WorldWideScience

Sample records for experiment vertex time

  1. A Future Vertex Locator with Precise Timing for the LHCb Experiment

    CERN Multimedia

    Mitreska, Biljana

    2017-01-01

    The LHCb experiment is designed to perform high precision measurements of matter-antimatter asymmetries and searches for rare and forbidden decays, with the aim of discovering new and unexpected particles and forces. In 2030 the LHC beam intensity will increase by a factor of 50 compared to current operations. This means increased samples of the particles we need to study, but it also presents experimental challenges. In particular, with current technology it becomes impossible to differentiate the many (>50) separate proton-proton collisions which occur for each bunch crossing. A Monte Carlo simulation was developed to model the operation of a silicon pixel vertex detector surrounding the collision region at LHCb, under the conditions expected after 2030, after the second upgrade of the Vertex Locator (VELO). The main goal was studying the effect of adding '4D' detectors which save high-precision timing information, in addition to the usual three spatial coordinates, as charged particles pass through them. W...

  2. Primary Vertex Reconstruction at the ATLAS Experiment

    CERN Document Server

    Grimm, Kathryn; The ATLAS collaboration

    2016-01-01

    Efficient and precise reconstruction of the primary vertex in an LHC collision is essential in both the reconstruction of the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of primary vertices in the busy, high pile-up environment of Run-2 of the LHC is a challenging task. New methods have been developed by the ATLAS experiment to reconstruct vertices in such environments. Advances in vertex seeding include methods taken from medical imaging, which allow for reconstruction of multiple vertices with small spatial separation. The adoption of this new seeding algorithm within the ATLAS adaptive vertex finding and fitting procedure will be discussed, and the first results of the new techniques from Run-2 data will be presented. Additionally, data-driven methods to evaluate vertex resolution will be presented with special focus on correct methods to evaluate the effect of the beam spot constraint; results from these methods in Ru...

  3. Simulations of silicon vertex tracker for star experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W. [Lawrence Berkeley Lab., CA (United States); Liko, D. [Institut fur Hochenenergiephysik, Vienna, (Austria); Cramer, J.; Prindle, D.; Trainor, T. [Univ. of Washington, Seattle (United States); Braithwaite, W. [Univ. of Arkansas, Little Rock (United States)

    1991-12-31

    The first computer simulations to optimize the Silicon Vertex Tracker (SVT) designed for the STAR experiment at RHIC are presented. The physics goals and the expected complexity of the events at RHIC dictate the design of a tracking system for the STAR experiment. The proposed tracking system will consist of a silicon vertex tracker (SVT) to locate the primary interaction and secondary decay vertices and to improve the momentum resolution, and a time projection chamber (TPC), positioned inside a solenoidal magnet, for continuous tracking.

  4. Silicon vertex detector upgrade in the ALPHA experiment

    CERN Document Server

    Amole, C; Ashkezari, M.D; Baquero-Ruiz, M; Bertsche, W; Burrows, C; Butler, E; Capra, A; Cesar, C.L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M.C; Gill, D.R; Gutierrez, A; Hangst, J.S; Hardy, W.N; Hayden, M.E; Humphries, A.J; Isaac, C.A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J.T.K; Menary, S; Napoli, S.C; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Rasmussen, C.Ø; Robicheaux, F; Sacramento, R.L; Sampson, J.A; Sarid, E; Seddon, D; Silveira, D.M; So, C; Stracka, S; Tharp, T; Thompson, R.I; Thornhill, J; Tooley, M.P; Van Der Werf, D.P; Wells, D

    2013-01-01

    The Silicon Vertex Detector (SVD) is the main diagnostic tool in the ALPHA-experiment. It provides precise spatial and timing information of antiproton (antihydrogen) annihilation events (vertices), and most importantly, the SVD is capable of directly identifying and analysing single annihilation events, thereby forming the basis of ALPHA ' s analysis. This paper describes the ALPHA SVD and its upgrade, installed in the ALPHA ' s new neutral atom trap.

  5. Primary Vertex Reconstruction with the ATLAS Experiment

    CERN Document Server

    Casper, David William; The ATLAS collaboration

    2017-01-01

    ATLAS reconstructs primary vertices with high efficiency and resolution. These vertices serve as input to other mission critical analysis tools, and are relied on by many physics analyses. This presentation surveys the ATLAS primary vertex reconstruction algorithms, and describes validity checks done using real data. The complications introduced by pileup are discussed, along with refinements currently under study.

  6. The silicon vertex detector of the Belle II experiment

    Science.gov (United States)

    Friedl, Markus; Bergauer, Thomas; Gfall, Immanuel; Irmler, Christian; Valentan, Manfred

    2011-02-01

    After 10 years of successful operation, the Belle experiment at KEK (Tsukuba, Japan) will be completed in 2010. Thereafter, a major upgrade of the KEK-B machine is foreseen until 2014, aiming at a final luminosity of 8×10 35 cm -2 s -1, which is about 40 times higher than the present peak value. Consequently, also the Belle experiment needs to be changed and the Silicon Vertex Detector (SVD) in particular will be completely replaced as it already operates close to its limits in the present system. The future SVD (a.k.a. SuperSVD) will consist of four layers of double-sided silicon strip detectors like the present one, but at larger radii, because it will be complemented by a two-layer pixel detector as the innermost sensing device. The SuperSVD will be entirely composed of silicon sensors made from 6 in. wafers read out by APV25 front-end chips that were originally developed for the CMS experiment at the LHC. Several years of R&D effort led to innovations such as the Origami chip-on-sensor concept and readout electronics with hit time finding which were successfully demonstrated on prototypes. These features will be included in the final system which is presently being designed. This paper will give an overview of the SuperSVD and present results from prototype tests ranging from detector modules to back-end electronics.

  7. The FIRST experiment: interaction region and MAPS vertex detector

    Science.gov (United States)

    Spiriti, E.; de Napoli, M.; Romano, F.; FIRST Collaboration

    2011-06-01

    The improvement of the precision of the measurement of the nuclear cross-section, in order to fulfill the requirements of the actual Monte Carlo simulations for hadrontherapy and space radioprotection, is the main goal of the FIRST experiment. After a brief introduction on the treatment planning in hadrontherapy, this paper describes main characteristics and components of the experiment. The features of the interaction region detectors and their main needs (low material budget, high angular coverage, two tracks resolution and large trigger rate) are discussed. Special emphasis is devoted in discussing the new silicon pixel vertex detector, in particular its new developed data acquisition and its characterization with the first test results obtained with a prototype of the detector.

  8. The MAPS based PXL vertex detector for the STAR experiment

    Science.gov (United States)

    Contin, G.; Anderssen, E.; Greiner, L.; Schambach, J.; Silber, J.; Stezelberger, T.; Sun, X.; Szelezniak, M.; Vu, C.; Wieman, H.; Woodmansee, S.

    2015-03-01

    The Heavy Flavor Tracker (HFT) was installed in the STAR experiment for the 2014 heavy ion run of RHIC. Designed to improve the vertex resolution and extend the measurement capabilities in the heavy flavor domain, the HFT is composed of three different silicon detectors based on CMOS monolithic active pixels (MAPS), pads and strips respectively, arranged in four concentric cylinders close to the STAR interaction point. The two innermost HFT layers are placed at a radius of 2.7 and 8 cm from the beam line, respectively, and accommodate 400 ultra-thin (50 μ m) high resolution MAPS sensors arranged in 10-sensor ladders to cover a total silicon area of 0.16 m2. Each sensor includes a pixel array of 928 rows and 960 columns with a 20.7 μ m pixel pitch, providing a sensitive area of ~ 3.8 cm2. The architecture is based on a column parallel readout with amplification and correlated double sampling inside each pixel. Each column is terminated with a high precision discriminator, is read out in a rolling shutter mode and the output is processed through an integrated zero suppression logic. The results are stored in two SRAM with ping-pong arrangement for a continuous readout. The sensor features 185.6 μ s readout time and 170 mW/cm2 power dissipation. The detector is air-cooled, allowing a global material budget as low as 0.39% on the inner layer. A novel mechanical approach to detector insertion enables effective installation and integration of the pixel layers within an 8 hour shift during the on-going STAR run.In addition to a detailed description of the detector characteristics, the experience of the first months of data taking will be presented in this paper, with a particular focus on sensor threshold calibration, latch-up protection procedures and general system operations aimed at stabilizing the running conditions. Issues faced during the 2014 run will be discussed together with the implemented solutions. A preliminary analysis of the detector performance

  9. Tracking and Vertexing for the Heavy Photon Search Experiment

    Science.gov (United States)

    Uemura, Sho; HPS Collaboration

    2015-04-01

    The Heavy Photon Search (HPS) requires precision tracking and vertexing of e+e- pairs against a high background in a difficult experimental environment. The silicon vertex tracker (SVT) for HPS uses actively cooled silicon microstrip sensors with fast readout electronics. To maximize acceptance and vertex resolution with a relatively small detector, the SVT operates directly downstream of the target, close to the beam line, and inside of a dipole magnet. This talk presents the design and performance of the HPS SVT.

  10. The silicon vertex detector of the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, T. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technology Guwahati, Assam 781039 (India); Bilka, T. [Faculty of Mathematics and Physics, Charles University, 121 16 Prague (Czech Republic); Bosi, F. [INFN Sezione di Pisa, I-56127 Pisa (Italy); Bosisio, L. [Dipartimento di Fisica, Universitá di Trieste, I-34127 Trieste (Italy); INFN Sezione di Trieste, I-34127 Trieste (Italy); Bozek, A. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); and others

    2016-07-11

    The silicon vertex detector of the Belle II experiment, structured in a lantern shape, consists of four layers of ladders, fabricated from two to five silicon sensors. The APV25 readout ASIC chips are mounted on one side of the ladder to minimize the signal path for reducing the capacitive noise; signals from the sensor backside are transmitted to the chip by bent flexible fan-out circuits. The ladder is assembled using several dedicated jigs. Sensor motion on the jig is minimized by vacuum chucking. The gluing procedure provides such a rigid foundation that later leads to the desired wire bonding performance. The full ladder with electrically functional sensors is consistently completed with a fully developed assembly procedure, and its sensor offsets from the design values are found to be less than 200 μm. The potential functionality of the ladder is also demonstrated by the radioactive source test.

  11. The BaBar silicon vertex tracker, performance and running experience

    CERN Document Server

    Re, V; Bozzi, C; Carassiti, V; Cotta-Ramusino, A; Piemontese, L; Breon, A B; Brown, D; Clark, A R; Goozen, F; Hernikl, C; Kerth, L T; Gritsan, A; Lynch, G; Perazzo, A; Roe, N A; Zizka, G; Roberts, D; Schieck, J; Brenna, E; Citterio, M; Lanni, F; Palombo, F; Ratti, L; Manfredi, P F; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bosi, F; Bucci, F; Calderini, G; Carpinelli, M; Ceccanti, M; Forti, F; Gagliardi, D J; Giorgi, M A; Lusiani, A; Mammini, P; Morganti, M; Morsani, F; Neri, N; Paoloni, E; Profeti, A; Rama, M; Rizzo, G; Sandrelli, F; Simi, G; Triggiani, G; Walsh, J; Burchat, Patricia R; Cheng, C; Kirkby, D; Meyer, T I; Roat, C; Bóna, M; Bianchi, F; Gamba, D; Trapani, P; Bosisio, L; Della Ricca, G; Dittongo, S; Lanceri, L; Pompili, A; Poropat, P; Rashevskaia, I; Vuagnin, G; Burke, S; Callahan, D; Campagnari, C; Dahmes, B; Hale, D; Hart, P; Kuznetsova, N; Kyre, S; Levy, S; Long, O; May, J; Mazur, M; Richman, J; Verkerke, W; Witherell, M; Beringer, J; Eisner, A M; Frey, A; Grillo, A A; Grothe, M; Johnson, R P; Kröger, W; Lockman, W S; Pulliam, T; Rowe, W; Schmitz, R E; Seiden, A; Spencer, E N; Turri, M; Walkowiak, W; Wilder, M; Wilson, M; Charles, E; Elmer, P; Nielsen, J; Orejudos, W; Scott, I; Zobernig, H

    2002-01-01

    The Silicon Vertex Tracker (SVT) of the BaBar experiment at the PEP-II asymmetric B factory is a five-layer double-sided, AC-coupled silicon microstrip detector. It represents the crucial element to precisely measure the decay position of B mesons and extract time-dependent CP asymmetries. The SVT architecture is shown and its performance is described, with emphasis on hit resolutions and efficiencies.

  12. Computing the Tutte Polynomial in Vertex-Exponential Time

    DEFF Research Database (Denmark)

    Björklund, Andreas; Husfeldt, Thore; Kaski, Petteri

    2008-01-01

    The deletion–contraction algorithm is perhapsthe most popular method for computing a host of fundamental graph invariants such as the chromatic, flow, and reliability polynomials in graph theory, the Jones polynomial of an alternating link in knot theory, and the partition functions of the models...... algorithm that computes the Tutte polynomial—and hence, all the aforementioned invariants and more—of an arbitrary graph in time within a polynomial factor of the number of connected vertex sets. The algorithm actually evaluates a multivariate generalization of the Tutte polynomial by making use...... of Ising, Potts, and Fortuin–Kasteleyn in statistical physics. Prior to this work, deletion–contraction was also the fastest known general-purpose algorithm for these invariants, running in time roughly proportional to the number of spanning trees in the input graph.Here, we give a substantially faster...

  13. Determination of the primary vertex position in the NA36 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, E.; Lovhoiden, G.; Thorsteinsen, T. (Bergen Univ. (Norway). Dept. of Physics); Barnes, P.D.; Diebold, G.E.; Franklin, G.; Quinn, B.; Schumacher, R. (Carnegie-Mellon Univ., Pittsburgh, PA (USA). Dept. of Physics); Castano, B.; Fernandez, C.; Garabatos, C.; Garzon, J.A.; Gomez, A.; Lopez-Ponte, S.; Mosquera, J.; Plo, M.; Ramil, A.; Yanez, A.; Yepes, P. (Universidad de Santiago de Compostela (Spain). Dept. de Fisica de Particulas); Cherney, M. (Creighton Univ., Omaha, NE (USA). Dept. of Physics); Cohler, M. (York Univ. (UK). Dept. of Physics); Cruz, B. de la; Ladron de Guevara, P.; Perez de los Heros, C. (Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain). Div. de Fisica de Particulas); Dulny, B. (Institute of Nuclear Physics, Krakow (Poland) Vienna Univ. (Austria). Inst. fuer Hochenergiephysik); Fruehwirth, R.; Hrubec, J.; Liko, D.; MacNaughton, J.; Neuhofer, G.; Regler, M.; Rohringer, H.; Stampfer, D.; Traxler, J. (Vienna Univ. (Aust

    1991-02-15

    A new method is described for finding the primary vertex in a relativistic heavy-ion experiment with multiple nuclear targets. Due to the large number of tracks the use of an economic algorithm is essential. The method comes from system theory and is based on an application of the Kalman filter. The small uncertainty in the vertex position obtained provides a reliable target assignment for the interaction. (orig.).

  14. Online track and vertex reconstruction on GPUs for the Mu3e experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bruch, Dorothea vom [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz (Germany); Collaboration: Mu3e-Collaboration

    2016-07-01

    The Mu3e experiment searches for the lepton flavour violating decay μ → eee, aiming at a branching ratio sensitivity better than 10{sup -16}.To reach this sensitivity, muon rates above 10{sup 9} μ/s are required. A high precision silicon tracking detector combined with excellent timing resolution from scintillating fibers and tiles will measure the momenta, vertices and timing of the decay products of muons stopped in the target to suppress background. The trigger-less readout system will deliver about 100 GB/s of zero-suppressed data. A network of optical links and switching FPGAs sends the complete detector data for a time slice to one node of the filter farm. An FPGA inside the filter farm PC transfers the event data to the GPU via PCIe direct memory access. The GPU finds and fits tracks using a 3D tracking algorithm for multiple scattering dominated resolution. In a second step, a three track vertex fit is performed, allowing for a reduction of the output data rate to below 100 MB/s by removing combinatorial background. The talk discusses the data flow from the FPGA to the GPU as well as the implementation and performance of the track and vertex fits on the GPU.

  15. Online Data Reduction using Track and Vertex Reconstruction on GPUs for the Mu3e Experiment

    Science.gov (United States)

    vom Bruch, Dorothea

    2017-08-01

    The Mu3e experiment searches for the lepton flavour violating decay μ+ → e+e-e+, aiming to achieve a sensitivity of 2 · 10-15 in its first phase and ultimately aspiring to a final sensitivity of 10-16. During the first phase of the experiment, a muon rate of ˜ 108 μ/s will be available, resulting in a data rate of ˜ 80 Gbit/s. The trigger-less readout system is based on optical links and switching FPGAs sending the complete detector data for a time slice to one node of the filter farm. A full online reconstruction is necessary to reduce the data rate to a manageable amount to be written to disk. Graphics processing units (GPUs) are used to fit tracks with a non-iterative 3D tracking algorithm for multiple scattering dominated resolution. In addition, a three track vertex selection is performed by calculating the vertex position from the intersections of the tracks. Together with kinematic cuts, this allows for a reduction of the output data rate to below 100MB/s using 12 DAQ PCs.

  16. The performance of diphoton primary vertex reconstruction methods in H → γγ+Met channel of ATLAS experiment

    Science.gov (United States)

    Tomiwa, K. G.

