is therefore also lensed. We propose that the signature of weak gravitational lensing of the Lyα forest could be measured using similar techniques that have been applied to the lensed cosmic microwave background (CMB), and which have also been proposed for application to spectral data from 21-cm radio telescopes. As with 21-cm data, the forest has the advantage of spectral information, potentially yielding many lensed `slices' at different redshifts. We perform an illustrative idealized test, generating a high-resolution angular grid of quasars (of order arcminute separation), and lensing the Lyα forest spectra at redshifts z = 2-3 using a foreground density field. We find that standard quadratic estimators can be used to reconstruct images of the foreground mass distribution at z ˜ 1. There currently exists a wealth of Lyα forest data from quasar and galaxy spectral surveys, with smaller sightline separations expected in the future. Lyα forest lensing is sensitive to the foreground mass distribution at redshifts intermediate between CMB lensing and galaxy shear, and avoids the difficulties of shape measurement associated with the latter. With further refinement and application of mass reconstruction techniques, weak gravitational lensing of the high-redshift Lyα forest may become a useful new cosmological probe.

  15. Radiation hard silicon microstrip detectors for Tevatron experiments

    International Nuclear Information System (INIS)

    Korjenevski, Sergey

    2004-01-01

    The Silicon Microstrip Tracking detectors at the CDF and D0 experiments have now been operating for almost three years at Fermilab. These detectors were designed originally for an integrated luminosity of 2fb -1 . As the expected luminosity for Run IIb at the Tevatron collider was initially envisioned to reach 15fb -1 , radiation tolerances of both devices were revisited, culminating in proposals for new systems. With reduced expectations for total luminosity at ∼6fb -1 , the full detector-replacement projects were terminated. The CDF detector is expected nevertheless to cope efficiently with the lower anticipated dose, however, the D0 experiment is planning a smaller-scale project: a Layer-0 (L0) upgrade of the silicon tracker (D0SMT). The new device will fit between the beam line and the inner layer of the current Tracker. Built of single-sided sensors, this upgrade is expected to perform well in the harsh radiation environment, and be able to withstand an integrated luminosity of 15fb -1 . Prototypes of Run IIb sensors were irradiated using 10MeV protons at the tandem Van de Graaff at the James R. McDonald Laboratory at Kansas State University. A fit to the 10MeV proton data yields a damage parameter αp=11x10-17Acm. This is consistent with results from RD48 (αp=9.9x10-17Acm). The scaling of damage to 1MeV neutron fluence uses a hardness factor (κ) derived from the non-ionizing components of the energy loss (NEIL). NEIL predicts a hardness factor of 3.87 for 10MeV protons. We obtained an experimental value of this factor of 2.54, or 34% smaller than scaling predictions from NEIL

  16. Observation of Central Exclusive Diphoton Production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Brucken, Jens Erik [Univ. of Helsinki (Finland); Helsinki Inst. of Physics (Finland)

    2013-01-01

    We have observed exclusive γγ production in proton-antiproton collisions at the Tevatron at √ s = 1.96 TeV. We use data corresponding to 1.11 ± 0.07 fb-1 integrated luminosity taken by the Run II Collider Detector at Fermilab, with a trigger requiring two electromagnetic showers, each with transverse energy ET > 2 GeV, and vetoing on hits in the forward beam shower counters. We select events with two electromagnetic showers, each with transverse energy ET > 2.5 GeV and pseudorapidity |η| < 1.0, with no other particles detected in -7.4 < η < +7.4. The two showers have similar ET and an azimuthal angle separation Δφ ~ π; we find 34 events with exactly two matching charged particle tracks, agreeing with expectations for the QED process p¯p → p+e+e- + ¯p by two photon exchange; and we find 43 events with no tracks. The latter are candidates for the exclusive process p¯p → p + γγ + ¯p by double pomeron exchange. We use the strip and wire chambers at the longitudinal shower maximum position within the calorimeter to measure a possible exclusive background from IP + IP → π0π0, and conclude that it is consistent with zero and is < 15 events at 95% C.L. The measured cross section is σγγ,excl(|η| < 1, ET (γ) > 2.5 GeV) = 2.48 +0.40 -0.35(stat) +0.40 -0.51(syst) pb and in agreement with the theoretical predictions. This process is closely related to exclusive Higgs boson production pp → p + H + p at the Large Hadron Collider. The observation of the exclusive production of diphotons shows that exclusive Higgs production can happen and could be observed with a proper experimental setup.

  17. Search for the single top quarks produced in s-channel via electroweak interactions at s = 1.96 at the Tevatron

    International Nuclear Information System (INIS)

    Jabeen, Shabnam

    2006-01-01

    The authors present a search for single top quarks produced in the s-channel electroweak production mode. The search is performed in the electron+jets decay channels, with one or more secondary-vertex tagged jets to indicate the presence of a b-jet and hence improving the signal:background ratio. Separation between signal and background is further enhanced by the use of Feed Forward Neural networks. 360 pb -1 of Run II data used for this analysis was delivered by the Tevatron, and collected by D0 between August 2002 and August 2004. The resulting 95% confidence level upper limit is 4 pb

  18. Search for the single top quarks produced in s-channel via electroweak interactions at √s = 1.96 at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Jabeen, Shabnam [Univ. of Kansas, Lawrence, KS (United States)

    2006-01-01

    The authors present a search for single top quarks produced in the s-channel electroweak production mode. The search is performed in the electron+jets decay channels, with one or more secondary-vertex tagged jets to indicate the presence of a b-jet and hence improving the signal:background ratio. Separation between signal and background is further enhanced by the use of Feed Forward Neural networks. 360 pb-1 of Run II data used for this analysis was delivered by the Tevatron, and collected by D0 between August 2002 and August 2004. The resulting 95% confidence level upper limit is 4 pb.

  19. 2007 2008 ACADEMIC TRAINING PROGRAMME: Tevatron: The Cinderella Story or The Art Of Collider Commissioning

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 01, 03, 04, 05 October 2007 Main Auditorium, bldg. 500 Tevatron: The Cinderella Story or The Art Of Collider Commissioning V. SHILTSEV / Fermi National Accelerator Laboraty, Batavia IL, USA The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world’s highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world’s High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we’ll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing"...

  20. Prospects for 6- to 10-Tesla magnets for a Tevatron upgrade

    International Nuclear Information System (INIS)

    Mantsch, P.M.

    1989-01-01

    This paper reports on prospects for 6- to 10-tesla magnets for a Teratron upgrade. The first SSC physics is at least 10 years away. An upgrade of the Fermilab Tevatron will ensure the continuity of a vigorous high-energy physics program until the SSC turns on. Three basic proposals are under consideration: (1) bar pp at 3 x 10 31 --Increase luminosity by improvements to the bar p source. (2) p bar p at 1 TeV and 2 x 10 32 --Move the main ring to a new tunnel, build a second Tevatron ring. (3) bar pp > 1.5 TeV and 7 x 10 30 --Replace the Tevatron with a higher energy ring. The last two options require new higher-field magnets. The second option requires about a hundred 6.6-tesla dipoles in addition to a ring of Tevatron-strength (4.4-T) magnets. These higher-field magnets are necessary in both rings to lengthen the straight sections in order to realize the collision optics. The third option requires a ring of magnets of 6.6 T or slightly higher to replace the present Tevatron plus a number of special 8- to 9-tesla magnets

  1. The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

    International Nuclear Information System (INIS)

    Baumbaugh, A.; Briegel, C.; Brown, B.C.; Capista, D.; Drennan, C.; Fellenz, B.; Knickerbocker, K.; Lewis, J.D.; Marchionni, A.; Needles, C.; Olson, M.

    2011-01-01

    A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. The system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and show a number of examples of its use in both the Main Injector and Tevatron.

  2. Prospects for 6 to 10 tesla magnets for a TEVATRON upgrade

    International Nuclear Information System (INIS)

    Mantsch, Paul M.

    1988-01-01

    The first SSC physics is at least 10 years away. An upgrade of the Fermilab Tevatron will ensure the continuity of a vigorous high-energy physics program until the SSC turns on. Three basic proposals are under consideration: /bar p/p at 3 /times/ 10 31 --Increase luminosity by improvements to the p source. pp at 1 TeV and 2 /times/ 10 32 --Move the main ring to a new tunnel, build a second Tevatron ring, and /bar p/p > 1.5 TeV and 7 /times/ 10 30 --Replace the tevatron with a higher energy ring. The last two options requires about a hundred 6.6-tesla dipoles in addition to a ring of Tevatron strength (4.4 T) magnets. These higher-field magnets are necessary in both rings to lengthen the straight sections in order to realize the collision optics. The third option requires a ring of magnets of 6.6 T or slightly higher to replace the present Tevatron plus a number of special 8--9 tesla magnets. The viability of the high-energy option then depends on the practicality of sizable numbers of reliable 8--9 tesla dipoles as well as 800 6.6-tesla dipoles. The following develops a specification for an 8.8 T dipole, examines the design considerations and reviews the current state of high-field magnet development. 22 figs., 3 tabs

  3. The Scales of Gravitational Lensing

    Directory of Open Access Journals (Sweden)

    Francesco De Paolis

    2016-03-01

    Full Text Available After exactly a century since the formulation of the general theory of relativity, the phenomenon of gravitational lensing is still an extremely powerful method for investigating in astrophysics and cosmology. Indeed, it is adopted to study the distribution of the stellar component in the Milky Way, to study dark matter and dark energy on very large scales and even to discover exoplanets. Moreover, thanks to technological developments, it will allow the measure of the physical parameters (mass, angular momentum and electric charge of supermassive black holes in the center of ours and nearby galaxies.

  4. CERN scientists take part in the Tevatron Run II performance review committee

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Tevatron Run II is under way at Fermilab, exploring the high-energy frontier with upgraded detectors that will address some of the biggest questions in particle physics.Until CERN's LHC switches on, the Tevatron proton-antiproton collider is the world's only source of top quarks. It is the only place where we can search for supersymmetry, for the Higgs boson, and for signatures of additional dimensions of space-time. The US Department of Energy (DOE) recently convened a high-level international review committee to examine Fermilab experts' first-phase plans for the accelerator complex. Pictured here with a dipole magnet in CERN's LHC magnet test facility are the four CERN scientists who took part in the DOE's Tevatron review. Left to right: Francesco Ruggiero, Massimo Placidi, Flemming Pedersen, and Karlheinz Schindl. Further information: CERN Courier 43 (1)

  5. Double-diffractive processes in high-resolution missing-mass experiments at the Tevatron

    International Nuclear Information System (INIS)

    Khoze, V.A.; Martin, A.D.

    2001-01-01

    We evaluate, in a model-independent way, the signal-to-background ratio for Higgs→b anti b detection in exclusive double-diffractive events at the Tevatron and the LHC. For the missing-mass approach to be able to identify the Higgs boson, it will be necessary to use a central jet detector and to tag b quark jets. The signal is predicted to be very small at the Tevatron, but observable at the LHC. However we note that the background, that is double-diffractive dijet production, may serve as a unique gluon factory. We also give estimates for the double-diffractive production of χ c and χ b mesons at the Tevatron. We emphasize that a high-resolution missing-mass measurement, on its own, is insufficient to identify rare processes. (orig.)

  6. Fermilab Tevatron and CERN LEP II probes of minimal and string-motivated supergravity models

    International Nuclear Information System (INIS)

    Baer, H.; Gunion, J.F.; Kao, C.; Pois, H.

    1995-01-01

    We explore the ability of the Fermilab Tevatron to probe minimal supersymmetry with high-energy-scale boundary conditions motivated by supersymmetry breaking in the context of minimal and string-motivated supergravity theory. A number of boundary condition possibilities are considered: dilatonlike string boundary conditions applied at the standard GUT unification scale or alternatively at the string scale; and extreme (''no-scale'') minimal supergravity boundary conditions imposed at the GUT scale or string scale. For numerous specific cases within each scenario the sparticle spectra are computed and then fed into ISAGET 7.07 so that explicit signatures can be examined in detail. We find that, for some of the boundary condition choices, large regions of parameter space can be explored via same-sign dilepton and isolated trilepton signals. For other choices, the mass reach of Tevatron collider experiments is much more limited. We also compare the mass reach of Tevatron experiments with the corresponding reach at CERN LEP 200

  7. Age-related compaction of lens fibers affects the structure and optical properties of rabbit lenses

    Directory of Open Access Journals (Sweden)

    Al-Ghoul Walid M

    2007-12-01

    Full Text Available Abstract Background The goal of this investigation was to correlate particular age-related structural changes (compaction to the amount of scatter in rabbit lenses and to determine if significant fiber compaction occurred in the nuclear and inner cortical regions. Methods New Zealand White rabbits at 16–20 months old (adult; n = 10 and at 3.5–4 years old (aged; n = 10 were utilized for this study. Immediately after euthanising, scatter was assessed in fresh lenses by low power helium-neon laser scan analysis. Scatter data was analyzed both for whole lenses and regionally, to facilitate correlation with morphometric data. After functional analysis, lenses were fixed and processed for scanning electron microcopy (SEM; right eyes and light microscopy (LM; left eyes. Morphometric analysis of SEM images was utilized to evaluate compaction of nuclear fibers. Similarly, measurements from LM images were used to assess compaction of inner cortical fibers. Results Scatter was significantly greater in aged lenses as compared to adult lenses in all regions analyzed, however the difference in the mean was slightly more pronounced in the inner cortical region. The anterior and posterior elliptical angles at 1 mm (inner fetal nucleus were significantly decreased in aged vs. adult lenses (anterior, p = 0.040; posterior, p = 0.036. However, the average elliptical angles at 2.5 mm (outer fetal nucleus were not significantly different in adult and aged lenses since all lenses examined had comparable angles to inner fetal fibers of aged lenses, i.e. they were all compacted. In cortical fibers, measures of average cross-sectional fiber area were significantly different at diameters of both 6 and 7 mm as a function of age (p = 0.011 and p = 0.005, respectively. Accordingly, the estimated fiber volume was significantly decreased in aged as compared to adult lenses at both 6 mm diameter (p = 0.016 and 7 mm diameter (p = 0.010. Conclusion Morphometric data indicates

  8. High resolution transmission imaging without lenses

    International Nuclear Information System (INIS)

    Rodenburg, J M; Hurst, A C; Maiden, A

    2010-01-01

    The whole history of transmission imaging has been dominated by the lens, whether used in visible-light optics, electron optics or X-ray optics. Lenses can be thought of as a very efficient method of processing a wave front scattered from an object into an image of that object. An alternative approach is to undertake this image-formation process using a computational technique. The crudest scattering experiment is to simply record the intensity of a diffraction pattern. Recent progress in so-called diffractive imaging has shown that it is possible to recover the phase of a scattered wavefield from its diffraction pattern alone, as long as the object (or the illumination on the object) is of finite extent. In this paper we present results from a very efficient phase retrieval method which can image infinitely large fields of view. It may have important applications in improving resolution in electron microscopy, or at least allowing low specification microscopes to achieve resolution comparable to state-of-the-art machines.

  9. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Klint, K.E.S.; Nilsson, B.

    2012-01-01

    Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...

  10. Planck 2015 results: XV. Gravitational lensing

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.

    2016-01-01

    We present the most significant measurement of the cosmic microwave background (CMB) lensing potential to date (at a level of 40σ), using temperature and polarization data from the Planck 2015 full-mission release. Using a polarization-only estimator, we detect lensing at a significance of 5σ. We...

  11. Lenses and Perception: Investigations with Light

    Science.gov (United States)

    Akcay, Hakan

    2005-01-01

    The main goals of these activities are to help students learn how a convex lens can serve as a magnifying lens and how light travels and creates images. These explorations will introduce middle school students to different types of lenses and how they work. Students will observe and describe how lenses bend light that passes through them and how…

  12. BAYESIAN INFERENCE OF CMB GRAVITATIONAL LENSING

    Energy Technology Data Exchange (ETDEWEB)

    Anderes, Ethan [Department of Statistics, University of California, Davis, CA 95616 (United States); Wandelt, Benjamin D.; Lavaux, Guilhem [Sorbonne Universités, UPMC Univ Paris 06 and CNRS, UMR7095, Institut d’Astrophysique de Paris, F-75014, Paris (France)

    2015-08-01

    The Planck satellite, along with several ground-based telescopes, has mapped the cosmic microwave background (CMB) at sufficient resolution and signal-to-noise so as to allow a detection of the subtle distortions due to the gravitational influence of the intervening matter distribution. A natural modeling approach is to write a Bayesian hierarchical model for the lensed CMB in terms of the unlensed CMB and the lensing potential. So far there has been no feasible algorithm for inferring the posterior distribution of the lensing potential from the lensed CMB map. We propose a solution that allows efficient Markov Chain Monte Carlo sampling from the joint posterior of the lensing potential and the unlensed CMB map using the Hamiltonian Monte Carlo technique. The main conceptual step in the solution is a re-parameterization of CMB lensing in terms of the lensed CMB and the “inverse lensing” potential. We demonstrate a fast implementation on simulated data, including noise and a sky cut, that uses a further acceleration based on a very mild approximation of the inverse lensing potential. We find that the resulting Markov Chain has short correlation lengths and excellent convergence properties, making it promising for applications to high-resolution CMB data sets in the future.

  13. Measuring the top anti-t Production Cross-Section in the Electron + Jets Channel in Proton - Anti-proton Collisions at s**(1/2) = 1.96-TeV with the D0 Detector at the Tevatron: A Monte Carlo Study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Su-Jung; /Bonn U.

    2004-02-01

    The measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV using the final state with an electron and jets is studied with Monte Carlo event samples. All methods used in the real data analysis to measure efficiencies and to estimate the background contributions are examined. The studies focus on measuring the electron reconstruction efficiencies as well as on improving the electron identification and background suppression. With a generated input cross section of 7 pb the following result is obtained: {sigma}{sub t{bar t}} = (7 {+-} 1.63(stat){sub -1.14}{sup +0.94} (syst)) pb.

  14. Heavy quark production at the TEVATRON and HERA using kt-factorization with CCFM evolution

    International Nuclear Information System (INIS)

    Jung, H.

    2001-10-01

    The application of k t -factorization supplemented with the CCFM small-x evolution equation to heavy quark production at the TEVATRON and at HERA is discussed. The bb production cross sections at the TEVATRON can be consistently described using the k t -factorization formalism together with the unintegrated gluon density obtained within the CCFM evolution approach from a fit to HERA F 2 data. Special attention is drawn to the comparison with measured visible cross sections, which are compared to the hadron level Monte Carlo generator Cascade. (orig.)

  15. Common mode noise on the main Tevatron bus and associated beam emittance growth

    International Nuclear Information System (INIS)

    Zhang, P.; Johnson, R.P.; Kuchnir, M.; Siergiej, D.; Wolff, D.

    1991-05-01

    Overlap of betatron tune frequencies with the power supply noise spectrum can cause transverse beam emittance growth in a storage ring. We have studied this effect for tunes near the integer, where the betatron frequency is low. By injecting noise onto the main power supply bus, it was determined that common mode noise was the dominant source of emittance growth. A noise suppression feed-back loop was then used to reduce the noise and the emittance growth. These experiments are described as are investigations of the common mode propagation along the Tevatron bus and measurements of the fields generated by common mode excitation of isolated Tevatron magnets. 3 refs., 4 figs

  16. Solutions for care of silicone hydrogel lenses.

    Science.gov (United States)

    Willcox, Mark D P

    2013-01-01

    During wear of contact lenses on a daily wear basis, it is necessary to disinfect the lens overnight before reinserting the lens the next day. The ability of the solutions used for this to disinfect lenses and lens cases is important for safe lens wear. The literature on the disinfecting ability of multipurpose disinfecting solutions (MPDS) commonly used with silicone hydrogel lenses reported during the period 2000 to 2012 is reviewed, as this is the period of time during which these lenses have been commercially available. Particular emphasis is placed on the ability of disinfecting solutions to control colonization of lens cases by microbes and changes in composition and use of the solutions. In addition, the literature is reviewed on ways of minimizing lens case microbial contamination. Maintaining the hygiene of contact lenses and lens cases is important in minimizing various forms of corneal infiltrative events that occur during lens wear. Although lens case contamination is not associated with different lenses, it is determined by use of different MPDS. MPDS that allow more frequent or heavy contamination of cases by Gram-negative bacteria are associated with a higher incidence of corneal infiltrative events. MPDS are now available that contain dual disinfectants. Wiping lens cases with tissues or using lens cases that incorporate silver are associated with reductions in contamination in clinical trials. Similarly, using MPDS to rub and rinse lenses before disinfection may reduce levels of microbes on lenses. The MPDS also contain surfactants that help reduce deposition and denaturation of proteins on lenses. Improvements in MPDS formulations and hygiene practices may help to reduce the incidence of adverse events that are seen during use with silicone hydrogel lenses.

  17. Adherence of Pseudomonas aeruginosa to contact lenses

    International Nuclear Information System (INIS)

    Miller, M.J.

    1988-01-01

    The purpose of this research was to examined the interactions of P. aeruginosa with hydrogel contact lenses and other substrata, and characterize adherence to lenses under various physiological and physicochemical conditions. Isolates adhered to polystyrene, glass, and hydrogel lenses. With certain lens types, radiolabeled cells showed decreased adherence with increasing water content of the lenses, however, this correlation with not found for all lenses. Adherence to rigid gas permeable lenses was markedly greater than adherence to hydrogels. Best adherence occurred near pH 7 and at a sodium chloride concentration of 50 mM. Passive adhesion of heat-killed cells to hydrogels was lower than the adherence obtained of viable cells. Adherence to hydrogels was enhanced by mucin, lactoferrin, lysozyme, IgA, bovine serum albumin, and a mixture of these macromolecules. Adherence to coated and uncoated lenses was greater with a daily-wear hydrogel when compared with an extended-wear hydrogel of similar polymer composition. Greater adherence was attributed to a higher concentration of adsorbed macromolecules on the 45% water-content lens in comparison to the 55% water-content lens

  18. Investigations of Galaxy Clusters Using Gravitational Lensing

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Matthew P. [Northern Illinois Univ., DeKalb, IL (United States)

    2014-08-01

    In this dissertation, we discuss the properties of galaxy clusters that have been determined using strong and weak gravitational lensing. A galaxy cluster is a collection of galaxies that are bound together by the force of gravity, while gravitational lensing is the bending of light by gravity. Strong lensing is the formation of arcs or rings of light surrounding clusters and weak lensing is a change in the apparent shapes of many galaxies. In this work we examine the properties of several samples of galaxy clusters using gravitational lensing. In Chapter 1 we introduce astrophysical theory of galaxy clusters and gravitational lensing. In Chapter 2 we examine evidence from our data that galaxy clusters are more concentrated than cosmology would predict. In Chapter 3 we investigate whether our assumptions about the number of galaxies in our clusters was valid by examining new data. In Chapter 4 we describe a determination of a relationship between mass and number of galaxies in a cluster at higher redshift than has been found before. In Chapter 5 we describe a model of the mass distribution in one of the ten lensing systems discovered by our group at Fermilab. Finally in Chapter 6 we summarize our conclusions.

  19. The Reach of CERN LEP2 and Fermilab Tevatron Upgrades for Higgs Bosons in Supersymmetric Models

    CERN Document Server

    Baer, Howard W; Tata, Xerxes; Baer, Howard; Tata, Xerxes

    1999-01-01

    Luminosity upgrades of the Fermilab Tevatron pbar-p collider have been shown to allow experimental detection of a Standard Model (SM) Higgs boson up to $m_{H_{SM}}\\sim 120$ GeV via $WH_{SM} \\to \\ell\

  20. Recent results on QCD at the Tevatron (CDF and D0)

    International Nuclear Information System (INIS)

    Meschi, E.

    1993-11-01

    In the last run the Tevatron collider delivered an integrated luminosity of 29.9 pb -1 to CDF and D0. We describe here some preliminary result from analyses of relevant QCD processes in the 1992--1993 data from the two experiments

  1. B_s oscillation and prospects for delta m_s at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Menzemer, Stephanie; /MIT

    2005-07-01

    Till the start of the LHC, the Tevatron is the only running accelerator which produces enough B{sub s} mesons to perform {Delta}m{sub s} measurements. The status--as it was at the time of the conference--of two different {Delta}m{sub s} analysis performed both by the CDF and D0 collaboration will be presented.

  2. BTEV: a dedicated B physics detector at the Fermilab Tevatron Collider

    International Nuclear Information System (INIS)

    Butler, J.N.

    1996-11-01

    The capabilities of future Dedicated Hadron Collider B Physics experiments are discussed and compared to experiments that will run in the next few years. The design for such an experiment at the Tevatron Collider is presented and an evolutionary path for developing it is outlined. 9 refs., 3 figs., 4 tabs

  3. Combination of measurements of the top-quark pair production cross section from the Tevatron Collider

    Czech Academy of Sciences Publication Activity Database

    Aaltonen, T.; Abazov, V. M.; Abbott, B.; Kupčo, Alexander; Lokajíček, Miloš; Lysák, Roman

    2014-01-01

    Roč. 89, č. 7 (2014), "072001-1"-"072001-16" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : Batavia TEVATRON Coll * quantum chromodynamics * perturbation theory * statistical analysis * CDF * DZERO Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  4. W/Z + Jets and W/Z + Heavy Flavor Jets at the Tevatron

    International Nuclear Information System (INIS)

    Salto, Oriol

    2009-01-01

    The precision measurements of Boson + jets production performed with the Tevatron data have provided an excellent opportunity to test perturbative QCD calculations and the predictions from the new matrix elements techniques. In this contribution, the latest results by CDF and DO experiments are discussed

  5. W/Z + Jets and W/Z + Heavy Flavor Jets at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Salto, Oriol [Institut de Fisica d' Altes Energies, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)

    2009-01-15

    The precision measurements of Boson + jets production performed with the Tevatron data have provided an excellent opportunity to test perturbative QCD calculations and the predictions from the new matrix elements techniques. In this contribution, the latest results by CDF and DO experiments are discussed.

  6. Angular Distributions of Three Jet Events in Proton - Anti-Proton Collisions at the Fermilab Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Carey, Robert Matthew [Harvard U.

    1989-07-01

    A measurement of three jet angular distributions is made at $\\sqrt{s}$ = 1.8 TeV in protonantiproton collisions at the F'ermilab Tevatron using the Collider Detector _at Ferm.ilab (CDF). Results are presented for three different center of mass variables, cos $\\theta$, $\\psi$, and $\\xi$ and are compared to QCD predictions.

  7. Nanofocusing refractive X-ray lenses

    Energy Technology Data Exchange (ETDEWEB)

    Boye, Pit

    2010-02-05

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  8. Nanofocusing refractive X-ray lenses

    International Nuclear Information System (INIS)

    Boye, Pit

    2010-01-01

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  9. Practical demonstration of the theory of the principle of reflection and refraction of light polarized lenses

    International Nuclear Information System (INIS)

    Miranda Diaz, L. J.

    2016-01-01

    Using an optical system comprising a light source to semiconductor, two collimating lenses, one rotating polarizer, two focusing lenses and an electronic circuit mounted amplifiers based on operational, two pulse outputs of variable width is obtained according to the orientation of the plane of polarized light incident on the lenses coplanar standing together with the electronic circuit inside the optoelectronic head. The difference between the width of both pulses is equivalent to the amount has rotated the plane of polarization and is calculated by the use and programming of a PIC and displayed on an alphanumeric LCD. the result of the measurements are shown performed well plates that you can see the change in the value on the LCD to rotate the polarizer. (Author)

  10. Electron and photon identification in the D0 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrina, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J. -F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M. -A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Raja, R.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y. -T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.; Yu, J. M.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.

    2014-06-01

    The electron and photon reconstruction and identification algorithms used by the D0 Collaboration at the Fermilab Tevatron collider are described. The determination of the electron energy scale and resolution is presented. Studies of the performance of the electron and photon reconstruction and identification are summarized.

  11. Search for WH Associated Production in the l upsilon b-bbar Final State Using the DØ Detector at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jonathan [Paris Diderot Univ. (France)

    2011-09-15

    The Standard Model is the framework which allows to describe interactions between particles and their dynamics. The Higgs mechanism is a solution to naturally introduce a mass term in the theoretical description of this model. After electroweak spontaneous symmetry breaking, a new massive scalar particle is introduced, the Higgs boson. Since it hasn’t been discovered yet, the search for the Higgs boson is carried at the Tevatron, which is a p$\\bar{p}$ collider at a center-of-mass of 1.96 TeV. For MH <115 GeV, the dominant decay mode is H → b$\\bar{b}$ . The analysis presented in this document is focused on the 100< MH <150 GeV mass range, in the channel where the Higgs boson is produced in assocation with a W boson which decays either to an electron or muon and a neutrino. The study of this final state relies on informations collected from all parts of the DØ detector. A result based on 5.3 fb-1 of RunII Tevatron collisions is presented here. In order to increase the sensitivity to the signal, the analysis is separated in different sub-channels according to the lepton flavour, number of jets in the final state, number of jets identified as originated from b quarks and data taking periods. After selecting events, a multivariate analysis technique is used to separate signal-like events from the expected physics and instrumental backgrounds. A good agreement between data and simulation is observed. As no signal excess is observed in data, an observed (expected) upper limit of 4.5 (4.8) for MH = 115 GeV is set on the ratio of the WH cross section multiplied by the H → b$\\bar{b}$ branching fraction to its standard model prediction, at 95% confidence level. Since the final Tevatron dataset is soon to be analyzed, an effort is brought to achieve the maximum sensitivity. A preliminary analysis updated in Summer 2011 is presented as well as future improvements to be considered in the final publication for the search in

  12. Comparison of surface roughness and bacterial adhesion between cosmetic contact lenses and conventional contact lenses.

    Science.gov (United States)

    Ji, Yong Woo; Cho, Young Joo; Lee, Chul Hee; Hong, Soon Ho; Chung, Dong Yong; Kim, Eung Kweon; Lee, Hyung Keun

    2015-01-01

    To compare physical characteristics of cosmetic contact lenses (Cos-CLs) and conventional contact lenses (Con-CLs) that might affect susceptibility to bacterial adhesion on the contact lens (CL) surface. Surface characteristics of Cos-CLs and Con-CLs made from the same material by the same manufacturer were measured by atomic force microscopy (AFM) and scanning electron microscopy. To determine the extent and rate of bacterial adhesion, Cos-CL and Con-CL were immersed in serum-free Roswell Park Memorial Institute media containing Staphylococcus aureus or Pseudomonas aeruginosa. Additionally, the rate of removal of adherent bacteria was evaluated using hand rubbing or immersion in multipurpose disinfecting solutions (MPDS). The mean surface roughness (root mean square and peak-to-valley value) measured by AFM was significantly higher for Cos-CL than for Con-CL. At each time point, significantly more S. aureus and P. aeruginosa adhered to Cos-CL than to Con-CL, which correlated with the surface roughness of CL. In Cos-CL, bacteria were mainly found on the tinted surface rather than on the noncolored or convex areas. Pseudomonas aeruginosa attached earlier than S. aureus to all types of CL. However, P. aeruginosa was more easily removed from the surface of CL than S. aureus by hand rubbing or MPDS soaking. Increased surface roughness is an important physical factor for bacterial adhesion in Cos-CL, which may explain why rates of bacterial keratitis rates are higher in Cos-CL users in CL physical characteristics.

  13. Nanofocusing Parabolic Refractive X-Ray Lenses

    International Nuclear Information System (INIS)

    Schroer, C.G.; Kuhlmann, M.; Hunger, U.T.; Guenzler, T.F.; Kurapova, O.; Feste, S.; Lengeler, B.; Drakopoulos, M.; Somogyi, A.; Simionovici, A. S.; Snigirev, A.; Snigireva, I.

    2004-01-01

    Parabolic refractive x-ray lenses with short focal distance can generate intensive hard x-ray microbeams with lateral extensions in the 100nm range even at short distance from a synchrotron radiation source. We have fabricated planar parabolic lenses made of silicon that have a focal distance in the range of a few millimeters at hard x-ray energies. In a crossed geometry, two lenses were used to generate a microbeam with a lateral size of 330nm by 110nm at 25keV in a distance of 41.8m from the synchrotron radiation source. First microdiffraction and fluorescence microtomography experiments were carried out with these lenses. Using diamond as lens material, microbeams with lateral size down to 20nm and below are conceivable in the energy range from 10 to 100keV

  14. Revised Unfilling Procedure for Solid Lithium Lenses

    International Nuclear Information System (INIS)

    Leveling, A.

    2003-01-01

    A procedure for unfilling used lithium lenses to has been described in Pbar Note 664. To date, the procedure has been used to disassemble lenses 20, 21, 17, 18, and 16. As a result of this work, some parts of the original procedure were found to be time consuming and ineffective. Modifications to the original procedure have been made to streamline the process and are discussed in this note. The revised procedure is included in this note.

  15. Microbial adherence to cosmetic contact lenses.

    Science.gov (United States)

    Chan, Ka Yin; Cho, Pauline; Boost, Maureen

    2014-08-01

    To investigate whether cosmetic contact lenses (CCL) with surface pigments affect microbial adherence. Fifteen brands of CCL were purchased from optical, non-optical retail outlets, and via the Internet. A standardized rub-off test was performed on each CCL (five lenses per brand) to confirm the location of the pigments. The rub-off test comprised gentle rubbing on the surfaces of each CCL with wetted cotton buds for a maximum of 20 rubs per surface. A new set of CCL (five lenses per brand) were incubated in Pseudomonas aeruginosa overnight. Viable counts of adhered bacteria were determined by the number of colony-forming units (CFU) on agar media on each lens. The adherence of P. aeruginosa as well as Staphylococcus aureus and Serratia marcescens to three brands of CCL (A-C) (five lenses per brand) were also compared to their adherences on their clear counterparts. Only two of the 15 brands of CCL tested (brands B and C) had pigments that did not detach with the rub-off test. The remaining 13 brands of CCL all failed the rub-off test and these lenses showed higher P. aeruginosa adherence (8.7 × 10(5)-1.9 × 10(6) CFU/lens). Brands B and C lenses showed at least six times less bacterial adhesion than the other 13 brands. Compared to their clear counterparts, bacterial adherence to brands B and C lenses did not differ significantly, whereas brand A lenses showed significantly higher adherence. Surface pigments on CCL resulted in significantly higher bacterial adherence. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  16. Comments on the Gravitational lensing Magnification

    OpenAIRE

    Takashi, HAMANA; Astronomical Institute, Tohoku University

    1998-01-01

    We rederive a relation between gravitational lensing magnification relative to the standard Friedmann distance and one relative to the Dyer-Roeder distance by investigating the null geodesic deviation equation. We show that the relation comes from a natural consequence of the definition of the lensing magnification matrices and is not based on the averaging of the magnifications, which has conventionally been used to derive it. We therefore conclude that the relation is true for each individu...

  17. Comments on the gravitational lensing magnification

    OpenAIRE

    Hamana, Takashi

    1998-01-01

    We rederive a relation between gravitational lensing magnification relative to the standard Friedmann distance and one relative to the Dyer-Roeder distance by investigating the null geodesic deviation equation. We show that the relation comes from a natural consequence of the definition of the lensing magnification matrices and is not based on the averaging of the magnifications, which has conventionally been used to derive it. We therefore conclude that the relation is true for each individu...

  18. Factors influencing bacterial adhesion to contact lenses.

    Science.gov (United States)

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The adhesion of this strain reaches maximum numbers within 1h in most in vitro studies and a biofilm has generally formed within 24 h of cells adhering to the lens surface. Physical and chemical properties of contact lens material affect bacterial adhesion. The water content of hydroxyethylmethacrylate (HEMA)-based lenses and their iconicity affect the ability of bacteria to adhere. The higher hydrophobicity of silicone hydrogel lenses compared to HEMA-based lenses has been implicated in the higher numbers of bacteria that can adhere to their surfaces. Lens wear has different effects on bacterial adhesion, partly due to differences between wearers, responses of bacterial strains and the ability of certain tear film proteins when bound to a lens surface to kill certain types of bacteria.

  19. Predicting gravitational lensing by stellar remnants

    Science.gov (United States)

    Harding, Alexander J.; Stefano, R. Di; Lépine, S.; Urama, J.; Pham, D.; Baker, C.

    2018-03-01

    Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper, we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, five black holes, and ≈35 000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here, we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With Hubble Space Telescope, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets.

  20. Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier-Thery, Solene [Univ. Pierre et Marie Curie, Paris (France)

    2010-06-01

    The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb -1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

  1. Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

    International Nuclear Information System (INIS)

    Chevalier-Thery, Solene

    2010-01-01

    The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb -1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

  2. Prevention of bacterial colonization of contact lenses with covalently attached selenium and effects on the rabbit cornea.

    Science.gov (United States)

    Mathews, Steven M; Spallholz, Julian E; Grimson, Mark J; Dubielzig, Richard R; Gray, Tracy; Reid, Ted W

    2006-08-01

    Although silicone hydrogel materials have produced many corneal health benefits to patients wearing contact lenses, bacteria that cause acute red eye or corneal ulcers are still a concern. A coating that inhibits bacterial colonization while not adversely affecting the cornea should improve the safety of contact lens wear. A covalent selenium (Se) coating on contact lenses was evaluated for safety using rabbits and prevention of bacterial colonization of the contact lenses in vitro. Contact lenses coated with Se were worn on an extended-wear schedule for up to 2 months by 10 New Zealand White rabbits. Corneal health was evaluated with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. Lenses worn by the rabbits were analyzed for protein and lipid deposits. In addition, the ability of Se to block bacterial colonization was tested in vitro by incubating lenses in a Pseudomonas aeruginosa broth followed by scanning electron microscopy of the contact lens surface. The covalent Se coating decreased bacterial colonization in vitro while not adversely affecting the corneal health of rabbits in vivo. The Se coating produced no noticeable negative effects as observed with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. The Se coating did not affect protein or lipid deposition on the contact lenses. The data from this pilot study suggest that a Se coating on contact lenses might reduce acute red eye and bacterial ulceration because of an inhibition of bacterial colonization. In addition, our safety tests suggest that this positive effect can be produced without an adverse effect on corneal health.

  3. Adhesion of Pseudomonas aeruginosa to orthokeratology and alignment lenses.

    Science.gov (United States)

    Choo, Jennifer D; Holden, Brien A; Papas, Eric B; Willcox, Mark D P

    2009-02-01

    To determine whether contact lenses designed for orthokeratology (OK) are colonized by greater numbers of bacteria compared with standard (alignment fitted) design rigid gas permeable lenses before and after lens wear. Eighteen 1-year-old cats were randomly fitted with an OK lens in one eye and an alignment fitted (AF) lens in the other eye. Both lenses were made in the same diameter and central thickness and of the same material. Two separate wearing periods of 2 weeks and 6 weeks were used. After each wearing period, lenses were soaked in Pseudomonas aeruginosa (6294 or 6206) for 10 min. The lenses were then reinserted onto their respective corneas for a wearing period of 16 hours after which lenses were collected and remaining adhered bacteria quantified. Unworn control lenses were also soaked and bacteria enumerated for comparison. There were no significant differences in the number of bacteria adherent to unworn AF and OK lenses. Analysis of lenses after wear showed OK lenses retained significantly higher numbers of viable bacteria than AF lenses in all studies. OK lenses retain more bacteria than AF rigid gas permeable lenses after bacteria-loaded overnight lens wear. This may increase the risk for an infection in OK patients should suitable conditions be present. Specific education on the cleaning of OK lenses is essential.

  4. Forward-Backward Asymmetry of Top Quark Pair Productionn at the Fermilab Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Ziqing [Texas A & M Univ., College Station, TX (United States)

    2015-12-01

    This dissertation presents the final measurements of the forward-backward asymmetry (AFB) of top quark-antiquark pair events (t t-) at the Collider Detector at Fermilab (CDF) experiment. The t t- events are produced in proton{anti-proton collisions with a center of mass energy of 1:96 TeV during the Run II of the Fermilab Tevatron. The measurements are performed with the full CDF Run II data (9.1 fb-1) in the final state that contain two charged leptons (electrons or muons, the dilepton final state), and are designed to con rm or deny the evidence-level excess in the AFB measurements in the final state with a single lepton and hadronic jets (lepton+jets final state) as well as the excess in the preliminary measurements in the dilepton final state with the first half of the CDF Run II data. New measurements include the leptonic AFB (AlFB), the lepton-pair AFB (All FB) and the reconstructed top AFB (At t FB). Each are combined with the previous results from the lepton+jets final state measured at the CDF experiment. The inclusive Al FB, All FB, and At t FB measured in the dilepton final state are 0.072 ± 0.060, 0.076 ± 0.081, and 0.12 ± 0.13, to be compared with the Standard Model (SM) predictions of 0.038 ± 0.003, 0.048 ± 0.004, and 0.010 ± 0.006, respectively. The CDF combination of AlFB and At t FB are 0.090+0:028 -0.026, and 0.160 ± 0.045, respectively. The overall results are consistent with the SM predictions.

  5. Precision cosmology with weak gravitational lensing

    Science.gov (United States)

    Hearin, Andrew P.

    In recent years, cosmological science has developed a highly predictive model for the universe on large scales that is in quantitative agreement with a wide range of astronomical observations. While the number and diversity of successes of this model provide great confidence that our general picture of cosmology is correct, numerous puzzles remain. In this dissertation, I analyze the potential of planned and near future galaxy surveys to provide new understanding of several unanswered questions in cosmology, and address some of the leading challenges to this observational program. In particular, I study an emerging technique called cosmic shear, the weak gravitational lensing produced by large scale structure. I focus on developing strategies to optimally use the cosmic shear signal observed in galaxy imaging surveys to uncover the physics of dark energy and the early universe. In chapter 1 I give an overview of a few unsolved mysteries in cosmology and I motivate weak lensing as a cosmological probe. I discuss the use of weak lensing as a test of general relativity in chapter 2 and assess the threat to such tests presented by our uncertainty in the physics of galaxy formation. Interpreting the cosmic shear signal requires knowledge of the redshift distribution of the lensed galaxies. This redshift distribution will be significantly uncertain since it must be determined photometrically. In chapter 3 I investigate the influence of photometric redshift errors on our ability to constrain dark energy models with weak lensing. The ability to study dark energy with cosmic shear is also limited by the imprecision in our understanding of the physics of gravitational collapse. In chapter 4 I present the stringent calibration requirements on this source of uncertainty. I study the potential of weak lensing to resolve a debate over a long-standing anomaly in CMB measurements in chapter 5. Finally, in chapter 6 I summarize my findings and conclude with a brief discussion of my

  6. Gravitationally Lensed Quasars in Gaia: II. Discovery of 24 Lensed Quasars

    Science.gov (United States)

    Lemon, Cameron A.; Auger, Matthew W.; McMahon, Richard G.; Ostrovski, Fernanda

    2018-04-01

    We report the discovery, spectroscopic confirmation and preliminary characterisation of 24 gravitationally lensed quasars identified using Gaia observations. Candidates were selected in the Pan-STARRS footprint with quasar-like WISE colours or as photometric quasars from SDSS, requiring either multiple detections in Gaia or a single Gaia detection near a morphological galaxy. The Pan-STARRS grizY images were modelled for the most promising candidates and 60 candidate systems were followed up with the William Herschel Telescope. 13 of the lenses were discovered as Gaia multiples and 10 as single Gaia detections near galaxies. We also discover 1 lens identified through a quasar emission line in an SDSS galaxy spectrum. The lenses have median image separation 2.13″ and the source redshifts range from 1.06 to 3.36. 4 systems are quadruply-imaged and 20 are doubly-imaged. Deep CFHT data reveal an Einstein ring in one double system. We also report 12 quasar pairs, 10 of which have components at the same redshift and require further follow-up to rule out the lensing hypothesis. We compare the properties of these lenses and other known lenses recovered by our search method to a complete sample of simulated lenses to show the lenses we are missing are mainly those with small separations and higher source redshifts. The initial Gaia data release only catalogues all images of ˜ 30% of known bright lensed quasars, however the improved completeness of Gaia data release 2 will help find all bright lensed quasars on the sky.

  7. Measurement of Beam Tunes in the Tevatron Using the BBQ System

    International Nuclear Information System (INIS)

    Edstrom, Dean R.

    2009-01-01

    Measuring the betatron tunes in any synchrotron is of critical importance to ensuring the stability of beam in the synchrotron. The Base Band Tune, or BBQ, measurement system was developed by Marek Gasior of CERN and has been installed at Brookhaven and Fermilab as a part of the LHC Accelerator Research Program, or LARP. The BBQ was installed in the Tevatron to evaluate its effectiveness at reading proton and antiproton tunes at its flattop energy of 980 GeV. The primary objectives of this thesis are to examine the methods used to measure the tune using the BBQ tune measurement system, to incorporate the system into the Fermilab accelerator controls system, ACNET, and to compare the BBQ to existing tune measurement systems in the Tevatron

  8. 132 ns Bunch Spacing in the Tevatron Proton-Antiproton Collider

    International Nuclear Information System (INIS)

    Holmes, S.D.; Holt, J.; Johnstone, J.A.; Marriner, J.; Martens, M.; McGinnis, D.

    1994-12-01

    Following completion of the Fermilab Main Injector it is expected that the Tevatron proton-antiproton collider will be operating at a luminosity in excess of 5x10 3l cm -2 with 36 proton and antiproton bunches spaced at 396 nsec. At this luminosity, each of the experimental detectors will see approximately 1.3 interactions per crossing. Potential improvements to the collider low beta and rf systems could push the luminosity beyond 10x10 3l cm -2 sec -1 , resulting in more than three interactions per crossing if the bunch separation is left unchanged. This paper discusses issues related to moving to ∼100 bunch operation, with bunch spacings of 132 nsec, in the Tevatron. Specific scenarios and associated hardware requirements are described

  9. Measurement of Beam Tunes in the Tevatron Using the BBQ System

    Energy Technology Data Exchange (ETDEWEB)

    Edstrom, Dean R.; /Indiana U.

    2009-04-01

    Measuring the betatron tunes in any synchrotron is of critical importance to ensuring the stability of beam in the synchrotron. The Base Band Tune, or BBQ, measurement system was developed by Marek Gasior of CERN and has been installed at Brookhaven and Fermilab as a part of the LHC Accelerator Research Program, or LARP. The BBQ was installed in the Tevatron to evaluate its effectiveness at reading proton and antiproton tunes at its flattop energy of 980 GeV. The primary objectives of this thesis are to examine the methods used to measure the tune using the BBQ tune measurement system, to incorporate the system into the Fermilab accelerator controls system, ACNET, and to compare the BBQ to existing tune measurement systems in the Tevatron.

  10. LHC charge asymmetry as constraint on models for the Tevatron top anomaly

    International Nuclear Information System (INIS)

    Craig, Nathaniel; Kilic, Can; Strassler, Matthew J.

    2011-01-01

    The forward-backward asymmetry A FB tt in top quark production at the Tevatron has been observed to be anomalously large by both CDF and D0. It has been suggested that a model with a W ' coupling to td and ub might explain this anomaly, and other anomalies in B mesons. Single-top-quark production in this model is large, and arguably in conflict with Tevatron measurements. However the model might still be viable if A FB tt is somewhat smaller than its current measured central value. We show that even with smaller couplings, the model can be discovered (or strongly excluded) at the LHC using the 2010 data sets. We find that a suitable charge-asymmetry measurement is a powerful tool that can be used to constrain this and other sources of anomalous single-top production, and perhaps other new high-energy charge-asymmetric processes.

  11. New measurements of sextupole field decay and snapback effect on Tevatron dipole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Velev, G.V.; Bauer, P.; Carcagno, R.; DiMarco, J.; Lamm, M.; Orris, D.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2006-07-01

    To perform detailed studies of the dynamic effects in superconducting accelerator magnets, a fast continuous harmonics measurement system based on the application of a digital signal processor (DSP) has been built at Fermilab. Using this new system, the dynamic effects in the sextupole field, such as the field decay during the dwell at injection and the rapid subsequent ''snapback'' during the first few seconds of the energy ramp, are evaluated for more than ten Tevatron dipoles from the spare pool. The results confirm the previously observed fast drift in the first several seconds of the sextupole decay and provide additional information on a scaling law for predicting snapback duration. The information presented here can be used for an optimization of the Tevatron and for future LHC operations.

  12. New measurements of sextupole field decay and snapback effect on Tevatron dipole magnets

    International Nuclear Information System (INIS)

    Velev, G.V.; Bauer, P.; Carcagno, R.; DiMarco, J.; Lamm, M.; Orris, D.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.; Fermilab

    2006-01-01

    To perform detailed studies of the dynamic effects in superconducting accelerator magnets, a fast continuous harmonics measurement system based on the application of a digital signal processor (DSP) has been built at Fermilab. Using this new system, the dynamic effects in the sextupole field, such as the field decay during the dwell at injection and the rapid subsequent ''snapback'' during the first few seconds of the energy ramp, are evaluated for more than ten Tevatron dipoles from the spare pool. The results confirm the previously observed fast drift in the first several seconds of the sextupole decay and provide additional information on a scaling law for predicting snapback duration. The information presented here can be used for an optimization of the Tevatron and for future LHC operations

  13. Cornering gauge-mediated supersymmetry breaking with quasistable sleptons at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Martin, S.P.; Wells, J.D.

    1999-01-01

    There are many theoretical reasons why heavy quasistable charged particles might exist. Pair production of such particles at the Fermilab Tevatron can produce highly ionizing tracks or fake muons. In gauge-mediated supersymmetry breaking, sparticle production can lead to events with a pair of quasistable sleptons, a significant fraction of which will have the same electric charge. Depending on the production mechanism and the decay chain, they may also be accompanied by additional energetic leptons. We study the relative importance of the resulting signals for the Tevatron run II. The relative fraction of same-sign tracks to other background-free signals is an important diagnostic tool in gauge-mediated supersymmetry breaking that may provide information about mass splittings, tanβ, and the number of messengers communicating supersymmetry breaking. copyright 1999 The American Physical Society

  14. Studies of time dependence of fields in TEVATRON superconducting dipole magnets

    International Nuclear Information System (INIS)

    Hanft, R.W.; Brown, B.C.; Herrup, D.A.; Lamm, M.J.; McInturff, A.D.; Syphers, M.J.

    1988-01-01

    The time variation in the magnetic field of a model Tevatron dipole magnet at constant excitation current has been studied. Variations in symmetry allowed harmonic components over long time ranges show a log t behavior indicative of ''flux creep.'' Both short time range and long time range behavior depend in a detailed way on the excitation history. Similar effects are seen in the remnant fields present in full-scale Tevatron dipoles following current ramping. Both magnitudes and time dependences are observed to depend on details for the ramps, such as ramp rate, flattop duration, and number of ramps. In a few magnets, variations are also seen in symmetry unallowed harmonics. 9 refs., 10 figs

  15. Deterioration of the Skew Quadrupole Moment in Tevatron Dipoles Over Time

    CERN Document Server

    Syphers, Michael J

    2005-01-01

    During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by t...

  16. Relative radiosensitivity of rat lenses as a function of age

    International Nuclear Information System (INIS)

    Merriam, G.R. Jr.; Szechter, A.

    1975-01-01

    The effect of age on the development of radiation cataracts in rat lenses has been investigated using the Columbia--Sherman rat as an experiment model. A detailed pattern of age dependence was obtained at several different dose levels. In general at dose levels from 200 to 300 rads the lens changes occurred sooner and progressed faster in the adult lenses than in young lenses. In the dose range from 300 rads to 900 rads opacities developed sooner in the young lenses but progression was faster and severe opacities developed sooner in adult lenses. Above 900 rads opacities developed sooner and progressed faster in the young lenses. (U.S.)

  17. An End of Service Life Assessment of PMMA Lenses from Veteran Concentrator Photovoltaic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C.; Khonkar, Hussameldin I.; Herrero, Rebecca; Anton, Ignacio; Johnson, David K.; Vinzant, Todd B.; Deutch, Steve; To, Bobby; Sala, Gabriel; Kurtz, Sarah R.

    2017-03-21

    The optical performance of poly(methyl methacrylate) lenses from veteran concentrator photovoltaic modules was examined after the end of their service life. Lenses from the Martin-Marietta and Intersol module designs were examined from the 'Solar Village' site near Riyadh, Saudi Arabia, as well as the Phoenix Sky Harbor airport, followed by the Arizona Public Service Solar Test and Research (APS-STaR) center in Tempe, Arizona. The various lens specimens were deployed for 20, 27, and 22 years, respectively. Optical characterizations included lens efficiency (Solar Simulator instrument), material transmittance and haze (of coupons cut from veteran lenses, then measured again after their faceted back surface was polished, and then measured again after the incident front surface was polished), and direct transmittance (as a function of detector's acceptance angle, using the Very Low Angular Beam Spread ('VLABS') instrument). Lens efficiency measurements compared the central region to the entire lens, also using hot and cold mirror measurements to diagnose differences in performance. A series of subsequent characterizations was performed because a decrease in performance of greater than 10% was observed for some of the veteran lenses. Surface roughness was examined using atomic force microscopy and scanning electron microscopy. Facet geometry (tip and valley radius) was quantified on cross-sectioned specimens. Molecular weight was compared between the incident and faceted surfaces of the lenses.

  18. SVX II a silicon vertex detector for run II of the tevatron

    International Nuclear Information System (INIS)

    Bortoletto, D.

    1994-11-01

    A microstrip silicon detector SVX II has been proposed for the upgrade of the vertex detector of the CDF experiment to be installed for run II of the Tevatron in 1998. Three barrels of four layers of double sided detectors will cover the interaction region. The requirement of the silicon tracker and the specification of the sensors are discussed together with the proposed R ampersand D to verify the performance of the prototypes detectors produced by Sintef, Micron and Hamamatsu

  19. Top quark production cross-section at the Tevatron Run 2

    OpenAIRE

    Cabrera, S.

    2003-01-01

    The top quark pair production cross-section ${\\sigma}_{t\\bar{t}}$ has been measured in $p\\bar{p}$ collisions at center of mass energies of 1.96 TeV using Tevatron Run 2 data. In the begining of Run 2 both CDF and D\\O\\ $\\sigma_{t\\bar{t}}$ measurements in the {\\it dilepton} channel $t\\bar{t}{\\to}WbW\\bar{b}{\\to}\\bar{\\ell}{\

  20. Design and operation of the quench protection system for the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Martin, P.S.

    1986-05-01

    A method is required to protect the magnets of a superconducting accelerator from possible overheating or overvoltage conditions in the event that some magnets quench, that is, are elevated in temperature such that they are no longer superconducting. A brief discussion of the basic properties of superconductors and the phenomenon of quench propagation is given, followed by the configuration of a quench protection system for the Fermilab Tevatron

  1. Theoretical interest in B-Meson physics at the B factories, Tevatron and the LHC

    International Nuclear Information System (INIS)

    Ali, A.

    2007-12-01

    We review the salient features of B-meson physics, with particular emphasis on the measurements carried out at the B-factories and Tevatron, theoretical progress in understanding these measurements in the context of the standard model, and anticipation at the LHC. Topics discussed specifically are the current status of the Cabibbo-Kobayashi-Maskawa matrix, the CP-violating phases, rare radiative and semileptonic decays, and some selected non-leptonic two-body decays of the B mesons. (orig.)

  2. Cornering gauge-mediated supersymmetry breaking with quasi-stable sleptons at the Tevatron

    OpenAIRE

    Martin, Stephen P.; Wells, James D.

    1998-01-01

    There are many theoretical reasons why heavy quasi-stable charged particles might exist. Pair production of such particles at the Tevatron can produce highly ionizing tracks (HITs) or fake muons. In gauge-mediated supersymmetry breaking, sparticle production can lead to events with a pair of quasi-stable sleptons, a significant fraction of which will have the same electric charge. Depending on the production mechanism and the decay chain, they may also be accompanied by additional energetic l...

  3. Advanced forward calorimetry for the SSC and TeVatron collider

    International Nuclear Information System (INIS)

    DiBitonto, D.; Van Peteghem, P.M.; Geiger, R.L.; McIntyre, P.M.; Pang, Y.; Thane, J.M.; White, J.T.; Atac, M.

    1989-01-01

    We describe a project to develop fast, radiation hardened forward calorimetry for the SSC and TeVatron collider. Detector technologies discussed are based on gas and warm liquid media. In particular, we present the design of an ultrasensitive hybrid charge preamplifier for liquid technology capable of operating at 0.1-1 GHz. The actual detector bandwidth will depend on the choice of detector media used and the maximum allowable operating high voltage. (orig.)

  4. Coherent betatron instability driven by electrostatic separators: Stability analysis of the Tevatron

    International Nuclear Information System (INIS)

    Harfoush, F.A.; Bogacz, S.A.

    1989-03-01

    This paper outlines possible intensity limits due to the coherent betatron motion for the upgraded Tevatron with the electrostatic separators. Numerical simulation shows that this new vacuum chamber structure dominates the high frequency part of the coupling impedance spectrum and more likely will excite a slow head-tail instability. A simple stability analysis yields the characteristic growth-time of the unstable modes. 4 refs., 4 figs., 1 tab

  5. Theoretical interest in B-Meson physics at the B factories, Tevatron and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A.

    2007-12-15

    We review the salient features of B-meson physics, with particular emphasis on the measurements carried out at the B-factories and Tevatron, theoretical progress in understanding these measurements in the context of the standard model, and anticipation at the LHC. Topics discussed specifically are the current status of the Cabibbo-Kobayashi-Maskawa matrix, the CP-violating phases, rare radiative and semileptonic decays, and some selected non-leptonic two-body decays of the B mesons. (orig.)

  6. DESIGN OF THE MULTIORDER INTRAOCULAR LENSES

    Directory of Open Access Journals (Sweden)

    V. G. Kolobrodov

    2015-01-01

    Full Text Available Intraocular lenses (IOLs are used to replace the natural crystalline lens of the eye. Just few basic designs of IOLs are used clinically. Multiorder diffractive lenses (MODL which operate simultaneously in several diffractive orders were proposed to decrease the chromatic aberration. Properties analysis of MODL showed a possibility to use them to develop new designs of IOLs. The purpose of this paper was to develop a new method of designing of multiorder intraocular lenses with decreased chromatic aberration. The theoretical research of the lens properties was carried out. The diffraction efficiency dependence with the change of wavelength was studied. A computer simulation of MODL in a schematic model of the human eye was carried out. It is found the capability of the multiorder diffractive lenses to focus polychromatic light into a segment on the optical axis with high diffraction efficiency. At each point of the segment is present each component of the spectral range, which will build a color image in combination. The paper describes the new design method of intraocular lenses with reduced chromaticism and with endless adaptation. An optical system of an eye with an intraocular lens that provides sharp vision of objects located at a distance of 700 mm to infinity is modeled.