    2017-09-01

    The search for new physics in the H → γγ+met relies on how well the missing transverse energy is reconstructed. The Met algorithm used by the ATLAS experiment in turns uses input variables like photon and jets which depend on the reconstruction of the primary vertex. This document presents the performance of di-photon vertex reconstruction algorithms (hardest vertex method and Neural Network method). Comparing the performance of these algorithms for the nominal Standard Model sample and the Beyond Standard Model sample, we see the overall performance of the Neural Network method of primary vertex selection performed better than the Hardest vertex method.

  17. The silicon Micro Vertex Detector of the P bar ANDA experiment

    Science.gov (United States)

    Calvo, D.; Panda Collaboration

    2013-08-01

    The P bar ANDA experiment will make use of cooled antiproton beams of unprecedented quality that will become available at the Facility for Antiproton and Ion Research in Darmstadt, featuring a 1.5-15 GeV/c momentum range. The physics program includes measurements of hyperons produced at low energies, spectroscopy of charmonium and open-charm mesons. To handle the forward peaked particle distribution due to the Lorentz boost, the apparatus is arranged in an asymmetric layout around the interaction point. In particular the Micro Vertex Detector based on silicon devices will have a rather unusual geometry. The MVD features fast data readout, since the experiment is triggerless, particle identification over the full range of energies, limited material budget and good spatial and time resolution. The status of the MVD design is shown and the present prototypes are described.

  18. The silicon Micro Vertex Detector of the P{sup ¯}ANDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, D., E-mail: calvo@to.infn.it [INFN–Sezione di Torino, Torino (Italy)

    2013-08-01

    The P{sup ¯}ANDA experiment will make use of cooled antiproton beams of unprecedented quality that will become available at the Facility for Antiproton and Ion Research in Darmstadt, featuring a 1.5–15 GeV/c momentum range. The physics program includes measurements of hyperons produced at low energies, spectroscopy of charmonium and open-charm mesons. To handle the forward peaked particle distribution due to the Lorentz boost, the apparatus is arranged in an asymmetric layout around the interaction point. In particular the Micro Vertex Detector based on silicon devices will have a rather unusual geometry. The MVD features fast data readout, since the experiment is triggerless, particle identification over the full range of energies, limited material budget and good spatial and time resolution. The status of the MVD design is shown and the present prototypes are described.

  19. A high rate, low radiation length Micro-Vertex-Detector for the P¯ANDA experiment

    Science.gov (United States)

    Stockmanns, Tobias

    2011-09-01

    The Micro-Vertex-Detector (MVD) of the P¯ANDA experiment is the innermost tracking detector. Its most challenging task is the identification of D-meson pairs by their delayed decay point which is about 100- 500 μm from the production point. In addition to the necessary high spatial resolution, it needs a time resolution on the order of 10 ns, a moderate radiation hardness, an untriggered readout of hit data up to 500 MBit/s and a low radiation length. To meet these challenging requirements an intense R&D program is ongoing on all parts of the MVD. This article gives an overview of the ongoing technical developments with a focus on the pixel part of the project.

  20. The MAPS-based vertex detector for the STAR experiment: Lessons learned and performance

    Energy Technology Data Exchange (ETDEWEB)

    Contin, Giacomo, E-mail: gcontin@lbl.gov

    2016-09-21

    The PiXeL detector (PXL) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. The PXL, together with the Intermediate Silicon Tracker (IST) and the Silicon Strip Detector (SSD), form the Heavy Flavor Tracker (HFT), which has been designed to improve the vertex resolution and extend the STAR measurement capabilities in the heavy flavor domain, providing a clean probe for studying the Quark–Gluon Plasma. The two PXL layers are placed at a radius of 2.8 and 8 cm from the beam line, respectively, and is based on ultra-thin high resolution MAPS sensors. The sensor features 20.7 μm pixel pitch, 185.6 μs readout time and 170 mW/cm{sup 2} power dissipation. The detector is air-cooled, allowing a global material budget of 0.4% radiation length on the innermost layer. A novel mechanical approach to detector insertion allows for fast installation and integration of the pixel sub detector. The HFT took data in Au+Au collisions at 200 GeV during the 2014 RHIC run. Modified during the RHIC shutdown to improve its reliability, material budget, and tracking capabilities, the HFT took data in p+p and p+Au collisions at √s{sub NN}=200 GeV in the 2015 RHIC run. In this paper we present detector specifications, experience from the construction and operations, and lessons learned. We also show preliminary results from 2014 Au+Au data analyses, demonstrating the capabilities of charm reconstruction with the HFT. - Highlights: • First MAPS-based vertex detector in a collider experiment. • Achieved low material budget of 0.39% of radiation length per detector layer. • Track pointing resolution to the primary vertex better than 10⊕24 GeV/p×c μm. • Gain in significance for the topological reconstruction of the D{sup 0}−>K+π decay in STAR. • Observed latch-up induced damage of MAPS sensors.

  1. A MAPS Based Micro-Vertex Detector for the STAR Experiment

    Science.gov (United States)

    Schambach, Joachim; Anderssen, Eric; Contin, Giacomo; Greiner, Leo; Silber, Joe; Stezelberger, Thorsten; Sun, Xiangming; Szelezniak, Michal; Videbaek, Flemming; Vu, Chinh; Wieman, Howard; Woodmansee, Sam

    For the 2014 heavy ion run of RHIC a new micro-vertex detector called the Heavy Flavor Tracker (HFT) was installed in the STAR experiment. The HFT consists of three detector subsystems with various silicon technologies arranged in 4 approximately concentric cylinders close to the STAR interaction point designed to improve the STAR detector's vertex resolution and extend its measurement capabilities in the heavy flavor domain. The two innermost HFT layers are placed at radii of 2.8 cm and 8 cm from the beam line. These layers are constructed with 400 high resolution sensors based on CMOS Monolithic Active Pixel Sensor (MAPS) technology arranged in 10-sensor ladders mounted on 10 thin carbon fiber sectors to cover a total silicon area of 0.16 m2. Each sensor of this PiXeL ("PXL") sub-detector combines a pixel array of 928 rows and 960 columns with a 20.7 μm pixel pitch together with front-end electronics and zero-suppression circuitry in one silicon die providing a sensitive area of ˜3.8 cm2. This sensor architecture features 185.6 μs readout time and 170 mW/cm2 power dissipation. This low power dissipation allows the PXL detector to be air-cooled, and with the sensors thinned down to 50 μm results in a global material budget of only 0.4% radiation length per layer. A novel mechanical approach to detector insertion allows us to effectively install and integrate the PXL sub-detector within a 12 hour period during an on-going multi-month data taking period. The detector requirements, architecture and design, as well as the performance after installation, are presented in this paper.

  2. Commissioning and operation of the vertex locator (VELO) at the LHCb experiment

    Science.gov (United States)

    Van Lysebetten, A.

    2010-05-01

    The Vertex Locator (VELO) of the LHCb experiment consists of two halves each equipped with 23 silicon modules along the beam direction. The detector is mounted in a setup similar to Roman pots. The VELO will offer a powerful tool for primary and secondary vertex reconstruction. In order to achieve this, the detector went through a complete and thorough commissioning phase. This process spans a range of activities: individual module characterization in testbeams, detector integration, system tests and offline alignment procedures. After this extensive commissioning period the LHCb experiment entered a new exciting phase during the year 2008. The experiment saw the first beam! Moreover with data taken in the VELO detector the first LHC induced tracks could be reconstructed.

  3. Travel-Time Maps: Linear Cartograms with Fixed Vertex Locations

    NARCIS (Netherlands)

    Buchin, Kevin; Goethem, Arthur van; Hoffmann, Michael; van Kreveld, Marc; Speckmann, Bettina; Michael, P.

    2014-01-01

    Linear cartograms visualize travel times between locations, usually by deforming the underlying map such that Euclidean distance corresponds to travel time. We introduce an alternative model, where the map and the locations remain fixed, but edges are drawn as sinusoid curves. Now the travel time

  4. The Vertex detector of the LHCb Experiment The VeLo

    CERN Document Server

    Saavedra, Aldo F

    2007-01-01

    The LHCb experiment is the dedicated b physics experiment of the LHC that will study CP violation and rare b decays. Its vertex detector called VeLo (Vertex Locator) has been designed to achieve an impact parameter resolution of 14μm + 35μm/pT and a propertime resolution of 40fs−1. The main components of the detector and module are introduced focusing on the radiation hard front end Beetle chip, the radiation tolerant silicon sensors and the readout system of the detector. In preliminary testbeam results a resolution of 8μm and 4μm for tracks of angle 0.16rad has been measured. Construction, assembly and commissioning are currently on going. The latest commissioning showing the successful performance of the VeLo alignment algorithm.

  5. A readout system for the micro-vertex-detector demonstrator for the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Schrader, Christoph

    2011-06-09

    The Compressed Baryonic Matter Experiment (CBM) is a fixed target heavy ion experiment currently in preparation at the future FAIR accelerator complex in Darmstadt. The CBM experiment focuses on the measurements of diagnostic probes of the early and dense phase of the fireball at beam energies from 8 up to 45 AGeV. As observables, rare hadronic, leptonic and photonic probes are used, including open charm. Open charm will be identified by reconstructing the secondary decay vertex of the corresponding short lived particles. As the central component for track reconstruction, a detector system based on silicon semiconductor detectors is planned. The first three stations of the Silicon Tracking System (STS) make up the so-called Micro-Vertex-Detector (MVD) operating in moderate vacuum. Because of the well-balanced compromise between an excellent spatial resolution (few {mu}m), low material budget ({proportional_to}50 {mu}m Si), adequate radiation tolerance and readout speed, Monolithic Active Pixel Sensors (MAPS) based on CMOS technology are more suited than any other technology for the reconstruction of the secondary vertex in CBM. A new detector concept has to be developed. Two MVD-Demonstrator modules have been successfully tested with 120 GeV pions at the CERN-SPS. The main topic of this thesis is the development of a control and readout concept of several MVD-Demonstrator modules with a common data acquisition system. In order to achieve the required results a front-end electronics device has been developed which is capable of reading the analogue signals of two sensors on a ex-print cable. The high data rate of the MAPS sensors (1.2 Gbit per second and sensor by 50 MHz and 12 bit ADC resolution) requires a readout system which processes the data on-line in a pipeline to avoid dead times. In order to implement the pipeline processing an FPGA is used, which is located on an additional hardware platform. In order to integrate the MVD-Demonstrator readout board in the

  6. The STAR Vertex Position Detector

    Energy Technology Data Exchange (ETDEWEB)

    Llope, W.J., E-mail: llope@rice.edu [Rice University, Houston, TX 77005 (United States); Zhou, J.; Nussbaum, T. [Rice University, Houston, TX 77005 (United States); Hoffmann, G.W. [University of Texas, Austin, TX 78712 (United States); Asselta, K. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Brandenburg, J.D.; Butterworth, J. [Rice University, Houston, TX 77005 (United States); Camarda, T.; Christie, W. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Crawford, H.J. [University of California, Berkeley, CA 94720 (United States); Dong, X. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Engelage, J. [University of California, Berkeley, CA 94720 (United States); Eppley, G.; Geurts, F. [Rice University, Houston, TX 77005 (United States); Hammond, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Judd, E. [University of California, Berkeley, CA 94720 (United States); McDonald, D.L. [Rice University, Houston, TX 77005 (United States); Perkins, C. [University of California, Berkeley, CA 94720 (United States); Ruan, L.; Scheblein, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

    2014-09-21

    The 2×3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2×19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event “start time” needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ∼100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ∼1 cm.

  7. Typical solution time for a vertex-covering algorithm on finite-connectivity random graphs

    OpenAIRE

    Weigt, Martin; Hartmann, Alexander K.

    2000-01-01

    In this letter, we analytically describe the typical solution time needed by a backtracking algorithm to solve the vertex-cover problem on finite-connectivity random graphs. We find two different transitions: The first one is algorithm-dependent and marks the dynamical transition from linear to exponential solution times. The second one gives the maximum computational complexity, and is found exactly at the threshold where the system undergoes an algorithm-independent phase transition in its ...

  8. Vertex Reconstruction in CMS

    CERN Document Server

    Chabanat, E; D'Hondt, J; Vanlaer, P; Prokofiev, K; Speer, T; Frühwirth, R; Waltenberger, W

    2005-01-01

    Because of the high track multiplicity in the final states expected in proton collisions at the LHC experiments, novel vertex reconstruction algorithms are required. The vertex reconstruction problem can be decomposed into a pattern recognition problem ("vertex finding") and an estimation problem ("vertex fitting"). Starting from least-square methods, ways to render the classical algorithms more robust are discussed and the statistical properties of the novel methods are shown. A whole set of different approaches for the vertex finding problem is presented and compared in relevant physics channels.

  9. Design and performance studies of the micro-vertex-detector for the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Amar-Youcef, Samir

    2012-04-12

    The CBM experiment is a fixed target experiment to be installed at the future accelerator facility at GSI/FAIR. It will investigate the properties of nuclear matter at extreme conditions and its underlying strong interaction. The research of the CBM experiment, which focuses on the regime of highest net-baryon densities and moderate temperatures, is complementary to this of the experiments at RHIC/BNL (STAR) and LHC/CERN (ALICE), which mainly focuses on the regime of high energy and zero net-baryon densities. The corresponding conditions in the CBM experiment can be produced in heavy-ion collisions at beam energies between 10 and 40 AGeV. Heavy particles, as e.g. charm carrying particles, could be sensitive to the properties of the medium in the early phase of the collision. However due to the short lifetime of open charm particles, they can only be reconstructed via their decay products and the corresponding track topology. Consequently in order to reconstruct the decay vertex with a high accuracy an ultrathin detector system with excellent spatial resolution is required. For the precise vertexing a microvertex detector (MVD) is envisaged, which has to be located directly behind the target and has to operate in the vacuum. Monolithic Active Pixel Sensors (MAPS) are the most promising candidates for the underlying sensor technology for the MVD of the CBM experiment. In the context of this thesis first attempts haven been initiated in order to integrate mechanically MAPS sensors into an ultra-thin detector dedicated to the CBM experiment. The mechanical integration necessarily needs to contain the MAPS sensors, electrical services and a support structure to cool and mount the sensors. As, apart from the intrinsic properties of the sensor, the support structures contribute notably to the specific functions and properties of the detector, particular care has to be taken during its development. Its implementation is not meant to push already the limits, rather it is

  10. The TORCH time-of-flight detector for particle identification and photon vertex association

    Science.gov (United States)

    Castillo García, L.; Brook, N.; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; van Dijk, M.

    2017-02-01

    TORCH (Time Of internally Reflected CHerenkov light) is a novel time-of-flight detector, designed to provide π /K/p particle identification up to 0~ 1 GeV/c momentum and beyond. To achieve this, a time resolution of ~ 15 ps combining information from 0~ 3 detected photons is required over a 10 m flight path. Large areas can be covered with TORCH, nominally up to 30 m2. One such application is for the LHCb experiment, to complement the particle identification capabilities of its RICH detectors. TORCH has a DIRC-like construction with 10 mm-thick synthetic amorphous fused-silica plates as a radiator. Cherenkov photons propagate by total internal reflection to the plate edges and there are focussed onto an array of position-sensitive photodetectors. Custom-built micro-channel plate photo-multipliers (MCP-PMTs) are being developed in collaboration with industry to provide the lifetime, granularity and time resolution to meet the TORCH specifications. In the present paper, laboratory tests of the MCP-PMTs developed for TORCH and its readout electronics are presented. Test beam measurements of a prototype TORCH detector in a low-momentum mixed beam of pions and protons are highlighted. Time resolutions for individual photons approaching 100 ps is achieved, after correction for dispersion effects in the quartz medium. In addition to the particle identification capabilities, the high-precision timing information that TORCH provides could be used at the high-luminosity LHC to associate high-energy photons with the correct primary interaction vertex amongst the many expected.

  11. The Neuro-Z-Vertex Trigger of the Belle II Experiment

    Science.gov (United States)

    Skambraks, Sebastian; Neuhaus, Sara; Kiesling, Christian

    2016-11-01

    A neural network z vertex trigger is planned for the upcoming Belle II detector at the SuperKEKB collider. This neural algorithm is based on a single track 3D parameter estimation using only hit and drift time information from the central drift chamber. Due to the high luminosity (L = 8 × 1035 cm-2 s-1) Belle II will have to face high levels of beam induced background, making a z vertex reconstruction at the first level trigger mandatory. Using the neural z vertex algorithm, the requirements of the standard track trigger can be strongly relaxed. By this, the trigger efficiencies, especially for low multiplicity events, e.g. τ pair production, can be significantly increased. This contribution presents the foreseen neural network trigger setup and the preceding 2D track finder. Special focus is put on the proposal and evaluation of a possible 3D upgrade of the 2D track finder. Additionally, details are given on a dedicated setup for the upcoming cosmic ray test.

  12. Exploratory study of a novel low occupancy vertex detector architecture based on high precision timing for high luminosity particle colliders

    Energy Technology Data Exchange (ETDEWEB)

    Orel, Peter, E-mail: porel@hawaii.edu; Varner, Gary S.; Niknejadi, Pardis

    2017-06-11

    Vertex detectors provide space–time coordinates for the traversing charged particle decay products closest to the interaction point. Resolving these increasingly intense particle fluences at high luminosity particle colliders, such as SuperKEKB, is an ever growing challenge. This results in a non-negligible occupancy of the vertex detector using existing low material budget techniques. Consequently, new approaches are being studied that meet the vertexing requirements while lowering the occupancy. In this paper, we introduce a novel vertex detector architecture. Its design relies on an asynchronous digital pixel matrix in combination with a readout based on high precision time-of-flight measurement. Denoted the Timing Vertex Detector (TVD), it consists of a binary pixel array, a transmission line for signal collection, and a readout ASIC. The TVD aims to have a spatial resolution comparable to the existing Belle2 vertex detector. At the same time it offers a reduced occupancy by a factor of ten while decreasing the channel count by almost three orders of magnitude. Consequently, reducing the event size from about 1 MB/event to about 5.9 kB/event.