  7. Weak lensing in generalized gravity theories

    International Nuclear Information System (INIS)

    Acquaviva, Viviana; Baccigalupi, Carlo; Perrotta, Francesca

    2004-01-01

    We extend the theory of weak gravitational lensing to cosmologies with generalized gravity, described in the Lagrangian by a generic function depending on the Ricci scalar and a nonminimal coupled scalar field. We work out the generalized Poisson equations relating the dynamics of the fluctuating components to the two gauge-invariant scalar gravitational potentials, fixing the contributions from the modified background expansion and fluctuations. We show how the lensing equation gets modified by the cosmic expansion as well as by the presence of anisotropic stress, which is non-null at the linear level both in scalar-tensor gravity and in theories where the gravitational Lagrangian term features a nonminimal dependence on the Ricci scalar. Starting from the geodesic deviation, we derive the generalized expressions for the shear tensor and projected lensing potential, encoding the spacetime variation of the effective gravitational constant and isolating the contribution of the anisotropic stress, which introduces a correction due to the spatial correlation between the gravitational potentials. Finally, we work out the expressions of the lensing convergence power spectrum as well as the correlation between the lensing potential and the integrated Sachs-Wolfe effect affecting cosmic microwave background total intensity and polarization anisotropies. To illustrate phenomenologically the effects, we work out approximate expressions for the quantities above in extended quintessence scenarios where the scalar field coupled to gravity plays the role of the dark energy

  8. Diffraction and Total Cross-Section at the Tevatron and the LHC

    CERN Document Server

    Deile, M; Aurola, A; Avati, V; Berardi, V; Bottigli, U; Bozzo, M; Brucken, E; Buzzo, A; Calicchio, M; Capurro, F; Catanesi, M G; Ciocci, M A; Cuneo, S; Da Vià, C; Dimovasili, E; Eggert, K; Eraluoto, M; Ferro, F; Giachero, A; Guillaud, J P; Hasi, J; Haug, F; Heino, J; Hilden, T; Jarron, P; Kalliopuska, J; Kaspar, J; Kempa, J; Kenney, C; Kok, A; Kundrát, V; Kurvinen, K; Lami, S; Lamsa, J; Latino, G; Lauhakangas, R; Lippmaa, J; Lokajícek, M; Lo Vetere, M; Macina, D; Macri, M; Meucci, M; Minutoli, S; Morelli, A; Musico, P; Negri, M; Niewiadomski, H; Noschis, E; Ojala, J; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Paoletti, R; Parker, S; Perrot, Anne Laure; Radermacher, E; Radicioni, E; Robutti, E; Ropelewski, Leszek; Ruggiero, G; Saarikko, H; Sanguinetti, G; Santroni, A; Saramad, S; Sauli, Fabio; Scribano, A; Sette, G; Smotlacha, J; Snoeys, W; Taylor, C; Toppinen, A; Turini, N; Van Remortel, N; Verardo, L; Verdier, A; Watts, S; Whitmore, J

    2006-01-01

    At the Tevatron, the total p_bar-p cross-section has been measured by CDF at 546 GeV and 1.8 TeV, and by E710/E811 at 1.8 TeV. The two results at 1.8 TeV disagree by 2.6 standard deviations, introducing big uncertainties into extrapolations to higher energies. At the LHC, the TOTEM collaboration is preparing to resolve the ambiguity by measuring the total p-p cross-section with a precision of about 1 %. Like at the Tevatron experiments, the luminosity-independent method based on the Optical Theorem will be used. The Tevatron experiments have also performed a vast range of studies about soft and hard diffractive events, partly with antiproton tagging by Roman Pots, partly with rapidity gap tagging. At the LHC, the combined CMS/TOTEM experiments will carry out their diffractive programme with an unprecedented rapidity coverage and Roman Pot spectrometers on both sides of the interaction point. The physics menu comprises detailed studies of soft diffractive differential cross-sections, diffractive structure func...

  9. Study and optimal correction of a systematic skew quadrupole field in the Tevatron

    International Nuclear Information System (INIS)

    Snopok, Pavel; Johnstone, Carol; Berz, Martin; Ovsyannikov, Dmitry A.; Ovsyannikov, Alexander D.

    2006-01-01

    Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY INFINITY [M. Berz, COSY INFINITY version 8.1 user's guide and reference manual, Department of Physics and Astronomy MSUHEP-20704, Michigan State University (2002). URL http://cosy.pa.msu.edu/cosymanu/index.html]. Two correction schemes with one family locally correcting each arc and eight independent correctors in the straight sections for global correction are proposed and shown to dramatically improve linearity and performance of the baseline Tevatron lattice

  10. Probing the Higgs sector of high-scale SUSY-breaking models at the Tevatron

    International Nuclear Information System (INIS)

    Carena, Marcela; Liu, Tao

    2010-12-01

    A canonical signature of the Minimal Supersymmetric Standard Model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and Standard Model (SM)-like couplings to the electroweak gauge bosons. In this note we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY)-breaking, including the Constrained MSSM (CMSSM), minimal Gauge Mediated SUSY-breaking (mGMSB), and minimal Anomaly Mediated SUSY-breaking (mAMSB). We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb -1 per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb -1 , our projection shows that evidence at the 3σ level for the light Higgs boson could be expected in extended regions of parameter space. (orig.)

  11. Motivation and detectability of an invisibly decaying Higgs boson at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Martin, S.P.; Wells, J.D.

    1999-01-01

    A Higgs boson with a mass below 150 GeV has a total decay width of less than 20 MeV into accessible standard model states. This narrow width means that the usual branching fractions for such a light Higgs boson are highly susceptible to any new particles to which it has unsuppressed couplings. In particular, there are many reasonable and interesting theoretical ideas that naturally imply an invisibly decaying Higgs boson. The motivations include models with light supersymmetric neutralinos, spontaneously broken lepton number, radiatively generated neutrino masses, additional singlet scalar(s), or right-handed neutrinos in the extra dimensions of TeV gravity. We discuss these approaches to model building and their implications for Higgs boson phenomenology in future Fermilab Tevatron runs. We find, for example, that the Tevatron with 30 fb -1 integrated luminosity can make a 3σ observation in the l + l - +E/ T channel for a 125 GeV Higgs boson that is produced with the same strength as the standard model Higgs boson but always decays invisibly. We also analyze the b bar b+E/ T final state signal and conclude that it is not as sensitive, but it may assist in excluding the possibility of an invisibly decaying Higgs boson or enable confirmation of an observed signal in the dilepton channel. We argue that a comprehensive Higgs boson search at the Tevatron should include the possibility that the Higgs boson decays invisibly. copyright 1999 The American Physical Society

  12. Probing the Higgs sector of high-scale SUSY-breaking models at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Carena, Marcela [Fermi National Accelerator Laboratory, Batavia, IL (United States); Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; Draper, Patrick [Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; Heinemeyer, Sven [Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Liu, Tao [Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; California Univ., Santa Barbara, CA (United States). Dept. of Physics; Wagner, Carlos E.M. [Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; Argonne National Laboratory, Argonne, IL (United States). HEP Div.; Chicago Univ., Chicago, IL (United States). KICP and Dept. of Physics; Weiglein, Georg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    A canonical signature of the Minimal Supersymmetric Standard Model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and Standard Model (SM)-like couplings to the electroweak gauge bosons. In this note we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY)-breaking, including the Constrained MSSM (CMSSM), minimal Gauge Mediated SUSY-breaking (mGMSB), and minimal Anomaly Mediated SUSY-breaking (mAMSB). We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb{sup -1} per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb{sup -1}, our projection shows that evidence at the 3{sigma} level for the light Higgs boson could be expected in extended regions of parameter space. (orig.)

  13. Multifocal versus monofocal intraocular lenses after cataract extraction

    Directory of Open Access Journals (Sweden)

    Daniel Calladine

    Full Text Available BACKGROUND: Good unaided distance visual acuity is now a realistic expectation following cataract surgery and intraocular lens (IOL implantation. Near vision, however, still requires additional refractive power, usually in the form of reading glasses. Multiple optic (multifocal IOLs are available which claim to allow good vision at a range of distances. It is unclear whether this benefit outweighs the optical compromises inherent in multifocal IOLs. OBJECTIVES: The objective of this review was to assess the effects of multifocal IOLs, including effects on visual acuity, subjective visual satisfaction, spectacle dependence, glare and contrast sensitivity, compared to standard monofocal lenses in people undergoing cataract surgery. METHODS: Search methods: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register, The Cochrane Library 2012, Issue 2, MEDLINE (January 1946 to March 2012, EMBASE (January 1980 to March 2012, the metaRegister of Controlled Trials (mRCT (www.controlled-trials.com, ClinicalTrials.gov (www.clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP (www.who.int/ictrp/search/en. We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 6 March 2012. We searched the reference lists of relevant articles and contacted investigators of included studies and manufacturers of multifocal IOLs for information about additional published and unpublished studies. Selection criteria: All randomised controlled trials comparing a multifocal IOL of any type with a monofocal IOL as control were included. Both unilateral and bilateral implantation trials were included. Data collection and analysis: Two authors collected data and assessed trial quality. Where possible, we pooled data from the individual studies using a random-effects model, otherwise we tabulated data. MAIN RESULTS: Sixteen completed trials

  14. Relations between focusing power of space-charge lenses and external electromagnetic fields

    International Nuclear Information System (INIS)

    Yu Qingchang; Qiu Hong; Huang Jiachang

    1991-01-01

    Under different external electromagnetic fields, the electron densities of the electron cloud in a self-sustaning spece-charge lens are measured with the radio-frequency method and the energy distributions of the ions produced in ionization are measured with the stopping field method. From them the relations between the focusing power of space-charge lenses and the external electromagnetic fields are determined. The available region of the Lebedev-Morozov formula is discussed

  15. New shower maximum trigger for electrons and photons at CDF

    International Nuclear Information System (INIS)

    Amidei, D.; Burkett, K.; Gerdes, D.; Miao, C.; Wolinski, D.

    1994-01-01

    For the 1994 Tevatron collider run, CDF has upgraded the electron and photo trigger hardware to make use of shower position and size information from the central shower maximum detector. For electrons, the upgrade has resulted in a 50% reduction in backgrounds while retaining approximately 90% of the signal. The new trigger also eliminates the background to photon triggers from single-phototube spikes

  16. New shower maximum trigger for electrons and photons at CDF

    International Nuclear Information System (INIS)

    Gerdes, D.

    1994-08-01

    For the 1994 Tevatron collider run, CDF has upgraded the electron and photon trigger hardware to make use of shower position and size information from the central shower maximum detector. For electrons, the upgrade has resulted in a 50% reduction in backgrounds while retaining approximately 90% of the signal. The new trigger also eliminates the background to photon triggers from single-phototube discharge

  17. Stationary nonimaging lenses for solar concentration.

    Science.gov (United States)

    Kotsidas, Panagiotis; Chatzi, Eleni; Modi, Vijay

    2010-09-20

    A novel approach for the design of refractive lenses is presented, where the lens is mounted on a stationary aperture and the Sun is tracked by a moving solar cell. The purpose of this work is to design a quasi-stationary concentrator by replacing the two-axis tracking of the Sun with internal motion of the miniaturized solar cell inside the module. Families of lenses are designed with a variation of the simultaneous multiple surface technique in which the sawtooth genetic algorithm is implemented to optimize the geometric variables of the optic in order to produce high fluxes for a range of incidence angles. Finally, we show examples of the technique for lenses with 60° and 30° acceptance half-angles, with low to medium attainable concentrations.

  18. Gravitational Lensing from a Spacetime Perspective

    Directory of Open Access Journals (Sweden)

    Perlick Volker

    2004-09-01

    Full Text Available The theory of gravitational lensing is reviewed from a spacetime perspective, without quasi-Newtonian approximations. More precisely, the review covers all aspects of gravitational lensing where light propagation is described in terms of lightlike geodesics of a metric of Lorentzian signature. It includes the basic equations and the relevant techniques for calculating the position, the shape, and the brightness of images in an arbitrary general-relativistic spacetime. It also includes general theorems on the classification of caustics, on criteria for multiple imaging, and on the possible number of images. The general results are illustrated with examples of spacetimes where the lensing features can be explicitly calculated, including the Schwarzschild spacetime, the Kerr spacetime, the spacetime of a straight string, plane gravitational waves, and others.

  19. Weak lensing in the Dark Energy Survey

    Science.gov (United States)

    Troxel, Michael

    2016-03-01

    I will present the current status of weak lensing results from the Dark Energy Survey (DES). DES will survey 5000 square degrees in five photometric bands (grizY), and has already provided a competitive weak lensing catalog from Science Verification data covering just 3% of the final survey footprint. I will summarize the status of shear catalog production using observations from the first year of the survey and discuss recent weak lensing science results from DES. Finally, I will report on the outlook for future cosmological analyses in DES including the two-point cosmic shear correlation function and discuss challenges that DES and future surveys will face in achieving a control of systematics that allows us to take full advantage of the available statistical power of our shear catalogs.

  20. Nanofocusing parabolic refractive x-ray lenses

    International Nuclear Information System (INIS)

    Schroer, C.G.; Kuhlmann, M.; Hunger, U.T.; Guenzler, T.F.; Kurapova, O.; Feste, S.; Frehse, F.; Lengeler, B.; Drakopoulos, M.; Somogyi, A.; Simionovici, A.S.; Snigirev, A.; Snigireva, I.; Schug, C.; Schroeder, W.H.

    2003-01-01

    Parabolic refractive x-ray lenses with short focal distance can generate intensive hard x-ray microbeams with lateral extensions in the 100 nm range even at a short distance from a synchrotron radiation source. We have fabricated planar parabolic lenses made of silicon that have a focal distance in the range of a few millimeters at hard x-ray energies. In a crossed geometry, two lenses were used to generate a microbeam with a lateral size of 380 nm by 210 nm at 25 keV in a distance of 42 m from the synchrotron radiation source. Using diamond as the lens material, microbeams with a lateral size down to 20 nm and below are conceivable in the energy range from 10 to 100 keV

  1. Optical performance of random anti-reflection structured surfaces (rARSS) on spherical lenses

    Science.gov (United States)

    Taylor, Courtney D.

    Random anti-reflection structured surfaces (rARSS) have been reported to improve transmittance of optical-grade fused silica planar substrates to values greater than 99%. These textures are fabricated directly on the substrates using reactive-ion/inductively-coupled plasma etching (RIE/ICP) techniques, and often result in transmitted spectra with no measurable interference effects (fringes) for a wide range of wavelengths. The RIE/ICP processes used in the fabrication process to etch the rARSS is anisotropic and thus well suited for planar components. The improvement in spectral transmission has been found to be independent of optical incidence angles for values from 0° to +/-30°. Qualifying and quantifying the rARSS performance on curved substrates, such as convex lenses, is required to optimize the fabrication of the desired AR effect on optical-power elements. In this work, rARSS was fabricated on fused silica plano-convex (PCX) and plano-concave (PCV) lenses using a planar-substrate optimized RIE process to maximize optical transmission in the range from 500 to 1100 nm. An additional set of lenses were etched in a non-optimized ICP process to provide additional comparisons. Results are presented from optical transmission and beam propagation tests (optimized lenses only) of rARSS lenses for both TE and TM incident polarizations at a wavelength of 633 nm and over a 70° full field of view in both singlet and doublet configurations. These results suggest optimization of the fabrication process is not required, mainly due to the wide angle-of-incidence AR tolerance performance of the rARSS lenses. Non-optimized recipe lenses showed low transmission enhancement, and confirmed the need to optimized etch recipes prior to process transfer of PCX/PCV lenses. Beam propagation tests indicated no major beam degradation through the optimized lens elements. Scanning electron microscopy (SEM) images confirmed different structure between optimized and non-optimized samples

  2. Soft-contact-lenses-induced complications

    Directory of Open Access Journals (Sweden)

    Suvajac Gordana

    2008-01-01

    Full Text Available Background/Aim. Soft contact lenses occupy significant place in ophthalmology, both in the correction of refraction anomalies and in the treatment of many eye diseases. The number of patients that wear soft contact lenses for the purpose of correcting ametropia is constantly increasing. Due to the increasing number of wearers, the percentage of complications that can lead to serious eye damage and serious vision loss is also increasing. The aim of this study was to point out the most common complications related to soft contact lens use. Methods. In the period from 1995−2004 this prospective study included 510 patients wearing soft contact lenses for correcting ametropia. None of the patients wore contact lenses before and none suffered from any system or local diseases that could affected the development of eventual complications. The study took seven years with the patients who wore conventional lenses and three years with those who wore replacement contact lenses. All the necessary ophthalmologic examinations were done (visual acuity, refractokeratometry, the quantity of tear film, biomicroscopic examination of anterior eye segment. All the complications were filmed by video camera. Results. Of all the patients, 19 had blepharitis, 73 suffered from “dry eye”, 57 had conjunctival hyperemia, 12 had conjunctivitis, 34 had gigantopapillary conjunctivitis (GPC, 93 had punctiform epitheliopathy, 20 had corneal infiltration, one patient had keratitis, 91 had corneal vascularisation, and 95 patients had corneal deposits. Conclusion. Both the type and frequency of complications related to soft contact lens use in our group of patients, proved to be significant. Some of this complications (keratitis can significantly damage vision and lead to loss of vision and sometimes can require operative treatment.

  3. The Mathematical Theory of Multifocal Lenses

    Institute of Scientific and Technical Information of China (English)

    Jacob RUBINSTEIN

    2017-01-01

    This paper presents the fundamental optical concepts of designing multifocal ophthalmic lenses and the mathematical methods associated with them.In particular,it is shown that the design methodology is heavily based on differential geometric ideas such as Willmore surfaces.A key role is played by Hamilton's eikonal functions.It is shown that these functions capture all the information on the local blur and distortion created by the lenses.Along the way,formulas for computing the eikonal functions are derived.Finally,the author lists a few intriguing mathematical problems and novel concepts in optics as future projects.

  4. Achromatic Cooling Channel with Li Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Balbekov, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2002-04-29

    A linear cooling channel with Li lenses, solenoids, and 201 MHz RF cavities is considered. A special lattice design is used to minimize chromatic aberrations by suppression of several betatron resonances. Transverse emittance of muon beam decreases from 2 mm to 0.5 mm at the channel of about 110 m length. Longitudinal heating is modest, therefore transmission of the channel is rather high: 96% without decay and 90% with decay. Minimal beam emittance achievable by similar channel estimated as about 0.25 mm at surface field of Li lenses 10 T.

  5. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu

    2015-01-01

    This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

  6. Dynamics of Fermat potentials in nonperturbative gravitational lensing

    International Nuclear Information System (INIS)

    Frittelli, Simonetta; Newman, Ezra T.

    2002-01-01

    We present a framework, based on the null-surface formulation of general relativity, for discussing the dynamics of Fermat potentials for gravitational lensing in a generic situation without approximations of any kind. Additionally, we derive two lens equations: one for the case of thick compact lenses and the other one for lensing by gravitational waves. These equations in principle generalize the astrophysical scheme for lensing by removing the thin-lens approximation while retaining the weak fields

  7. W boson production and mass at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Stelzer-Chilton, Oliver; /Toronto U.

    2005-06-01

    The CDF and D0 collaborations have analyzed up to {approx} 200 pb{sup -1} of Run 2 physics data to measure W production properties such as the W cross section, the W width, lepton universality and the W charge asymmetry. From the cross section measurements, CDF obtains a lepton universality of g{sub {mu}}/g{sub e} = 0.998 {+-} 0.012 and g{sub {tau}}/g{sub e} = 0.99 {+-} 0.04 and an indirect W width of {Lambda}{sub W} = 2079 {+-} 41 MeV. D0 measured the W width directly and finds {Lambda}{sub W} = 2011 {+-} 142 MeV. CDF has estimated the uncertainties on the W boson mass measurements in the electron and muon decay channels and obtains an overall uncertainty of 76 MeV.

  8. Low-energy beam transport using space-charge lenses

    International Nuclear Information System (INIS)

    Meusel, O.; Bechtold, A.; Pozimski, J.; Ratzinger, U.; Schempp, A.; Klein, H.

    2005-01-01

    Space-charge lenses (SCL) of the Gabor type provide strong cylinder symmetric focusing for low-energy ion beams using a confined nonneutral plasma. They need modest magnetic and electrostatic field strength and provide a short installation length when compared to conventional LEBT-lenses like quadrupoles and magnetic solenoids. The density distribution of the enclosed space charge within the Gabor lens is given by the confinement in transverse and longitudinal directions. In the case of a positive ion beam, the space charge of the confined electron cloud may cause an overcompensation of the ion beam space-charge force and consequently focuses the beam. To investigate the capabilities of an SCL double-lens system for ion beam into an RFQ, a test injector was installed at IAP and put into operation successfully. Furthermore, to study the focusing capabilities of this lens at beam energies up to 500 keV, a high-field Gabor lens was built and installed downstream of the RFQ. Experimental results of the beam injection into the RFQ are presented as well as those of these first bunched beam-focusing tests with the 110 A keV He + beam

  9. Bacterial and fungal biofilm formation on contact lenses and their susceptibility to lens care solutions

    Directory of Open Access Journals (Sweden)

    Siddharth Kackar

    2017-01-01

    Full Text Available Background: Microbial biofilm formation on contact lenses and lens storage cases may be a risk factor for contact lens-associated corneal infections. Various types of contact lens care solutions are used to reduce microbial growths on lenses. Objectives: The present study aimed at comparing the growths of biofilms on the different contact lenses and lens cases. The study also aimed at determining the effect of lens care solutions and bacteriophage on these biofilms. Materials and Methods: One type of hard lens and two types of soft lenses were used for the study. The organisms used were Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 60193 and Escherichia coli ATCC 25922. Biofilm production was performed by modified O'Toole and Kolter method and effect of lens cleaning solutions and a crude coliphage on biofilms was also studied. Results were visualised using scanning electron microscopy and quantitated by colony counting method and spectrophotometric measurement of optical density (OD. Statistical analysis was done by SPSS 11.5, Kruskal–Wallis test and Chi-square test. Results: Soft lens cleaning solutions had a significant inhibitory effect (P = 0.020 on biofilm formation on soft lenses and also lens cases (P < 0.001. Soft lens cleaning solution 2 was more efficient than solution 1. However, no such inhibitory effect was observed with regard to hard lens cleaning solution, but for a significant reduction in the OD values (P < 0.001. There was no significant inhibitory effect by bacteriophages. Conclusion: This study showed the importance of selecting the appropriate lens cleaning solution to prevent biofilm production on contact lenses.

  10. Analysis of luminosity distributions of strong lensing galaxies: subtraction of diffuse lensed signal

    Science.gov (United States)

    Biernaux, J.; Magain, P.; Hauret, C.

    2017-08-01

    Context. Strong gravitational lensing gives access to the total mass distribution of galaxies. It can unveil a great deal of information about the lenses' dark matter content when combined with the study of the lenses' light profile. However, gravitational lensing galaxies, by definition, appear surrounded by lensed signal, both point-like and diffuse, that is irrelevant to the lens flux. Therefore, the observer is most often restricted to studying the innermost portions of the galaxy, where classical fitting methods show some instabilities. Aims: We aim at subtracting that lensed signal and at characterising some lenses' light profile by computing their shape parameters (half-light radius, ellipticity, and position angle). Our objective is to evaluate the total integrated flux in an aperture the size of the Einstein ring in order to obtain a robust estimate of the quantity of ordinary (luminous) matter in each system. Methods: We are expanding the work we started in a previous paper that consisted in subtracting point-like lensed images and in independently measuring each shape parameter. We improve it by designing a subtraction of the diffuse lensed signal, based only on one simple hypothesis of symmetry. We apply it to the cases where it proves to be necessary. This extra step improves our study of the shape parameters and we refine it even more by upgrading our half-light radius measurement method. We also calculate the impact of our specific image processing on the error bars. Results: The diffuse lensed signal subtraction makes it possible to study a larger portion of relevant galactic flux, as the radius of the fitting region increases by on average 17%. We retrieve new half-light radii values that are on average 11% smaller than in our previous work, although the uncertainties overlap in most cases. This shows that not taking the diffuse lensed signal into account may lead to a significant overestimate of the half-light radius. We are also able to measure

  11. Cosmological applications of strong gravitational lensing

    DEFF Research Database (Denmark)

    Paraficz, Danuta

    value of the energy density of the two above components, together with measuring the Hubble constant that determines the age of the Universe, is a major goal of modern astrophysics. An interesting method for estimating these parameters is strong gravitational lensing of quasars (QSOs). As shown...

  12. A gravitationally lensed quasar discovered in OGLE

    Science.gov (United States)

    Kostrzewa-Rutkowska, Zuzanna; Kozłowski, Szymon; Lemon, Cameron; Anguita, T.; Greiner, J.; Auger, M. W.; Wyrzykowski, Ł.; Apostolovski, Y.; Bolmer, J.; Udalski, A.; Szymański, M. K.; Soszyński, I.; Poleski, R.; Pietrukowicz, P.; Skowron, J.; Mróz, P.; Ulaczyk, K.; Pawlak, M.

    2018-05-01

    We report the discovery of a new gravitationally lensed quasar (double) from the Optical Gravitational Lensing Experiment (OGLE) identified inside the ˜670deg2 area encompassing the Magellanic Clouds. The source was selected as one of ˜60 `red W1 - W2' mid-infrared objects from WISE and having a significant amount of variability in OGLE for both two (or more) nearby sources. This is the first detection of a gravitational lens, where the discovery is made `the other way around', meaning we first measured the time delay between the two lensed quasar images of -132 Technology Telescope spectra. The spectral energy distribution (SED) fitting with the fixed source redshift provided the estimate of the lensing galaxy redshift of z ≈ 0.9 ± 0.2 (90 per cent CL), while its type is more likely to be elliptical (the SED-inferred and lens-model stellar mass is more likely present in ellipticals) than spiral (preferred redshift by the lens model).

  13. Weak lensing probes of modified gravity

    International Nuclear Information System (INIS)

    Schmidt, Fabian

    2008-01-01

    We study the effect of modifications to general relativity on large-scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the Dvali-Gabadadze-Porrati model, and tensor-vector-scalar theory. Weak lensing is sensitive to the growth of structure and the relation between matter and gravitational potentials, both of which will in general be affected by modified gravity. Restricting ourselves to linear scales, we compare the predictions for galaxy-shear and shear-shear correlations of each modified gravity cosmology to those of an effective dark energy cosmology with the same expansion history. In this way, the effects of modified gravity on the growth of perturbations are separated from the expansion history. We also propose a test which isolates the matter-potential relation from the growth factor and matter power spectrum. For all three modified gravity models, the predictions for galaxy and shear correlations will be discernible from those of dark energy with very high significance in future weak lensing surveys. Furthermore, each model predicts a measurably distinct scale dependence and redshift evolution of galaxy and shear correlations, which can be traced back to the physical foundations of each model. We show that the signal-to-noise for detecting signatures of modified gravity is much higher for weak lensing observables as compared to the integrated Sachs-Wolfe effect, measured via the galaxy-cosmic microwave background cross-correlation.

  14. Strong gravitational lensing by Sgr A*

    International Nuclear Information System (INIS)

    Bin-Nun, Amitai Y

    2011-01-01

    In recent years, there has been increasing recognition of the potential to use the galactic center as a probe of general relativity in the strong field. There is almost certainly a black hole at Sgr A* in the galactic center, and this would allow us to have the opportunity to probe dynamics near the exterior of the black hole. In the last decade, there has been theoretical research into extreme gravitational lensing in the galactic center. Unlike in most applications of gravitational lensing, where the bending angle is of the order of, at most, an arc minute, very large bending angles are possible for light that closely approaches a black hole. Photons may even loop multiple times around a black hole before reaching the observer. There have been many proposals to use light's close approach to the black hole as a probe of the black hole metric. Of particular interest are the properties of images formed from the light of S stars orbiting in the galactic center. This paper will review some of the attempts made to study extreme lensing as well as extend the analysis of S star lensing. In particular, we are interested in the effect of a Reissner-Nordstrom like 1/r 2 term in the metric and how this would affect the properties of relativistic images.

  15. Quantum Spin Lenses in Atomic Arrays

    Directory of Open Access Journals (Sweden)

    A. W. Glaetzle

    2017-09-01

    Full Text Available We propose and discuss quantum spin lenses, where quantum states of delocalized spin excitations in an atomic medium are focused in space in a coherent quantum process down to (essentially single atoms. These can be employed to create controlled interactions in a quantum light-matter interface, where photonic qubits stored in an atomic ensemble are mapped to a quantum register represented by single atoms. We propose Hamiltonians for quantum spin lenses as inhomogeneous spin models on lattices, which can be realized with Rydberg atoms in 1D, 2D, and 3D, and with strings of trapped ions. We discuss both linear and nonlinear quantum spin lenses: in a nonlinear lens, repulsive spin-spin interactions lead to focusing dynamics conditional to the number of spin excitations. This allows the mapping of quantum superpositions of delocalized spin excitations to superpositions of spatial spin patterns, which can be addressed by light fields and manipulated. Finally, we propose multifocal quantum spin lenses as a way to generate and distribute entanglement between distant atoms in an atomic lattice array.