  13. Exploratory study of a novel low occupancy vertex detector architecture based on high precision timing for high luminosity particle colliders

    Science.gov (United States)

    Orel, Peter; Varner, Gary S.; Niknejadi, Pardis

    2017-06-01

    Vertex detectors provide space-time coordinates for the traversing charged particle decay products closest to the interaction point. Resolving these increasingly intense particle fluences at high luminosity particle colliders, such as SuperKEKB, is an ever growing challenge. This results in a non-negligible occupancy of the vertex detector using existing low material budget techniques. Consequently, new approaches are being studied that meet the vertexing requirements while lowering the occupancy. In this paper, we introduce a novel vertex detector architecture. Its design relies on an asynchronous digital pixel matrix in combination with a readout based on high precision time-of-flight measurement. Denoted the Timing Vertex Detector (TVD), it consists of a binary pixel array, a transmission line for signal collection, and a readout ASIC. The TVD aims to have a spatial resolution comparable to the existing Belle2 vertex detector. At the same time it offers a reduced occupancy by a factor of ten while decreasing the channel count by almost three orders of magnitude. Consequently, reducing the event size from about 1 MB/event to about 5.9 kB/event.

  14. Overview of the Micro Vertex Detector for the P bar ANDA experiment

    Science.gov (United States)

    Calvo, Daniela

    2017-02-01

    The P bar ANDA experiment is devoted to study interactions between cooled antiproton beams and a fixed target (the interaction rate is of about 107 events/s), hydrogen or heavier nuclei. The innermost tracker of P bar ANDA is the Micro Vertex Detector (MVD), specially designed to ensure the secondary vertex resolution for the discrimination of short-lived charmonium states. Hybrid epitaxial silicon pixels and double-sided silicon microstrips will equip four barrels, arranged around the interaction point, and six forward disks. The experiment features a triggerless architecture with a master clock of 160 MHz, therefore the MVD has to run with a continuous data transmission where the hits need precise timestamps. The energy loss of the particles in the sensor will be measured as well. The challenging request of a triggerless readout suggested to develop custom readout chips for both pixel (ToPix) and microstrip (PASTA) devices. To validate components and the triggerless readout architecture, prototypes have been built and tested. After an overview of the MVD, the technological aspects and performances of some prototypes will be reported.

  15. First-year experience with the Ba Bar silicon vertex tracker

    CERN Document Server

    Bozzi, C; Cotta-Ramusino, A; Dittongo, S; Folegani, M; Piemontese, L; Abbott, B K; Breon, A B; Clark, A R; Dow, S; Fan, Q; Goozen, F; Hernikl, C; Karcher, A; Kerth, L T; Kipnis, I; Kluth, S; Lynch, G; Levi, M; Luft, P; Luo, L; Nyman, M A; Pedrali-Noy, M; Roe, N A; Zizka, G; Roberts, D; Schieck, J; Barni, D; Brenna, E; Defendi, I; Forti, A C; Giugni, D; Lanni, F; Palombo, F; Vaniev, V; Leona, A; Mandelli, E; Manfredi, P F; Perazzo, A; Re, V; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bosi, F; Calderini, G; Carpinelli, M; Forti, F; Gagliardi, D; Giorgi, M A; Lusiani, A; Mammini, P; Morganti, M; Morsani, F; Neri, N; Paoloni, E; Profeti, A; Rama, M; Rampino, G; Rizzo, G; Sandrelli, F; Simi, G; Triggiani, G; Tritto, S; Vitale, R; Walsh, J; Burchat, Patricia R; Cheng, C; Kirkby, D; Meyer, T; Roat, C; Bóna, M; Bianchi, F; Daudo, F; Di Girolamo, B; Gamba, D; Giraudo, G; Grosso, P; Romero, A; Smol, A; Trapani, P; Zanin, D; Bosisio, L; Della Ricca, G; Rashevskaia, I; Lanceri, L; Pompili, A; Poropat, P; Prest, M; Rastelli, C; Vallazza, E; Vuagnin, G; Hast, C; Potter, E P; Sharma, V; Burke, S; Callahan, D; Campagnari, C; Dahmes, B; Eppich, A; Hale, D; Hall, K; Hart, P; Kuznetsova, N; Kyre, S; Levy, S; Long, O; May, J; Richman, J; Verkerke, W; Witherell, M; Beringer, J; Eisner, A M; Frey, A; Grillo, A; Grothe, M; Johnson, R; Kröger, W; Lockman, W; Pulliam, T; Rowe, W; Schmitz, R; Seiden, A; Spencer, E; Turri, M; Walkowiak, W; Wilder, M; Charles, E; Elmer, P; Nielsen, J; Orejudos, W; Scott, I; Zobernig, H

    2001-01-01

    Within its first year of operation, the BaBar Silicon Vertex Tracker (SVT) has accomplished its primary design goal, measuring the z vertex coordinate with sufficient accuracy as to allow the measurement of the time-dependent CP asymmetry in the neutral B-meson system. The SVT consists of five layers of double-sided, AC-coupled silicon-strip detectors of 300 mu m thickness with a readout strip pitch of 50-210 mu m and a stereo angle of 90 deg. between the strips on the two sides. Detector alignment and performance with respect to spatial resolution and efficiency in the reconstruction of single hits are discussed. In the day-to-day operation of the SVT, radiation damage and protection issues were of primary concern. The SVT is equipped with a dedicated system (SVTRAD) for radiation monitoring and protection, using reverse-biased photodiodes. The evolution of the SVTRAD thresholds on the tolerated radiation level is described. Results on the first-year radiation exposure as measured with the SVTRAD system and ...

  16. Development of CMOS pixel sensors for tracking and vertexing in high energy physics experiments

    CERN Document Server

    Senyukov, Serhiy; Besson, Auguste; Claus, Giles; Cousin, Loic; Dulinski, Wojciech; Goffe, Mathieu; Hippolyte, Boris; Maria, Robert; Molnar, Levente; Sanchez Castro, Xitzel; Winter, Marc

    2014-01-01

    CMOS pixel sensors (CPS) represent a novel technological approach to building charged particle detectors. CMOS processes allow to integrate a sensing volume and readout electronics in a single silicon die allowing to build sensors with a small pixel pitch ($\\sim 20 \\mu m$) and low material budget ($\\sim 0.2-0.3\\% X_0$) per layer. These characteristics make CPS an attractive option for vertexing and tracking systems of high energy physics experiments. Moreover, thanks to the mass production industrial CMOS processes used for the manufacturing of CPS the fabrication construction cost can be significantly reduced in comparison to more standard semiconductor technologies. However, the attainable performance level of the CPS in terms of radiation hardness and readout speed is mostly determined by the fabrication parameters of the CMOS processes available on the market rather than by the CPS intrinsic potential. The permanent evolution of commercial CMOS processes towards smaller feature sizes and high resistivity ...

  17. Performance of the reconstruction algorithms of the FIRST experiment pixel sensors vertex detector

    CERN Document Server

    Rescigno, R; Juliani, D; Spiriti, E; Baudot, J; Abou-Haidar, Z; Agodi, C; Alvarez, M A G; Aumann, T; Battistoni, G; Bocci, A; Böhlen, T T; Boudard, A; Brunetti, A; Carpinelli, M; Cirrone, G A P; Cortes-Giraldo, M A; Cuttone, G; De Napoli, M; Durante, M; Gallardo, M I; Golosio, B; Iarocci, E; Iazzi, F; Ickert, G; Introzzi, R; Krimmer, J; Kurz, N; Labalme, M; Leifels, Y; Le Fevre, A; Leray, S; Marchetto, F; Monaco, V; Morone, M C; Oliva, P; Paoloni, A; Patera, V; Piersanti, L; Pleskac, R; Quesada, J M; Randazzo, N; Romano, F; Rossi, D; Rousseau, M; Sacchi, R; Sala, P; Sarti, A; Scheidenberger, C; Schuy, C; Sciubba, A; Sfienti, C; Simon, H; Sipala, V; Tropea, S; Vanstalle, M; Younis, H

    2014-01-01

    Hadrontherapy treatments use charged particles (e.g. protons and carbon ions) to treat tumors. During a therapeutic treatment with carbon ions, the beam undergoes nuclear fragmentation processes giving rise to significant yields of secondary charged particles. An accurate prediction of these production rates is necessary to estimate precisely the dose deposited into the tumours and the surrounding healthy tissues. Nowadays, a limited set of double differential carbon fragmentation cross-section is available. Experimental data are necessary to benchmark Monte Carlo simulations for their use in hadrontherapy. The purpose of the FIRST experiment is to study nuclear fragmentation processes of ions with kinetic energy in the range from 100 to 1000 MeV/u. Tracks are reconstructed using information from a pixel silicon detector based on the CMOS technology. The performances achieved using this device for hadrontherapy purpose are discussed. For each reconstruction step (clustering, tracking and vertexing), different...

  18. LHCb VErtex LOcator (VELO) upgrade

    Science.gov (United States)

    Reid, M. M.; LHCb VELO Group

    2013-01-01

    The VErtex LOcator (VELO) is a vital piece of apparatus providing tracking, triggering and vertexing to the LHCb experiment. Its superb impact parameter resolution and high efficiency enable LHCb to make precision measurements and searches for New Physics in the flavour sector. These proceedings focus on the R&D for the future LHCb VELO detector to be installed in the upgraded LHCb experiment. In order to increase hadronic yields and to be able to run at higher luminosities LHCb plans to upgrade the front end electronics, currently limited by a first level hardware trigger. For the silicon vertex detector this implies a complete rebuild of the modules and electronics, with improved cooling capability to cope with the high voltages and currents expected after significant radiation damage has been accrued. This paper presents the design considerations for the vertex detector upgrade together with the two proposed options for the sensor layout, based on strips or pixels. As part of the R&D programme a pixel based tracking telescope has been developed for use in testbeams, to gain experience with pixel tracking and to evaluate the technologies under consideration. This paper presents results from the last years running of the TimePix telescope and describes the integration of various test devices.

  19. PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.

    Energy Technology Data Exchange (ETDEWEB)

    AKIBA,Y.

    2004-03-30

    We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over broad x-range. With the present PHENIX detector, heavy-quark production has been measured indirectly through the observation of single electrons. These measurements are inherently limited in accuracy by systematic uncertainties resulting from the large electron background from Dalitz decays and photon conversions. In particular, the statistical nature of the analysis does not allow for a model-independent separation of the charm and beauty contributions. The VTX detector will provide vertex tracking with a resolution of <50 {micro}m over a large coverage both in rapidity (|{eta}| < 1.2) and in azimuthal angle ({Delta}{phi} {approx

  20. PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    AKIBA,Y.

    2004-10-01

    We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--(a) Potential enhancement of charm production, (b) Open beauty production, (c) Flavor dependence of jet quenching and QCD energy loss, (d) Accurate charm reference for quarkonium, (e) Thermal dilepton radiation, (f) High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}, and (g) Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--(a) {Delta}G/G with charm, (b) {Delta}G/G with beauty, and (c) x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over broad x-range.

  1. The silicon drift vertex detector for the STAR experiment at RHIC

    CERN Document Server

    Pandey, S U; Beuttenmüller, Rolf H; Caines, H; Chen, W; Dimassimo, D; Dyke, H; Elliot, D; Eremin, V; Grau, M; Hoffmann, G W; Humanic, T; Ilyashenko, Yu S; Kotov, I; Kraner, H W; Kuczewski, P; Leonhardt, B; Li, Z; Liaw, C J; Lo Curto, G; Middelkamp, P; Minor, R; Munhoz, M; Ott, G; Pruneau, C A; Rykov, V L; Schambach, J; Sedlmeir, J; Soja, B; Sugarbaker, E R; Takahashi, J; Wilson, K; Wilson, R

    2002-01-01

    The current status of the STAR Silicon Vertex Tracker (SVT) is presented. The performance of the Silicon Drift Detectors (SDD) is discussed. Results for a recent 15 layer SDD tracker which prototypes all components of the SVT are presented. The enhanced physics capabilities of the STAR detector due to the addition of the SVT are addressed.

  2. Development of a pixel sensor with fine space-time resolution based on SOI technology for the ILC vertex detector

    Science.gov (United States)

    Ono, Shun; Togawa, Manabu; Tsuji, Ryoji; Mori, Teppei; Yamada, Miho; Arai, Yasuo; Tsuboyama, Toru; Hanagaki, Kazunori

    2017-02-01

    We have been developing a new monolithic pixel sensor with silicon-on-insulator (SOI) technology for the International Linear Collider (ILC) vertex detector system. The SOI monolithic pixel detector is realized using standard CMOS circuits fabricated on a fully depleted sensor layer. The new SOI sensor SOFIST can store both the position and timing information of charged particles in each 20×20 μm2 pixel. The position resolution is further improved by the position weighted with the charges spread to multiple pixels. The pixel also records the hit timing with an embedded time-stamp circuit. The sensor chip has column-parallel analog-to-digital conversion (ADC) circuits and zero-suppression logic for high-speed data readout. We are designing and evaluating some prototype sensor chips for optimizing and minimizing the pixel circuit.

  3. Past Experiences and Future Trends on Vertex Detector Cooling at LHC

    CERN Document Server

    Petagna, Paolo

    2014-01-01

    Substantially different approaches have been ad opted for the refrigeration plants of the first generation of vertex detectors at LHC: those of ALICE, ATLAS and CMS use PFC fluids, either in single phase or in a traditional Joule-Thomson cycle, while carbon dioxide in a pumped two-phase loop has been selected for the LHCb VELO. For what concerns the on-board thermal management of the sensors and related electronics, a traditional design has been followed, based on a common general approach and only differing in the specific choices related to the local configuration. Although the global performance of the detectors in this first phase of LHC operation can be claimed as fully satisfactory, it appears that the additional challenges posed by the coming upgrade phases can only be tackled through an effort on technology innovation and, in particular on much stronger and earlier integration of all the cooling-related aspects in the detector conception. Carbon dioxide seems to be the preferred choice for the refrige...

  4. Characterisation of a radiation hard front-end chip for the vertex detector of the LHCb experiment at CERN

    CERN Document Server

    Van Bakel, N; Bulten, H J; Feuerstack-Raible, M; Jans, E; Ketel, T; Klous, S; Löchner, S; Sexauer, E; Smale, N J; Snoek, H; Trunk, U; Van Beuzekom, M G; Verkooijen, H

    2003-01-01

    The Beetle is a 128 channel analog pipelined readout chip which is intended for use in the silicon vertex locator (VELO) of the LHCb experiment at CERN. The Beetle chip is specially designed to withstand high radiation doses. Two Beetle1.1 chips bonded to a silicon strip detector have been tested with minimum ionizing particles. The main goal was to measure the signal-to-noise (S/N) ratio of the Beetle1.1 connected to a prototype VELO detector. Furthermore we investigated the general behaviour of the Beetle1.1. In this note we present the chip architecture, the measured (S/N) numbers as well as some characteristics (e.g. risetime, spillover) of the Beetle1.1 chip. Results from a total ionizing dose irradiation test are reported.

  5. Extending the Riemann-Solver-Free High-Order Space-Time Discontinuous Galerkin Cell Vertex Scheme (DG-CVS) to Solve Compressible Magnetohydrodynamics EquationsEquations

    Science.gov (United States)

    2016-06-08

    method [35]. The core idea is to construct a staggered space-time mesh through alternate cell -centered CEs and vertex-centered CEs (cf. Fig. 1 (right...volume integral and the surface integral. 3.2 Cell -Vertex Solution Updating Strategy The DG-CVS inherits the core idea of the CE/SE method using a...Illustration of space-time flux conservation on a 1-D cell -level CE. To further illustrate the idea of enforcing the space-time flux conservation

  6. The Belle Silicon Vertex Detector

    CERN Document Server

    Kawasaki, T

    2002-01-01

    The Belle Silicon Vertex Detector (SVD) started working from June 1999 at the KEK B-factory experiment. The main purpose of the SVD is to make precise measurements of the B decay vertex position, which are essential for the observation of CP asymmetries. Excellent vertex resolution and a good detection efficiency are required for the SVD. In the present paper, the performance of Belle SVD is reviewed. The upgrade plan for the SVD2, which is under construction and will be installed in summer 2002, is also presented.

  7. A time-based front-end ASIC for the silicon micro strip sensors of the bar PANDA Micro Vertex Detector

    Science.gov (United States)

    Di Pietro, V.; Brinkmann, K.-Th.; Riccardi, A.; Ritman, J.; Rivetti, A.; Rolo, M. D.; Stockmanns, T.; Zambanini, A.

    2016-03-01

    The bar PANDA (Antiproton Annihilation at Darmstadt) experiment foresees many detectors for tracking, particle identification and calorimetry. Among them, the innermost is the MVD (Micro Vertex Detector) responsible for a precise tracking and the reconstruction of secondary vertices. This detector will be built from both hybrid pixel (two inner barrels and six forward disks) and double-sided micro strip (two outer barrels and outer rim of the last two disks) silicon sensors. A time-based approach has been chosen for the readout ASIC of the strip sensors. The PASTA (bar PANDA Strip ASIC) chip aims at high resolution time-stamping and charge information through the Time over Threshold (ToT) technique. It benefits from a Time to Digital Converter (TDC) allowing a time bin width down to 50 ps. The analog front-end was designed to serve both n-type and p-type strips and the performed simulations show remarkable performances in terms of linearity and electronic noise. The TDC consists of an analog interpolator, a digital local controller, and a digital global controller as the common back-end for all of the 64 channels.