  16. Software for Fermat's Principle and Lenses

    Science.gov (United States)

    Mihas, Pavlos

    2012-01-01

    Fermat's principle is considered as a unifying concept. It is usually presented erroneously as a "least time principle". In this paper we present some software that shows cases of maxima and minima and the application of Fermat's principle to the problem of focusing in lenses. (Contains 12 figures.)

  17. Studying dark matter haloes with weak lensing

    NARCIS (Netherlands)

    Velander, Malin Barbro Margareta

    2012-01-01

    Our Universe is comprised not only of normal matter but also of unknown components: dark matter and dark energy. This Thesis recounts studies of dark matter haloes, using a technique known as weak gravitational lensing, in order to learn more about the nature of these dark components. The haloes

  18. Tear exchange and contact lenses: a review.

    Science.gov (United States)

    Muntz, Alex; Subbaraman, Lakshman N; Sorbara, Luigina; Jones, Lyndon

    2015-01-01

    Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  19. Multiply imaged Transient Events in Cluster Lenses

    Science.gov (United States)

    Narasimha, Delampady

    2018-04-01

    ARIES had a successful gravitational microlens project during 1998-2002. A similar monitor for Transient Events in galaxies at high redshift lensed by rich galaxy-clusters provides a challenging possibility with important cosmological implications. Rich galaxy-clusters at intermediate redshifts are powerful gravitational lenses which produce multiple images, in the shape of giant arcs of 5-20" extent, of distant background galaxies in their field. Weak lens shear of the background galaxy distribution can reliably trace the lens mass profile. Multiple images of supernovae or GRBs in the background galaxies can be recorded in a systematic monitor of the system. An unlensed high redshift supernova might not be observable, but when lensed by a galaxy-cluster, it will stand out because the point event brightens relative to the host. The color profile of a high redshift lensed point event will be much more reliable than an unlensed one due to much less host contamination. An estimate of the time delay enables observation of the full light curve of the subsequent images of the event. ARIES can have outside collaboration for multiband simultaneous lightcurves of other images. The measured time delay and position of images of the transient event provide better cosmological constraints including distance scale of the Universe. The Devasthal telescope can detect one or more events by monitoring half a dozen cluster fields over three years time.

  20. Coatings and Tints of Spectacle Lenses

    Directory of Open Access Journals (Sweden)

    H. Zeki Büyükyıldız

    2012-10-01

    Full Text Available Spectacle lenses are made of mineral or organic (plastic materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1 Anti-reflection coatings, 2 Hard coatings, 3 Clean coat, 4 Mirror coatings, 5 Color tint coating (one of coloring processes, 6 Photochromic coating (one of photochromic processes, and 7 Anti-fog coatings. Anti-reflection coatings reduce unwanted reflections from the lens surfaces and increase light transmission. Hard coatings are applied for preventing the plastic lens surface from scratches and abrasion. Hard coatings are not required for the mineral lenses due to their hardness. Clean coat makes the lens surface smooth and hydrophobic. Thus, it prevents the adherence of dust, tarnish, and dirt particles on the lens surface. Mirror coatings are applied onto the sunglasses for cosmetic purpose. Color tinted and photochromic lenses are used for sun protection and absorption of the harmful UV radiations. Anti-fog coatings make the lens surface hydrophilic and prevent the coalescence of tiny water droplets on the lens surface that reduces light transmission. (Turk J Ophthalmol 2012; 42: 359-69

  1. Teaching the Theory of Real Lenses.

    Science.gov (United States)

    Walther, A.

    1996-01-01

    Presents an approach to the study of real lenses that would not contradict Fermat's principle. Shows how the rudiments of the correct theory can be incorporated into courses to provide students a clearer notion of what they can expect in laboratory situations. (DDR)

  2. Are Disposable and Standard Gonioscopy Lenses Comparable?

    Science.gov (United States)

    Lee, Bonny; Szirth, Bernard C; Fechtner, Robert D; Khouri, Albert S

    2017-04-01

    Gonioscopy is important in the evaluation and treatment of glaucoma. With increased scrutiny of acceptable sterilization processes for health care instruments, disposable gonioscopy lenses have recently been introduced. Single-time use lenses are theorized to decrease infection risk and eliminate the issue of wear and tear seen on standard, reusable lenses. However, patient care would be compromised if the quality of images produced by the disposable lens were inferior to those produced by the reusable lens. The purpose of this study was to compare the quality of images produced by disposable versus standard gonioscopy lenses. A disposable single mirror lens (Sensor Medical Technology) and a standard Volk G-1 gonioscopy lens were used to image 21 volunteers who were prospectively recruited for the study. Images of the inferior and temporal angles of each subject's left eye were acquired using a slit-lamp camera through the disposable and standard gonioscopy lens. In total, 74 images were graded using the Spaeth gonioscopic system and for clarity and quality. Clarity was scored as 1 or 2 and defined as either (1) all structures perceived or (2) all structures not perceived. Quality was scored as 1, 2, or 3, and defined as (1) all angle landmarks clear and well focused, (2) some angle landmarks clear, others blurred, or (3) angle landmarks could not be ascertained. The 74 images were divided into images taken with the disposable single mirror lens and images taken with the standard Volk G-1 gonioscopy lens. The clarity and quality scores for each of these 2 image groups were averaged and P-values were calculated. Average quality of images produced with the standard lens was 1.46±0.56 compared with 1.54±0.61 for those produced with the disposable lens (P=0.55). Average clarity of images produced with the standard lens was 1.47±0.51 compared with 1.49±0.51 (P=0.90) with the disposable lens. We conclude that there is no significant difference in quality of images

  3. X-ray lenses with large aperture

    International Nuclear Information System (INIS)

    Simon, Markus

    2010-01-01

    Up to now, most X-ray imaging setups are based on absorption contrast imaging. There is a demand for focused X-rays in many X-ray analysis applications, either to increase the resolution of an imaging system, or, to reduce the time effort of an experiment through higher photon flux. For photon energies higher than 15 keV refractive X-ray optics are more efficient in comparison to non-refractive X-ray optics. The aim of this work was to develop X-ray lenses with large apertures and high transparency. By increasing the number of refracting surfaces while removing unnecessary lens material such lenses have been developed. Utilizing this approach the overall beam deflection angle is large with respect to the lens material it propagates through and so the transparency of the lens is increased. Within this work, X-ray lenses consisting of several thousands of prisms with an edge length in the range of micrometers have been developed and fabricated by deep X-ray lithography. Deep X-ray lithography enables high precision microstrucures with smooth sidewalls and large aspect ratios. The aperture of high-transparency X-ray lenses made this way is greater than 1 mm. They are suitable for photon energies in the range of 8 keV to 24 keV and offer a focal width of smaller than 10 μm at a transparency of around 40%. Furthermore, rolled X-ray lenses have been developed, that are made out of a microstructured polyimide film, which is cut according to the requirements regarding focal length and photon energy. The microstructured film is fabricated by molding, using an anisotropically etched silicon wafer as molding tool. Its mean roughness is in the range of nanometers. The film features prismatic structures, its surface topology is similar to an asparagus field. The measured diameter of the point focus was 18 μm to 31 μm, the calculated opticla efficiency was 37%. Future work will concentrate on increasing the aspect ratio of Prism Lenses and on increasing the rolling accuracy

  4. Identification of $\\tau$ leptons and Higgs boson search in the $\\mu+\\tau$ final state at the D0 experiment at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Madar, Romain [Univ. of Paris, Orsay (France)

    2011-01-01

    The gauge symmetry is the heart of our understanding of the electroweak interaction and describes all the current experimental results. However, the intrinsic incompatibility between the gauge invariance and the mass of particles leads to the introduction of a new particle, the Higgs boson, for which we have no experimental evidence as of today. This thesis describes the Higgs boson search in the μ + τ final state in 7.3 fb-1 of pp collisions at √s = 1.96 TeV collected by the DØ detector at the Tevatron. This analysis completes the golden channels (dimuons, electron-muon, dielectrons) exploiting the decay chain H → WW → ℓvℓv , which is the main Higgs boson decay mode in the mass window accessible to the Tevatron. Since the final state includes a lepton, work was done to improve their identification among jets. An increase of 15% was achieved thanks to the the following : changing tuning parameters for the identification neural network, use of the kinematical dependence of the algorithm performances, incorporation of the τ lepton life time information and full study of the additionnal information coming from the central preshower measurements. Then, since the dominant background of the μ + τ Higgs boson search is W+jets (where one jet fakes a τ ), a method was developed to obtain good modeling of this background, not provided by the default simulation. This method is based, among other things, on the charge correlation between the muon and the τ candidate which allows for calibration of this background in the data excluding the signal region. Finally, all the kinematic and/or topological differences between the signal and the background were exploited to optimize this search, reaching an (observed) expected sensitivity of 7.8 (6.6) times the Standard Model for mH = 165 GeV=c2. In addition, this result was also interpreted in a fourth fermion generation scenario. For the first time, this analysis is included in the D

  5. The behavior of the Tevatron at energies greater than 1000 GeV

    International Nuclear Information System (INIS)

    Pogorelko, O.

    1991-04-01

    If, as appears likely, the top quark lies at the upper range of the mass reach of the Tevatron, then increasing the energy of the collider operation could prove to be a crucial factor in the future program together with projected luminosity enhancements. While a significant amount of data exists on individual magnets up to an energy of 1000 GeV, there are no detailed measurements above this value. We focus on the operating range beyond 1000 GeV in an attempt to see whether there is any realistic opportunity to extend the energy range of the Tevatron into this regime. The proposed modifications to the Tevatron Cryogenic System will provide sufficient cooling to lower the operating temperature of the 1000 superconducting magnets from the present 4.6--4.8K (1-φ inlet temperature) down to a range of 3.6--3.8K. At this temperature the short sample quench current for the dipole magnets should increase from the present value of ∼4000A (900 GeV) up to a level approaching 4800A (1100 GeV.) Increasing the peak current in the dipoles produces some important questions related to possible mechanical effects including catastrophic failure, the change of magnetic field quality, and quench protection problems resulting from the increased stored energy. In this note we shall examine these effects and comment on the existing data on low temperature operation. We have only considered the dipole magnets since the quadrupoles should not limit performance. We have not looked at the interaction region magnets which involve different considerations

  6. Review of searches for Higgs bosons and beyond the standard model physics at the Tevatron

    International Nuclear Information System (INIS)

    Duperrin, Arnaud

    2009-01-01

    The energy frontier is currently at the Fermilab Tevatron accelerator, which collides protons and antiprotons at a center-of-mass energy of 1.96 TeV. The luminosity delivered to the CDF and DOe experiments has now surpassed the 4 fb -1 . This paper reviews the most recent direct searches for Higgs bosons and beyond-the-standard-model (BSM) physics at the tevatron. The results reported correspond to an integrated luminosity of up to 2.5 fb -1 of Run II data collected by the two Collaborations. Searches covered include the standard model (SM) Higgs boson (including sensitivity projections), the neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM), charged Higgs bosons and extended Higgs models, supersymmetric decays that conserve or violate R-parity, gauge-mediated supersymmetric breaking models, long-lived particles, leptoquarks, compositeness, extra gauge bosons, extra dimensions, and finally signature-based searches. Given the excellent performance of the collider and the continued productivity of the experiments, the Tevatron physics potential looks promising for discovery with the coming larger data sets. In particular, evidence for the SM Higgs boson could be obtained if its mass is light or near 160 GeV. The observed (expected) upper limits are currently a factor of 3.7 (3.3) higher than the expected SM Higgs boson cross section at m H =115 GeV and 1.1(1.6) at m H =160 GeV at 95% C.L. (orig.)

  7. Recent results on top, bottom and exotic physics at the Tevatron

    International Nuclear Information System (INIS)

    Shaw, N.M.

    1993-08-01

    A summary of results from the recently concluded 1991--1993 Tevatron run is presented. Selected topics from b physics and exotic particle searches from the CDF and D0 collaborations are reviewed. Preliminary results from the CDF top search, using 12pb -1 from the 1992--1993 run, are given. In particular, the lepton + b-tag and dilepton analyses are discussed. Preliminary results from the CDF dilepton analysis places a lower limit on the top quark mass of 108GeV/c 2 at the 95% C.L

  8. Search for chargino and neutralino at Run II of the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Canepa, Anadi [Purdue Univ., West Lafayette, IN (United States)

    2006-08-01

    In this dissertation we present a search for the associated production of charginos and neutralinos, the supersymmetric partners of the Standard Model bosons. We analyze a data sample representing 745 pb-1 of integrated luminosity collected by the CDF experiment at the p$\\bar{p}$ Tevatron collider. We compare the Standard Model predictions with the observed data selecting events with three leptons and missing transverse energy. Finding no excess, we combine the results of our search with similar analyses carried out at CDF and set an upper limit on the chargino mass in SUSY scenarios.

  9. Production measurements on the quadrupole correctors for the new Low- Beta System for the Tevatron Collider

    International Nuclear Information System (INIS)

    Mokhtarani, A.; Brown, B.C.; Hanft, R.; Oleck, A.R.; Peterson, T.; Turkot, F.

    1991-05-01

    Each of the Low Beta Systems for the Tevatron Collider requires 12 spool pieces; eight of the spool pieces contain superconducting quadrupoles as part of the low beta insertion as well as standard correction magnets. The remaining four provide correction magnets, beam position monitors, and current feeds for the neighboring low beta main quadrupoles. Thirty-two of these new spools have been fabricated. We describe here the mechanical, cryogenic and magnetic properties of these new spools as determined in the production test and measurement activities. 8 refs., 7 figs., 1 tab

  10. Microwave Schottky diagnostic systems for the Fermilab Tevatron, Recycler, and CERN Large Hadron Collider

    Directory of Open Access Journals (Sweden)

    Ralph J. Pasquinelli

    2011-07-01

    Full Text Available A means for noninvasive measurement of transverse and longitudinal characteristics of bunched beams in synchrotrons has been developed based on high sensitivity slotted waveguide pickups. The pickups allow for bandwidths exceeding hundreds of MHz while maintaining good beam sensitivity characteristics. Wide bandwidth is essential to allow bunch-by-bunch measurements by means of a fast gate. The Schottky detector system is installed and successfully commissioned in the Fermilab Tevatron, Recycler and CERN LHC synchrotrons. Measurement capabilities include tune, chromaticity, and momentum spread of single or multiple beam bunches in any combination. With appropriate calibrations, emittance can also be measured by integrating the area under the incoherent tune sidebands.

  11. Open charm production in the Parton Reggeization approach. From Tevatron to LHC

    International Nuclear Information System (INIS)

    Nefedov, M.A.; Karpishkov, A.V.; Saleev, V.A.; Shipilova, A.V.; Hamburg Univ.

    2014-10-01

    We study the inclusive hadroproduction of D 0 , D + , D *+ , and D s + mesons at leading order in the parton Reggeization approach endowed with universal fragmentation functions fitted to e + e - annihilation data from CERN LEP1. We have described D-meson transverse momentum distributions measured in the central region of rapidity by the CDF Collaboration at Tevatron (vertical stroke y vertical stroke 2.0) measured by the LHCb Collaboration also has been studied and expected disagreement between our theoretical predictions and data has been obtained.

  12. First measurement of the W-boson mass in run II of the Tevatron.

    Science.gov (United States)

    Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Daronco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Denis, R St; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-10-12

    We present a measurement of the W-boson mass using 200 pb{-1} of data collected in pp[over ] collisions at sqrt[s]=1.96 TeV by the CDF II detector at run II of the Fermilab Tevatron. With a sample of 63 964 W-->enu candidates and 51 128 W-->munu candidates, we measure M_{W}=80 413+/-34{stat}+/-34{syst}=80,413+/-48 MeV/c;{2}. This is the most precise single measurement of the W-boson mass to date.

  13. Reshimming of Tevatron dipoles: A Process-quality and lessons-learned perspective

    International Nuclear Information System (INIS)

    Blowers, J.N.; Carson, J.A.; Hanft, R.W.; Harding, D.J.; Robotham, R.W.

    2005-01-01

    Over the last two years corrections have been made for the skew quadrupole moment in 530 of the 774 installed dipoles in the Tevatron. This process of modifying the magnets in situ has inherent risk of degrading the performance of the superconducting accelerator. In order to manage the risk, as well as to ensure the corrections were done consistently, formal quality tools were used to plan and verify the work. The quality tools used to define the process and for quality control are discussed, along with highlights of lessons learned

  14. Reshimming of Tevatron Dipoles; A Process-Quality and Lessons-Learned Perspective

    CERN Document Server

    Blowers, James N; Harding, David J; John, Carson; Robotham, William

    2005-01-01

    Over the last two years corrections have been made for the skew quadrupole moment in 530 of the 774 installed dipoles in the Tevatron. This process of modifying the magnets in situ has inherent risk of degrading the performance of the superconducting accelerator. In order to manage the risk, as well as to ensure the corrections were done consistently, formal quality tools were used to plan and verify the work. The quality tools used to define the process and for quality control are discussed, along with highlights of lessons learned.

  15. Considerations of bunch-spacing options for multi-bunch operation of the Tevatron Collider

    International Nuclear Information System (INIS)

    Dugan, G.

    1989-01-01

    This discussion will consider a number of points relevant to limitations, advantages and disadvantages of various arrangements of bunches in the Tevatron proton-antiproton collider. The considerations discussed here will be limited to: (a) bunch spacing symmetry and relation to the relative luminosity at B0 and D0 and the beam-beam interaction with separated beams; (b) bunch spacing constraints imposed by Main Ring RF coalescing and the optics of beam separation at B0 and D0; and (c) bunch spacing constraints imposed by injection and abort kicker timing requirements, and by the Antiproton Source RF unstacking process. 20 figs., 17 tabs

  16. Theory-motivated benchmark models and superpartners at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Kane, G.L.; Nelson, Brent D.; Wang Liantao; Wang, Ting T.; Lykken, J.; Mrenna, Stephen

    2003-01-01

    Recently published benchmark models have contained rather heavy superpartners. To test the robustness of this result, several benchmark models have been constructed based on theoretically well-motivated approaches, particularly string-based ones. These include variations on anomaly- and gauge-mediated models, as well as gravity mediation. The resulting spectra often have light gauginos that are produced in significant quantities at the Fermilab Tevatron collider, or will be at a 500 GeV linear collider. The signatures also provide interesting challenges for the CERN LHC. In addition, these models are capable of accounting for electroweak symmetry breaking with less severe cancellations among soft supersymmetry breaking parameters than previous benchmark models

  17. A programmable finite state module for use with the Fermilab Tevatron Clock

    International Nuclear Information System (INIS)

    Beechy, D.

    1987-10-01

    A VME module has been designed which implements several programmable finite state machines that use the Tevatron Clock signal as inputs. In addition to normal finite state machine type outputs, the module, called the VME Finite State Machine, or VFSM, records a history of changes of state so that the exact path through the state diagram can be determined. There is also provision for triggering and recording from an external digitizer so that samples can be taken and recorded under very precisely defined circumstances

  18. Review of Physics Results from the Tevatron: Searches for New Particles and Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Toback, David [Texas A-M; ŽIvković, Lidija [Belgrade U.

    2015-02-17

    We present a summary of results for searches for new particles and interactions at the Fermilab Tevatron collider by the CDF and the D0 experiments. These include results from Run I as well as Run II for the time period up to July 2014. We focus on searches for supersymmetry, as well as other models of new physics such as new fermions and bosons, various models of excited fermions, leptoquarks, technicolor, hidden-valley model particles, long-lived particles, extra dimensions, dark matter particles, and signature-based searches.

  19. Jet Substructure at the Tevatron and LHC: New results, new tools, new benchmarks

    CERN Document Server

    Altheimer, A; Asquith, L; Brooijmans, G; Butterworth, J; Campanelli, M; Chapleau, B; Cholakian, A E; Chou, J P; Dasgupta, M; Davison, A; Dolen, J; Ellis, S D; Essig, R; Fan, J J; Field, R; Fregoso, A; Gallicchio, J; Gershtein, Y; Gomes, A; Haas, A; Halkiadakis, E; Halyo, V; Hoeche, S; Hook, A; Hornig, A; Huang, P; Izaguirre, E; Jankowiak, M; Kribs, G; Krohn, D; Larkoski, A J; Lath, A; Lee, C; Lee, S J; Loch, P; Maksimovic, P; Martinez, M; Miller, D W; Plehn, T; Prokofiev, K; Rahmat, R; Rappoccio, S; Safonov, A; Salam, G P; Schumann, S; Schwartz, M D; Schwartzman, A; Seymour, M; Shao, J; Sinervo, P; Son, M; Soper, D E; Spannowsky, M; Stewart, I W; Strassler, M; Strauss, E; Takeuchi, M; Thaler, J; Thomas, S; Tweedie, B; Vasquez Sierra, R; Vermilion, C K; Villaplana, M; Vos, M; Wacker, J; Walker, D; Walsh, J R; Wang, L-T; Wilbur, S; Yavin, I; Zhu, W

    2012-01-01

    In this report we review recent theoretical progress and the latest experimental results in jet substructure from the Tevatron and the LHC. We review the status of and outlook for calculation and simulation tools for studying jet substructure. Following up on the report of the Boost 2010 workshop, we present a new set of benchmark comparisons of substructure techniques, focusing on the set of variables and grooming methods that are collectively known as "top taggers". To facilitate further exploration, we have attempted to collect, harmonise, and publish software implementations of these techniques.

  20. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    International Nuclear Information System (INIS)

    Seletskiy, Sergey M.; Rochester U.

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the first cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cooling. The Recycler Electron Cooler (REC) is the key component of the Tevatron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV carrying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 (micro)rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible. Chapter 1 is an introduction where I describe briefly the theory and the history of electron cooling, and derive the requirements to the quality of electron beam and requirements to the basic parameters of the Recycler Electron Cooler. Chapter 2 is devoted to the theoretical consideration of the motion of electrons in the cooling section, description of the cooling section and of the measurement of the magnetic fields. In Chapter 3 I consider different factors that increase the effective electron angle in the cooling section and suggest certain algorithms for the suppression of parasitic angles. Chapter 4 is devoted to the measurements of the energy of the electron beam. In the concluding Chapter 5 I review

  1. Multiple Parton Interactions in p$bar{p}$ Collisions in D0 Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Golovanov, Georgy [Joint Inst. for Nuclear Research (JINR), Dubna (Russia)

    2016-01-01

    The thesis is devoted to the study of processes with multiple parton interactions (MPI) in a ppbar collision collected by D0 detector at the Fermilab Tevatron collider at sqrt(s) = 1.96 TeV. The study includes measurements of MPI event fraction and effective cross section, a process-independent parameter related to the effective interaction region inside the nucleon. The measurements are done using events with a photon and three hadronic jets in the final state. The measured effective cross section is used to estimate background from MPI for WH production at the Tevatron energy

  2. Physical Conditions of a Lensed Star-Forming Galaxy at Z=1.7

    Science.gov (United States)

    Rigby, Jane; Wuyts, E.; Gladders, M.; Sharon, K.; Becker, G. D.

    2010-01-01

    We report rest-frame optical Keck/NIRSPEC spectroscopy of the brightest lensed galaxy yet discovered, RCSGA 032727-132609 at z=1.7037. From precise measurements of the nebular lines, we infer a number of physical properties: redshift, extinction, star formation rate, ionization parameter, electron density, electron temperature, oxygen abundance, and N/O, Ne/O, and Ar/O abundance ratios. The limit on [O III] 4363 A tightly constrains the oxygen abundance via the "direct" or Tc method, for the first time in all metallicity galaxy at z approx.2. We compare this result to several standard "bright-line" O abundance diagnostics, thereby testing these empirically calibrated diagnostics in situ. Finally, we explore the positions of lensed and unlensed galaxies in standard diagnostic diagrams, and explore the diversity of ionization conditions and mass-metallicity ratios at z=2.

  3. The Physical Conditions of a Lensed Star-Forming Galaxy at Z=1.7

    Science.gov (United States)

    Rigby, Jane; Wuyts, E.; Gladders, M.; Sharon, K.; Becker, G.

    2011-01-01

    We report rest-frame optical Keck/NIRSPEC spectroscopy of the brightest lensed galaxy yet discovered, RCSGA 032727-132609 at z=1.7037. From precise measurements of the nebular lines, we infer a number of physical properties: redshift ' extinction, star formation rate ' ionization parameter, electron density, electron temperature, oxygen abundance, and N/O, Ne/O, and Ar/O abundance ratios, The limit on [O III] 4363 A tightly constrains the oxygen abundance via the "direct" or Te method, for the first time in an average-metallicity galaxy at z approx.2. We compare this result to several standard "bright-line" O abundance diagnostics, thereby testing these empirically-calibrated diagnostics in situ. Finally, we explore the positions of lensed and unlensed galaxies in standard diagnostic diagrams, to explore the diversity of ionization conditions and mass-metallicity ratios at z=2.

  4. A new case of gravitational lensing

    International Nuclear Information System (INIS)

    Surdej, J.; Swings, J.-P.; Borgeest, U.; Kayser, R.; Refsdal, S.; Courvoisier, T.J.-L.; Kellermann, K.I.; Kuehr, H.

    1987-01-01

    The authors report a brief description of a gravitational lens system UM673 = Q0142 - 100 = PHL3703. It consists of two images, A and B, separated by 2.2 arc s at a redshift zsub(q) = 2.719. The lensing galaxy has also been found. It lies very near the line connecting the two QSO (quasi-stellar objects) images, approx. 0.8 arc s from the fainter one. Application of gravitational optometry to this system leads to a value Msub(o) or approx. = 2.4 x 10 11 M solar masses for the mass of the lensing galaxy and to Δt approx. 7 weeks for the most likely travel-time difference between the two light paths to the QSO. (author)

  5. Nulling tomography with weak gravitational lensing

    International Nuclear Information System (INIS)

    Huterer, Dragan; White, Martin

    2005-01-01

    We explore several strategies of eliminating (or nulling) the small-scale information in weak lensing convergence power spectrum measurements in order to protect against undesirable effects, for example, the effects of baryonic cooling and pressure forces on the distribution of large-scale structures. We selectively throw out the small-scale information in the convergence power spectrum that is most sensitive to the unwanted bias, while trying to retain most of the sensitivity to cosmological parameters. The strategies are effective in the difficult but realistic situations when we are able to guess the form of the contaminating effect only approximately. However, we also find that the simplest scheme of simply not using information from the largest multipoles works about as well as the proposed techniques in most, although not all, realistic cases. We advocate further exploration of nulling techniques and believe that they will find important applications in the weak lensing data mining

  6. Poisson equation for weak gravitational lensing

    International Nuclear Information System (INIS)

    Kling, Thomas P.; Campbell, Bryan

    2008-01-01

    Using the Newman and Penrose [E. T. Newman and R. Penrose, J. Math. Phys. (N.Y.) 3, 566 (1962).] spin-coefficient formalism, we examine the full Bianchi identities of general relativity in the context of gravitational lensing, where the matter and space-time curvature are projected into a lens plane perpendicular to the line of sight. From one component of the Bianchi identity, we provide a rigorous, new derivation of a Poisson equation for the projected matter density where the source term involves second derivatives of the observed weak gravitational lensing shear. We also show that the other components of the Bianchi identity reveal no new results. Numerical integration of the Poisson equation in test cases shows an accurate mass map can be constructed from the combination of a ground-based, wide-field image and a Hubble Space Telescope image of the same system

  7. Astrophysical observations: lensing and eclipsing Einstein's theories.

    Science.gov (United States)

    Bennett, Charles L

    2005-02-11

    Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics.

  8. Calibration of fisheye lenses for hemispherical photography

    International Nuclear Information System (INIS)

    Diaci, J.; Kolar, U.

    2000-01-01

    Hemispherical photography represents one of the most appropriate methods of estimating averages of solar radiation over extended periods of time. This method is based upon the use of extremely wide-angle fisheye lenses, which produce large projection distortion. To correctly interpret hemispherical photography we have to know the projection characteristics of the fisheye lens in combination with a camera body. This can be achieved through lens calibration. The first part of the article explains in detail the calibration method for fisheye lenses which are used to assess the solar radiation in forest ecology research. In the second part the results of calibration for fisheye lens Sigma 8 mm, f/4 (MF, N) are presented. The lens was used on a Nikon F50 camera body

  9. Antifouling leaching technique for optical lenses

    Science.gov (United States)

    Strahle, William J.; Perez, C. L.; Martini, Marinna A.

    1994-01-01

    The effectiveness of optical lenses deployed in water less than 100 m deep is significantly reduced by biofouling caused by the settlement of macrofauna, such as barnacles, hydroids, and tunicates. However, machineable porous plastic rings can be used to dispense antifoulant into the water in front of the lens to retard macrofaunal growth without obstructing the light path. Unlike coatings which can degrade the optical performance, antifouling rings do not interfere with the instrument optics. The authors have designed plastic, reusable cup-like antifouling rings to slip over the optical lenses of a transmissometer. These rings have been used for several deployments on shallow moorings in Massachusetts Bay, MA and have increased the time before fouling degrades optical characteristics

  10. Calculation of integrated luminosity for beams stored in the Tevatron collider

    International Nuclear Information System (INIS)

    Finley, D.A.