  8. Aleph silicon microstrip vertex detector

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This microstrip vertex locator was located at the heart of the ALEPH experiment, one of the four experiments at the Large Electron-Positron (LEP) collider. In the experiments at CERN's LEP, which ran from 1989 to 2000, modern silicon microvertex detectors, such as those used at ALEPH, monitored the production of short-lived particles close to the beam pipe.

  9. The LHCb Vertex Locator

    CERN Document Server

    Eklund, L

    2004-01-01

    LHCb is an experiment at the Large Hadron Collider (LHC), dedicated to the study of b-hadron physics. The Vertex Locator (VELO) is a sub-detector which reconstructs primary and secondary vertices, which is of importance for the processes under study. It is a silicon micro-strip detector operated in a harsh radiation environment with demands of high read-out speed and the use of minimal material. In this paper, the LHCb VELO is introduced and the technology choices of the detector are motivated. We report on the present status of the project and one possible upgrade technology is presented.

  10. Adaptive Vertex Fitting

    CERN Document Server

    Frühwirth, R; Vanlaer, Pascal

    2007-01-01

    Vertex fitting frequently has to deal with both mis-associated tracks and mis-measured track errors. A robust, adaptive method is presented that is able to cope with contaminated data. The method is formulated as an iterative re-weighted Kalman filter. Annealing is introduced to avoid local minima in the optimization. For the initialization of the adaptive filter a robust algorithm is presented that turns out to perform well in a wide range of applications. The tuning of the annealing schedule and of the cut-off parameter is described, using simulated data from the CMS experiment. Finally, the adaptive property of the method is illustrated in two examples.

  11. Search for long-lived supersymmetry particles by signature of a high track-multiplicity displaced vertex using the LHC-ATLAS Experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00360876

    Long-lived supersymmetry (SUSY) particles decaying within the tracking volume of the LHC-ATLAS Experiment can be reconstructed as a displaced vertex (DV). The search strategy involves attempting to reassemble the decay point of the long-lived particles (LLPs) by fitting vertices from the trajectories arising from the charged decay products. A search, looking for a signature of a massive high track-multiplicity DV has been conducted using data collected during 2012 by the LHC-ATLAS Experiment at $\\sqrt{s}~=~8$ TeV, equaling to an integrated luminosity of 20.3 fb$^{-1}$. A signature of a massive displaced vertex is especially powerful due to the lack of any heavy long-lived standard model particles. Thereby, giving an analysis that is nearly background free. This dissertation describes the new, much more generic, "$DV+\\text{jets}$" channel. In this channel events with high momentum jets and at least one displaced vertex are considered. Eliminating the requirement of an associated $\\mu$ generated, to date of w...

  12. New vertex reconstruction algorithms for CMS

    CERN Document Server

    Frühwirth, R; Prokofiev, Kirill; Speer, T.; Vanlaer, P.; Chabanat, E.; Estre, N.

    2003-01-01

    The reconstruction of interaction vertices can be decomposed into a pattern recognition problem (``vertex finding'') and a statistical problem (``vertex fitting''). We briefly review classical methods. We introduce novel approaches and motivate them in the framework of high-luminosity experiments like at the LHC. We then show comparisons with the classical methods in relevant physics channels

  13. The CLIC Vertex Detector

    CERN Document Server

    Dannheim, D

    2015-01-01

    The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a meas- urement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t → W b will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit tim- ing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC ver- tex det...

  14. STAR Vertex Detector Upgrade Development

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, Leo C.; Matis, Howard S.; Stezelberger, Thorsten; Vu,Chinh Q.; Wieman, Howard; Szelezniak, Michal; Sun, Xiangming

    2008-01-28

    We report on the development and prototyping efforts undertaken with the goal of producing a micro-vertex detector for the STAR experiment at the RHIC accelerator at BNL. We present the basic detector requirements and show a sensor development path, conceptual mechanical design candidates and readout architecture. Prototyping and beam test results with current generation MimoSTAR-2 sensors and a readout system featuring FPGA based on-the-fly hit finding and data sparsification are also presented.

  15. The Belle II Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, M., E-mail: markus.friedl@oeaw.ac.at [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Ackermann, K. [MPI Munich, Föhringer Ring 6, 80805 München (Germany); Aihara, H. [University of Tokyo, Department of Physics, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Aziz, T. [Tata Institute of Fundamental Research, Experimental High Energy Physics Group, Homi Bhabha Road, Mumbai 400 005 (India); Bergauer, T. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Bozek, A. [Institute of Nuclear Physics, Division of Particle Physics and Astrophysics, ul. Radzikowskiego 152, 31 342 Krakow (Poland); Campbell, A. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Dingfelder, J. [University of Bonn, Department of Physics and Astronomy, Nussallee 12, 53115 Bonn (Germany); Drasal, Z. [Charles University, Institute of Particle and Nuclear Physics, Ke Karlovu 3, 121 16 Praha 2 (Czech Republic); Frankenberger, A. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Gadow, K. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Gfall, I. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Haba, J.; Hara, K.; Hara, T. [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Higuchi, T. [University of Tokyo, Kavli Institute for Physics and Mathematics of the Universe, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Himori, S. [Tohoku University, Department of Physics, Aoba Aramaki Aoba-ku, Sendai 980-8578 (Japan); Irmler, C. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Ishikawa, A. [Tohoku University, Department of Physics, Aoba Aramaki Aoba-ku, Sendai 980-8578 (Japan); Joo, C. [Seoul National University, High Energy Physics Laboratory, 25-107 Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of); and others

    2013-12-21

    The KEKB machine and the Belle experiment in Tsukuba (Japan) are now undergoing an upgrade, leading to an ultimate luminosity of 8×10{sup 35}cm{sup −2}s{sup −1} in order to measure rare decays in the B system with high statistics. The previous vertex detector cannot cope with this 40-fold increase of luminosity and thus needs to be replaced. Belle II will be equipped with a two-layer Pixel Detector surrounding the beam pipe, and four layers of double-sided silicon strip sensors at higher radii than the old detector. The Silicon Vertex Detector (SVD) will have a total sensitive area of 1.13m{sup 2} and 223,744 channels—twice as many as its predecessor. All silicon sensors will be made from 150 mm wafers in order to maximize their size and thus to reduce the relative contribution of the support structure. The forward part has slanted sensors of trapezoidal shape to improve the measurement precision and to minimize the amount of material as seen by particles from the vertex. Fast-shaping front-end amplifiers will be used in conjunction with an online hit time reconstruction algorithm in order to reduce the occupancy to the level of a few percent at most. A novel “Origami” chip-on-sensor scheme is used to minimize both the distance between strips and amplifier (thus reducing the electronic noise) as well as the overall material budget. This report gives an overview on the status of the Belle II SVD and its components, including sensors, front-end detector ladders, mechanics, cooling and the readout electronics.

  16. The CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, S.; Carter, H.; Flaugher, B. [and others

    1993-09-01

    A silicon strip vertex detector was designed, constructed and commissioned at the CDF experiment at the Tevatron collider at Fermilab. The mechanical design of the detector, its cooling and monitoring are presented. The front end electronics employing a custom VLSI chip, the readout electronics and various components of the SVX system are described. The system performance and the experience with the operation of the detector in the radiation environment are discussed. The device has been taking colliding beams data since May of 1992, performing at its best design specifications and enhancing the physics program of CDF.

  17. The LHCb level 1 vertex trigger

    CERN Document Server

    Koratzinos, M

    1999-01-01

    Summary form only given. The Level 1 Vertex trigger of LHCb has certain features that make it unique amongst the LHC experiment trigger schemes: The problem it addresses is a reduction factor of 25 for minimum bias events while retaining good efficiency for signal B events. The best way to achieve such reduction factors is to rely on the most striking property of those B events, the long decay time of the B particles. The trigger therefore has to reconstruct the event around the interaction region and tag signal events using topological criteria. An accurate vertex detector is one of the key components of LHCb and a natural choice for providing the data for such a triggering scheme. The algorithm for the reconstruction of the event is complicated and not readily parallelisable in its totality. We are therefore proposing an architecture that resembles a high-level trigger architecture, where the event building function is performed by a switch network and each event is processed by a single processor, part of ...

  18. Vertexing and Tracking Software at LHCb

    CERN Document Server

    Bowen, Espen Eie

    2015-01-01

    The LHCb experiment is a dedicated heavy flavour experiment at the LHC. Its primary goal is to search for indirect evidence of New Physics in CP violation and rare decays of beauty and charm hadrons. The detector includes a high granularity silicon-strip vertex detector, a silicon-strip detector upstream of the magnet and three stations of silicon-strip detectors and straw drift tubes downstream of the magnet. The software used to perform the track reconstruction and primary vertex reconstruction is described in detail along with a discussion of its performance.

  19. CCD-based vertex detectors

    CERN Document Server

    Damerell, C J S

    2005-01-01

    Over the past 20 years, CCD-based vertex detectors have been used to construct some of the most precise 'tracking microscopes' in particle physics. They were initially used by the ACCMOR collaboration for fixed target experiments in CERN, where they enabled the lifetimes of some of the shortest-lived charm particles to be measured precisely. The migration to collider experiments was accomplished in the SLD experiment, where the original 120 Mpixel detector was later upgraded to one with 307 Mpixels. This detector was used in a range of physics studies which exceeded the capability of the LEP detectors, including the most precise limit to date on the Bs mixing parameter. This success, and the high background hit densities that will inevitably be encountered at the future TeV-scale linear collider, have established the need for a silicon pixel-based vertex detector at this machine. The technical options have now been broadened to include a wide range of possible silicon imaging technologies as well as CCDs (mon...

  20. Real-time alignment of the LHCb vertex detector and observation of charmless baryonic decays $B^0_{(s)} \\rightarrow p \\overline{p} h^+ h^{\\prime-}$

    CERN Document Server

    Dujany, Giulio

    This thesis presents measurements of the branching fractions of the charmless baryonic decays $B^0_{(s)}\\to p\\overline{p} h^+h^{\\prime-}$ , where $h^{(\\prime)}$ denotes a kaon or a pion. Three new modes ($B^0\\to p\\overline{p} \\pi^+\\pi^-$, $B^0_{s}\\to p\\overline{p} K^+K^-$ and $B^0_{s}\\to p\\overline{p} K^{\\pm}\\pi^{\\mp}$) are observed for the first time and evidence is found for a fourth ($B^0\\to p\\overline{p} K^+K^-$). The inclusive branching fraction of $B^0\\to p\\overline{p} K^{\\pm}\\pi^{\\mp}$ is measured for the first time and the upper limit is set on the branching fraction of the $B^0_{s}\\to p\\overline{p} \\pi^+\\pi^-$ decay. This represents the first observation of four-body charmless baryonic decays of a $B_s$ meson and one of the first observations of baryonic $B^0_{s}$ decays. The implementation of the real-time alignment of LHCb's vertex detector is also described. The novel real-time alignment and calibration strategy adopted by LHCb is essential to allow more stable data taking conditions and an optima...

  1. A Fast Vertex Fitter for ATLAS Level 2 Trigger

    CERN Document Server

    Emeliyanov, D

    2007-01-01

    A vertex fitting algorithm developed for the Level 2 Trigger of the ATLAS experiment is presented. The algorithm features a Kalman filter with a decorrelating measurement transformation which reduces the computational burden of the vertex fit. The algorithm has been tested on data produced using a full Monte Carlo detector simulation. Results regarding the precision and speed of the algorithm are presented.

  2. Alignment of the LHCb vertex locator

    Science.gov (United States)

    Gersabeck, M.

    2009-01-01

    LHCb will commence data taking as the first dedicated heavy flavour experiment at a hadron collider in 2008. A very high hit precision from its vertex detector (vertex locator, VELO) is essential to meet the tight requirements of vertex reconstruction in B-physics. The single hit precision of the VELO is better than 10 μm. However, the VELO is operated only 8 mm from the beam and must be retracted and reinserted each LHC fill. Hence, the detector places unique demands on its alignment algorithm. The partially assembled VELO system has already been tested in a beam test. The novel software alignment methods are presented together with their interplay with the metrology measurements. Results from Monte Carlo simulation studies are discussed and recent beam test results are shown that prove the method's precision at the micron level.

  3. Performance of the LHCb Vertex Locator

    CERN Document Server

    Bjørnstad, Pal Marius

    2011-01-01

    The Vertex Locator is a silicon microstrip detector which provides the LHCb experiment with high precision measurements of tracks and decay vertices. The VELO sensors are exposed to a radiation dose of (2.5-6.5) x 10$^{13}n_{eq}$/cm$^2$ per fb$^{-1}$ in the area which is most irradiated. A best hit resolution of 4$mu$ is obtained for angled tracks, in agreement with expectations. The VELO has a vertex position resolution down to 11$mu$m in the transverse direction and an excellent momentum dependent performance.

  4. Quantum vertex model for reversible classical computing.

    Science.gov (United States)

    Chamon, C; Mucciolo, E R; Ruckenstein, A E; Yang, Z-C

    2017-05-12

    Mappings of classical computation onto statistical mechanics models have led to remarkable successes in addressing some complex computational problems. However, such mappings display thermodynamic phase transitions that may prevent reaching solution even for easy problems known to be solvable in polynomial time. Here we map universal reversible classical computations onto a planar vertex model that exhibits no bulk classical thermodynamic phase transition, independent of the computational circuit. Within our approach the solution of the computation is encoded in the ground state of the vertex model and its complexity is reflected in the dynamics of the relaxation of the system to its ground state. We use thermal annealing with and without 'learning' to explore typical computational problems. We also construct a mapping of the vertex model into the Chimera architecture of the D-Wave machine, initiating an approach to reversible classical computation based on state-of-the-art implementations of quantum annealing.

  5. Quantum vertex model for reversible classical computing

    Science.gov (United States)

    Chamon, C.; Mucciolo, E. R.; Ruckenstein, A. E.; Yang, Z.-C.

    2017-05-01

    Mappings of classical computation onto statistical mechanics models have led to remarkable successes in addressing some complex computational problems. However, such mappings display thermodynamic phase transitions that may prevent reaching solution even for easy problems known to be solvable in polynomial time. Here we map universal reversible classical computations onto a planar vertex model that exhibits no bulk classical thermodynamic phase transition, independent of the computational circuit. Within our approach the solution of the computation is encoded in the ground state of the vertex model and its complexity is reflected in the dynamics of the relaxation of the system to its ground state. We use thermal annealing with and without `learning' to explore typical computational problems. We also construct a mapping of the vertex model into the Chimera architecture of the D-Wave machine, initiating an approach to reversible classical computation based on state-of-the-art implementations of quantum annealing.

  6. Robust Vertex Fitters

    CERN Document Server

    Speer, Thomas; Vanlaer, Pascal; Waltenberger, Wolfgang

    2005-01-01

    While linear least-square estimators are optimal when the model is linear and all random noise is Gaussian, they are very sensitive to outlying tracks. Non-linear vertex reconstruction algorithms offer a higher degree of robustness against such outliers Two of the algorithms presented, the Adaptive filter and the Trimmed Kalman filter are able to down-weight or discard these outlying tracks, while a third, the Gaussian-sum filter, offers a better treatment of non-Gaussian distributions of track parameter errors when these are modelled by Gaussian mixtures.

  7. Representing vertex-transitive Vertex-transitive graphs on Groupoids

    African Journals Online (AJOL)

    Vertex-transitive graphs are one of the most favoured class of graphs in modelling scientific phenomena if symmetry is at issue. An understanding of these graphs should, therefore, be an obvious undertaking. Here, we present a characterisation of vertex-transitive graphs as left loop graphs and expose the measure of ...

  8. Magnetic wormholes and vertex operators

    Energy Technology Data Exchange (ETDEWEB)

    Singh, H. (Institute of Physics, Bhubaneswar-751 005 (India))

    1994-10-15

    We consider wormhole solutions in 2+1 Euclidean dimensions. A duality transformation is introduced to derive a new action from the magnetic wormhole action of Gupta, Hughes, Preskill, and Wise. The classical solution is presented. The vertex operators corresponding to the wormhole are derived. Conformally coupled scalars and spinors are considered in the wormhole background and the vertex operators are computed.

  9. EAMJ Vertex June.indd

    African Journals Online (AJOL)

    2009-06-06

    Jun 6, 2009 ... VERTEX EPIDURAL HAEMATOMA MANIFESTING WITH BILATERAL UPPER. LIMB DECEREBRATE POSTURE: CASE REPORT. J. G. KIBOI and I. M. MURIITHI. SUMMARY. Vertex epidural haematomas (VEDH) are rare and difficulties are encountered in diagnosis and management. This is a case report ...

  10. The NA60 silicon vertex spectrometer

    CERN Document Server

    Banicz, K; Floris, M; Heuser, J M; Keil, M; Lourenço, C; Ohnishi, H; Radermacher, E; Shahoyan, R; Usai, G

    2005-01-01

    The NA60 experiment studies the production of open charm and prompt dimuons in proton-nucleus and nucleus-nucleus collisions at the CERN SPS. To access the kinematics of charged particles already at the vertex level, a radiation tolerant silicon pixel detector has been placed in a 2.5T magnetic field near the target. This vertex spectrometer was built from 96 ALICE1LHCB pixel chips arranged in 12 tracking planes. The vertex spectrometer was successfully operated in a run with a 158GeV/nucleon indium ion beam incident on indium targets in October-November 2003. During the five-week-long run it was exposed to high levels of radiation distributed inhomogeneously over the detector. The most exposed regions of the silicon sensors underwent type inversion. With only a fraction of the total statistics analysed, the vertex spectrometer can already be seen to have dramatically enhanced the physics performance of NA60 with respect to that of its predecessors1).

  11. A FASTBUS flash ADC system for the Mark II vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Barker, L.

    1988-10-01

    This is a description of a flash ADC system built for the Mark II experiment at the Stanford Linear Accelerator Center (SLAC). This system was designed for use in the experiment's vertex chamber where signals could occur over a relatively long time, approximately 10 microseconds. This long time, coupled with fast cable amplifiers, necessitated an alternate design approach than was used with a dE/dX FASTBUS flash ADC design. 1 ref., 6 figs.

  12. Development of the ATHENA vertex detector

    Science.gov (United States)

    Riedler, P.

    2000-12-01

    The ATHENA experiment [1] is a new experiment at the anti-proton decelerator (AD) at CERN. Its goal is the production, detection and spectroscopic investigation of anti-hydrogen in a magneto-static trap. The experimental technique used will allow to compare the atomic structure of matter and anti-matter to a level of 10-15 and thus provides a test for CPT conservation. In order to unambiguously detect the annihilation of anti-hydrogen atoms a detector system consisting of double sided silicon strip detectors and CsI-crystals was developed. The complete vertex detector has to be operated at 77 K. An overview of the experiment is given and the development of the vertex detector is presented.

  13. Development of the ATHENA vertex detector

    CERN Document Server

    Riedler, P

    2000-01-01

    The ATHENA experiment [2000] is a new experiment at the antiproton decelerator (AD) at CERN. Its goal is the production, detection and spectroscopic investigation of antihydrogen in a magnetostatic trap. The experimental technique used will allow to compare the atomic structure of matter and antimatter to a level of 10/sup -15/ and thus provides a test for CPT conservation. In order to unambiguously detect the annihilation of antihydrogen atoms, a detector system consisting of double sided silicon strip detectors and CsI-crystals was developed. The complete vertex detector has to be operated at 77 K. An overview of the experiment is given and the development of the vertex detector is presented. (4 refs).

  14. First results from the LHCb Vertex Locator

    Science.gov (United States)

    McGregor, G.; LHCb VELO Group

    2011-06-01

    The Vertex Locator (VELO) is the component of the LHCb experiment nearest to the interaction point. It is a silicon strip detector comprised of two retractable halves and during stable running the inner-most active silicon sits approximately 8 mm from the beams. Here we briefly describe the LHCb VELO and present early performance results with data taken in the first half of 2010.

  15. Primary vertex reconstruction with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00286780

    2016-01-01

    Efficient and precise reconstruction of the primary vertex in a LHC collision is essential for determining the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of primary vertices in the busy, high pile-up environment of Run-2 of the LHC is a challenging task. The algorithms developed by the ATLAS experiments to reconstruct multiple vertices with small spatial separation are presented.

  16. Performance of the ATLAS primary vertex reconstruction algorithms

    CERN Document Server

    Zhang, Matt

    2017-01-01

    The reconstruction of primary vertices in the busy, high pile up environment of the LHC is a challenging task. The challenges and novel methods developed by the ATLAS experiment to reconstruct vertices in such environments will be presented. Such advances in vertex seeding include methods taken from medical imagining, which allow for reconstruction of very nearby vertices will be highlighted. The performance of the current vertexing algorithms using early Run-2 data will be presented and compared to results from simulation.

  17. Alignment of the ZEUS micro-vertex detector

    CERN Document Server

    Mankel, R

    2007-01-01

    The Micro-Vertex Detector (MVD) represents one of the major upgrades of the ZEUS detector for run II of the HERA ep collider at DESY. The MVD is a high-resolution silicon strip vertex detector designed to greatly enhance the tagging capabilities for event signatures with long-lived particles. This article describes the concepts and methods of theMVDalignment, and summarizes the experience from their application in context with real data from the HERA-II run.

  18. ATLAS strategy for primary vertex reconstruction during Run-II of the LHC

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2015-01-01

    Based on experience gained from run-I of the LHC, the ATLAS vertex reconstruction group has developed a refined primary vertex reconstruction strategy for run-II.  With instantaneous luminosity exceeding 10^34 cm-2 s-1, an average of 40 to 50 pp collisions per bunch crossing are expected. Together with the increase of the center-of-mass collision energy from 8 TeV to 13 TeV, this will create a challenging environment for primary vertex pattern recognition. This contribution explains the ATLAS strategy for primary vertex reconstruction in high pile-up conditions.  The new approach is based on vertex seeding with a medical-imaging algorithm, adaptive reconstruction of vertex positions, and iterative recombination of occasional split vertices. The mathematical foundation and software implementation of the method are described in detail. Monte Carlo-based estimates of vertex reconstruction performance for LHC run-II are presented.

  19. Vertex Reconstruction and Performance in ATLAS

    CERN Document Server

    Whitmore, Ben William; The ATLAS collaboration

    2017-01-01

    Efficient and precise reconstruction of the primary vertices in LHC collisions is essential in both the reconstruction of the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of the primary vertices in the busy, high pile up environment of the LHC is a challenging task. The challenges and novel methods developed by the ATLAS experiment to reconstruct vertices in such environments will be presented. The performance of the current vertexing algorithms using Run-2 data will be presented and compared to results from simulation. Additionally, data-driven methods to evaluate vertex resolution, and details of upgrades to the ATLAS inner detector will be presented.

  20. Vertex Reconstruction at STAR: Overview and Performance Evaluation

    Science.gov (United States)

    Smirnov, D.; Lauret, J.; Perevoztchikov, V.; Van Buren, G.; Webb, J.

    2017-10-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) has a rich physics program ranging from studies of the Quark Gluon Plasma to the exploration of the spin structure of the proton. Many measurements carried out by the STAR collaboration rely on the efficient reconstruction and precise knowledge of the position of the primary-interaction vertex. Throughout the years two main vertex finders have been predominantly utilized in event reconstruction by the experiment: MinutVF and PPV with their application domains focusing on heavy ion and proton-proton events respectively. In this work we give a brief overview and discuss recent improvements to the vertex finding algorithms implemented in the STAR software library. In our studies we focus on the finding efficiency and the quality of the reconstructed primary vertex. We examine the effect of an additional constraint, imposed by an independent measurement of the beam line position, when it is applied during the fit. We evaluate the significance of the improved primary vertex resolution on identification of the secondary decay vertices occurring inside the beam pipe. Finally, we present a method and its software implementation developed to measure the performance of the primary vertex reconstruction algorithms.

  1. The LHCb Vertex Locator Upgrade

    Science.gov (United States)

    Szumlak, T.

    2017-12-01

    The Large Hadron Collider beauty LHCb detector is a dedicated flavour physics experiment, designed to efficiently detect decays of b- and c-hadrons to perform precise studies of CP violation and rare decays. At the end of Run 2, many of the LHCb measurements will remain statistically dominated. In order to increase the trigger yield for purely hadronic channels, the hardware trigger will be removed, and the full detector will be read out at 40 MHz. This, in combination with the five-fold increase in luminosity necessitates radical changes to LHCb's electronics with entire subdetector replacements required in some cases. The Vertex Locator (VELO) surrounding the interaction region is used to reconstruct the proton-proton collision points (primary vertices) and decay vertices of long-lived particles (secondary vertices). The upgraded VELO will be equipped with silicon hybrid pixel sensors, each read out by VeloPix ASICs. The highest occupancy ASICs will have pixel hit rates of 900 Mhit/s and produce an output data rate of over 15 Gbit/s, with a total rate of 1.6 Tbit/s anticipated for the whole detector. Selected highlights of this challenging and ambitious project are described in this paper.

  2. Performance of the LHCb Vertex Locator

    CERN Document Server

    INSPIRE-00258707; Affolder, A.; Akiba, K.; Alexander, M.; Ali, S.; Appleby, R.B.; Artuso, M.; Bates, A.; Bay, A.; Behrendt, O.; Benton, J.; van Beuzekom, M.; Bjornstad, P.M.; Bogdanova, G.; Borghi, S.; Borgia, A.; Bowcock, T.J.V.; van den Brand, J.; Brown, H.; Buytaert, J.; Callot, O.; Carroll, J.; Casse, G.; Collins, P.; De Capua, S.; Doets, M.; Donleavy, S.; Dossett, D.; Dumps, R.; Eckstein, D.; Eklund, L.; Farinelli, C.; Farry, S.; Ferro-Luzzi, M.; Frei, R.; Garofoli, J.; Gersabeck, M.; Gershon, T.; Gong, A.; Gong, H.; Gordon, H.; Haefeli, G.; Harrison, J.; Heijne, V.; Hennessy, K.; Hulsbergen, W.; Huse, T.; Hutchcroft, D.; Jaeger, A.; Jalocha, P.; Jans, E.; John, M.; Keaveney, J.; Ketel, T.; Korolev, M.; Kraan, M.; Lastovicka, T.; Lafferty, G.; Latham, T.; Lefeuvre, G.; Leflat, A.; Liles, M.; van Lysebetten, A.; MacGregor, G.; Marinho, F.; McNulty, R.; Merkin, M.; Moran, D.; Mountain, R.; Mous, I.; Mylroie-Smith, J.; Needham, M.; Nikitin, N.; Noor, A.; Oblakowska-Mucha, A.; Papadelis, A.; Pappagallo, M.; Parkes, C.; Patel, G.D.; Rakotomiaramanana, B.; Redford, S.; Reid, M.; Rinnert, K.; Rodrigues, E.; Saavedra, A.F.; Schiller, M.; Schneider, O.; Shears, T.; Silva Coutinho, R.; Smith, N.A.; Szumlak, T.; Thomas, C.; van Tilburg, J.; Tobin, M.; Velthuis, J.; Verlaat, B.; Viret, S.; Volkov, V.; Wallace, C.; Wang, J.; Webber, A.; Whitehead, M.; Zverev, E.

    2014-01-01

    The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in the LHCb experiment. The performance of the detector during the first years of its physics operation is reviewed. The system is operated in vacuum, uses a bi-phase CO2 cooling system, and the sensors are moved to 7 mm from the LHC beam for physics data taking. The performance and stability of these characteristic features of the detector are described, and details of the material budget are given. The calibration of the timing and the data processing algorithms that are implemented in FPGAs are described. The system performance is fully characterised. The sensors have a signal to noise ratio of approximately 20 and a best hit resolution of 4 microns is achieved at the optimal track angle. The typical detector occupancy for minimum bias events in standard operating conditions in 2011 is around 0.5%, and the detector has less than 1% of faulty strips. The proximity of the detector to the beam means ...

  3. Prototyping the CBM Micro Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Koziel, Michal [University of Frankfurt, Frankfurt am Main (Germany); Collaboration: CBM-MVD-Collaboration

    2013-07-01

    For the reconstruction of Open Charm Hadrons with the CBM experiment a Micro Vertex Detector (MVD) with an excellent resolution of the secondary decay vertex (< 70 μm along the beam axis) is required. To achieve this vertex resolution a material budget of a few 0.1% X0 is mandatory for the individual detector stations positioned downstream in close vicinity to the target. To further reduce the multiple scattering the MVD operates in vacuum. The need of prototyping and characterizing the CBM-MVD motivated the construction of an advanced device - a beam telescope - giving the opportunity to exercise the following aspects: handling and integration of ultra-thin CMOS sensors on advanced materials like CVD diamond, double sided sensor assembly for ultra-precise tracking, cooling, scalable readout and slow control, development of data analysis framework and first steps towards implementation of tracking algorithms into a FPGA-based hardware. This group report aims to summarize the activity towards fabrication of the CBM-MVD prototype.

  4. Silicon technologies for the CLIC vertex detector

    Science.gov (United States)

    Spannagel, S.

    2017-06-01

    CLIC is a proposed linear e+e- collider designed to provide particle collisions at center-of-mass energies of up to 3 TeV. Precise measurements of the properties of the top quark and the Higgs boson, as well as searches for Beyond the Standard Model physics require a highly performant CLIC detector. In particular the vertex detector must provide a single point resolution of only a few micrometers while not exceeding the envisaged material budget of around 0.2% X0 per layer. Beam-beam interactions and beamstrahlung processes impose an additional requirement on the timestamping capabilities of the vertex detector of about 10 ns. These goals can only be met by using novel techniques in the sensor and ASIC design as well as in the detector construction. The R&D program for the CLIC vertex detector explores various technologies in order to meet these demands. The feasibility of planar sensors with a thickness of 50-150 μm, including different active edge designs, are evaluated using Timepix3 ASICs. First prototypes of the CLICpix readout ASIC, implemented in 65 nm CMOS technology and with a pixel size of 25×25μm 2, have been produced and tested in particle beams. An updated version of the ASIC with a larger pixel matrix and improved precision of the time-over-threshold and time-of-arrival measurements has been submitted. Different hybridization concepts have been developed for the interconnection between the sensor and readout ASIC, ranging from small-pitch bump bonding of planar sensors to capacitive coupling of active HV-CMOS sensors. Detector simulations based on Geant 4 and TCAD are compared with experimental results to assess and optimize the performance of the various designs. This contribution gives an overview of the R&D program undertaken for the CLIC vertex detector and presents performance measurements of the prototype detectors currently under investigation.

  5. Spin wave Feynman diagram vertex computation package

    Science.gov (United States)

    Price, Alexander; Javernick, Philip; Datta, Trinanjan

    Spin wave theory is a well-established theoretical technique that can correctly predict the physical behavior of ordered magnetic states. However, computing the effects of an interacting spin wave theory incorporating magnons involve a laborious by hand derivation of Feynman diagram vertices. The process is tedious and time consuming. Hence, to improve productivity and have another means to check the analytical calculations, we have devised a Feynman Diagram Vertex Computation package. In this talk, we will describe our research group's effort to implement a Mathematica based symbolic Feynman diagram vertex computation package that computes spin wave vertices. Utilizing the non-commutative algebra package NCAlgebra as an add-on to Mathematica, symbolic expressions for the Feynman diagram vertices of a Heisenberg quantum antiferromagnet are obtained. Our existing code reproduces the well-known expressions of a nearest neighbor square lattice Heisenberg model. We also discuss the case of a triangular lattice Heisenberg model where non collinear terms contribute to the vertex interactions.

  6. Vertexing for b-Tagging

    CERN Document Server

    The ATLAS Collaboration

    2009-01-01

    Tagging of $b$-quark jets, ``$b$-tagging'', is an important ingredient for Standard Model analyses as well as for searches for new physics. A property of $b$-quark jets exploited by $b$-tagging algorithms is the presence of secondary $b$- and $c$-hadron decay vertices. In this note, methods for the explicit reconstruction of secondary and/or tertiary decay vertices of $b$- and $c$-hadron decays are presented. The performance of the secondary vertex based $b$-tagging algorithms and the dependences on the event topology and jet kinematics are studied. The efficient reconstruction of the primary interaction vertex is also crucial for $b$-tagging, especially in the presence of pile-up interaction vertices at LHC luminosity. The ATLAS primary vertex reconstruction strategies and performances are presented in this note as well.

  7. The personal experience of time

    CERN Document Server

    Wessman, Alden

    1977-01-01

    The fundamental nature of human time experience has concerned artists, poets, philosophers, and scientists throughout the ages. Any consideration of human action requires awareness of its temporal aspects. However, simply to view time in the same units and dimensions as the physicist employs in describing events robs personal time of its "lived" quality. The use of physical time concepts in the description of human events is often artificial and misleading. It fails to account for the facts that human time estimates rarely match clock and calendar time; that societies and individuals demonstrate vast differences in their constructions and uses of time; and that temporal perceptions and attitudes change within an individual both during a single day and throughout his life span. The present volume does not view time as something that is sensed in the same way that one would sense or perceive spatial or sensory stimuli. Rather, it views time as a complex set of personally experienced cognitive constructs used by...

  8. Optimising of design parameters of the TESLA vertex detector and search for events with isolated leptons and large missing transverse momentum with the ZEUS-experiment (HERA II)

    Energy Technology Data Exchange (ETDEWEB)

    Adler, V.

    2006-06-15

    In this thesis, a search for events with isolated leptons and large missing transverse momentum at HERA is presented. Data with an integrated luminosity of 40.76 pb{sup -1} of e{sup +}p-collisions collected with the ZEUS detector at a CMS energy of 318 GeV during the HERA II running period in the years 2003 and 2004 were used. Some extensions of the SM contain FCNC processes at tree level, which could lead to a significantly enhanced rate of singly produced t-quarks at HERA (e{sup {+-}}p {yields} e{sup {+-}}tX). The signature of interest originates from the decay t {yields} bW{sup +} with a subsequent leptonic decay of the W-boson (W{sup +} {yields} e{sup +}{nu}{sub e}, {mu}{sup +}{nu}{sub {mu}}, {tau}{sup +}{nu}{sub {tau}}). After the final selection, one event was found in data in the combined e- and {mu}-channels, where 1.27{+-}0.15 were expected from SM predictions. The selection efficiency in these channels was 13.4{sup +1.8}{sub -0.8}% for a t-quark mass of 175 GeV. In combination with independent searches in HERA I data in both, the leptonic and hadronic channel, limits on the FCNC couplings through photon and Z-boson exchange were derived. The NLO limit {kappa}{sub tu{gamma}}<0.160{sup +0.014}{sub -0.012} at 95% CL for a t-quark mass of 175 GeV is the most stringent so far. Together with the most stingent limit on v{sub tuz} of 0.37, an upper cross section limit of {sigma}{sub single} {sub t}<0.186{sup +0.029}{sub -0.012} pb was obtained.Also a limit on the cross section of single W-boson production of {sigma}{sub single} {sub W}<1.54{sup +0.67}{sub -0.41} pb was obtained at 95% CL. In this thesis, also a simulation study to optimise design parameters of a MAPS based vertex detector for a future ILC is presented. The study was based on the TESLA TDR. In order to evaluate the effect of different design options for the vertex detector on the physics performance of the whole detector, the reconstruction of the t-quark mass from the signal process e{sup +}e

  9. Connections for small vertex models

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 110; Issue 1. Connections for Small Vertex Models. R Srinivasan. Volume 110 Issue 1 February 2000 pp 35-53 ... Author Affiliations. R Srinivasan1. Mehta Research Institute of Mathematics and Mathematical Physics, Allahabad 211 019, India ...