    1989-01-01

    A model for calculating the integrated luminosity of beams stored in the Tevatron collider will be presented. The model determines the instantaneous luminosity by calculating the overlap integral of bunched beams passing through the interaction region. The calculation accounts for the variation in beam size due to the beta functions and also for effects due to finite longitudinal emittance and non-zero dispersion in the interaction region. The integrated luminosity is calculated for the beams as they evolve due to processes including collisions and intrabeam scattering. The model has been applied to both the extant and upgraded Tevatron collider, but is not limited to them. The original motivation for developing the computer model was to determine the reduction in luminosity due to beams with non-zero longitudinal emittances. There are two effects: the transverse beam size is increased where the dispersion is non-zero; the finite length of the beam bunch combined with an increasing β function results in an increased transverse beam size at the ends of the bunch. The derivation of a sufficiently useful analytic expression for the luminosity proved to be intractable. Instead, a numerical integration computer program was developed to calculate the luminosity in the presence of a finite longitudinal emittance. The program was then expanded into a model which allows the luminosity to vary due to changes in emittances and reduction in bunch intensities. At that point, it was not difficult to calculate the integrated luminosity. 5 refs., 2 figs., 4 tabs

  11. Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo

    CERN Document Server

    Shiltsev, V.; Drozhdin, A.; Johnson, T.; Legan, A.; Mokhov, N.; Reilly, R.; Still, D.; Tesarek, R.; Zagel, J.; Peggs, S.; Assmann, R.; Previtali, V.; Scandale, W.; Chesnokov, Y.; Yazynin, I.; Guidi, V.; Ivanov, Y.

    2010-01-01

    The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding be...

  12. Non-perturbative QCD Effects and the Top Mass at the Tevatron

    CERN Document Server

    Wicke, Daniel

    2008-01-01

    The modelling of non-perturbative effects is an important part of modern collider physics simulations. In hadron collisions there is some indication that the modelling of the interactions of the beam remnants, the underlying event, may require non-trivial colour reconnection effects to be present. We recently introduced a universally applicable toy model of such reconnections, based on hadronising strings. This model, which has one free parameter, has been implemented in the Pythia event generator. We then considered several parameter sets (`tunes'), constrained by fits to Tevatron minimum-bias data, and determined the sensitivity of a simplified top mass analysis to these effects, in exclusive semi-leptonic top events at the Tevatron. A first attempt at isolating the genuine non-perturbative effects gave an estimate of order +-0.5GeV from non-perturbative uncertainties. The results presented here are an update to the original study and include recent bug fixes of Pythia that influenced the tunings investigat...

  13. A light stop and its consequences at the Tevatron and LEP II

    CERN Document Server

    López, J L; Zichichi, Antonino

    1995-01-01

    An interesting prediction of a string-inspired {\\em one-parameter} SU(5)\\times U(1) supergravity model, is the fact that the lightest member (\\tilde t_1) of the top-squark doublet (\\tilde t_1,\\tilde t_2), may be substantially lighter than the top quark. This sparticle (\\tilde t_1) may be readily pair-produced at the Tevatron and, if m_{\\tilde t_1}\\lsim130\\GeV, even be observed at the end of Run IB. Top-squark production may also be an important source of sought-for top-quark signatures in the dilepton and \\ell+jets channels. Therefore, a re-analysis of the top data sample in the presence of a possibly light top-squark appears necessary before definitive statements concerning the discovery of the top quark can be made. Such a light top-squark is linked with a light supersymmetric spectrum which can certainly be searched for at the Tevatron through trilepton and squark-gluino searches, and at LEPII through direct \\tilde t_1 pair-production (for m_{\\tilde t_1}\\lsim100\\GeV) and via chargino and Higgs-boson search...

  14. LHC Predictions from a Tevatron Anomaly in the Top Quark Forward-Backward Asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yang; Hewett, JoAnne L.; Kaplan, Jared; Rizzo, Thomas G.; /SLAC

    2011-08-12

    We examine the implications of the recent CDF measurement of the top-quark forward-backward asymmetry, focusing on a scenario with a new color octet vector boson at 1-3 TeV. We study several models, as well as a general effective field theory, and determine the parameter space which provides the best simultaneous fit to the CDF asymmetry, the Tevatron top pair production cross section, and the exclusion regions from LHC dijet resonance and contact interaction searches. Flavor constraints on these models are more subtle and less severe than the literature indicates. We find a large region of allowed parameter space at high axigluon mass and a smaller region at low mass; we match the latter to an SU(3){sub 1} x SU(3){sub 2}/SU(3){sub c} coset model with a heavy vector-like fermion. Our scenario produces discoverable effects at the LHC with only 1-2 inverse femtobarns of luminosity at 7-8 TeV. Lastly, we point out that a Tevatron measurement of the b-quark forward-backward asymmetry would be very helpful in characterizing the physics underlying the top-quark asymmetry.

  15. Beam beam tune shifts for 36 bunch operation in the Tevatron

    International Nuclear Information System (INIS)

    Bagley, P.

    1996-10-01

    We are preparing to upgrade the Tevatron Collider from 6 to 36 bunch operation. The 36 bunches are in 3 ''trains'' of 12 bunches. The spacing between bunches within a train is 21 RF buckets (53.106 MHz) and 139 empty buckets separate the trains. Because the 36 bunches are not evenly spaced around the machine, the different bunches within a train pass the opposing bunches at different points in the ring and so feel different beam beam effects. Through most of the machine the beams have helical separation, so these are mainly long range beam beam effects. As a first, very simple step, we've looked at the differences in the tunes of the different anti-proton (anti p) bunches. During the 36 bunch studies in Fall 1995, we used a new tune measurement system to measure these in several different machine conditions. We compare these measurements to calculations of the tunes for a anti p with zero transverse and longitudinal oscillation amplitudes. We discuss experimental problems, and the assumptions, approximations, and effects included in the calculations. Our main intent is to gain confidence that we can accurately model beam beam effects in the Tevatron

  16. Reach of the Fermilab Tevatron and CERN LHC for gaugino mediated SUSY breaking models

    International Nuclear Information System (INIS)

    Baer, Howard; Belyaev, Alexander; Krupovnickas, Tadas; Tata, Xerxes

    2002-01-01

    In supersymmetric models with gaugino mediated SUSY breaking (gMSB), it is assumed that SUSY breaking on a hidden brane is communicated to the visible brane via gauge superfields which propagate in the bulk. This leads to GUT models where the common gaugino mass m 1/2 is the only soft SUSY breaking term to receive contributions at the tree level. To obtain a viable phenomenology, it is assumed that the gaugino mass is induced at some scale M c beyond the GUT scale, and that additional renormalization group running takes place between M c and M GUT as in a SUSY GUT. We assume an SU(5) SUSY GUT above the GUT scale, and compute the SUSY particle spectrum expected in models with gMSB. We use the Monte Carlo program ISAJET to simulate signals within the gMSB model, and compute the SUSY reach including cuts and triggers appropriate to Fermilab Tevatron and CERN LHC experiments. We find no reach for SUSY by the Tevatron collider in the trilepton channel. At the CERN LHC, values of m 1/2 =1000 (1160) GeV can be probed with 10 (100) fb -1 of integrated luminosity, corresponding to a reach in terms of m g-tilde of 2150 (2500) GeV. The gMSB model and MSUGRA can likely only be differentiated at a linear e + e - collider with sufficient energy to produce sleptons and charginos

  17. Long-range beam-beam interactions in the Tevatron: Comparing simulation to tune shift data

    International Nuclear Information System (INIS)

    Saritepe, S.; Michelotti, L.; Peggs, S.

    1990-07-01

    Fermilab upgrade plans for the collider operation include a separation scheme in the Tevatron, in which protons and antiprotons are placed on separate helical orbits. The average separation distance between the closed orbits will be 5σ (σ of the proton bunch) except at the interaction regions, B0 and D0, where they collide head-on. The maximum beam-beam total tune shift in the Tevatron is approximately 0.024 (the workable tune space between 5th and 7th order resonances), which was reached in the 1988--1989 collider tun. Helical separation scheme allows us to increase the luminosity by reducing the total beam-beam tune shift. The number of bunches per beam will be 6 in the 1991 collider tun, to be increased to 36 in the following collider runs. To test the viability of this scenario, helical orbit studies are being conducted. The most recent studies concentrated on the injection of 36 proton bunches, procedures related to opening and closing of the helix, the feed-down circuits and the beam-beam interaction. In this paper, we present the results of the beam-beam interaction studies only. Our emphasis is on the tune shift measurements and the comparison to simulation. 4 refs., 9 figs., 2 tabs

  18. Production of single top quark - results from the Tevatron and the LHC

    CERN Document Server

    Moon, Chang-Seong

    2014-01-01

    We present the most recent measurements of single top quark production cross section by the CDF and D0 experiments at the Fermilab Tevatron Collider and the ATLAS and CMS experiments at the Large Hadron Collider (LHC). The data were collected at the Tevatron corresponding to an integrated luminosity of up to 9.7 fb$^{-1}$ of proton-antiproton ($p\\bar p$) collisions at a centre-of-mass energy of 1.96 TeV and at the LHC corresponding to an integrated luminosity of up to 4.9 fb$^{-1}$ of proton-proton ($pp$) collisions at a centre-of-mass energy of 7 TeV in 2011 and up to 20.3 fb$^{-1}$ at a centre-of-mass energy of 8 TeV in 2012. The measurements of single top quark production in $s$-channel, $t$-channel and associated production of a top quark and a $W$-boson ($tW$ production) are presented separately and lower limits on the CKM matrix element $|V_{tb}|$ from the single top quark cross section are set.

  19. Sources of b quarks at the Fermilab Tevatron and their correlations

    International Nuclear Information System (INIS)

    Field, R.D.

    2002-01-01

    The leading-logarithm order QCD hard scattering Monte Carlo models of HERWIG, ISAJET, and PYTHIA are used to study the sources of b quarks at the Fermilab Tevatron. The reactions responsible for producing b and b(bar sign) quarks are separated into three categories: flavor creation, flavor excitation, and parton-shower or fragmentation. Flavor creation corresponds to the production of a bb(bar sign) pair by gluon fusion or by annihilation of light quarks, while flavor excitation corresponds to a b or b(bar sign) quark being knocked out of the initial state by a gluon or a light quark or antiquark. The third source occurs when a bb(bar sign) pair is produced within a parton shower or during the fragmentation process of a gluon or a light quark or antiquark (includes gluon splitting). The QCD Monte Carlo models indicate that all three sources of b quarks are important at the Tevatron and when combined they qualitatively describe the inclusive cross-section data. Correlations between the b and b(bar sign) quark are very different for the three sources and can be used to isolate the individual contributions

  20. Linear beam-beam tune shift calculations for the Tevatron Collider

    International Nuclear Information System (INIS)

    Johnson, D.

    1989-01-01

    A realistic estimate of the linear beam-beam tune shift is necessary for the selection of an optimum working point in the tune diagram. Estimates of the beam-beam tune shift using the ''Round Beam Approximation'' (RBA) have over estimated the tune shift for the Tevatron. For a hadron machine with unequal lattice functions and beam sizes, an explicit calculation using the beam size at the crossings is required. Calculations for various Tevatron lattices used in Collider operation are presented. Comparisons between the RBA and the explicit calculation, for elliptical beams, are presented. This paper discusses the calculation of the linear tune shift using the program SYNCH. Selection of a working point is discussed. The magnitude of the tune shift is influenced by the choice of crossing points in the lattice as determined by the pbar ''cogging effects''. Also discussed is current cogging procedures and presents results of calculations for tune shifts at various crossing points in the lattice. Finally, a comparison of early pbar tune measurements with the present linear tune shift calculations is presented. 17 refs., 13 figs., 3 tabs

  1. Microbial adhesion to silicone hydrogel lenses: a review.

    Science.gov (United States)

    Willcox, Mark D P

    2013-01-01

    Microbial adhesion to contact lenses is believed to be one of the initiating events in the formation of many corneal infiltrative events, including microbial keratitis, that occur during contact lens wear. The advent of silicone hydrogel lenses has not reduced the incidence of these events. This may partly be related to the ability of microbes to adhere to these lenses. The aim of this study was to review the published literature on microbial adhesion to contact lenses, focusing on adhesion to silicone hydrogel lenses. The literature on microbial adhesion to contact lenses was searched, along with associated literature on adverse events that occur during contact lens wear. Particular reference was paid to the years 1995 through 2012 because this encompasses the time when the first clinical trials of silicone hydrogel lenses were reported, and their commercial availability and the publication of epidemiology studies on adverse events were studied. In vitro studies of bacterial adhesion to unworn silicone hydrogel lens have shown that generally, bacteria adhere to these lenses in greater numbers than to the hydroxyethyl methacrylate-based soft lenses. Lens wear has different effects on microbial adhesion, and this is dependent on the type of lens and microbial species/genera that is studied. Biofilms that can be formed on any lens type tend to protect the bacteria and fungi from the effects on disinfectants. Fungal hyphae can penetrate the surface of most types of lenses. Acanthamoeba adhere in greater numbers to first-generation silicone hydrogel lenses compared with the second-generation or hydroxyethyl methacrylate-based soft lenses. Microbial adhesion to silicone hydrogel lenses occurs and is associated with the production of corneal infiltrative events during lens wear.

  2. Gravitational lensing by a Horndeski black hole

    Energy Technology Data Exchange (ETDEWEB)

    Badia, Javier [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Eiroa, Ernesto F. [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Universidad de Buenos Aires, Ciudad Universitaria Pabellon I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2017-11-15

    In this article we study gravitational lensing by non-rotating and asymptotically flat black holes in Horndeski theory. By adopting the strong deflection limit, we calculate the deflection angle, from which we obtain the positions and the magnifications of the relativistic images. We compare our results with those corresponding to black holes in General Relativity. We analyze the astrophysical consequences in the case of the nearest supermassive black holes. (orig.)

  3. Gravitational lensing by a Horndeski black hole

    International Nuclear Information System (INIS)

    Badia, Javier; Eiroa, Ernesto F.

    2017-01-01

    In this article we study gravitational lensing by non-rotating and asymptotically flat black holes in Horndeski theory. By adopting the strong deflection limit, we calculate the deflection angle, from which we obtain the positions and the magnifications of the relativistic images. We compare our results with those corresponding to black holes in General Relativity. We analyze the astrophysical consequences in the case of the nearest supermassive black holes. (orig.)

  4. Automatic centring and bonding of lenses

    Science.gov (United States)

    Krey, Stefan; Heinisch, J.; Dumitrescu, E.

    2007-05-01

    We present an automatic bonding station which is able to center and bond individual lenses or doublets to a barrel with sub micron centring accuracy. The complete manufacturing cycle includes the glue dispensing and UV curing. During the process the state of centring is continuously controlled by the vision software, and the final result is recorded to a file for process statistics. Simple pass or fail results are displayed to the operator at the end of the process.

  5. Gravitational lensing in metric theories of gravity

    International Nuclear Information System (INIS)

    Sereno, Mauro

    2003-01-01

    Gravitational lensing in metric theories of gravity is discussed. I introduce a generalized approximate metric element, inclusive of both post-post-Newtonian contributions and a gravitomagnetic field. Following Fermat's principle and standard hypotheses, I derive the time delay function and deflection angle caused by an isolated mass distribution. Several astrophysical systems are considered. In most of the cases, the gravitomagnetic correction offers the best perspectives for an observational detection. Actual measurements distinguish only marginally different metric theories from each other

  6. Automation Enhancement of Multilayer Laue Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Lauer K. R.; Conley R.

    2010-12-01

    X-ray optics fabrication at Brookhaven National Laboratory has been facilitated by a new, state of the art magnetron sputtering physical deposition system. With its nine magnetron sputtering cathodes and substrate carrier that moves on a linear rail via a UHV brushless linear servo motor, the system is capable of accurately depositing the many thousands of layers necessary for multilayer Laue lenses. I have engineered a versatile and automated control program from scratch for the base system and many subsystems. Its main features include a custom scripting language, a fully customizable graphical user interface, wireless and remote control, and a terminal-based interface. This control system has already been successfully used in the creation of many types of x-ray optics, including several thousand layer multilayer Laue lenses.Before reaching the point at which a deposition can be run, stencil-like masks for the sputtering cathodes must be created to ensure the proper distribution of sputtered atoms. Quality of multilayer Laue lenses can also be difficult to measure, given the size of the thin film layers. I employ my knowledge of software and algorithms to further ease these previously painstaking processes with custom programs. Additionally, I will give an overview of an x-ray optic simulator package I helped develop during the summer of 2010. In the interest of keeping my software free and open, I have worked mostly with the multiplatform Python and the PyQt application framework, utilizing C and C++ where necessary.

  7. Gravitational lensing of the SNLS supernovae

    International Nuclear Information System (INIS)

    Kronborg, T.

    2011-01-01

    Type Ia supernovae have become an essential tool of modern observational cosmology. By studying the distance-redshift relation of a large number of supernovae, the nature of dark energy can be unveiled. Distances to Type Ia SNe are however affected by gravitational lensing which can induce systematic effects in the measurement of cosmology. The majority of the supernovae is slightly de-magnified whereas a small fraction is significantly magnified due to the mass distribution along the line of sight. This causes naturally an additional dispersion in the observed magnitudes. There are two different ways to estimate the magnification of a supernova. A first method consists in comparing the supernova luminosity, which is measured to about 15% precision, to the mean SN luminosity at the same redshift. Another estimate can be obtained from predicting the magnification induced by the foreground matter density modeled from the measurements of the luminosity of the galaxies with an initial prior on the mass-luminosity relation of the galaxies. A correlation between these 2 estimates will make it possible to tune the initially used mass-luminosity relation resulting in an independent measurement of the dark matter clustering based on the luminosity of SNe Ia. Evidently, this measurement depends crucially on the detection of this correlation also referred to as the lensing signal. This thesis is dedicated to the measurement of the lensing signal in the SNLS 3-year sample. (author)

  8. Primordial black holes survive SN lensing constraints

    Science.gov (United States)

    García-Bellido, Juan; Clesse, Sébastien; Fleury, Pierre

    2018-06-01

    It has been claimed in [arxiv:1712.02240] that massive primordial black holes (PBH) cannot constitute all of the dark matter (DM), because their gravitational-lensing imprint on the Hubble diagram of type Ia supernovae (SN) would be incompatible with present observations. In this note, we critically review those constraints and find several caveats on the analysis. First of all, the constraints on the fraction α of PBH in matter seem to be driven by a very restrictive choice of priors on the cosmological parameters. In particular, the degeneracy between Ωm and α was ignored and thus, by fixing Ωm, transferred the constraining power of SN magnitudes to α. Furthermore, by considering more realistic physical sizes for the type-Ia supernovae, we find an effect on the SN lensing magnification distribution that leads to significantly looser constraints. Moreover, considering a wide mass spectrum of PBH, such as a lognormal distribution, further softens the constraints from SN lensing. Finally, we find that the fraction of PBH that could constitute DM today is bounded by fPBH < 1 . 09(1 . 38) , for JLA (Union 2.1) catalogs, and thus it is perfectly compatible with an all-PBH dark matter scenario in the LIGO band.

  9. Beryllium parabolic refractive x-ray lenses

    International Nuclear Information System (INIS)

    Lengeler, B.; Schroer, C.G.; Kuhlmann, M.; Benner, B.; Guenzler, T.F.; Kurapova, O.; Somogyi, A.; Snigirev, A.; Snigireva, I.

    2004-01-01

    Parabolic refractive x-ray lenses are novel optical components for the hard x-ray range from about 5 keV to about 120 keV. They focus in both directions. They are compact, robust, and easy to align and to operate. They can be used like glass lenses are used for visible light, the main difference being that the numerical aperture N.A. is much smaller than 1 (of order 10-4 to 10-3). Their main applications are in micro- and nanofocusing, in imaging by absorption and phase contrast and in fluorescence mode. In combination with tomography they allow for 3-dimensional imaging of opaque media with submicrometer resolution. Finally, they can be used in speckle spectroscopy by means of coherent x-ray scattering. Beryllium as lens material strongly enhances the transmission and the field of view as compared to aluminium. With increased N.A. the lateral resolution is also considerably improved with Be lenses. References to a number of applications are given

  10. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  11. Galaxy–Galaxy Weak-lensing Measurements from SDSS. I. Image Processing and Lensing Signals

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wentao [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China); Yang, Xiaohu; Zhang, Jun; Tweed, Dylan [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Fu, Liping; Shu, Chenggang [Shanghai Key Lab for Astrophysics, Shanghai Normal University, 100 Guilin Road, 200234, Shanghai (China); Mo, H. J. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Bosch, Frank C. van den [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Li, Ran [Key Laboratory for Computational Astrophysics, Partner Group of the Max Planck Institute for Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Li, Nan [Department of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Liu, Xiangkun; Pan, Chuzhong [Department of Astronomy, Peking University, Beijing 100871 (China); Wang, Yiran [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States); Radovich, Mario, E-mail: walt@shao.ac.cn, E-mail: xyang@sjtu.edu.cn [INAF-Osservatorio Astronomico di Napoli, via Moiariello 16, I-80131 Napoli (Italy)

    2017-02-10

    We present our image processing pipeline that corrects the systematics introduced by the point-spread function (PSF). Using this pipeline, we processed Sloan Digital Sky Survey (SDSS) DR7 imaging data in r band and generated a galaxy catalog containing the shape information. Based on our shape measurements of the galaxy images from SDSS DR7, we extract the galaxy–galaxy (GG) lensing signals around foreground spectroscopic galaxies binned in different luminosities and stellar masses. We estimated the systematics, e.g., selection bias, PSF reconstruction bias, PSF dilution bias, shear responsivity bias, and noise rectification bias, which in total is between −9.1% and 20.8% at 2 σ levels. The overall GG lensing signals we measured are in good agreement with Mandelbaum et al. The reduced χ {sup 2} between the two measurements in different luminosity bins are from 0.43 to 0.83. Larger reduced χ {sup 2} from 0.60 to 1.87 are seen for different stellar mass bins, which is mainly caused by the different stellar mass estimator. The results in this paper with higher signal-to-noise ratio are due to the larger survey area than SDSS DR4, confirming that more luminous/massive galaxies bear stronger GG lensing signals. We divide the foreground galaxies into red/blue and star-forming/quenched subsamples and measure their GG lensing signals. We find that, at a specific stellar mass/luminosity, the red/quenched galaxies have stronger GG lensing signals than their counterparts, especially at large radii. These GG lensing signals can be used to probe the galaxy–halo mass relations and their environmental dependences in the halo occupation or conditional luminosity function framework.

  12. Experimental Study of W Z Intermediate Bosons Associated Production with the CDF Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Pozzobon, Nicola; /Pisa U.

    2007-09-01

    Studying WZ associated production at the Fermilab Tevatron Collider is of great importance for two main reasons. On the one hand, this process would be sensitive to anomalies in the triple gauge couplings such that any deviation from the value predicted by the Standard Model would be indicative of new physics. In addition, by choosing to focus on the final state where the Z boson decays to b{bar b} pairs, the event topology would be the same as expected for associated production of a W and a Standard Model light Higgs boson (m{sub H} {approx}< 135 GeV) which decays into b{bar b} pairs most of times. The process WH {yields} W b{bar b} has an expected {sigma} {center_dot} B about five times lower than WZ {yields} Wb{bar b} for m{sub H} {approx_equal} 120 GeV. Therefore, observing this process would be a benchmark for an even more difficult search aiming at discovering the light Higgs in the WH {yields} Wb{bar b} process. After so many years of Tevatron operation only a weak WZ signal was recently observed in the full leptonic decay channel, which suffers from much less competition from background. Searching for the Z in the b{bar b} decay channel in this process is clearly a very challenging endeavour. In the work described in this thesis, WZ production is searched for in a final state where the W decays leptonically to an electron-neutrino pair or a muon-neutrino pair, with associated production of a jet pair consistent with Z decays. A set of candidate events is obtained by applying appropriate cuts to the parameters of events collected by wide acceptance leptonic triggers. To improve the signal fraction of the selected events, an algorithm was used to tag b-flavored jets by means of their content of long lived b-hadrons and corrections were developed to the jet algorithm to improve the b-jet energy resolution for a better reconstruction of the Z mass. In order to sense the presence of a signal one needs to estimate the amount of background. The relative content of

  13. Search for supersymmetric Higgs bosons in the D0 experiment at the Tevatron; Recherche de bosons de Higgs supersymetriques au Tevatron dans l'experience D0

    Energy Technology Data Exchange (ETDEWEB)

    Michaut, M

    2006-09-15

    A search for the neutral Higgs bosons of the minimal supersymmetric extension of the standard model is performed in the 3 or 4 jets channels, pp-bar {yields} {phi}({yields} bb-bar)b(b-bar) with {phi} = h, H or A. For this purpose, the data collected with the D0 detector from 2002 to 2006 at the Tevatron hadronic collider with a center of mass energy of 1.96 TeV are analyzed. A complete study of the triggering is first done. The triggering conditions are optimized in order to keep the more signal fraction possible. Furthermore, a method is developed to predict the triggering efficiencies on our signal and backgrounds using only the data. Then an analysis method that allows the prediction of our background without the help of simulations is studied. No excess in events is observed in the data sample analyzed, corresponding to an integrated luminosity of 0.9 fb{sup -1}, so limits are set in the minimal supersymmetric extension of the standard model. At 95% confidence level, the following limits are found: tan({beta}) < 46 - 121 for m{sub {phi}} equals 100 - 170 GeV. (author)

  14. Search for supersymmetric Higgs bosons in the D0 experiment at the Tevatron; Recherche de bosons de Higgs supersymetriques au Tevatron dans l'experience D0

    Energy Technology Data Exchange (ETDEWEB)

    Michaut, M

    2006-09-15

    A search for the neutral Higgs bosons of the minimal supersymmetric extension of the standard model is performed in the 3 or 4 jets channels, pp-bar {yields} {phi}({yields} bb-bar)b(b-bar) with {phi} = h, H or A. For this purpose, the data collected with the D0 detector from 2002 to 2006 at the Tevatron hadronic collider with a center of mass energy of 1.96 TeV are analyzed. A complete study of the triggering is first done. The triggering conditions are optimized in order to keep the more signal fraction possible. Furthermore, a method is developed to predict the triggering efficiencies on our signal and backgrounds using only the data. Then an analysis method that allows the prediction of our background without the help of simulations is studied. No excess in events is observed in the data sample analyzed, corresponding to an integrated luminosity of 0.9 fb{sup -1}, so limits are set in the minimal supersymmetric extension of the standard model. At 95% confidence level, the following limits are found: tan({beta}) < 46 - 121 for m{sub {phi}} equals 100 - 170 GeV. (author)

  15. [IOP measurement through frequent-replacement soft contact lenses].

    Science.gov (United States)

    Touboul, J

    2008-07-01

    Intraocular pressure (IOP) can be measured through soft contact lenses with an air-puff tonometer. These measurements seemed accurate for low-power negative lenses. For positive soft contact lenses, IOP is overestimated. The measurement of IOP through a soft contact lens is acceptable in clinical practice only for glaucoma screening. In glaucomatous patients or patients with ocular hypertension, IOP measurements should be performed without a contact lens. The main technique for IOP measurement remains Goldmann applanation tonometry.

  16. Do swimming goggles limit microbial contamination of contact lenses?

    Science.gov (United States)

    Wu, Yvonne T; Tran, Jess; Truong, Michelle; Harmis, Najat; Zhu, Hua; Stapleton, Fiona

    2011-04-01

    Wearing goggles over contact lenses while swimming is often recommended by eye care professionals. Limited data are available to assess this recommendation. The purpose of this study was to examine whether wearing goggles while swimming limits bacterial colonization on contact lenses and whether the type of lens worn affects contamination rates. Twenty-three subjects underwent two swimming sessions at an ocean (salt water) pool (Maroubra beach Rock Pool, Sydney, Australia). Silicone hydrogel (Ciba Focus Night and Day) or hydrogel lenses (Ciba Focus Daily) were inserted into subjects' eyes before 30 min of swimming sessions, and subjects used modified goggles to mimic goggled and non-goggled conditions. At the end of each session, lenses were collected for microbial investigation. Viable bacterial colonies were classified as gram positive and gram negative and enumerated. The level of bacterial colonization on contact lenses between goggled and non-goggled conditions and between the two lens materials were compared. The range of colony forming units recovered from goggled lenses were 0 to 930 compared with 0 to 1210 on non-goggled lenses. The majority of subjects (16/23) had more microorganisms in the non-goggled condition than when wearing goggles (p = 0.03). Gram negative organisms were found in three non-goggled lenses. No significant difference was shown in the number of bacteria isolated from silicone hydrogel and hydrogel lenses (p > 0.6) irrespective of wearing goggles. Water samples had consistently higher numbers of bacterial counts than those adhered to the lenses; however, no association was found between the number of bacteria in the water sample and those found on the contact lenses. Consistently, fewer bacterial colonies were found on the goggled contact lens, thus suggesting goggles offer some protection against bacterial colonization of contact lenses while swimming. These data would support the recommendation encouraging lens wearers to use goggles

  17. Plasma lenses for SLAC Final Focus Test facility

    International Nuclear Information System (INIS)

    Betz, D.; Cline, D.; Joshi, C.; Rajagopalan, S.; Rosenzweig, J.; Su, J.J.; Williams, R.; Chen, P.; Gundersen, M.; Katsouleas, T.; Norem, J.