  10. LHCb vertex locator, overview and recent progress

    CERN Document Server

    Eklund, Lars

    2005-01-01

    The LHCb experiment is dedicated to the study of b-hadron physics. The vertex locator (VELO) is the sub-detector that reconstructs primary and secondary vertices, which are of importance for the processes under study. The VELO detector is described and results from a beam test with close to final components are presented. The paper also reports on the reconstruction of interaction vertices in the silicon detectors and a method to correct for cross talk in the serial analogue link is described.

  11. Core Stability of Vertex Cover Games

    OpenAIRE

    Fang, Qizhi; Kong, Liang; Zhao, Jia

    2008-01-01

    In this paper, we focus on the core stability of vertex cover games, which arise from vertex cover problems on graphs. Based on duality theory of linear programming, we prove that a balanced vertex cover game has a stable core if and only if every edge belongs to a maximum matching in the underlying graph. We also prove that for a totally balanced vertex cover game, the core largeness, extendability, and exactness are all equivalent, which implies core stability. Furtherm...

  12. Cancer survivors' experience of time

    DEFF Research Database (Denmark)

    Rasmussen, Dorte M.; Elverdam, Beth

    2007-01-01

    survivors over time to explore how perceptions and experiences change. METHODS: An exploratory study was carried out in 2002-2004 with a purposive sample of adults who had experienced various forms of cancer. Data collection included 9 weeks of participant observation at a Cancer Rehabilitation Centre...... and ethnographic interviews with 23 informants. Ten men and 13 women were interviewed twice: 2 weeks after their stay and 18 months later. FINDINGS: Data were analysed from a culture-analytical perspective. Three main themes regarding the survivors' handling and perception of time were found: (1) cancer disrupts......AIM: This paper reports a study to explore how cancer survivors talk about, experience and manage time in everyday life. BACKGROUND: There is an increasing interest in specific physical and psychosocial aspects of life after cancer diagnosis and treatment, but hardly any research follows cancer...

  13. A Novel Vertex Affinity for Community Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    We propose a novel vertex affinity measure in this paper. The new vertex affinity quantifies the proximity between two vertices in terms of their clustering strength and is ideal for such graph analytics applications as community detection. We also developed a framework that combines simple graph searches and resistance circuit formulas to compute the vertex affinity efficiently. We study the properties of the new affinity measure empirically in comparison to those of other popular vertex proximity metrics. Our results show that the existing metrics are ill-suited for community detection due to their lack of fundamental properties that are essential for correctly capturing inter- and intra-cluster vertex proximity.

  14. Identifying vertex covers in graphs

    DEFF Research Database (Denmark)

    Henning, Michael A.; Yeo, Anders

    2012-01-01

    An identifying vertex cover in a graph G is a subset T of vertices in G that has a nonempty intersection with every edge of G such that T distinguishes the edges, that is, e∩T ≠ 0 for every edge e in G and e∩T ≠ f∩T for every two distinct edges e and f in G. The identifying vertex cover number TD......(G) of G is the minimum size of an identifying vertex cover in G. We observe that TD(G)+ρ(G) = |V (G)|, where ρ(G) denotes the packing number of G. We conjecture that if G is a graph of order n and size m with maximum degree Δ, then TD(G) ≤(Δ(Δ-1)/ Δ2+1)n + (2/Δ2+1) m. If the conjecture is true......, then the bound is best possible for all Δ ≥ 1. We prove this conjecture when Δ ≥ 1 and G is a Δ-regular graph. The three known Moore graphs of diameter 2, namely the 5-cycle, the Petersen graph and the Hoffman-Singleton graph, are examples of regular graphs that achieves equality in the upper bound. We also...

  15. Lectures on the Topological Vertex

    CERN Document Server

    Mariño, M

    2008-01-01

    In this lectures, I will summarize the approach to Gromov–Witten invariants on toric Calabi–Yau threefolds based on large N dualities. Since the large N duality/topological vertex approach computes Gromov–Witten invariants in terms of Chern–Simons knot and link invariants, Sect. 2 is devoted to a review of these. Section 3 reviews topological strings and Gromov–Witten invariants, and gives some information about the open string case. Section 4 introduces the class of geometries we will deal with, namely toric (noncompact) Calabi–Yau manifolds, and we present a useful graphical way to represent these manifolds which constitutes the geometric core of the theory of the topological vertex. Finally, in Sect. 5, we define the vertex and present some explicit formulae for it and some simple applications. A brief Appendix contains useful information about symmetric polynomials. It has not been possible to present all the relevant background and physical derivations in this set of lectures. However, these...

  16. Simulations with the PANDA micro-vertex-detector

    Energy Technology Data Exchange (ETDEWEB)

    Kliemt, Ralf

    2013-07-17

    The PANDA experiment will be built at the upcoming FAIR facility at GSI in Darmstadt, featuring antiproton-proton reactions hadron physics in a medium energy range. Charm physics will play an important role and therefore secondary decays relatively close to the interaction zone as well. The MVD will be the detector closest to these and will provide high-quality vertex position measurements. Alongside the detector layout and hardware development a detailed detector simulation and reconstruction software is required. This work contains the detailed description and the performance studies of the software developed for the MVD. Furthermore, vertexing tools are introduced and their performance is studied for the MVD.

  17. First Results from the LHCb Vertex Locator

    CERN Multimedia

    Borghi, S

    2010-01-01

    LHCb is a dedicated experiment to study new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO), and hence the detector is critical for both the trigger and offline physics analyses. The VELO is the silicon detector surrounding the interaction point, and is the closest LHC vertex detector to the interaction point, located only 7 mm from the LHC beam during normal operation. The detector will operate in an extreme and highly non-uniform radiation environment. The VELO consists of two retractable detector halves with 21 silicon micro-strip tracking modules each. A module is composed of two n+-on-n 300 micron thick half disc sensors with R-measuring and Phi-measuring micro-strip geometry, mounted on a carbon fibre support paddle. The minimum pitch is approximately 40 $\\mu$m. The detector is also equipped with one n-on-p module. The detectors are operated in vacuum and a...

  18. Managing Bias Leakage Currents and High Data Rates in the BABAR Silicon Vertex Tracker

    CERN Document Server

    Garra-Tico, J; Bondioli, M; Bruinsma, M; Curry, S; Kirkby, D; Burke, S; Callahan, D; Campagnari, C; Cunha, A; Hale, D; Kyre, S; Richman, J; Beck, T; Eisner, A M; Kroseberg, J; Lockman, W S; Nesom, G; Seiden, A; Spradlin, P; Winstrom, L; Brown, D; Dardin, S; Goozen, F; Kerth, L T; Lynch, G; Roe, N A; Anderson, J; Chen, C; Lae, C K; Roberts, D; Simi, G; Tuggle, J; Lazzaro, A; Lombardo, V; Palombo, F; Ratti, L; Angelini, C; Batignani, G; Bettarini, S; Bosi, F; Bucci, F; Calderini, G; Carpinelli, M; Ceccanti, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Mammini, P; Manfredi, P F; Marchiori, G; Mazur, M; Morganti, M; Morsani, F; Neri, N; Paoloni, E; Profeti, A; Rama, M; Rizzo, G; Walsh, J; Elmer, P; Long, O; Charles, E; Perazzo, A; Burchat, P; Edwards, A J; Miyashita, T S; Majewski, S; Petersen, B A; Bona, M; Bianchi, F; Gamba, D; Trapani, P; Bomben, M; Bosisio, L; Cartaro, C; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Gao, Y Y; Gritsan, A V; Guo, Z J

    2008-01-01

    The silicon vertex tracker at the BABAR experiment is the primary device used in measuring the distance between B0 and meson decay vertices for the extraction of CP asymmetries. It consists of five layers of double-sided, AC-coupled silicon modules, read out by custom integrated circuits. It has run well consistently for eight years. I report on three years of experience in managing problematic bias leakage currents in the fourth layer. In addition, I report on recent success in decreasing the data acquisition time by reducing the readout window.

  19. W. K. H. Panofsky Prize Talk: The Silicon Vertex Trigger

    Science.gov (United States)

    Ristori, Luciano

    2009-05-01

    I will discuss the importance of real-time selection of events at a hadron collider, the ideas that led to the conception of the Silicon Vertex Trigger (SVT) and some historical notes on its construction and commissioning. I will also highlight some remarkable results obtained by CDF with the data selected by the SVT.

  20. Primary Vertex Reconstruction for Upgrade at LHCb

    CERN Document Server

    Wanczyk, Joanna

    2016-01-01

    The aim of the LHCb experiment is the study of beauty and charm hadron decays with the main focus on CP violating phenomena and searches for physics beyond the Standard Model through rare decays. At the present, the second data taking period is ongoing, which is called Run II. After 2018 during the long shutdown, the replacement of signicant parts of the LHCb detector is planned. One of main changes is upgrade of the present software and hardware trigger to a more rapid full software trigger. Primary Vertex (PV) is a basis for the further tracking and it is sensitive to the LHC running conditions, which are going to change for the Upgrade. In particular, the center-of-mass collision energy should reach the maximum value of 14 TeV. As a result the quality of the reconstruction has to be studied and the reconstruction algorithms have to be optimized.

  1. The upgrade of the LHCb Vertex Locator

    CERN Document Server

    INSPIRE-00344700

    2014-01-01

    The LHCb experiment is set for a significant upgrade, which will be ready for Run~3 of the LHC in 2020. This upgrade will allow LHCb to run at a significantly higher instantaneous luminosity and collect an integrated luminosity of $50\\,\\text{fb}^{-1}$ by the end of Run~4. In this process the Vertex locator (VELO) detector will be upgraded to a pixel-based silicon detector. The upgraded VELO will improve upon the current detector by being closer to the beam and having lower material modules with microchannel cooling and a thinner RF-foil. Simulations have shown that it will maintain its excellent performance, even after the radiation damage caused by collecting an integrated luminosity of $50\\,\\text{fb}^{-1}$.

  2. Vertex Reconstruction in ATLAS Run II

    CERN Document Server

    Zhang, Matt; The ATLAS collaboration

    2016-01-01

    Vertex reconstruction is the process of taking reconstructed tracks and using them to determine the locations of proton collisions. In this poster we present the performance of our current vertex reconstruction algorithm, and look at investigations into potential improvements from a new seed finding method.

  3. Vertex Tracking at a Future Linear Collider

    CERN Document Server

    Battaglia, Marco

    2011-01-01

    The anticipated physics program at an high energy e+e- linear collider places special emphasis on the accuracy in extrapolating charged particle tracks to their production vertex to tag heavy quarks and leptons. This paper reviews physics motivations and performance requirements, sensor R&D directions and current results of the studies for a vertex tracker at a future linear collider.

  4. Zoom on the partially constructed VELO (VErtex LOcator) of the LHCb experiment, before transport to the H8 testbeam in November 2006

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The picture shows 10 double sided modules mounted on the detector base. In the final experiment there will be two bases, each containing 21 modules. Each module contains two silicon sensors, which look like split compact discs, one measuring radial coordinate and one phi coordinate. Each sensor has 2048 strips, which approach to within 40 micrometers of each other at the closest point. The support frame will be removed before installation in the LHCb experiment and a very thin foil inserted between the sensors and the LHC beams, only 5 mm away.

  5. Zoom on the partially constructed VELO (VErtex LOcator) of the LHCb experiment, before transport to the H8 testbeam in November 2006.

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The picture shows 10 double sided modules mounted on the detector base. In the final experiment there will be two bases, each containing 21 modules. Each module contains two silicon sensors, which look like split compact discs, one measuring radial coordinate and one phi coordinate. Each sensor has 2048 strips, which approach to within 40 micrometers of each other at the closest point. The support frame will be removed before installation in the LHCb experiment and a very thin foil inserted between the sensors and the LHC beams, only 5 mm away.

  6. Characterization of Si detectors, search for vertex and potentiality of detecting a light charged Higgs boson in the CMS experiment; Caracterisation des detecteurs silicium, recherche de Vertex et etude du potentiel de decouverte d'un boson de Higgs charge leger dans l'experience CMS

    Energy Technology Data Exchange (ETDEWEB)

    Estre, N

    2004-07-01

    The CMS (compact muon solenoid) detector that will be set on the future LHC (large hadron collider) accelerator will enable us to continue our search for the Higgs boson as well as to look for any hint for a new physics beyond the standard model. CMS is composed of an efficient muon detector, an electromagnetic calorimeter and of a tracker with high spatial resolution, this tracker is the topic of this thesis. The tracker will allow an accurate reconstruction of charged-particles trajectories and the reconstruction of the primary interaction vertex. The tracker's technology is based on micro-strip Si detectors, tests performed with the SPS particle beam show that these detectors have an impact reconstruction efficiency greater than 98% and a piling-up rate limited to 6%. The spatial resolution concerning particle trajectories is about 45 {mu}m for an interval of 183 {mu}m between 2 strips. The simulation for the search for a light charged Higgs boson show that an excess of {tau}{nu}{sub {tau}} + bb-bar + qq-bar' events is possible to be observed for any value of tan({beta}) up to M{sub A} = 122 GeV/c{sup 2} during the first year of operation and up to 136 GeV/c{sup 2} afterwards. With the assumption that this event excess is due to the decay of charged Higgs bosons we can state that the assessment of its mass will be possible till m{sub H} = 150 GeV/c{sup 2} with an accuracy of 15 GeV/c{sup 2}. (A.C.)

  7. Minimal vertex covers of random trees

    OpenAIRE

    Coulomb, Stephane

    2004-01-01

    We study minimal vertex covers of trees. Contrarily to the number $N_{vc}(A)$ of minimal vertex covers of the tree $A$, $\\log N_{vc}(A)$ is a self-averaging quantity. We show that, for large sizes $n$, $\\lim_{n\\to +\\infty} _n/n= 0.1033252\\pm 10^{-7}$. The basic idea is, given a tree, to concentrate on its degenerate vertices, that is those vertices which belong to some minimal vertex cover but not to all of them. Deletion of the other vertices induces a forest of totally degenerate trees. We ...

  8. Technical Design Report for the: PANDA Micro Vertex Detector

    CERN Document Server

    Erni, W; Krusche, B; Steinacher, M; Heng, Y; Liu, Z; Liu, H; Shen, X; Wang, Q; Xu, H; Albrecht, M; Becker, J; Eickel, K; Feldbauer, F; Fink, M; Friedel, P; Heinsius, F H; Held, T; Koch, H; Kopf, B; Leyhe, M; Motzko, C; Pelizäus, M; Pychy, J; Roth, B; Schröder, T; Schulze, J; Steinke, M; Trifterer, T; Wiedner, U; Zhong, J; Beck, R; Becker, M; Bianco, S; Brinkmann, K -Th; Hammann, C; Hinterberger, F; Jäkel, R; Kaiser, D; Kliemt, R; Koop, K; Schmidt, C; Schnell, R; Thoma, U; Vlasov, P; Wendel, C; Winnebeck, A; Würschig, Th; Zaunick, H -G; Bianconi, A; Bragadireanu, M; Caprini, M; Ciubancan, M; Pantea, D; Tarta, P -D; De Napoli, M; Giacoppo, F; Rapisarda, E; Sfienti, C; Fiutowski, T; Idzik, N; Mindur, B; Przyborowski, D; Swientek, K; Bialkowski, E; Budzanowski, A; Czech, B; Kliczewski, S; Kozela, A; Kulessa, P; Lebiedowicz, P; Malgorzata, K; Pysz, K; Schäfer, W; Siudak, R; Szczurek, A; Brandys, P; Czyzewski, T; Czyzycki, W; Domagala, M; Hawryluk, M; Filo, G; Kwiatkowski, D; Lisowski, E; Lisowski, F; Bardan, W; Gil, D; Kamys, B; Kistryn, St; Korcyl, K; Krzemieñ, W; Magiera, A; Moskal, P; Rudy, Z; Salabura, P; Smyrski, J; Wroñska, A; Al-Turany, M; Arora, R; Augustin, I; Deppe, H; Dutta, D; Flemming, H; Götzen, K; Hohler, G; Karabowicz, R; Lehmann, D; Lewandowski, B; Lühning, J; Maas, F; Orth, H; Peters, K; Saito, T; Schepers, G; Schmidt, C J; Schmitt, L; Schwarz, C; Schwiening, J; Voss, B; Wieczorek, P; Wilms, A; Abazov, V M; Alexeev, G D; Arefiev, V A; Astakhov, V I; Barabanov, M Yu; Batyunya, B V; Davydov, Yu I; Dodokhov, V Kh; Efremov, A A; Fedunov, A G; Feshchenko, A A; Galoyan, A S; Grigoryan, S; Karmokov, A; Koshurnikov, E K; Lobanov, V I; Lobanov, Yu Yu; Makarov, A F; Malinina, L V; Malyshev, V L; Mustafaev, G A; Olshevski, A G; Pasyuk, M A; Perevalova, E A; Piskun, A A; Pocheptsov, T A; Pontecorvo, G; Rodionov, V K; Rogov, Yu N; Salmin, R A; Samartsev, A G; Sapozhnikov, M G; Shabratova, G S; Skachkova, A N; Skachkov, N B; Strokovsky, E A; Suleimanov, M K; Teshev, R Sh; Tokmenin, V V; Uzhinsky, V V; Vodopyanov, A S; Zaporozhets, S A; Zhuravlev, N I; Zorin, A G; Branford, D; Glazier, D; Watts, D; Woods, P; Britting, A; Eyrich, W; Lehmann, A; Uhlig, F; Dobbs, S; Metreveli, Z; Seth, K; Tann, B; Tomaradze, A; Bettoni, D; Carassiti, V; Dalpiaz, P; Drago, A; Fioravanti, E; Garzia, I; Negrini, M; Savriè, M; Stancari, G; Dulach, B; Gianotti, P; Guaraldo, C; Lucherini, V; Pace, E; Bersani, A; Macri, M; Marinelli, M; Parodi, R F; Dormenev, V; Drexler, P; Düren, M; Eisner, T; Foehl, K; Hayrapetyan, A; Koch, P; Krïoch, B; Kühn, W; Lange, S; Liang, Y; Liu, M; Merle, O; Metag, V; Moritz, M; Nanova, M; Novotny, R; Spruck, B; Stenzel, H; Strackbein, C; Thiel, M; Wang, Q; Clarkson, T; Euan, C; Hill, G; Hoek, M; Ireland, D; Kaiser, R; Keri, T; Lehmann, I; Livingston, K; Lumsden, P; MacGregor, D; McKinnon, B; Montgomery, R; Murray, M; Protopopescu, D; Rosner, G; Seitz, B; Yang, G; Babai, M; Biegun, A K; Glazenborg-Kluttig, A; Guliyev, E; Jothi, V S; Kavatsyuk, M; Lemmens, P; Löhner, H; Messchendorp, J; Poelman, T; Smit, H; van der Weele, J C; Sohlbach, H; Büscher, M; Dosdall, R; Dzhygadlo, R; Esch, S; Gillitzer, A; Goldenbaum, F; Grunwald, D; Jha, V; Kemmerling, G; Kleines, H; Lehrach, A; Maier, R; Mertens, M; Ohm, H; Pohl, D L; Prasuhn, D; Randriamalala, T; Ritman, J; Roeder, M; Sterzenbach, G; Stockmanns, T; Wintz, P; Wüstner, P; Xu, H; Kisiel, J; Li, S; Li, Z; Sun, Z; Xu, H; Fissum, K; Hansen, K; Isaksson, L; Lundin, M; Schröder, B; Achenbach, P; Denig, A; Distler, M; Fritsch, M; Kangh, D; Karavdina, A; Lauth, W; Michel, M; Espi, M C Mora; Pochodzalla, J; Sanchez, S; Sanchez-Lorente, A; Sfienti, C; Weber, T; Dormenev, V I; Fedorov, A A; Korzhik, M V; Missevitch, O V; Boukharov, A; Malyshev, O; Marishev, I; Semenov, A; Varma, R; Höppner, C; Ketzer, B; Konorov, I; Mann, A; Neubert, S; Paul, S; Vandenbroucke, M; Zhang, Q; Khoukaz, A; Rausmann, T; Täschner, A; Wessels, J; Baldin, E; Kotov, K; Peleganchuk, S; Tikhonov, Yu; Hennino, T; Imre, M; Kunne, R; Galliard, C Le; Normand, J P Le; Marchand, D; Maroni, A; Ong, S; Pouthas, J; Ramstein, B; Rosier, P; Sudol, M; Theneau, C; Tomasi-Gustafsson, E; Van de Wiele, J; Zerguerras, T; Boca, G; Braghieri, A; Costanza, S; Fontana, A; Genova, P; Lavezzi, L; Montagna, P; Rotondi, A; Buda, V; Abramov, V V; Davidenko, A M; Derevschikov, A A; Goncharenko, Y M; Grishin, V N; Kachanov, V A; Konstantinov, D A; Kormilitsin, V A; Matulenko, Y A; Melnik, Y M; Meschanin, A P; Minaev, N G; Mochalov, V V; Morozov, D A; Nogach, L V; Nurushev, S B; Ryazantsev, A V; Semenov, P A; Soloviev, L F; Uzunian, A V; Vasiliev, A N; Yakutin, A E; Belostotski, S; Gavrilov, G; Itzotov, A; Kisselev, A; Kravchenko, P; Manaenkov, S; Miklukho, O; Naryshkin, Y; Veretennikov, D; Vikhrov, V; Zhadanov, A; Bäck, T; Cederwall, B; Bargholtz, C; Gerén, L; Tegnér, P E; Thørngren, P; von Würtemberg, K M; Fava, L; Alberto, D; Amoroso, A; Bussa, M P; Busso, L; De Mori, F; Destefanis, M; Ferrero, L; Greco, M; Kugathasan, T; Maggiora, M; Marcello, S; Sosio, S; Spataro, S; Calvo, D; Coli, S; De Remigis, P; Filippi, A; Giraudo, G; Lusso, S; Mazza, G; Mignone, M; Rivetti, A; Wheadon, R; Zotti, L; Morra, O; Iazzi, F; Lavagno, A; Quarati, P; Szymanska, K; Birsa, R; Bradamante, F; Bressan, A; Martin, A; Clement, H; Galnander, B; Calén, H; Fransson, K; Johansson, T; Kupsc, A; Marciniewski, P; Thomé, E; Wolke, M; Zlomanczuk, J; Díaz, J; Ortiz, A; Buda, P; Dmowski, K; Korzeniewski, R; Przemyslaw, D; Slowinski, B; Borsuk, S; Chlopik, A; Guzik, Z; Kopec, J; Kozlowski, T; Melnychuk, D; Plominski, M; Szewinski, J; Traczyk, K; Zwieglinski, B; Bühler, P; Gruber, A; Kienle, P; Marton, J; Widmann, E; Zmeskal, J

    2012-01-01

    This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is outlined.

  9. VERTEX ANTIMAGIC TOTAL LABELING PADA GRAPHMULTICYCLE

    Directory of Open Access Journals (Sweden)

    Dominikus Arif Budi Prasetyo pythagors

    2015-01-01

    Full Text Available Pelabelan graf merupakan bagian dari graf yang berkembang saat ini. Jenis pelabelan pada graf bergantungpada domainnya, yakni pelabelan sisi ajaib, pelabelan titik ajaib, dan pelabelan total ajaib. Pelabelan totalajaib pada graf dibedakan lagi berdasarkan komponen graf yang dievaluasi, yakni pelabelan total sisi ajaibdan pelabelan total titik ajaib. Pada pelabelan ajaib, bobot dari komponen graf yang dievaluasi adalah sama,jika bobotnya tidak sama maka dinamakan pelabelan tak-ajaib (antimagic. Misalkan G adalah graf denganbanyak titik p dan sisi q. Suatu pemetaan bijektif dari komponen-komponen graf ke bilangan bulat positif {1,2, …, (p+q} disebut called (a, d vertex antimagic total labelling (pelabelan total titik ajaib dari graf G jikabobot setiap titik (vertex merupakan barisan aritmetika naik. Pada artikel ini membahas bahwa grafmulticycle mCp memenuhi (a, d vertex antimagic total labelling dan beberapa bentuk pelabelannya.Kata kunci : graph multicycle, vertex antimagic total labeling

  10. Vertex occlusal radiography in localizing unerupted mesiodentes

    Directory of Open Access Journals (Sweden)

    P Chalakkal

    2011-01-01

    Full Text Available The aim was to compare the vertex occlusal projection with the anterior maxillary occlusal projection in localizing the position of mesiodentes. Mesiodentes were observed in an 8-year-old boy with an anterior maxillary occlusal radiograph. A vertex occlusal radiograph was taken to compare it with the former in terms of mesiodentes localization with respect to the maxillary central incisors. The vertex occlusal radiograph provided greater details of the position and proximity of mesiodentes with respect to the long axis of maxillary central incisors in comparison to the anterior maxillary occlusal radiograph. Vertex occlusal radiography is an important diagnostic tool in diagnosing the presence, position, and proximity of mesiodentes with respect to the long axis of normally aligned maxillary central incisors. However, it is not recommended for routine use in a patient as its radiation dose is higher than conventional intraoral radiographic methods.

  11. Defective Vertex Configurations in Quasicrystalline Structures

    Science.gov (United States)

    Ben-Abraham, S. I.

    Defective vertex configurations are important for the whole range of models for quasicrystalline structures from quasiperiodic tilings through random tilings to polyhedral glasses. The combinatorially possible vertex configurations are enumerated for the 1D Fibonacci chain, for the 2D Penrose pattern with its generalizations, as well as for the Beenker pattern and the triangle pattern, and for the 3D simple icosahedral tiling. The methods for quantifying the deviation of vertex configurations from perfection are reviewed. The simple method of partial dual overlap provides a means to estimate the abundancy of vertex configurations within random tilings. More sophisticated is the method of the defectivity functional; it is particularly suitable to deal with nearly perfect tilings. Local configurations are formally classified by characteristic integers: degree, rank and order. Some possible applications are hinted at.

  12. Spinfoam cosmology with the proper vertex amplitude

    Science.gov (United States)

    Vilensky, Ilya

    2017-11-01

    The proper vertex amplitude is derived from the Engle-Pereira-Rovelli-Livine vertex by restricting to a single gravitational sector in order to achieve the correct semi-classical behaviour. We apply the proper vertex to calculate a cosmological transition amplitude that can be viewed as the Hartle-Hawking wavefunction. To perform this calculation we deduce the integral form of the proper vertex and use extended stationary phase methods to estimate the large-volume limit. We show that the resulting amplitude satisfies an operator constraint whose classical analogue is the Hamiltonian constraint of the Friedmann-Robertson-Walker cosmology. We find that the constraint dynamically selects the relevant family of coherent states and demonstrate a similar dynamic selection in standard quantum mechanics. We investigate the effects of dynamical selection on long-range correlations.

  13. Editorial -Time for an experiment

    Directory of Open Access Journals (Sweden)

    Gráinne Conole

    2001-12-01

    Full Text Available This issue of the journal contains six very different papers exploring the issues around the use of learning technologies, which reflect the growing diversity of research interests and activities in this area. Oliver, Bradley and Boyle describe a project that is concerned with the development of online courses as part of a pan-European virtual university. The issues raised by the paper are timely given the current national initiative to develop a UK euniversity. McSporran and Young consider the impact of gender issues on online learning and contend that there is evidence to suggest that women achieve better results than men and that it is the loner male that is disadvantaged by distance learning. Condron reports on a TLTP (Teaching and Learning Technology Programme 3 project and in particular on the use of electronic resources to support dialogue in small-group teaching. Campbell, Littlejohn and Duncan also look at resources but from the perspective of encouraging the reuse of academic resources as part of an initiative to develop a Scottish electronic staff development library. Shaikh and Macaulay report on a study of the use of groupware to support collaborative learning. Finally, Davies and Denning identify six conceptual areas which they suggest are of relevance and significance for online behaviour.

  14. The silicon vertex locator for the LHCb upgrade

    CERN Document Server

    Head, Tim

    2014-01-01

    The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a triggerless system being read out at 40 MHz. The upgraded silicon vertex detector (VELO) must be light weight, radiation hard, and compatible with LHC vacuum requirements. It must be capable of fast pattern recognition, fast track reconstruction and high precision vertexing. This challenge is being met with a new VELO design based on hybrid pixel detectors positioned to within 5 mm of the LHC colliding beams. The detector will be shielded from the beam by a View the MathML source~300μm thick aluminium foil. Evaporative CO2 coolant circulating in micro-channels embedded in a thin silicon substrate will be used for cooling.

  15. The silicon vertex locator for the LHCb upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Head, Tim, E-mail: thead@cern.ch

    2014-11-21

    The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a triggerless system being read out at 40 MHz. The upgraded silicon vertex detector (VELO) must be light weight, radiation hard, and compatible with LHC vacuum requirements. It must be capable of fast pattern recognition, fast track reconstruction and high precision vertexing. This challenge is being met with a new VELO design based on hybrid pixel detectors positioned to within 5 mm of the LHC colliding beams. The detector will be shielded from the beam by a ∼300μm thick aluminium foil. Evaporative CO{sub 2} coolant circulating in micro-channels embedded in a thin silicon substrate will be used for cooling.

  16. OPAL Central Detector (Including vertex, jet and Z chambers)

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the different parts of the tracking system. (This piece includes the vertex, jet and Z chambers) In the picture above, the central detector is the piece being removed to the right.

  17. Radiation damage in the LHCb Vertex Locator

    CERN Document Server

    Affolder, A; Alexander, M; Ali, S; Artuso, M; Benton, J; van Beuzekom, M; Bjørnstad, P M; Bogdanova, G; Borghi, S; Bowcock, T J V; Brown, H; Buytaert, J; Casse, G; Collins, P; De Capua, S; Dossett, D; Eklund, L; Farinelli, C; Garofoli, J; Gersabeck, M; Gershon, T; Gordon, H; Harrison, J; Heijne, V; Hennessy, K; Hutchcroft, D; Jans, E; John, M; Ketel, T; Lafferty, G; Latham, T; Leflat, A; Liles, M; Moran, D; Mous, I; Oblakowska-Mucha, A; Parkes, C; Patel, G D; Redford, S; Reid, M M; Rinnert, K; Rodrigues, E; Schiller, M; Szumlak, T; Thomas, C; Velthuis, J; Volkov, V; Webber, A D; Whitehead, M; Zverev, E

    2013-01-01

    The LHCb Vertex Locator (VELO) is a silicon strip detector designed to reconstruct charged particle trajectories and vertices produced at the LHCb interaction region. During the first two years of data collection, the 84 VELO sensors have been exposed to a range of fluences up to a maximum value of approximately $\\rm{45 \\times 10^{12}\\,1\\,MeV}$ neutron equivalent ($\\rm{1\\,MeV\\,n_{eq}}$). At the operational sensor temperature of approximately $-7\\,^{\\circ}\\rm{C}$, the average rate of sensor current increase is 18$\\mu$ A per $\\rm{fb^{-1}}$, in excellent agreement with predictions. The silicon effective bandgap has been determined using current versus temperature scan data after irradiation, with an average value of $E_{g}=1.16\\pm0.03\\pm0.04\\,\\rm{eV}$ obtained. The first observation of n-on-n sensor type inversion at the LHC has been made, occurring at a fluence of around $15 \\times 10 ^{12}$ of $1\\,\\rm{MeV\\,n_{eq}}$. The only n-on-p sensors in use at the LHC have also been studied. With an initial fluence of ap...

  18. Tracking and Vertexing with the ATLAS Inner Detector in the LHC Run-2

    CERN Document Server

    Choi, Kyungeon; The ATLAS collaboration

    2017-01-01

    Run-2 of the Large Hadron Collider (LHC) has provided new challenges to track and vertex reconstruction with higher centre-of-mass energies and luminosity leading to increasingly high-multiplicity envi- ronments, boosted, and highly-collimated physics objects. We present an overview of the ATLAS Inner Detector tracker in Run-2 including the track reconstruction algorithm, time-dependent alignment, tracking and vertexing performance.

  19. MINOS: A vertex tracker coupled to a thick liquid-hydrogen target for in-beam spectroscopy of exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Obertelli, A.; Delbart, A.; Anvar, S.; Audirac, L.; Authelet, G.; Bruyneel, B.; Calvet, D.; Chateau, F.; Corsi, A.; Gheller, J.M.; Giganon, A.; Lahonde-Hamdoun, C.; Leboeuf, D.; Loiseau, D.; Mohamed, A.; Mols, J.P.; Peron, C.; Peyaud, A.; Pollacco, E.C.; Prono, G.; Rousse, J.Y.; Santamaria, C. [CEA, Centre de Saclay, IRFU, Gif-sur-Yvette (France); Baba, H.; Doornenbal, P.; Otsu, H.; Uesaka, T. [RIKEN Nishina Center, Wako, Saitama (Japan)

    2014-01-15

    MINOS is a new apparatus dedicated to in-beam nuclear structure experiments with low-intensity exotic beams in inverse kinematics at intermediate energies above 150 MeV/nucleon. The device is composed of a thick liquid-hydrogen target coupled to a compact time projection chamber (TPC) serving as a vertex tracker. Either used for in-beam gamma spectroscopy of bound excited states or invariant-mass spectroscopy of unbound states, MINOS aims at improving the luminosity by a very significant factor compared to standard solid-target material experiments while improving experimental resolutions. (orig.)

  20. A Vertex and Tracking Detector System for CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)718101

    2017-01-01

    The physics aims at the proposed future CLIC high-energy linear $e^+e^−$ collider pose challenging demands on the performance of the detector system. In particular the vertex and tracking detectors have to combine precision measurements with robustness against the expected high rates of beam-induced backgrounds. The requirements include ultra-low mass, facilitated by power pulsing and air cooling in the vertex-detector region, small cell sizes and precision hit timing at the few-ns level. A detector concept meeting these requirements has been developed and an integrated R&D program addressing the challenges is progressing in the areas of ultra-thin sensors and readout ASICs, interconnect technology, mechanical integration and cooling.