    1991-01-01

    A collaborative group of accelerator and plasma physicists and engineers has formed with an interest in exploring the use of plasma lenses to meet the needs of future colliders. Analytic and computational models of plasma lenses are briefly reviewed and several design examples for the SLAC Final Focus Test Beam are presented. The examples include discrete, thick, and adiabatic lenses. A potential plasma source with desirable lens characteristics is presented

  18. Corrections for gravitational lensing of supernovae: better than average?

    OpenAIRE

    Gunnarsson, Christofer; Dahlen, Tomas; Goobar, Ariel; Jonsson, Jakob; Mortsell, Edvard

    2005-01-01

    We investigate the possibility of correcting for the magnification due to gravitational lensing of standard candle sources, such as Type Ia supernovae. Our method uses the observed properties of the foreground galaxies along the lines-of-sight to each source and the accuracy of the lensing correction depends on the quality and depth of these observations as well as the uncertainties in translating the observed luminosities to the matter distribution in the lensing galaxies. The current work i...

  19. Experimental results on $t\\bar{t}+W/Z/\\gamma$ and SM top couplings from the Tevatron and the LHC

    CERN Document Server

    Vazquez Schroeder, Tamara

    2014-01-01

    Experimental results from the CDF and D0 Collaborations at the Tevatron and the ATLAS and CMS Collaborations at the LHC on the processes related to probing top quark couplings are presented. Evidence of both $t\\bar{t}Z$ and $t\\bar{t}W$ processes is reported. All measurements are in agreement with the SM expectations.

  20. Review of parton distributions and implications for the Tevatron and the LHC Partons in Collision at Physics in Collision

    CERN Document Server

    Huston, J

    2001-01-01

    This talk is intended to serve as a pedagogical guide on the determination of, the proper use of, and the uncertainties of parton distribution functions and their impact on physics cross sections at the Tevatron and LHC. A longer writeup of this talk is available at http://www.pa.msu.edu./~huston/lhc/lhc_pdfnote.ps. (12 refs).

  1. Three-dimensional quadrupole lenses made with permanent magnets

    International Nuclear Information System (INIS)

    Ivanov, A.S.

    1984-01-01

    The performance of accelerator systems with quadrupole magnets can be improved by using permanent magnets in quadrupole lenses. This requires better methods for treating the three-dimensional nature of the magnetic fields and the nonlinear characteristics of the magnets. A numerical method is described for simulating three-dimensional magnetic fields and used to analyze quadrupole lenses and doublets with permanent magnets. The results, which are confirmed experimentally, indicate that both the quadrupole magnetic gradient and the effective field length are changed in permanent-magnet quadrupole lenses when the pole lengths and the gap between the lenses are varied while the other characteristics of the magnets remain unchanged

  2. Contact lenses fitting after intracorneal ring segments implantation in keratoconus

    Directory of Open Access Journals (Sweden)

    Luciane Bugmann Moreira

    2013-08-01

    Full Text Available PURPOSE: Evaluate contact lenses fitting after intracorneal ring implantation for keratoconus, its visual acuity and comfort. METHODS: Retrospective study of patients undergoing contact lenses fitting, after intracorneal ring for keratoconus. The criterion for contact lens fitting was unsatisfactory visual acuity with spectacle correction as referred by the patients. All patients were intolerants to contact lenses prior to intracorneal implantation. Visual acuity analysis was done by conversion of Snellen to logMAR scales. The comfort was evaluated according subjective questioning of good, medium or poor comfort. RESULTS: Nineteen patients were included in the study. Two patients (10.5% did not achieved good comfort with contact lenses and underwent penetrating keratoplasties. All the others 17 patients showed good or medium comfort. Four rigid gas-permeable contact lenses were fitted, one piggyback approach, 3 toric soft contact lenses, 2 soft lenses specially design for keratoconus and 7 disposable soft lenses. The average visual acuity improved from 0.77 ± 0.37 to 0.19 ± 0.13 logMAR units after contact lenses fitting. CONCLUSION: Contact lens fitting after intracorneal ring is possible, provides good comfort, improves visual acuity, and therefore, may postpone the need for penetrating keratoplasty.

  3. Bacterial adhesion to unworn and worn silicone hydrogel lenses.

    Science.gov (United States)

    Vijay, Ajay Kumar; Zhu, Hua; Ozkan, Jerome; Wu, Duojia; Masoudi, Simin; Bandara, Rani; Borazjani, Roya N; Willcox, Mark D P

    2012-08-01

    The objective of this study was to determine the bacterial adhesion to various silicone hydrogel lens materials and to determine whether lens wear modulated adhesion. Bacterial adhesion (total and viable cells) of Staphylococcus aureus (31, 38, and ATCC 6538) and Pseudomonas aeruginosa (6294, 6206, and GSU-3) to 10 commercially available different unworn and worn silicone hydrogel lenses was measured. Results of adhesion were correlated to polymer and surface properties of contact lenses. S. aureus adhesion to unworn lenses ranged from 2.8 × 10 to 4.4 × 10 colony forming units per lens. The highest adhesion was to lotrafilcon A lenses, and the lowest adhesion was to asmofilcon A lenses. P. aeruginosa adhesion to unworn lenses ranged from 8.9 × 10 to 3.2 × 10 colony forming units per lens. The highest adhesion was to comfilcon A lenses, and the lowest adhesion was to asmofilcon A and balafilcon A lenses. Lens wear altered bacterial adhesion, but the effect was specific to lens and strain type. Adhesion of bacteria, regardless of genera/species or lens wear, was generally correlated with the hydrophobicity of the lens; the less hydrophobic the lens surface, the greater the adhesion. P. aeruginosa adhered in higher numbers to lenses in comparison with S. aureus strains, regardless of the lens type or lens wear. The effect of lens wear was specific to strain and lens. Hydrophobicity of the silicone hydrogel lens surface influenced the adhesion of bacterial cells.

  4. Using Strong Gravitational Lensing to Identify Fossil Group Progenitors

    Science.gov (United States)

    Johnson, Lucas E.; Irwin, Jimmy A.; White, Raymond E., III; Wong, Ka-Wah; Maksym, W. Peter; Dupke, Renato A.; Miller, Eric D.; Carrasco, Eleazar R.

    2018-04-01

    Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.

  5. Superconductivity and electron microscopy

    International Nuclear Information System (INIS)

    Hawkes, P.W.; Valdre, U.

    1977-01-01

    In this review article, two aspects of the role of superconductivity in electron microscopy are examined: (i) the development of superconducting devices (mainly lenses) and their incorporation in electron microscopes; (ii) the development of electron microscope techniques for studying fundamental and technological problems associated with superconductivity. The first part opens with a brief account of the relevant properties of conventional lenses, after which the various types of superconducting lenses are described and their properties compared. The relative merits and inconveniences of superconducting and conventional lenses are examined, particular attention being paid to the spherical and chromatic aberration coefficients at accelerating voltages above a megavolt. This part closes with a survey of the various microscope designs that have been built or proposed, incorporating superconducting components. In the second part, some methods that have been or might be used in the study of superconductivity in the electron microscope are described. A brief account of the types of application for which they are suitable is given. (author)

  6. Digital Low Level RF Systems for Fermilab Main Ring and Tevatron

    Science.gov (United States)

    Chase, B.; Barnes, B.; Meisner, K.

    1997-05-01

    At Fermilab, a new Low Level RF system is successfully installed and operating in the Main Ring. Installation is proceeding for a Tevatron system. This upgrade replaces aging CAMAC/NIM components for an increase in accuracy, reliability, and flexibility. These VXI systems are based on a custom three channel direct digital synthesizer(DDS) module. Each synthesizer channel is capable of independent or ganged operation for both frequency and phase modulation. New frequency and phase values are computed at a 100kHz rate on the module's Analog Devices ADSP21062 (SHARC) digital signal processor. The DSP concurrently handles feedforward, feedback, and beam manipulations. Higher level state machines and the control system interface are handled at the crate level using the VxWorks operating system. This paper discusses the hardware, software and operational aspects of these LLRF systems.

  7. J/{psi} polarization at Tevatron and LHC. Nonrelativistic-QCD factorization at the crossroads

    Energy Technology Data Exchange (ETDEWEB)

    Butenschoen, Mathias; Kniel, Bernd A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2011-12-15

    We study the polarization observables of J/{psi} hadroproduction at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics. We complete the present knowledge of the relativistic corrections by also providing the contribution due to the intermediate {sup 3}P{sup [8]}{sub J} color-octet states, which turns out to be quite significant. Exploiting the color-octet long-distance matrix elements previously extracted through a global fit to experimental data of unpolarized J/{psi} production, we provide theoretical predictions in the helicity and Collins-Soper frames and compare them with data taken by CDF at Fermilab Tevatron I and II and by ALICE at CERN LHC. The notorious CDF J/{psi} polarization anomaly familiar from leading-order analyses persists at the quantum level, while the situation looks promising for the LHC, which is bound to bring final clarification.

  8. J/ψ polarization at Tevatron and LHC. Nonrelativistic-QCD factorization at the crossroads

    International Nuclear Information System (INIS)

    Butenschoen, Mathias; Kniel, Bernd A.

    2011-12-01

    We study the polarization observables of J/ψ hadroproduction at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics. We complete the present knowledge of the relativistic corrections by also providing the contribution due to the intermediate 3 P [8] J color-octet states, which turns out to be quite significant. Exploiting the color-octet long-distance matrix elements previously extracted through a global fit to experimental data of unpolarized J/ψ production, we provide theoretical predictions in the helicity and Collins-Soper frames and compare them with data taken by CDF at Fermilab Tevatron I and II and by ALICE at CERN LHC. The notorious CDF J/ψ polarization anomaly familiar from leading-order analyses persists at the quantum level, while the situation looks promising for the LHC, which is bound to bring final clarification.

  9. Beam-induced damage to the Tevatron components and what has been done about it

    International Nuclear Information System (INIS)

    Mokhov, N.V.; Czarapata, P.C.; Drozhdin, A.I.; Still, D.A.; Samulyak, R.V.

    2007-01-01

    A beam-induced damage to the Tevatron collimators happened in December 2003 was induced by a failure in the CDF Roman Pot detector positioning during the collider run. Possible scenarios of this failure resulted in an excessive halo generation and superconducting magnet quench have been studied via realistic simulations using the STRUCT and MARS14 codes. It is shown that the interaction of a misbehaved proton beam with the collimators result in a rapid local heating and a possible damage. A detailed consideration is given to the ablation process for the collimator material taking place in high vacuum. It is shown that ablation of tungsten (primary collimator) and stainless steel (secondary collimator) jaws results in creation of a groove in the jaw surface as was observed after the December's accident. The actions undertaken to avoid such an accident in future are described in detail. (author)

  10. Beam-induced damage to the Tevatron components and what has been done about it

    International Nuclear Information System (INIS)

    Mokhov, N.V.; Czarapata, P.C.; Drozhdin, A.I.; Still, D.A.; Samulyak, R.V.

    2006-01-01

    A beam-induced damage to the Tevatron collimators happened in December 2003 was induced by a failure in the CDF Roman Pot detector positioning during the collider run. Possible scenarios of this failure resulted in an excessive halo generation and superconducting magnet quench have been studied via realistic simulations using the STRUCT and MARS14 codes. It is shown that the interaction of a misbehaved proton beam with the collimators result in a rapid local heating and a possible damage. A detailed consideration is given to the ablation process for the collimator material taking place in high vacuum. It is shown that ablation of tungsten (primary collimator) and stainless steel (secondary collimator) jaws results in creation of a groove in the jaw surface as was observed after the December's accident. The actions undertaken to avoid such an accident in future are described in detail

  11. Colored resonances at the Tevatron: phenomenology and discovery potential in multijets

    International Nuclear Information System (INIS)

    Kilic, Can; Okui, Takemichi; Sundrum, Raman

    2008-01-01

    There exist several classes of theories beyond the Standard Model which contain massive spin-1 color octets, generically called ''colorons''. Indeed we argue that colorons inevitably appear in the spectrum whenever new colored particles feel an additional confining force. Colorons are distinctive at hadron colliders as this is the only environment in which they can be resonantly produced. In the simplest models we show that the coloron naturally decays to multijets via secondary resonances, which can be consistent with all existing bounds, even for colorons as light as a few hundred GeV. We perform representative case studies and show that a search in the four-jet channel at the Tevatron has strong signal significance, while the LHC faces formidable challenges for such a search.

  12. Search for the Higgs-Boson with the CDF experiment at Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Hennecke, Martin [Univ. of Karlsruhe (Germany)

    2005-06-10

    A search for a low-mass SM Higgs-Boson in the channel WH → lvb$\\bar{b}$ has been performed using neural networks. The data were taken by the CDF experiment at the p-$\\bar{p}$ collider Tevatron from 2000-2003, corresponding to in integrated luminosity of Lint = 162 pb-1 at a CMS-energy of √s = 1.96 TeV. 95% confidence level upper limits are set on σ × BR, the product of the production cross section times the Branching ratio, as a function of the Higgs boson mass. Cross sections above 8 pb are excluded for six different Higgs masses between 110 GeV/c2 and 150 GeV/c2. The required integrated luminosities for a 95% C.L. exclusion, 3σ evidence and 5σ discovery are calculated.

  13. Top anti-top Asymmetries at the Tevatron and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Yvonne Reinhild [DESY

    2012-11-01

    The heaviest known elementary particle today, the top quark, has been discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab. Recently, the CDF and D0 collaborations have studied the forward-backward asymmetry in ttbar events, resulting in measured values larger than the standard model prediction. With the start of the LHC at CERN in 2010, a new top quark factory has opened and asymmetry measurements in ttbar have also been performed in a proton proton environment with higher collision energy. No deviations from the standard model have been noticed so far in the measurements of ATLAS and CMS. This article discusses recent results of asymmetry measurements in ttbar events of the ATLAS, CDF, CMS and D0 collaborations.

  14. Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron.

    Science.gov (United States)

    Aaltonen, T; Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Agnew, J P; Alexeev, G D; Alkhazov, G; Alton, A; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Askew, A; Atkins, S; Auerbach, B; Augsten, K; Aurisano, A; Aushev, V; Aushev, Y; Avila, C; Azfar, F; Badaud, F; Badgett, W; Bae, T; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barbaro-Galtieri, A; Barberis, E; Baringer, P; Barnes, V E; Barnett, B A; Barria, P; Bartlett, J F; Bartos, P; Bassler, U; Bauce, M; Bazterra, V; Bean, A; Bedeschi, F; Begalli, M; Behari, S; Bellantoni, L; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Bhatti, A; Bland, K R; Blazey, G; Blessing, S; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bortoletto, D; Borysova, M; Boudreau, J; Boveia, A; Brandt, A; Brandt, O; Brigliadori, L; Brochmann, M; Brock, R; Bromberg, C; Bross, A; Brown, D; Brucken, E; Bu, X B; Budagov, J; Budd, H S; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burkett, K; Busetto, G; Bussey, P; Buszello, C P; Butti, P; Buzatu, A; Calamba, A; Camacho-Pérez, E; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Casey, B C K; Castilla-Valdez, H; Castro, A; Catastini, P; Caughron, S; Cauz, D; Cavaliere, V; Cerri, A; Cerrito, L; Chakrabarti, S; Chan, K M; Chandra, A; Chapelain, A; Chapon, E; Chen, G; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Cho, S W; Choi, S; Chokheli, D; Choudhary, B; Cihangir, S; Claes, D; Clark, A; Clarke, C; Clutter, J; Convery, M E; Conway, J; Cooke, M; Cooper, W E; Corbo, M; Corcoran, M; Cordelli, M; Couderc, F; Cousinou, M-C; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; Cuth, J; Cutts, D; Das, A; d'Ascenzo, N; Datta, M; Davies, G; de Barbaro, P; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Demortier, L; Deninno, M; Denisov, D; Denisov, S P; D'Errico, M; Desai, S; Deterre, C; DeVaughan, K; Devoto, F; Di Canto, A; Di Ruzza, B; Diehl, H T; Diesburg, M; Ding, P F; Dittmann, J R; Dominguez, A; Donati, S; D'Onofrio, M; Dorigo, M; Driutti, A; Drutskoy, A; Dubey, A; Dudko, L V; Duperrin, A; Dutt, S; Eads, M; Ebina, K; Edgar, R; Edmunds, D; Elagin, A; Ellison, J; Elvira, V D; Enari, Y; Erbacher, R; Errede, S; Esham, B; Evans, H; Evdokimov, A; Evdokimov, V N; Farrington, S; Fauré, A; Feng, L; Ferbel, T; Fernández Ramos, J P; Fiedler, F; Field, R; Filthaut, F; Fisher, W; Fisk, H E; Flanagan, G; Forrest, R; Fortner, M; Fox, H; Franc, J; Franklin, M; Freeman, J C; Frisch, H; Fuess, S; Funakoshi, Y; Galloni, C; Garbincius, P H; Garcia-Bellido, A; García-González, J A; Garfinkel, A F; Garosi, P; Gavrilov, V; Geng, W; Gerber, C E; Gerberich, H; Gerchtein, E; Gershtein, Y; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Ginther, G; Giokaris, N; Giromini, P; Glagolev, V; Glenzinski, D; Gogota, O; Gold, M; Goldin, D; Golossanov, A; Golovanov, G; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grosso-Pilcher, C; Grünendahl, S; Grünewald, M W; Guillemin, T; Guimaraes da Costa, J; Gutierrez, G; Gutierrez, P; Hahn, S R; Haley, J; Han, J Y; Han, L; Happacher, F; Hara, K; Harder, K; Hare, M; Harel, A; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hauptman, J M; Hays, C; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinrich, J; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herndon, M; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hocker, A; Hoeneisen, B; Hogan, J; Hohlfeld, M; Holzbauer, J L; Hong, Z; Hopkins, W; Hou, S; Howley, I; Hubacek, Z; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Introzzi, G; Iori, M; Ito, A S; Ivanov, A; Jabeen, S; Jaffré, M; James, E; Jang, D; Jayasinghe, A; Jayatilaka, B; Jeon, E J; Jeong, M S; Jesik, R; Jiang, P; Jindariani, S; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jones, M; Jonsson, P; Joo, K K; Joshi, J; Jun, S Y; Jung, A W; Junk, T R; Juste, A; Kajfasz, E; Kambeitz, M; Kamon, T; Karchin, P E; Karmanov, D; Kasmi, A; Kato, Y; Katsanos, I; Kaur, M; Kehoe, R; Kermiche, S; Ketchum, W; Keung, J; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S H; Kim, S B; Kim, Y J; Kim, Y K; Kimura, N; Kirby, M; Kiselevich, I; Kohli, J M; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kozelov, A V; Kraus, J; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kumar, A; Kupco, A; Kurata, M; Kurča, T; Kuzmin, V A; Laasanen, A T; Lammel, S; Lammers, S; Lancaster, M; Lannon, K; Latino, G; Lebrun, P; Lee, H S; Lee, H S; Lee, J S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Leo, S; Leone, S; Lewis, J D; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Limosani, A; Lincoln, D; Linnemann, J; Lipaev, V V; Lipeles, E; Lipton, R; Lister, A; Liu, H; Liu, Q; Liu, T; Liu, Y; Lobodenko, A; Lockwitz, S; Loginov, A; Lokajicek, M; Lopes de Sa, R; Lucchesi, D; Lucà, A; Lueck, J; Lujan, P; Lukens, P; Luna-Garcia, R; Lungu, G; Lyon, A L; Lys, J; Lysak, R; Maciel, A K A; Madar, R; Madrak, R; Maestro, P; Magaña-Villalba, R; Malik, S; Malik, S; Malyshev, V L; Manca, G; Manousakis-Katsikakis, A; Mansour, J; Marchese, L; Margaroli, F; Marino, P; Martínez-Ortega, J; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McCarthy, R; McGivern, C L; McNulty, R; Mehta, A; Mehtala, P; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Mesropian, C; Meyer, A; Meyer, J; Miao, T; Miconi, F; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondal, N K; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Mulhearn, M; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nagy, E; Nakano, I; Napier, A; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Nett, J; Neustroev, P; Nguyen, H T; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Nunnemann, T; Oakes, L; Oh, S H; Oh, Y D; Okusawa, T; Orava, R; Orduna, J; Ortolan, L; Osman, N; Pagliarone, C; Pal, A; Palencia, E; Palni, P; Papadimitriou, V; Parashar, N; Parihar, V; Park, S K; Parker, W; Partridge, R; Parua, N; Patwa, A; Pauletta, G; Paulini, M; Paus, C; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pleier, M-A; Podstavkov, V M; Pondrom, L; Popov, A V; Poprocki, S; Potamianos, K; Pranko, A; Prewitt, M; Price, D; Prokopenko, N; Prokoshin, F; Ptohos, F; Punzi, G; Qian, J; Quadt, A; Quinn, B; Ratoff, P N; Razumov, I; Redondo Fernández, I; Renton, P; Rescigno, M; Rimondi, F; Ripp-Baudot, I; Ristori, L; Rizatdinova, F; Robson, A; Rodriguez, T; Rolli, S; Rominsky, M; Ronzani, M; Roser, R; Rosner, J L; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Sajot, G; Sakumoto, W K; Sakurai, Y; Sánchez-Hernández, A; Sanders, M P; Santi, L; Santos, A S; Sato, K; Savage, G; Saveliev, V; Savitskyi, M; Savoy-Navarro, A; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schlabach, P; Schmidt, E E; Schott, M; Schwanenberger, C; Schwarz, T; Schwienhorst, R; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Sekaric, J; Semenov, A; Severini, H; Sforza, F; Shabalina, E; Shalhout, S Z; Shary, V; Shaw, S; Shchukin, A A; Shears, T; Shepard, P F; Shimojima, M; Shkola, O; Shochet, M; Shreyber-Tecker, I; Simak, V; Simonenko, A; Skubic, P; Slattery, P; Sliwa, K; Smith, J R; Snider, F D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, H; Sonnenschein, L; Sorin, V; Soustruznik, K; St Denis, R; Stancari, M; Stark, J; Stefaniuk, N; Stentz, D; Stoyanova, D A; Strauss, M; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Suter, L; Svoisky, P; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Titov, M; Toback, D; Tokar, S; Tokmenin, V V; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Ukegawa, F; Uozumi, S; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Vázquez, F; Velev, G; Vellidis, C; Verkheev, A Y; Vernieri, C; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vidal, M; Vilanova, D; Vilar, R; Vizán, J; Vogel, M; Vokac, P; Volpi, G; Wagner, P; Wahl, H D; Wallny, R; Wang, M H L S; Wang, S M; Warchol, J; Waters, D; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Williams, M R J; Wilson, G W; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wobisch, M; Wolbers, S; Wolfmeister, H; Wood, D R; Wright, T; Wu, X; Wu, Z; Wyatt, T R; Xie, Y; Yamada, R; Yamamoto, K; Yamato, D; Yang, S; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yeh, G P; Yi, K; Yin, H; Yip, K; Yoh, J; Yorita, K; Yoshida, T; Youn, S W; Yu, G B; Yu, I; Yu, J M; Zanetti, A M; Zeng, Y; Zennamo, J; Zhao, T G; Zhou, B; Zhou, C; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zucchelli, S

    2018-01-26

    The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A_{FB}^{tt[over ¯]}=0.128±0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.

  15. Q → qZ decays at Tevatron and SSC energies

    International Nuclear Information System (INIS)

    Agrawal, P.; Ellis, S.D.

    1990-09-01

    The possible existence of a new heavy quark Q that decays predominantly via the flavor changing neutral current transition Q → qZ is discussed. Candidates include a fourth generation charge -- 1/3 quark, or a more exotic vector-like quark. Such particles are interesting both as extensions of the Standard Model and due to their unique decay modes. The primary experimental indication of the pair production and subsequent decay of quarks is ZZ pair production at an essentially strong interaction rate. This mode can then constitute an unexpected background to the searches for other particles. In particular the channel Q bar Q → ZZ + X can generate a serious background to the search for the Higgs boson via the H 0 → ZZ mode at the SSC. Thus it is essential to search for such new heavy quarks at the Tevatron. Possible detection signatures for this purpose are discussed. 24 refs. , 1 fig., 3 tabs

  16. Status of the observed and predicted b anti-b production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Happacher, F.; Giromini, P.; /Frascati; Ptohos, F.; /Cyprus U.

    2005-09-01

    The authors review the experimental status of the b-quark production at the Fermilab Tevatron. They compare all available measurements to perturbative QCD predictions (NLO and FONLL) and also to the parton-level cross section evaluated with parton-shower Monte Carlo generators. They examine both the single b cross section and the so called b{bar b} correlations. The review shows that the experimental situation is quite complicated because the measurements appear to be inconsistent among themselves. In this situation, there is no solid basis to either claim that perturbative QCD is challenged by these measurements or, in contrast, that long-standing discrepancies between data and theory have been resolved by incrementally improving the measurements and the theoretical prediction.

  17. Quantum coherence, top transverse polarisation and the Tevatron asymmetry $A_{FB}^\\ell$

    CERN Document Server

    Aguilar-Saavedra, J A

    2014-01-01

    We revisit the relation between the asymmetries $A_{FB}$ and $A_{FB}^\\ell$ in $t \\bar t$ production at the Tevatron, using as new physics benchmark a colour octet. We find that $A_{FB}^\\ell$ receives large contributions from the interference between $\\lambda = \\pm 1/2$ top helicity states, which has been ignored in some of the previous literature on the subject. The omission of these contributions results in a severe underestimation of the asymmetry, around $1/2$ and $1/50$ of the true value for right-handed and left-handed top couplings to the octet, respectively. Interference effects are closely related to a $\\mathcal{O}(1)$ transverse top polarisation, as yet not considered in this context.

  18. First observation of vector boson pairs in a hadronic final state at the tevatron collider.

    Science.gov (United States)

    Aaltonen, T; Adelman, J; Akimoto, T; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; Di Canto, A; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Garosi, P; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Rutherford, B; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

    2009-08-28

    We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V = W, Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb(-1) of integrated luminosity of pp[over ] collisions at sqrt[s] = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516 + or - 239(stat) + or - 144(syst) diboson candidate events and measure a cross section sigma(pp[over ]-->VV + X) of 18.0 + or - 2.8(stat) + or - 2.4(syst) + or -1.1(lumi) pb, in agreement with the expectations of the standard model.

  19. Searches for diboson production at the Tevatron in final states containing heavy-flavor jets

    Directory of Open Access Journals (Sweden)

    Grivaz Jean-François

    2012-06-01

    Full Text Available Recent searches performed by the CDF and D0 collaborations at the Tevatron for diboson production in final states containing heavy-flavor jets are reported. The searches for WZ and ZZ can be regarded as the ultimate benchmark for the corresponding searches for a low-mass Higgs boson in the WH and ZH final states. Using the exact same techniques as for those Higgs boson searches, the D0 collaboration measured a cross section for WZ/ZZ production of 1.13 ± 0.36 times its expectation in the standard model, with a diboson signal significance of 3.3 standard deviations (2.9 expected.

  20. B-meson production in the Parton Reggeization approach at Tevatron and the LHC

    International Nuclear Information System (INIS)

    Karpishkov, A.V.; Saleev, V.A.; Nefedov, M.A.; Shipilova, A.V.; Samara State Aerospace Univ.; Hamburg Univ.

    2014-11-01

    We study the inclusive hadroproduction of B 0 , B + , and B 0 s mesons at leading order in the parton Reggeization approach using the universal fragmentation functions extracted from the combined e + e - annihilation data from CERN LEP1 and SLAC SLC colliders. We have described B-meson transverse momentum distributions measured in the central region of rapidity by the CDF Collaboration at Fermilab Tevatron and CMS Collaboration at LHC within uncertainties and without free parameters, applying Kimber-Martin-Ryskin unintegrated gluon distribution function in a proton. The forward B-meson production (2.0< y<4.5) measured by the LHCb Collaboration also has been studied and expected disagreement between our theoretical predictions and data has been obtained.

  1. Single top quarks at the Tevatron and observation of the s-channel production mode

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The presentation gives an overview of single-top-quark production at the Tevatron proton-antiproton collider. The talk covers measurements of the total s+t channel production cross section and the extraction of the CKM matrix element |V_tb|. Furthermore, separate analyses of the s-channel and t-channel production modes are discussed. The data correspond to total integrated luminosities of up to 9.7 fb-1 per experiment and represent in most cases the full Run-II dataset. Through a combination of the CDF and D0 measurements the first observation of single-top-quark production in the s-channel is claimed. This is particularly highlighted in the seminar.

  2. Diphoton production at Tevatron in the quasi-multiple-Regge-kinematics approach

    Energy Technology Data Exchange (ETDEWEB)

    Saleev, V.A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Samarskij Gosudarstvennyj Univ., Samara (Russian Federation)

    2009-12-15

    We study the production of prompt diphotons in the central region of rapidity within the frame- work of the quasi-multi-Regge-kinematics approach applying the hypothesis of quark and gluon Reggeization. We describe accurately and without free parameters the experimental data which were obtained by the CDF Collaboration at the Tevatron Collider. It is shown that the main contribution to studied process is given by the direct fusion of two Reggeized gluons into a photon pair, which is described by the effective Reggeon-Reggeon to particle-particle vertex. The contribution from the annihilation of Reggeized quark-antiquark pair into a diphoton is also considered. At the stage of numerical calculations we use the Kimber-Martin-Ryskin prescription for unintegrated quark and gluon distribution functions, with the Martin-Roberts-Stirling-Thorne collinear parton densities for a proton as input. (orig.)

  3. Report of the SUGRA Working Group for Run II of the Tevatron

    CERN Document Server

    Barger, V.; Flattum, E.; Falk, T.; Abel, S.; Accomando, E.; Anderson, G.; Arnowitt, R.; Azzi, P.; Baer, H.; Bagger, J.; Beenakker, W.; Belyaev, A.; Berger, E.; Berger, M.; Brhlik, M.; Blazek, T.; Blessing, S.; Bokhari, W.; Bruner, N.; Carena, M.; Chakraborty, D.; Chang, D.; Chankowski, P.; Chen, C.H.; Cheng, H.C.; Chertok, M.; Cho, G.C.; Claes, D.; Demina, R.; Done, J.; Duflot, L.; Dutta, Bhaskar; Eboli, O.J.P.; Eno, S.; Feng, J.; Ganis, G.; Gold, M.; Gregores, E.M.; Hagiwara, K.; Han, T.; Harris, B.; Hikasa, K.; Holck, C.; Kao, C.; Kato, Y.; Klasen, M.; Keung, W.Y.; Kramer, M.; Lammel, S.; Li, T.J.; Lykken, J.D.; Magro, M.; Mani, S.; Matchev, K.T.; Mangano, M.; Mercadante, P.; Mrenna, S.; Nachtman, J.; Nath, P.; Nojiri, M.M.; Nomerotski, A.; Norman, D.; Oishi, R.; Ono, K.; Paige, F.; Paterno, M.; Parke, S.; Pierce, D.; Pilaftsis, A.; Plehn, T.; Pompos, A.; Polonksy, N.; Pokorski, S.; Quintana, P.; Roco, M.; Saltzberg, D.; Savoy-Navarro, A.; Seiya, Y.; Smith, C.; Spira, M.; Spiropulu, M.; Sullivan, Z.; Szalapski, R.; Tannenbaum, B.; Tait, T.; Wackeroth, D.; Wang, Y.; White, J.; Williams, H.H.; Worcester, M.; Worm, S.; Zhang, R.J.; Zielinski, M.

    2000-01-01

    We present an analysis of the discovery reach for supersymmetric particles at the upgraded Tevatron collider, assuming that SUSY breaking results in universal soft breaking parameters at the grand unification scale, and that the lightest supersymmetric particle is stable and neutral. We first present a review of the literature, including the issues of unification, renormalization group evolution of the supersymmetry breaking parameters and the effect of radiative corrections on the effective low energy couplings and masses of the theory. We consider the experimental bounds coming from direct searches and those arising indirectly from precision data, cosmology and the requirement of vacuum stability. The issues of flavor and CP-violation are also addressed. The main subject of this study is to update sparticle production cross sections, make improved estimates of backgrounds, delineate the discovery reach in the supergravity framework, and examine how this might vary when assumptions about universality of soft...

  4. Enhancing the top-quark signal at Fermilab Tevatron using neural nets

    International Nuclear Information System (INIS)

    Ametller, L.; Garrido, L.; Talavera, P.

    1994-01-01

    We show, in agreement with previous studies, that neural nets can be useful for top-quark analysis at the Fermilab Tevatron. The main features of t bar t and background events in a mixed sample are projected on a single output, which controls the efficiency, purity, and statistical significance of the t bar t signal. We consider a feed-forward multilayer neural net for the CDF reported top-quark mass, using six kinematical variables as inputs. Our main results are based on the exhaustive comparison of the neural net performances with those obtainable from the standard experimental analysis, by imposing different sets of linear cuts over the same variables, showing how the neural net approach improves the standard analysis results

  5. Model-independent analysis of the Fermilab Tevatron turn-by-turn beam position monitor measurements

    Science.gov (United States)

    Petrenko, A. V.; Valishev, A. A.; Lebedev, V. A.

    2011-09-01

    Coherent transverse beam oscillations in the Tevatron were analyzed with the model-independent analysis (MIA) technique. This allowed one to obtain the model-independent values of coupled betatron amplitudes, phase advances, and dispersion function around the ring from a single dipole kick measurement. In order to solve the MIA mode mixing problem which limits the accuracy of determination of the optical functions, we have developed a new technique of rotational MIA mode untangling. The basic idea is to treat each beam position monitor (BPM) as two BPMs separated in a ring by exactly one turn. This leads to a simple criterion of MIA mode separation: the betatron phase advance between any BPM and its counterpart shifted by one turn should be equal to the betatron tune and therefore should not depend on the BPM position in the ring. Furthermore, we describe a MIA-based technique to locate vibrating magnets in a storage ring.

  6. Model-independent analysis of the Fermilab Tevatron turn-by-turn beam position monitor measurements

    Directory of Open Access Journals (Sweden)

    A. V. Petrenko

    2011-09-01

    Full Text Available Coherent transverse beam oscillations in the Tevatron were analyzed with the model-independent analysis (MIA technique. This allowed one to obtain the model-independent values of coupled betatron amplitudes, phase advances, and dispersion function around the ring from a single dipole kick measurement. In order to solve the MIA mode mixing problem which limits the accuracy of determination of the optical functions, we have developed a new technique of rotational MIA mode untangling. The basic idea is to treat each beam position monitor (BPM as two BPMs separated in a ring by exactly one turn. This leads to a simple criterion of MIA mode separation: the betatron phase advance between any BPM and its counterpart shifted by one turn should be equal to the betatron tune and therefore should not depend on the BPM position in the ring. Furthermore, we describe a MIA-based technique to locate vibrating magnets in a storage ring.

  7. Spurious Shear in Weak Lensing with LSST

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.; Kahn, S.M.; Jernigan, J.G.; Peterson, J.R.; AlSayyad, Y.; Ahmad, Z.; Bankert, J.; Bard, D.; Connolly, A.; Gibson, R.R.; Gilmore, K.; Grace, E.; Hannel, M.; Hodge, M.A.; Jee, M.J.; Jones, L.; Krughoff, S.; Lorenz, S.; Marshall, P.J.; Marshall, S.; Meert, A.

    2012-09-19

    The complete 10-year survey from the Large Synoptic Survey Telescope (LSST) will image {approx} 20,000 square degrees of sky in six filter bands every few nights, bringing the final survey depth to r {approx} 27.5, with over 4 billion well measured galaxies. To take full advantage of this unprecedented statistical power, the systematic errors associated with weak lensing measurements need to be controlled to a level similar to the statistical errors. This work is the first attempt to quantitatively estimate the absolute level and statistical properties of the systematic errors on weak lensing shear measurements due to the most important physical effects in the LSST system via high fidelity ray-tracing simulations. We identify and isolate the different sources of algorithm-independent, additive systematic errors on shear measurements for LSST and predict their impact on the final cosmic shear measurements using conventional weak lensing analysis techniques. We find that the main source of the errors comes from an inability to adequately characterise the atmospheric point spread function (PSF) due to its high frequency spatial variation on angular scales smaller than {approx} 10{prime} in the single short exposures, which propagates into a spurious shear correlation function at the 10{sup -4}-10{sup -3} level on these scales. With the large multi-epoch dataset that will be acquired by LSST, the stochastic errors average out, bringing the final spurious shear correlation function to a level very close to the statistical errors. Our results imply that the cosmological constraints from LSST will not be severely limited by these algorithm-independent, additive systematic effects.

  8. The Strong Lensing Time Delay Challenge (2014)

    Science.gov (United States)

    Liao, Kai; Dobler, G.; Fassnacht, C. D.; Treu, T.; Marshall, P. J.; Rumbaugh, N.; Linder, E.; Hojjati, A.

    2014-01-01

    Time delays between multiple images in strong lensing systems are a powerful probe of cosmology. At the moment the application of this technique is limited by the number of lensed quasars with measured time delays. However, the number of such systems is expected to increase dramatically in the next few years. Hundred such systems are expected within this decade, while the Large Synoptic Survey Telescope (LSST) is expected to deliver of order 1000 time delays in the 2020 decade. In order to exploit this bounty of lenses we needed to make sure the time delay determination algorithms have sufficiently high precision and accuracy. As a first step to test current algorithms and identify potential areas for improvement we have started a "Time Delay Challenge" (TDC). An "evil" team has created realistic simulated light curves, to be analyzed blindly by "good" teams. The challenge is open to all interested parties. The initial challenge consists of two steps (TDC0 and TDC1). TDC0 consists of a small number of datasets to be used as a training template. The non-mandatory deadline is December 1 2013. The "good" teams that complete TDC0 will be given access to TDC1. TDC1 consists of thousands of lightcurves, a number sufficient to test precision and accuracy at the subpercent level, necessary for time-delay cosmography. The deadline for responding to TDC1 is July 1 2014. Submissions will be analyzed and compared in terms of predefined metrics to establish the goodness-of-fit, efficiency, precision and accuracy of current algorithms. This poster describes the challenge in detail and gives instructions for participation.

  9. Effect of cholesterol deposition on bacterial adhesion to contact lenses.

    Science.gov (United States)

    Babaei Omali, Negar; Zhu, Hua; Zhao, Zhenjun; Ozkan, Jerome; Xu, Banglao; Borazjani, Roya; Willcox, Mark D P

    2011-08-01

    To examine the effect of cholesterol on the adhesion of bacteria to silicone hydrogel contact lenses. Contact lenses, collected from subjects wearing Acuvue Oasys or PureVision lenses, were extracted in chloroform:methanol (1:1, v/v) and amount of cholesterol was estimated by thin-layer chromatography. Unworn lenses were soaked in cholesterol, and the numbers of Pseudomonas aeruginosa strains or Staphylococcus aureus strains that adhered to the lenses were measured. Cholesterol was tested for effects on bacterial growth by incubating bacteria in medium containing cholesterol. From ex vivo PureVision lenses, 3.4 ± 0.3 μg/lens cholesterol was recovered, and from Acuvue Oasys lenses, 2.4 ± 0.2 to 1.0 ± 0.1 μg/lens cholesterol was extracted. Cholesterol did not alter the total or viable adhesion of any strain of P. aeruginosa or S. aureus (p > 0.05). However, worn PureVision lenses reduced the numbers of viable cells of P. aeruginosa (5.8 ± 0.4 log units) compared with unworn lenses (6.4 ± 0.2 log units, p = 0.001). Similarly, there were fewer numbers of S. aureus 031 adherent to worn PureVision (3.05 ± 0.8 log units) compared with unworn PureVision (4.6 ± 0.3 log units, p = 0.0001). Worn Acuvue Oasys lenses did not affect bacterial adhesion. Cholesterol showed no effect on the growth of any test strain. Although cholesterol has been shown to adsorb to contact lenses during wear, this lipid does not appear to modulate bacterial adhesion to a lens surface.

  10. Search for the Standard Model Higgs Boson associated with a W Boson using Matrix Element Technique in the CDF detector at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Barbara Alvarez [Univ. of Oviedo (Spain)

    2010-05-01

    In this thesis a direct search for the Standard Model Higgs boson production in association with a W boson at the CDF detector in the Tevatron is presented. This search contributes predominantly in the region of low mass Higgs region, when the mass of Higgs boson is less than about 135 GeV. The search is performed in a final state where the Higgs boson decays into two b quarks, and the W boson decays leptonically, to a charged lepton (it can be an electron or a muon) and a neutrino. This work is organized as follows. Chapter 2 gives an overview of the Standard Model theory of particle physics and presents the SM Higgs boson search results at LEP, and the Tevatron colliders, as well as the prospects for the SM Higgs boson searches at the LHC. The dataset used in this analysis corresponds to 4.8 fb-1 of integrated luminosity of p$\\bar{p}$ collisions at a center of mass energy of 1.96 TeV. That is the luminosity acquired between the beginning of the CDF Run II experiment, February 2002, and May 2009. The relevant aspects, for this analysis, of the Tevatron accelerator and the CDF detector are shown in Chapter 3. In Chapter 4 the particles and observables that make up the WH final state, electrons, muons, ET, and jets are presented. The CDF standard b-tagging algorithms to identify b jets, and the neural network flavor separator to distinguish them from other flavor jets are also described in Chapter 4. The main background contributions are those coming from heavy flavor production processes, such as those coming from Wbb, Wcc or Wc and tt. The signal and background signatures are discussed in Chapter 5 together with the Monte CArlo generators that have been used to simulate almost all the events used in this thesis. WH candidate events have a high-pT lepton (electron or muon), high missing transverse energy, and two or more than two jets in the final state. Chapter 6 describes the event selection applied in this analysis and the

  11. The lensing properties of the Einasto profile

    OpenAIRE

    Retana-Montenegro, E.; Frutos-Alfaro, F.

    2011-01-01

    In recent high resolution N-body CDM simulations, it has been had found that nonsingular three-parameter models, e.g. the Einasto profile has a better performance better than the singular two-parameter models, e.g. the Navarro, Frenk and White in the fitting of a wide range of dark matter halos. A problem with this profile is that the surface mass density is non-analytical for general values of the Einasto index. Therefore, its other lensing properties have the same problem. We obtain an exac...

  12. Optimizing outcomes with multifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gitansha Shreyas Sachdev

    2017-01-01

    Full Text Available Modern day cataract surgery is evolving from a visual restorative to a refractive procedure. The advent of multifocal intraocular lenses (MFIOLs allows greater spectacle independence and increased quality of life postoperatively. Since the inception in 1980s, MFIOLs have undergone various technical advancements including trifocal and extended depth of vision implants more recently. A thorough preoperative workup including the patients' visual needs and inherent ocular anatomy allows us to achieve superior outcomes. This review offers a comprehensive overview of the various types of MFIOLs and principles of optimizing outcomes through a comprehensive preoperative screening and management of postoperative complications.

  13. Magnified Weak Lensing Cross Correlation Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Melville P., Clowe, Douglas I.

    2010-11-30

    This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60

  14. Characterisation of adaptive fluidic silicone membrane lenses

    CSIR Research Space (South Africa)

    Schneider, F

    2009-09-01

    Full Text Available membrane shapes for a lens volume of 1 µl at divorce homogeneous membrane thicknesses. The measurement of the system behaviour is realized by the laser-profilometer in the dynamic mode. For the lens with a homogeneous membrane the membrane surface..., inhomogeneous membranes is application specific. On the one hand, systems with planar mem- branes are reasonable for a large focal length range, a constant optical lens quality and a short response time. On the other hand, the application of lenses...

  15. UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

    International Nuclear Information System (INIS)

    Spyratou, E.; Asproudis, I.; Tsoutsi, D.; Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A.

    2010-01-01

    Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV (λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

  16. UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

    Energy Technology Data Exchange (ETDEWEB)

    Spyratou, E., E-mail: ellas5@central.ntua.gr [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece); Asproudis, I. [Department of Ophthalmology, University Hospital of Ioannina, Ioannina, 45110 (Greece); Tsoutsi, D. [Department of Chemistry, University of Ioannina, Ioannina, 45110 (Greece); Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A. [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece)

    2010-02-01

    Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV ({lambda} = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

  17. Finding the Higgs boson of the standard model in the channel ZH → e+e-b(bar b) with the D0 detector at the Tevatron

    International Nuclear Information System (INIS)

    Calpas, Betty Constante

    2010-01-01

    The organization of this thesis consists of three main ideas: the first presents the theoretical framework and experimental, as well as objects used in the analysis and the second relates to the various work tasks of service that I performed on the calorimeter, and the third is the search for the Higgs boson in the channel ZH → e + e - b(bar b). Thus, this thesis has the following structure: Chapter 1 is an introduction to the standard model of particle physics and the Higgs mechanism; Chapter 2 is an overview of the complex and the acceleration of the Tevatron at Fermilab D0 detector; Chapter 3 is an introduction to physical objects used in this thesis; Chapter 4 presents the study made on correcting the energy measured in the calorimeter; Chapter 5 describes the study of certification of electrons in the calorimeter; Chapter 6 describes the study of certification of electrons in the intercryostat region of calorimeter; Chapter 7 Detailed analysis on the search for Higgs production in the channel ZH → e + e - b(bar b); and Chapter 8 presents the final results of the calculations of upper limits to the production cross section of the Higgs boson on a range of low masses.

  18. Gauge-invariant formalism of cosmological weak lensing

    Science.gov (United States)

    Yoo, Jaiyul; Grimm, Nastassia; Mitsou, Ermis; Amara, Adam; Refregier, Alexandre

    2018-04-01

    We present the gauge-invariant formalism of cosmological weak lensing, accounting for all the relativistic effects due to the scalar, vector, and tensor perturbations at the linear order. While the light propagation is fully described by the geodesic equation, the relation of the photon wavevector to the physical quantities requires the specification of the frames, where they are defined. By constructing the local tetrad bases at the observer and the source positions, we clarify the relation of the weak lensing observables such as the convergence, the shear, and the rotation to the physical size and shape defined in the source rest-frame and the observed angle and redshift measured in the observer rest-frame. Compared to the standard lensing formalism, additional relativistic effects contribute to all the lensing observables. We explicitly verify the gauge-invariance of the lensing observables and compare our results to previous work. In particular, we demonstrate that even in the presence of the vector and tensor perturbations, the physical rotation of the lensing observables vanishes at the linear order, while the tetrad basis rotates along the light propagation compared to a FRW coordinate. Though the latter is often used as a probe of primordial gravitational waves, the rotation of the tetrad basis is indeed not a physical observable. We further clarify its relation to the E-B decomposition in weak lensing. Our formalism provides a transparent and comprehensive perspective of cosmological weak lensing.

  19. 30 CFR 18.66 - Tests of windows and lenses.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of windows and lenses. 18.66 Section 18... Tests § 18.66 Tests of windows and lenses. (a) Impact tests. A 4-pound cylindrical weight with a 1-inch-diameter hemispherical striking surface shall be dropped (free fall) to strike the window or lens in its...

  20. Dimensional stability of lathe cut C.A.B. lenses.

    Science.gov (United States)

    Pearson, R M

    1978-08-01

    Measurements of the back central optical radius in the course of 336 hours of hydration of lathe cut corneal lenses disclosed changes in curvature which were more rapid and of greater magnitude than those previously reported for poly (methyl methacrylate) lenses.

  1. Influence of protein deposition on bacterial adhesion to contact lenses.

    Science.gov (United States)

    Subbaraman, Lakshman N; Borazjani, Roya; Zhu, Hua; Zhao, Zhenjun; Jones, Lyndon; Willcox, Mark D P

    2011-08-01

    The aim of the study is to determine the adhesion of Gram positive and Gram negative bacteria onto conventional hydrogel (CH) and silicone hydrogel (SH) contact lens materials with and without lysozyme, lactoferrin, and albumin coating. Four lens types (three SH-balafilcon A, lotrafilcon B, and senofilcon A; one CH-etafilcon A) were coated with lysozyme, lactoferrin, or albumin (uncoated lenses acted as controls) and then incubated in Staphylococcus aureus (Saur 31) or either of two strains of Pseudomonas aeruginosa (Paer 6294 and 6206) for 24 h at 37 °C. The total counts of the adhered bacteria were determined using the H-thymidine method and viable counts by counting the number of colony-forming units on agar media. All three strains adhered significantly lower to uncoated etafilcon A lenses compared with uncoated SH lenses (p 0.05). Lactoferrin coating on lenses increased binding (total and viable counts) of Saur 31 (p lenses showed significantly higher total counts (p lenses. Albumin coating of lenses increased binding (total and viable counts) of all three strains (p lenses does not possess antibacterial activity against certain bacterial strains, whereas lactoferrin possess an antibacterial effect against strains of P. aeruginosa.

  2. Biochemical analyses of lipids deposited on silicone hydrogel lenses

    Directory of Open Access Journals (Sweden)

    Shin Hatou

    2010-07-01

    Conclusions: The quantity of total lipid and cholesterol deposited on the 3 silicone hydrogel lenses tested did not differ. However, there were significant differences in the amounts of phospholipid deposited among the 3 silicone hydrogel lenses, of which clinical significance should be explored in the future study.

  3. Shallow rainwater lenses in deltaic areas with saline seepage

    NARCIS (Netherlands)

    Louw, de P.G.B.; Eeman, S.; Siemon, B.; `Voortman, B.R.; Gunnink, J.; Baaren, E.S.; Oude Essink, G.H.P.

    2011-01-01

    In deltaic areas with saline seepage, freshwater availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence and

  4. Shallow rainwater lenses in deltaic areas with saline seepage

    NARCIS (Netherlands)

    De Louw, Perry G.B.; Eeman, Sara; Siemon, Bernhard; Voortman, Bernard R.; Gunnink, Jan; Van Baaren, Esther S.; Oude Essink, Gualbert

    2011-01-01

    In deltaic areas with saline seepage, fresh water availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence

  5. From Spheric to Aspheric Solid Polymer Lenses: A Review

    Directory of Open Access Journals (Sweden)

    Kuo-Yung Hung

    2011-01-01

    Full Text Available This paper presents a new approach in the use of MEMS technology to fabricate micro-optofluidic polymer solid lenses in order to achieve the desired profile, focal length, numerical aperture, and spot size. The resulting polymer solid lenses can be applied in optical data storage systems, imaging systems, and automated optical inspection systems. In order to meet the various needs of different applications, polymer solid lenses may have a spherical or aspherical shape. The method of fabricating polymer solid lenses is different from methods used to fabricate tunable lenses with variable focal length or needing an external control system to change the lens geometry. The current trend in polymer solid lenses is toward the fabrication of microlenses with a high numerical aperture, small clear aperture (<2 mm, and high transmittance. In this paper we focus on the use of thermal energy and electrostatic force in shaping the lens profile, including both spherical and aspherical lenses. In addition, the paper discusses how to fabricate a lens with a high numerical aperture of 0.6 using MEMS and also compares the optical characteristics of polymer lens materials, including SU-8, Norland Optical Adhesive (NOA, and cyclic olefin copolymer (COC. Finally, new concepts and applications related to micro-optofluidic lenses and polymer materials are also discussed.

  6. Nanoplasmonic lenses for bacteria sorting (Presentation Recording)

    Science.gov (United States)

    Zhu, Xiangchao; Yanik, Ahmet A.

    2015-08-01

    We demonstrate that patches of two dimensional arrays of circular plasmonic nanoholes patterned on gold-titanium thin film enables subwavelength focusing of visible light in far field region. Efficient coupling of the light with the excited surface plasmon at metal dielectric interface results in strong light transmission. As a result, surface plasmon plays an important role in the far field focusing behavior of the nanohole-aperture patches device. Furthermore, the focal length of the focused beam was found to be predominantly dependent on the overall size of the patch, which is in good agreement with that calculated by Rayleigh-Sommerfield integral formula. The focused light beam can be utilized to separate bio-particles in the dynamic range from 0.1 μm to 1 μm through mainly overcoming the drag force induced by fluid flow. In our proposed model, focused light generated by our plasmonic lenses will push the larger bio-particles in size back to the source of fluid flow and allow the smaller particles to move towards the central aperture of the patch. Such a new kind of plasmonic lenses open up possibility of sorting bacterium-like particles with plasmonic nanolenses, and also represent a promising tool in the field of virology.

  7. Fermat potentials for nonperturbative gravitational lensing

    International Nuclear Information System (INIS)

    Frittelli, Simonetta; Kling, Thomas P.; Newman, Ezra T.

    2002-01-01

    The images of many distant galaxies are displaced, distorted and often multiplied by the presence of foreground massive galaxies near the line of sight; the foreground galaxies act as gravitational lenses. Commonly, the lens equation, which relates the placement and distortion of the images to the real source position in the thin-lens scenario, is obtained by extremizing the time of arrival among all the null paths from the source to the observer (Fermat's principle). We show that the construction of envelopes of certain families of null surfaces constitutes an alternative variational principle or version of Fermat's principle that leads naturally to a lens equation in a generic spacetime with any given metric. We illustrate the construction by deriving the lens equation for static asymptotically flat thin lens spacetimes. As an application of the approach, we find the bending angle for moving thin lenses in terms of the bending angle for the same deflector at rest. Finally we apply this construction to cosmological spacetimes (FRW) by using the fact they are all conformally related to Minkowski space

  8. Can strong gravitational lensing constrain dark energy?

    International Nuclear Information System (INIS)

    Lee, Seokcheon; Ng, K.-W.

    2007-01-01

    We discuss the ratio of the angular diameter distances from the source to the lens, D ds , and to the observer at present, D s , for various dark energy models. It is well known that the difference of D s s between the models is apparent and this quantity is used for the analysis of Type Ia supernovae. However we investigate the difference between the ratio of the angular diameter distances for a cosmological constant, (D ds /D s ) Λ , and that for other dark energy models, (D ds /D s ) other , in this paper. It has been known that there is lens model degeneracy in using strong gravitational lensing. Thus, we investigate the model independent observable quantity, Einstein radius (θ E ), which is proportional to both D ds /D s and velocity dispersion squared, σ v 2 . D ds /D s values depend on the parameters of each dark energy model individually. However, (D ds /D s ) Λ -(D ds /D s ) other for the various dark energy models, is well within the error of σ v for most of the parameter spaces of the dark energy models. Thus, a single strong gravitational lensing by use of the Einstein radius may not be a proper method to investigate the property of dark energy. However, better understanding to the mass profile of clusters in the future or other methods related to arc statistics rather than the distances may be used for constraints on dark energy

  9. Tackling The Dragon: Investigating Lensed Galaxy Structure

    Science.gov (United States)

    Fortenberry, Alexander; Livermore, Rachael

    2018-01-01

    Galaxies have been seen to have a rapid decrease in star formation beginning at a redshift of around 1-2 up to the present day. To understand the processes underpinning this change, we need to observe the inner structure of galaxies and understand where and how the stellar mass builds up. However, at high redshifts our observable resolution is limited, which hinders the accuracy of the data. The lack of resolution at high redshift can be counteracted with the use of gravitational lensing. The magnification provided by the gravitational lens between us and the galaxies in question enables us to see extreme detail within the galaxies. To begin fine-tuning this process, we used Hubble data of Abell 370, a galaxy cluster, which lenses a galaxy know as “The Dragon” at z=0.725. With the increased detail proved by the gravitational lens we provide a detailed analysis of the galaxy’s spatially resolved star formation rate, stellar age, and masses.

  10. The theory of stochastic cosmological lensing

    Energy Technology Data Exchange (ETDEWEB)

    Fleury, Pierre; Uzan, Jean-Philippe [Institut d' Astrophysique de Paris, UMR 7095 du CNRS, 98 bis Bd Arago, 75014 Paris (France); Larena, Julien, E-mail: fleury@iap.fr, E-mail: j.larena@ru.ac.za, E-mail: uzan@iap.fr [Department of Mathematics, Rhodes University, Grahamstown 6140 (South Africa)

    2015-11-01

    On the scale of the light beams subtended by small sources, e.g. supernovae, matter cannot be accurately described as a fluid, which questions the applicability of standard cosmic lensing to those cases. In this article, we propose a new formalism to deal with small-scale lensing as a diffusion process: the Sachs and Jacobi equations governing the propagation of narrow light beams are treated as Langevin equations. We derive the associated Fokker-Planck-Kolmogorov equations, and use them to deduce general analytical results on the mean and dispersion of the angular distance. This formalism is applied to random Einstein-Straus Swiss-cheese models, allowing us to: (1) show an explicit example of the involved calculations; (2) check the validity of the method against both ray-tracing simulations and direct numerical integration of the Langevin equation. As a byproduct, we obtain a post-Kantowski-Dyer-Roeder approximation, accounting for the effect of tidal distortions on the angular distance, in excellent agreement with numerical results. Besides, the dispersion of the angular distance is correctly reproduced in some regimes.

  11. Adaptive lenses using transparent dielectric elastomer actuators

    Science.gov (United States)

    Shian, Samuel; Diebold, Roger; Clarke, David

    2013-03-01

    Variable focal lenses, used in a vast number of applications such as endoscope, digital camera, binoculars, information storage, communication, and machine vision, are traditionally constructed as a lens system consisting of solid lenses and actuating mechanisms. However, such lens system is complex, bulky, inefficient, and costly. Each of these shortcomings can be addressed using an adaptive lens that performs as a lens system. In this presentation, we will show how we push the boundary of adaptive lens technology through the use of a transparent electroactive polymer actuator that is integral to the optics. Detail of our concepts and lens construction will be described as well as electromechanical and optical performances. Preliminary data indicate that our adaptive lens prototype is capable of varying its focus by more than 100%, which is higher than that of human eyes. Furthermore, we will show how our approach can be used to achieve certain controls over the lens characteristics such as adaptive aberration and optical axis, which are difficult or impossible to achieve in other adaptive lens configurations.

  12. Probing neutrino masses with CMB lensing extraction

    International Nuclear Information System (INIS)

    Lesgourgues, Julien; Perotto, Laurence; Pastor, Sergio; Piat, Michel

    2006-01-01

    We evaluate the ability of future cosmic microwave background (CMB) experiments to measure the power spectrum of large scale structure using quadratic estimators of the weak lensing deflection field. We calculate the sensitivity of upcoming CMB experiments such as BICEP, QUaD, BRAIN, ClOVER and Planck to the nonzero total neutrino mass M ν indicated by current neutrino oscillation data. We find that these experiments greatly benefit from lensing extraction techniques, improving their one-sigma sensitivity to M ν by a factor of order four. The combination of data from Planck and the SAMPAN mini-satellite project would lead to σ(M ν )∼0.1 eV, while a value as small as σ(M ν )∼0.035 eV is within the reach of a space mission based on bolometers with a passively cooled 3-4 m aperture telescope, representative of the most ambitious projects currently under investigation. We show that our results are robust not only considering possible difficulties in subtracting astrophysical foregrounds from the primary CMB signal but also when the minimal cosmological model (Λ Mixed Dark Matter) is generalized in order to include a possible scalar tilt running, a constant equation-of-state parameter for the dark energy and/or extra relativistic degrees of freedom

  13. Probabilistic Cosmological Mass Mapping from Weak Lensing Shear

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M. D.; Dawson, W. A. [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Ng, K. Y. [University of California, Davis, Davis, CA 95616 (United States); Marshall, P. J. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94035 (United States); Meyers, J. E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Bard, D. J., E-mail: schneider42@llnl.gov, E-mail: dstn@cmu.edu, E-mail: boutigny@in2p3.fr, E-mail: djbard@slac.stanford.edu, E-mail: jmeyers314@stanford.edu [National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720-8150 (United States)

    2017-04-10

    We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a spatial process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed cosmological lensing shear maps and a reconstruction of the mass distribution of the merging galaxy cluster Abell 781 using galaxy ellipticities measured with the Deep Lens Survey. Given interim posterior samples of lensing shear or convergence fields on the sky, we describe an algorithm to infer cosmological parameters via lens field marginalization. In the most general formulation of our algorithm we make no assumptions about weak shear or Gaussian-distributed shape noise or shears. Because we require solutions and matrix determinants of a linear system of dimension that scales with the number of galaxies, we expect our algorithm to require parallel high-performance computing resources for application to ongoing wide field lensing surveys.

  14. CMB lensing constraints on dark energy and modified gravity scenarios

    International Nuclear Information System (INIS)

    Calabrese, Erminia; Cooray, Asantha; Martinelli, Matteo; Melchiorri, Alessandro; Pagano, Luca; Slosar, Anze; Smoot, George F.

    2009-01-01

    Weak gravitational lensing leaves a characteristic imprint on the cosmic microwave background temperature and polarization angular power spectra. Here, we investigate the possible constraints on the integrated lensing potential from future cosmic microwave background angular spectra measurements expected from Planck and EPIC. We find that Planck and EPIC will constrain the amplitude of the integrated projected potential responsible for lensing at 6% and 1% level, respectively, with very little sensitivity to the shape of the lensing potential. We discuss the implications of such a measurement in constraining dark energy and modified gravity scalar-tensor theories. We then discuss the impact of a wrong assumption on the weak lensing potential amplitude on cosmological parameter inference.

  15. Jet shapes in hadron and electron colliders

    International Nuclear Information System (INIS)

    Wainer, N.

    1993-05-01

    High energy jets are observed both in hadronic machines like the Tevatron and electron machines like LEP. These jets have an extended structure in phase space which can be measured. This distribution is usually called the jet shape. There is an intrinsic relation between jet variables, like energy and direction, the jet algorithm used, and the jet shape. Jet shape differences can be used to separate quark and gluon jets

  16. Corneal erosions, bacterial contamination of contact lenses, and microbial keratitis.

    Science.gov (United States)

    Willcox, Mark D P; Naduvilath, Thomas J; Vaddavalli, Pravin K; Holden, Brien A; Ozkan, Jerome; Zhu, Hua

    2010-11-01

    To estimate the rate of corneal erosion coupled with gram-negative bacterial contamination of contact lenses and compare this with the rate of microbial keratitis (MK) with contact lenses. The rate of corneal erosion and contact lens contamination by gram-negative bacteria were calculated from several prospective trials. These rates were used to calculate the theoretical rate of corneal erosion happening at the same time as wearing a contact lens contaminated with gram-negative bacteria. This theoretical rate was then compared with the rates of MK reported in various epidemiological and clinical trials. Corneal erosions were more frequent during extended wear (0.6-2.6% of visits) compared with daily wear (0.01-0.05% of visits). No corneal erosions were observed for lenses worn on a daily disposable basis. Contamination rates for lenses worn on a daily disposable basis were the lowest (2.4%), whereas they were the highest for low Dk lenses worn on an extended wear basis (7.1%). The estimated rate of corneal erosions occurring at the same time as wearing lenses contaminated with gram-negative bacteria was the lowest during daily wear of low Dk lenses (1.56/10,000 [95% CI: 0.23-10.57]) and the highest during extended wear of high Dk lenses (38.55/10,000 [95% CI: 24.77-60.04]). These rates were similar in magnitude to the rates reported for MK of different hydrogel lenses worn on differing wear schedules. The coincidence of corneal erosions during lens wear with gram-negative bacterial contamination of lenses may account for the relative incidence of MK during lens wear with different lens materials and modes of use.

  17. Lenses matching of compound eye for target positioning

    Science.gov (United States)

    Guo, Fang; Zheng, Yan Pei; Wang, Keyi

    2012-10-01

    Compound eye, as a new imaging method with multi-lens for a large field of view, could complete target positioning and detection fastly, especially at close range. Therefore it could be applicated in the fields of military and medical treatment and aviation with vast market potential and development prospect. Yet the compound eye imaging method designed use three layer construction of multiple lens array arranged in a curved surface and refractive lens and imaging sensor of CMOS. In order to simplify process structure and increase the imaging area of every sub-eye, the imaging area of every eye is coved with the whole CMOS. Therefore, for several imaging point of one target, the corresponding lens of every imaging point is unkonown, and thus to identify. So an algorithm was put forward. Firstly, according to the Regular Geometry relationship of several adjacent lenses, data organization of seven lenses with a main lens was built. Subsequently, by the data organization, when one target was caught by several unknown lenses, we search every combined type of the received lenses. And for every combined type, two lenses were selected to combine and were used to calculate one three-dimensional (3D) coordinate of the target. If the 3D coordinates are same to the some combine type of the lenses numbers, in theory, the lenses and the imaging points are matched. So according to error of the 3D coordinates is calculated by the different seven lenses numbers combines, the unknown lenses could be distinguished. The experimental results show that the presented algorithm is feasible and can complete matching task for imaging points and corresponding lenses.

  18. A simple technique of intraocular lenses explantation for single-piece foldable lenses

    Directory of Open Access Journals (Sweden)

    Arup Bhaumik

    2017-01-01

    Full Text Available Foldable intraocular lenses (IOLs are most commonly used in modern-day cataract surgery. Explantation of these IOLs is not frequently encountered, but sometimes extreme situations may demand the same. Commonly explantation is achieved by bisecting the IOL inside the anterior chamber with a cutter and delivering the pieces out one by one. This may require corneal wound extension with associated damage and endothelial loss leading to visual deterioration. We devised a simple, innovative IOL explantation technique utilizing a modified Alcon A cartridge and snare. This can successfully refold the IOL to be explanted inside the eye and deliver it out through the same wound. The device has limitations with very thick optic lenses, multipiece, and silicon IOLs. In conclusion, we describe a simple, innovative, and reproducible technique to explant almost any single piece IOL without compromising the original surgery and yielding very satisfactory outcomes.

  19. Searches for the Standard Model Higgs boson at the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Wade C. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Junk, Thomas R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-01-01

    During Run II of the Tevatron collider, which took place from 2001 until 2011, the CDF and D0 detectors each collected approximately 10 fb -1 of collision data at a center-of-mass energy of . This dataset allowed for tests for the presence of the SM Higgs boson in the mass range 90-200 GeV in the production modes gg → H, W/ZH, vector-boson fusion, and H, with H decay modes H → , H → W+W-, H →

  20. Calcification of Hydrophilic Acrylic Intraocular Lenses With a Hydrophobic Surface: Laboratory Analysis of 6 Cases.

    Science.gov (United States)

    Gartaganis, Sotirios P; Prahs, Philipp; Lazari, Eftichia D; Gartaganis, Panos S; Helbig, Horst; Koutsoukos, Petros G

    2016-08-01

    To investigate the nature and characteristic features of deposits causing opacification of intraocular lenses (IOLs) based on the examination of clinical findings using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) analysis. Retrospective, observational case series. This is a multicenter study of 6 hydrophilic acrylic IOLs (Lentis LS-502-1; Oculentis GmbH, Berlin, Germany) with a hydrophobic surface that were explanted from 5 patients because of opacification. Three patients had an uncomplicated phacoemulsification. One patient underwent combined phacoemulsification and pars plana vitrectomy for retinal detachment and later silicone oil endotamponade owing to redetachment. The last patient had a pars plana vitrectomy and silicone oil instillation combined with phacoemulsification for tractive retinal detachment and diabetic retinopathy. The explanted lenses were submitted to our laboratory and were examined by SEM and EDX in order to identify the morphologic features and the composition of the deposits. SEM and EDX analyses confirmed the presence of calcific deposits in the interior of the opacified hydrophilic IOLs, with a pattern showing the formation of lumps on the surface. The lumps were due to subsurface formation of calcium phosphate crystalline deposits. The crystallite clusters seemed to diffuse from the IOL interior to the surface. We demonstrated the calcification pattern of the hydrophilic IOL (Lentis LS-502-1) with a hydrophobic surface. Although hydrophilic acrylic lenses have a hydrophobic surface, the development of calcification is a possible threat initiating from the hydrophilic subsurface of the IOLs. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Search for anomalous couplings in WW and WZ measurements at the Tevatron (D0 and CDF results)

    International Nuclear Information System (INIS)

    Diehl, H.T.

    1995-06-01

    The search for WW and WZ production in p anti p collisions at √s = 1.8 TeV using the CDF and D0 detectors is presented. Three analyses, one concentrating on the leptons + jets decay channels and two concentrating on the dilepton decay channels are described in detail. Limits on anomalous WWγ and WWZ trilinear gauge boson couplings are presented. Prospects for further study of diboson production and anomalous couplings with the Upgraded Tevatron are also presented

  2. Top-squark mixing effects in the supersymmetric electroweak corrections to top-quark production at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Yang, J.M.; Li, C.S.

    1996-01-01

    Taking into account the mixing effects between left- and right-handed top squarks, we calculate the genuine supersymmetric electroweak correction to top-quark production at the Fermilab Tevatron in the minimal supersymmetric model. The analytic expressions of the corrections to both the parton level cross section and the total hadronic cross section are presented. Some numerical examples are also given to show the size of the corrections. copyright 1996 The American Physical Society

  3. Combination of Tevatron searches for the standard model Higgs boson in the W+W- decay mode

    NARCIS (Netherlands)

    Aaltonen, T.; et al., [Unknown; Ancu, L.S.; de Jong, S.J.; Filthaut, F.; Galea, C.F.; Hegeman, J.G.; Houben, P.; Meijer, M.M.; Svoisky, P.; van den Berg, P.J.

    2010-01-01

    We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background

  4. DISCOVERY OF THE LARGEST KNOWN LENSED IMAGES FORMED BY A CRITICALLY CONVERGENT LENSING CLUSTER

    International Nuclear Information System (INIS)

    Zitrin, Adi; Broadhurst, Tom

    2009-01-01

    We identify the largest known lensed images of a single spiral galaxy, lying close to the center of the distant cluster MACS J1149.5+2223 (z = 0.544). These images cover a total area of ≅150 mbox '' and are magnified ≅200 times. Unusually, there is very little image distortion, implying that the central mass distribution is almost uniform over a wide area (r ≅ 200 kpc) with a surface density equal to the critical density for lensing, corresponding to maximal lens magnification. Many fainter multiply lensed galaxies are also uncovered by our model, outlining a very large tangential critical curve, of radius r ≅ 170 kpc, posing a potential challenge for the standard LCDM cosmology. Because of the uniform central mass distribution, a particularly clean measurement of the mass of the brightest cluster galaxy is possible here, for which we infer stars contribute most of the mass within a limiting radius of ≅30 kpc, with a mass-to-light ratio of M/L B ≅ 4.5(M/L) sun . This cluster with its uniform and central mass distribution acts analogously to a regular magnifying glass, converging light without distorting the images, resulting in the most powerful lens yet discovered for accessing the faint high-z universe.

  5. Lensing reconstruction from a patchwork of polarization maps

    International Nuclear Information System (INIS)

    Namikawa, Toshiya; Nagata, Ryo

    2014-01-01

    The lensing signals involved in CMB polarization maps have already been measured with ground-based experiments such as SPTpol and POLARBEAR, and would become important as a probe of cosmological and astrophysical issues in the near future. Sizes of polarization maps from ground-based experiments are, however, limited by contamination of long wavelength modes of observational noise. To further extract the lensing signals, we explore feasibility of measuring lensing signals from a collection of small sky maps each of which is observed separately by a ground-based large telescope, i.e., lensing reconstruction from a patchwork map of large sky coverage organized from small sky patches. We show that, although the B-mode power spectrum obtained from the patchwork map is biased due to baseline uncertainty, bias on the lensing potential would be negligible if the B-mode on scales larger than the blowup scale of 1/f noise is removed in the lensing reconstruction. As examples of cosmological applications, we also show 1) the cross-correlations between the reconstructed lensing potential and full-sky temperature/polarization maps from satellite missions such as PLANCK and LiteBIRD, and 2) the use of the reconstructed potential for delensing B-mode polarization of LiteBIRD observation

  6. The effect of weak lensing on distance estimates from supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mathew; Maartens, Roy [Department of Physics, University of the Western Cape, Cape Town 7535 (South Africa); Bacon, David J.; Nichol, Robert C.; Campbell, Heather; D' Andrea, Chris B. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Clarkson, Chris [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa); Bassett, Bruce A. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Cinabro, David [Wayne State University, Department of Physics and Astronomy, Detroit, MI 48202 (United States); Finley, David A.; Frieman, Joshua A. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Galbany, Lluis [CENTRA Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Olmstead, Matthew D. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Shapiro, Charles [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, La Canada Flintridge, CA 91109 (United States); Sollerman, Jesper, E-mail: matsmith2@gmail.com [The Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden)

    2014-01-01

    Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line of sight. We find that the correlation between this measurement and the Hubble residuals is consistent with the prediction from lensing (at a significance of 1.7σ). Strong correlations are also found between the residuals and supernova nuisance parameters after a linear correction is applied. When these other correlations are taken into account, the lensing signal is detected at 1.4σ. We show, for the first time, that distance estimates from supernovae can be improved when lensing is incorporated, by including a new parameter in the SALT2 methodology for determining distance moduli. The recovered value of the new parameter is consistent with the lensing prediction. Using cosmic microwave background data from WMAP7, H {sub 0} data from Hubble Space Telescope and Sloan Digital Sky Survey (SDSS) Baryon acoustic oscillations measurements, we find the best-fit value of the new lensing parameter and show that the central values and uncertainties on Ω {sub m} and w are unaffected. The lensing of supernovae, while only seen at marginal significance in this low-redshift sample, will be of vital importance for the next generation of surveys, such as DES and LSST, which will be systematics-dominated.

  7. Weak lensing cosmology beyond ΛCDM

    International Nuclear Information System (INIS)

    Das, Sudeep; Linder, Eric V.; Nakajima, Reiko; Putter, Roland de

    2012-01-01

    Weak gravitational lensing is one of the key probes of the cosmological model, dark energy, and dark matter, providing insight into both the cosmic expansion history and large scale structure growth history. Taking into account a broad spectrum of physics affecting growth — dynamical dark energy, extended gravity, neutrino masses, and spatial curvature — we analyze the cosmological constraints. Similarly we consider the effects of a range of systematic uncertainties, in shear measurement, photometric redshifts, intrinsic alignments, and the nonlinear power spectrum, on cosmological parameter extraction. We also investigate, and provide fitting formulas for, the influence of survey parameters such as redshift depth, galaxy number densities, and sky area on the cosmological constraints in the beyond-ΛCDM parameter space. Finally, we examine the robustness of results for different fiducial cosmologies

  8. Axial nonimaging characteristics of imaging lenses: discussion.

    Science.gov (United States)

    Siew, Ronian

    2016-05-01

    At observation planes away from the image plane, an imaging lens is a nonimaging optic. We examine the variation of axial irradiance with distance in image space and highlight the following little-known observation for discussion: On a per-unit-area basis, the position of the highest concentration in image space is generally not at the focal plane. This characteristic is contrary to common experience, and it offers an additional degree of freedom for the design of detection systems. Additionally, it would also apply to lenses with negative refractive index. The position of peak concentration and its irradiance is dependent upon the location and irradiance of the image. As such, this discussion also includes a close examination of expressions for image irradiance and explains how they are related to irradiance calculations beyond the image plane. This study is restricted to rotationally symmetric refractive imaging systems with incoherent extended Lambertian sources.

  9. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    This thesis deals with the development of silicon compound refractive lenses (Si-CRLs) for shaping hard x-ray beams. The CRLs are to be fabricated using state of the art microfabrication techniques. The primary goal of the thesis work is to produce Si-CRLs with considerably increased structure...... and characterized with respect to their shape. Their optical performances were tested at the European Synchrotron Radiation Facility (ESRF). Two 1D-focusing Si-CRLs suitable as condensers in hard-XRM were developed utilizing the aforementioned two different strategies. The first Si-condenser showed focusing of a 56...... of space for sample surroundings and ensure low-divergent and wide x-ray beams with narrow waists. Both results are substantial improvements to what was available at the start of this thesis work. The challenge of making x-ray objectives in silicon by interdigitation of lenslets alternately focusing...

  10. Mechanical properties of intra-ocular lenses

    Science.gov (United States)

    Ehrmann, Klaus; Kim, Eon; Parel, Jean-Marie

    2008-02-01

    Cataract surgery usually involves the replacement of the natural crystalline lens with a rigid or foldable intraocular lens to restore clear vision for the patient. While great efforts have been placed on optimising the shape and optical characteristics of IOLs, little is know about the mechanical properties of these devices and how they interact with the capsular bag once implanted. Mechanical properties measurements were performed on 8 of the most commonly implanted IOLs using a custom build micro tensometer. Measurement data will be presented for the stiffness of the haptic elements, the buckling resistance of foldable IOLs, the dynamic behaviour of the different lens materials and the axial compressibility. The biggest difference between the lens types was found between one-piece and 3-piece lenses with respect to the flexibility of the haptic elements

  11. Weak lensing galaxy cluster field reconstruction

    Science.gov (United States)

    Jullo, E.; Pires, S.; Jauzac, M.; Kneib, J.-P.

    2014-02-01

    In this paper, we compare three methods to reconstruct galaxy cluster density fields with weak lensing data. The first method called FLens integrates an inpainting concept to invert the shear field with possible gaps, and a multi-scale entropy denoising procedure to remove the noise contained in the final reconstruction, that arises mostly from the random intrinsic shape of the galaxies. The second and third methods are based on a model of the density field made of a multi-scale grid of radial basis functions. In one case, the model parameters are computed with a linear inversion involving a singular value decomposition (SVD). In the other case, the model parameters are estimated using a Bayesian Monte Carlo Markov Chain optimization implemented in the lensing software LENSTOOL. Methods are compared on simulated data with varying galaxy density fields. We pay particular attention to the errors estimated with resampling. We find the multi-scale grid model optimized with Monte Carlo Markov Chain to provide the best results, but at high computational cost, especially when considering resampling. The SVD method is much faster but yields noisy maps, although this can be mitigated with resampling. The FLens method is a good compromise with fast computation, high signal-to-noise ratio reconstruction, but lower resolution maps. All three methods are applied to the MACS J0717+3745 galaxy cluster field, and reveal the filamentary structure discovered in Jauzac et al. We conclude that sensitive priors can help to get high signal-to-noise ratio, and unbiased reconstructions.

  12. Constraints on cosmological models from strong gravitational lensing systems

    International Nuclear Information System (INIS)

    Cao, Shuo; Pan, Yu; Zhu, Zong-Hong; Biesiada, Marek; Godlowski, Wlodzimierz

    2012-01-01

    Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning the Hubble constant independent ratio between two angular diameter distances D ds /D s from various large systematic gravitational lens surveys and lensing by galaxy clusters combined with X-ray observations, and check the possibility to use it in the future as complementary to other cosmological probes. On one hand, strongly gravitationally lensed quasar-galaxy systems create such a new opportunity by combining stellar kinematics (central velocity dispersion measurements) with lensing geometry (Einstein radius determination from position of images). We apply such a method to a combined gravitational lens data set including 70 data points from Sloan Lens ACS (SLACS) and Lens Structure and Dynamics survey (LSD). On the other hand, a new sample of 10 lensing galaxy clusters with redshifts ranging from 0.1 to 0.6 carefully selected from strong gravitational lensing systems with both X-ray satellite observations and optical giant luminous arcs, is also used to constrain three dark energy models (ΛCDM, constant w and CPL) under a flat universe assumption. For the full sample (n = 80) and the restricted sample (n = 46) including 36 two-image lenses and 10 strong lensing arcs, we obtain relatively good fitting values of basic cosmological parameters, which generally agree with the results already known in the literature. This results encourages further development of this method and its use on larger samples obtained in the future

  13. Finding strong lenses in CFHTLS using convolutional neural networks

    Science.gov (United States)

    Jacobs, C.; Glazebrook, K.; Collett, T.; More, A.; McCarthy, C.

    2017-10-01

    We train and apply convolutional neural networks, a machine learning technique developed to learn from and classify image data, to Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) imaging for the identification of potential strong lensing systems. An ensemble of four convolutional neural networks was trained on images of simulated galaxy-galaxy lenses. The training sets consisted of a total of 62 406 simulated lenses and 64 673 non-lens negative examples generated with two different methodologies. An ensemble of trained networks was applied to all of the 171 deg2 of the CFHTLS wide field image data, identifying 18 861 candidates including 63 known and 139 other potential lens candidates. A second search of 1.4 million early-type galaxies selected from the survey catalogue as potential deflectors, identified 2465 candidates including 117 previously known lens candidates, 29 confirmed lenses/high-quality lens candidates, 266 novel probable or potential lenses and 2097 candidates we classify as false positives. For the catalogue-based search we estimate a completeness of 21-28 per cent with respect to detectable lenses and a purity of 15 per cent, with a false-positive rate of 1 in 671 images tested. We predict a human astronomer reviewing candidates produced by the system would identify 20 probable lenses and 100 possible lenses per hour in a sample selected by the robot. Convolutional neural networks are therefore a promising tool for use in the search for lenses in current and forthcoming surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope.

  14. Constraints on cosmological models from strong gravitational lensing systems

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Shuo; Pan, Yu; Zhu, Zong-Hong [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Biesiada, Marek [Department of Astrophysics and Cosmology, Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Godlowski, Wlodzimierz, E-mail: baodingcaoshuo@163.com, E-mail: panyu@cqupt.edu.cn, E-mail: biesiada@us.edu.pl, E-mail: godlowski@uni.opole.pl, E-mail: zhuzh@bnu.edu.cn [Institute of Physics, Opole University, Oleska 48, 45-052 Opole (Poland)

    2012-03-01

    Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning the Hubble constant independent ratio between two angular diameter distances D{sub ds}/D{sub s} from various large systematic gravitational lens surveys and lensing by galaxy clusters combined with X-ray observations, and check the possibility to use it in the future as complementary to other cosmological probes. On one hand, strongly gravitationally lensed quasar-galaxy systems create such a new opportunity by combining stellar kinematics (central velocity dispersion measurements) with lensing geometry (Einstein radius determination from position of images). We apply such a method to a combined gravitational lens data set including 70 data points from Sloan Lens ACS (SLACS) and Lens Structure and Dynamics survey (LSD). On the other hand, a new sample of 10 lensing galaxy clusters with redshifts ranging from 0.1 to 0.6 carefully selected from strong gravitational lensing systems with both X-ray satellite observations and optical giant luminous arcs, is also used to constrain three dark energy models (ΛCDM, constant w and CPL) under a flat universe assumption. For the full sample (n = 80) and the restricted sample (n = 46) including 36 two-image lenses and 10 strong lensing arcs, we obtain relatively good fitting values of basic cosmological parameters, which generally agree with the results already known in the literature. This results encourages further development of this method and its use on larger samples obtained in the future.

  15. Study of the production of the Σ b with the CDF detector at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Calancha Paredes, Constantino [Complutense Univ. of Madrid (Spain)

    2011-02-01

    The composition of matter is a topic in which the man has been interested throughout History. Since the introduction of the atom by Democritus in the 5th century BC until the establishment of the Standard Model, our successful theory that contains our current knowledge on the matter and their interactions, it has come a long way trying to solve this fundamental question. The efforts of many of the greatest minds to perform crucial experiments and develop theoretical models have helped to get deeper insight into the origin of the matter. Today we know that indivisible atoms postulated by Democritus are no longer true, and they are actually composed of a nucleus made of protons and neutrons (nucleons) with orbiting electrons through electromagnetic interactions. Also the nucleons are not fundamental particles but are composed of more fundamental ones called quarks. According to the present state of our knowledge, matter is composed of two types of particles: quarks and leptons. Leptons are believed to be fundamental particles and can occur freely in nature. Quarks are also fundamental particles, and there are no free in nature, but are confined to form hadrons. The hadrons may consist of a quark and an antiquark (mesons) or three quarks or three antiquarks (baryons). These quarks and leptons interact through the exchange of particles called bosons. Figure 1.1 summary the elementary particles in the Standard Model. Despite its enormous success we know that the Standard Model is incomplete. Some of the issues left unresolved by the Standard Model are the mechanism for electroweak symmetry breaking, the mass spectrum of the Standard Model or that the Universe is much more matter than antimatter. That means that it should exist a more general theory which include the Standard Model as a valid approximation for low energy. This more general theory must give answers to the previous unresolved questions. Accumulate more experimental information is crucial to get a deeper

  16. Measurement of the top quark mass using dilepton events and a neutrino weighting algorithm with the DOe experiment at the Tevatron (Run II)

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.

    2007-07-01

    Several measurements of the top quark mass in the dilepton final states with the DOe experiment are presented. The theoretical and experimental properties of the top quark are described together with a brief introduction of the Standard Model of particle physics and the physics of hadron collisions. An overview over the experimental setup is given. The Tevatron at Fermilab is presently the highest-energy hadron collider in the world with a center-of-mass energy of 1.96 TeV. There are two main experiments called CDF and DOe, A description of the components of the multipurpose DOe detector is given. The reconstruction of simulated events and data events is explained and the criteria for the identification of electrons, muons, jets, and missing transverse energy is given. The kinematics in the dilepton final state is underconstraint. Therefore, the top quark mass is extracted by the so-called Neutrino Weighting method. This method is introduced and several different approaches are described, compared, and enhanced. Results for the international summer conferences 2006 and winter 2007 are presented. The top quark mass measurement for the combination of all three dilepton channels with a dataset of 1.05 1/fb yields: mtop=172.5{+-}5.5 (stat.) {+-} 5.8 (syst.) GeV. This result is presently the most precise top quark mass measurement of the DOe experiment in the dilepton chann el. It entered the top quark mass wold average from March 2007. (orig.)

  17. Realization of first order optical systems using thin lenses

    International Nuclear Information System (INIS)

    Sudarshan, E.C.G.; Mukunda, N.; Simon, R.

    1983-09-01

    A first order optical system is investigated in full generality within the context of wave optics. We reduce the problem to a study of the ray transfer matrices. The simplest such systems correspond to axially symmetric propagation. Realization of such systems by centrally located lenses separated by finite distances is studied. It is shown that every axially symmetric first order system can be realized using at most three lenses. Among anisotropic systems it is proven that every symplectic ray transfer matrix, and no others, can be realized using lenses and free propagations. Suggestions for further study of the general first order system are outlined. 16 references

  18. Chromatic aberrations of electrostatic axisymmetric lenses produced by circular cylinders

    International Nuclear Information System (INIS)

    Baranova, L.A.; Ul'yanova, N.S.; Yavor, S.Ya.

    1989-01-01

    Ion beams both to test material and for technological processes have being used lately in science and technology more and more. Electrostatic lenses are used, as a rule, for such beam production. Coefficients of chromatic aberrration for a wide range of changes in lense parameters are calculated on the basis of analytical expressions to determine the potential in immerse and isolated lenses. The chromatic aberration coefficient is presented as a polynomial according to the degrees of reverse increase, that permits to calculate a circle of blurring of subject arbitrary position

  19. Strong deflection lensing by a Lee–Wick black hole

    Directory of Open Access Journals (Sweden)

    Shan-Shan Zhao

    2017-11-01

    Full Text Available We study strong deflection gravitational lensing by a Lee–Wick black hole, which is a non-singular black hole generated by a high derivative modification of Einstein–Hilbert action. The strong deflection lensing is expected to produce a set of relativistic images very closed to the event horizon of the black hole. We estimate its observables for the supermassive black hole in our Galactic center. It is found that the Lee–Wick black hole can be distinguished from the Schwarzschild black hole via such lensing effects when the UV scale is not very large, but the requiring resolution is much higher than current capability.

  20. Inclusive b and b anti b production with quasi-multi-Regge kinematics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A. [Hamburg Univ. (Germany). II. Institut fuer Theoretische Physik; Saleev, V.A.; Shipilova, A.V. [Samara State University (Russian Federation)

    2010-03-15

    We consider b-jet hadroproduction in the quasi-multi-Regge-kinematics approach based on the hypothesis of gluon and quark Reggeization in t-channel exchanges at high energies. The preliminary data on inclusive b-jet and b anti b-dijet production taken by the CDF Collaboration at the Fermilab Tevatron are well described without adjusting parameters. We find the main contribution to inclusive b-jet production to be the scattering of a Reggeized gluon and a Reggeized b-quark to a b quark, which is described by the effective Reggeon-Reggeon-quark vertex. The main contribution to b anti b-pair production arises from the scattering of two Reggeized gluons to a b anti b pair, which is described by the effective Reggeon-Reggeon-quark-quark vertex. Our analysis is based on the Kimber-Martin-Ryskin prescription for unintegrated gluon and quark distribution functions using as input the Martin-Roberts-Stirling-Thorne collinear parton distribution functions of the proton. (orig.)