  1. Limit Shapes in the Six Vertex Model

    Science.gov (United States)

    Sridhar, Ananth

    The purpose of this thesis is to present some new results about the six-vertex model and dimer model, andi in particular some aspects of the limit shapes that form in the thermodynamic limit and the partial differential equations that arise in their study. Chapter 1 provides a detailed introduction to limit shape phenomena and its mathematics. Chapter 2 reviews basic facts about the six-vertex model and dimer model and their properties in the thermodynamic limit. Chapter 3 investigates the role of integrability of the six vertex model in the formation of limit shapes. By integrability we mean, on one hand the discrete integrability of the six-vertex model in the sense of commutative families of transfer matrices, and on the other hand the integrability in the continuum limit in the Liouville sense of Poisson commutative families of functions (integrals of motion) on the phase space. The main result is to show that the partial differential equations describing the limit shape have an infinite number of conserved quantities. Chapter 4 explains the results of the previous chapter in a more general setting. The main result is a straightforward theorem in Hamiltonian mechanics, which gives conditions for the Poisson commutativity of two Hamiltonian functions in terms of their principal action functions. It suggests a generalization of our previous results to other integrable lattice models, for example, the generalizations of the six-vertex model related to other Lie algebras. Chapter 5 studies the six-vertex model for a special class of weights called the stochastic six-vertex model. for which the six vertex model is closely related to interacting particle models. The main result of this chapter is the derivation for the partial differential equations for the height function of the stochastic 6-vertex model on the cylinder. Chapter 6 studies models at the intersection of discrete geometry and statistical mechanics. The main result is the asymptotic expansion of the

  2. Vertex and Tracker Research and Development for CLIC

    CERN Document Server

    Munker, M

    2017-01-01

    Challenging detector requirements are imposed by the physics goals at the future multi-TeV e+e− Compact Linear Collider (CLIC). A single point resolution of 3 μm for the vertex detector and 7 μm for the tracker is required. Moreover, the CLIC vertex detector and tracker need to be extremely light weighted with a material budget of 0.2%X0 per layer in the vertex detector and 1 - 2%X0 in the tracker. A fast time slicing of 10 ns is further required to suppress background from beam-beam interactions. A wide range of sensor and readout ASIC technologies are investigated within the CLIC silicon pixel R&D; effort. Various hybrid planar sensor assemblies with a pixel size of 25 × 25 μm2 and 55 × 55 μm2 have been produced and characterised by laboratory measurements and during test-beam campaigns. Experimental and simulation results for thin (50 μm- 500 μm) slim edge and active-edge planar, and High-Voltage CMOS sensors hybridised to various readout ASICs (Timepix, Timepix3, CLICpix) are presented.

  3. A note on arbitrarily vertex decomposable graphs

    Directory of Open Access Journals (Sweden)

    Antoni Marczyk

    2006-01-01

    Full Text Available A graph \\(G\\ of order \\(n\\ is said to be arbitrarily vertex decomposable if for each sequence \\((n_{1},\\ldots,n_k\\ of positive integers such that \\(n_{1}+\\ldots+n_{k}=n\\ there exists a partition \\((V_{1},\\ldots,V_{k}\\ of the vertex set of \\(G\\ such that for each \\(i \\in \\{1,\\ldots,k\\}\\, \\(V_{i}\\ induces a connected subgraph of \\(G\\ on \\(n_i\\ vertices. In this paper we show that if \\(G\\ is a two-connected graph on \\(n\\ vertices with the independence number at most \\(\\lceil n/2\\rceil\\ and such that the degree sum of any pair of non-adjacent vertices is at least \\(n-3\\, then \\(G\\ is arbitrarily vertex decomposable. We present another result for connected graphs satisfying a similar condition, where the bound \\(n-3\\ is replaced by \\(n-2\\.

  4. Minimal vertex covers of random trees

    Science.gov (United States)

    Coulomb, Stéphane

    2005-06-01

    We study minimal vertex covers of trees. In contrast to the number Nvc(A) of minimal vertex covers of the tree A, logNvc(A) is a self-averaging quantity. We show that, for large sizes n, \\lim_{n\\to+\\infty } \\langle \\log N_{\\mathrm {vc}}(A)\\rangle_n/n= 0.103\\,3252\\pm 10^{-7} . The basic idea is, given a tree, to concentrate on its degenerate vertices, that is those vertices which belong to some minimal vertex cover but not to all of them. Deletion of the other vertices induces a forest of totally degenerate trees. We show that the problem reduces to the computation of the size distribution of this forest, which we perform analytically, and of the average \\langle \\log N_{\\mathrm {vc}}\\rangle over totally degenerate trees of given size, which we perform numerically.

  5. Vertex Detector Performance for CLICdet, FCCee & FCChh.

    CERN Document Server

    Rasmussen, Peter Winkel

    2017-01-01

    The performance of the vertex detectors planned for CLICdet, FCCee & FCChh was tested in this project. This was done my studying the figure of merit for a vertex detector which is the transverse impact parameter resolution $\\sigma(d_0)$. This was carried out by simulating single $\\mu^-$ at different energies, polar angles, $\\theta$ with a uniform distribution in the azimuthal angle $\\phi$. The events were reconstructed and the distribution $\\Delta(d_0) = d_{0,reco}-d_{0,true}$ was fitted with a Gaussian function where the width of the function resulted in $\\sigma(d_0)$. The effect of material budget and fit function on this was also tested.

  6. Vertex Reconstruction for AEGIS’ FACT Detector

    CERN Document Server

    Themistokleous, Neofytos

    2017-01-01

    My project dealt with the development of a vertex reconstruction technique to discriminate antihydrogen from background signals in the AEGIS apparatus. It involved the creation of a Toy Monte-Carlo to simulate particle annihilation events, and a vertex reconstruction utility based on the Bayesian theory of probability. The first results based on 107 generated events with single track in the detector are encouraging. For such events, the algorithm can reconstruct the z-coordinate accurately , while for the r-coordinate the result is less accurate.

  7. Interoceptive focus shapes the experience of time.

    Directory of Open Access Journals (Sweden)

    Olga Pollatos

    Full Text Available The perception of time is a fundamental part of human experience. Recent research suggests that the experience of time emerges from emotional and interoceptive (bodily states as processed in the insular cortex. Whether there is an interaction between the conscious awareness of interoceptive states and time distortions induced by emotions has rarely been investigated so far. We aimed to address this question by the use of a retrospective time estimation task comparing two groups of participants. One group had a focus on interoceptive states and one had a focus on exteroceptive information while watching film clips depicting fear, amusement and neutral content. Main results were that attention to interoceptive processes significantly affected subjective time experience. Fear was accompanied with subjective time dilation that was more pronounced in the group with interoceptive focus, while amusement led to a quicker passage of time which was also increased by interoceptive focus. We conclude that retrospective temporal distortions are directly influenced by attention to bodily responses. These effects might crucially interact with arousal levels. Sympathetic nervous system activation affecting memory build-up might be the decisive factor influencing retrospective time judgments. Our data substantially extend former research findings underscoring the relevance of interoception for the effects of emotional states on subjective time experience.

  8. A vertically integrated pixel readout device for the Vertex Detector at the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Grzegorz; Christian, David; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2008-12-01

    3D-Integrated Circuit technology enables higher densities of electronic circuitry per unit area without the use of nanoscale processes. It is advantageous for mixed mode design with precise analog circuitry because processes with conservative feature sizes typically present lower process dispersions and tolerate higher power supply voltages, resulting in larger separation of a signal from the noise floor. Heterogeneous wafers (different foundries or different process families) may be combined with some 3D integration methods, leading to the optimization of each tier in the 3D stack. Tracking and vertexing in future High-Energy Physics (HEP) experiments involves construction of detectors composed of up to a few billions of channels. Readout electronics must record the position and time of each measurement with the highest achievable precision. This paper reviews a prototype of the first 3D readout chip for HEP, designed for a vertex detector at the International Linear Collider. The prototype features 20 x 20 {micro}m{sup 2} pixels, laid out in an array of 64 x 64 elements and was fabricated in a 3-tier 0.18 {micro}m Fully Depleted SOI CMOS process at MIT-Lincoln Laboratory. The tests showed correct functional operation of the structure. The chip performs a zero-suppressed readout. Successive submissions are planned in a commercial 3D bulk 0.13 {micro}m CMOS process to overcome some of the disadvantages of an FDSOI process.

  9. LHCb Vertex Locator Upgrade Work Report

    CERN Document Server

    Estrada, Michael

    2017-01-01

    As the LHCb prepares for the planned upgrade of its vertex locator, there is a great need for supporting work such as the design and testing of apparatus that will ensure the smooth implementation of new hardware and infrastructure. My work this summer consisted largely of tasks to support this process.

  10. The MCP-based vertex detector

    CERN Document Server

    Gevorkov, L G; CERN. Geneva; Laptev, V D; Patarakin, O O; Valiev, F F

    1992-01-01

    We discuss the possible application of large area microchannel plates (MCPs) as a basic Abstract: element of a vertex detector unit. Two types of basic modules : (MCP + Delay Line) and (MCP + Microstrips) are suggested. The proposal exploits unique MCPàs features i.e. fine granularity, high intrinsic gain, high counting rates, good performance in the presence of a magnetic field.

  11. On Vertex Identifying Codes For Infinite Lattices

    OpenAIRE

    Stanton, Brendon

    2011-01-01

    PhD Thesis--A compilation of the papers: "Lower Bounds for Identifying Codes in Some Infinite Grids", "Improved Bounds for r-identifying Codes of the Hex Grid", and "Vertex Identifying Codes for the n-dimensional Lattics" along with some other results

  12. Silicon vertex detector for superheavy elements identification

    Directory of Open Access Journals (Sweden)

    Bednarek A.

    2012-07-01

    Full Text Available Silicon vertex detector for superheavy elements (SHE identification has been proposed. It will be constructed using very thin silicon detectors about 5 μm thickness. Results of test of 7.3 μm four inch silicon strip detector (SSD with fission fragments and α particles emitted by 252Cf source are presented

  13. Lifetime tests for MAC vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, H.N.

    1986-07-01

    A vertex chamber for MAC was proposed to increase precision in the measurement of the B hadron and tau lepton lifetimes. Thin-walled aluminized mylar drift tubes were used for detector elements. A study of radiation hardness was conducted under the conditions of the proposed design using different gases and different operating conditions. (LEW)

  14. Twisted Frobenius Identities from Vertex Operator Superalgebras

    Directory of Open Access Journals (Sweden)

    Alexander Zuevsky

    2017-01-01

    Full Text Available In consideration of the continuous orbifold partition function and a generating function for all n-point correlation functions for the rank two free fermion vertex operator superalgebra on the self-sewing torus, we introduce the twisted version of Frobenius identity.

  15. CLIC vertex detector R&D

    CERN Document Server

    Redford, S

    2014-01-01

    In order to achieve its primary objectives of heavy-flavour tagging and tau lepton identification, the CLIC vertex detector must precisely reconstruct displaced vertices. This re- quires accurate determination of the impact parameter and charge of tracks originating from the secondary vertex. Excellent spatial resolution must therefore be provided down to low polar angles, whilst maintaining low occupancy, low mass and low power dissipation. These requirements chal- lenge current technological limits, and demand a broad programme of R&D. A detector concept is currently under development, comprising a hybrid pixel detector of small-pitch readout ASICs implemented in 65nm CMOS technology (CLICpix) combined with ultra-thin sensors. The read- out chips are low-power, and power-pulsing is used to reduce further their power dissipation. This enables a forced gas cooling system in the vertex detector region. In this paper, the CLIC vertex detector requirements are reviewed and the current status of R&D on se...

  16. Ionization potentials of solids: the importance of vertex corrections.

    Science.gov (United States)

    Grüneis, Andreas; Kresse, Georg; Hinuma, Yoyo; Oba, Fumiyasu

    2014-03-07

    The ionization potential is a fundamental key quantity with great relevance to diverse material properties. We find that state of the art methods based on density functional theory and simple diagrammatic approaches as commonly taken in the GW approximation predict the ionization potentials of semiconductors and insulators unsatisfactorily. Good agreement between theory and experiment is obtained only when diagrams resulting from the antisymmetry of the many-electron wave function are taken into account via vertex corrections in the self-energy. The present approach describes both localized and delocalized states accurately, making it ideally suited for a wide class of materials and processes.

  17. Monitoring the stability of the ALEPH vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Sguazzoni, G.; Creanza, D.; De Palma, M.; Maggi, G.; Raso, G.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Burns, M.; Frank, M.; Maley, P.D.; Morel, M.; Wagner, A.; Focardi, E.; Parrini, G.; Scarlini, E.; Halley, A.; O' Shea, V.; Raine, C.; Barber, G.; Cameron, W.; Dornan, P.; Gentry, D.; Moutoussi, A.; Nash, J.; Price, D.; Stacey, A.; Toudup, L.W.; Williams, M.I.; Billault, M.; Blanc, P.E.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Coyle, P.; Curtil, C.; Destelle, J.J.; Diaconu, C.; Fouchez, D.; Karst, P.; Payre, P.; Rousseau, D.; Thulasidas, M.; Dietl, H.; Ganis, G.; Moser, H.G.; Settles, R.; Seywerd, H.; Waltermann, G.; Bosi, F.; Bozzi, C.; Dell' Orso, R.; Profeti, A.; Rizzo, G.; Verdini, P.G.; Bizzell, J.P.; Thompson, J.C.; Black, S.; Dann, J.; Kim, H.Y.; Konstantinidis, N.; Taylor, G.; Bosisio, L.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.; Elmer, P.; Walsh, J

    1999-08-01

    The ALEPH Silicon Vertex Detector features an optical fibre laser system to monitor its mechanical stability. The operating principle and the general performance of the laser system are described. The experience obtained during 1997 and 1998 operations confirms the important role that such a system can have with respect to the detector alignment requirements. In particular, the laser system has been used to monitor short-term temperature-related effects and long-term movements. These results and a description of the laser-based alignment correction applied to the 1998 data are presented.

  18. Cosmic ray test of the Belle II z-vertex trigger

    Energy Technology Data Exchange (ETDEWEB)

    Neuhaus, Sara; Skambraks, Sebastian [Technische Universitaet Muenchen (Germany); Chen, Yang; Kiesling, Christian [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2016-07-01

    The z-vertex trigger is part of the first level track trigger in the Belle II experiment. Its task is the rejection of tracks not coming from the interaction region, suppressing a large part of the machine background. Therefore the z-vertex trigger allows to relax other track trigger conditions and thus strongly increases the efficiency for channels with low track multiplicity (e.g. tau pair production). The track trigger works in several steps, first combining hits to track segments, followed by a 2D track finding in the transverse plane and finally the 3D reconstruction. Our method employs neural networks to estimate the z-vertex without explicit track reconstruction. For the first real test with cosmic rays special neural networks have been prepared. Although the track shape in the cosmic test is different than in the Belle II experiment, the neural networks require only a retraining with an appropriate data set to adapt to the new geometry.

  19. Performance of the CLAS12 Silicon Vertex Tracker modules

    Energy Technology Data Exchange (ETDEWEB)

    Antonioli, M.A.; Boiarinov, S.; Bonneau, P.; Elouadrhiri, L.; Eng, B. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Gotra, Y., E-mail: gotra@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kurbatov, E. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); Leffel, M.; Mandal, S.; McMullen, M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Merkin, M. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); Raydo, B.; Teachey, W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Tucker, R. [Arizona State University, Tempe, AZ (United States); Ungaro, M.; Yegneswaran, A.; Ziegler, V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2013-12-21

    For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156μm, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements. -- Highlights: •A Silicon Vertex Tracker has been designed for the central tracker of the CLAS12 experiment. •Using cantilevered module geometry allows minimizing amount of material in the tracking volume. •A dedicated Hybrid Flex Circuit Board has been developed to read out double sided module. •Module performance meets design goals of the CLAS12 Central Tracker.

  20. Evaporative CO2 cooling using microchannels etched in silicon for the future LHCb vertex detector

    CERN Document Server

    Nomerotski, A.; Collins, P.; Dumps, R.; Greening, E.; John, M.; Mapelli, A.; Leflat, A.; Li, Y.; Romagnoli, G.; Verlaat, B.

    2013-01-01

    The extreme radiation dose received by vertex detectors at the Large Hadron Collider dictates stringent requirements on their cooling systems. To be robust against radiation damage, sensors should be maintained below -20 degree C and at the same time, the considerable heat load generated in the readout chips and the sensors must be removed. Evaporative CO2 cooling using microchannels etched in a silicon plane in thermal contact with the readout chips is an attractive option. In this paper, we present the first results of microchannel prototypes with circulating, two-phase CO2 and compare them to simulations. We also discuss a practical design of upgraded VELO detector for the LHCb experiment employing this approach.

  1. Cosmic-Ray Airshower Timing Experiment

    Science.gov (United States)

    Duvernois, M. A.

    A new, small-scale, detector utilizing the finite thickness of air-shower "pancakes" has been developed and operated on the roof of the physics building at the University of Minnesota. (MR. CRATE = Minnesota Rooftop CosmicRay Air-shower Timing Experiment) The work started before the author was aware of the extensive work of Linsley and others with such detectors. The experiment will be expanded to three detectors operating in coincidence to look at showers from 1017 to 1019 eV and develop techniques for using a compact array in coincidence with underground detectors. Preliminary results and design will be discussed.

  2. Semi-infinite wedges and vertex operators

    CERN Document Server

    Stern, E

    1995-01-01

    The level 1 highest weight modules of the quantum affine algebra U_q(\\widehat{\\frak{sl}}_n) can be described as spaces of certain semi-infinite wedges. Using a q-antisymmetrization procedure, these semi-infinite wedges can be realized inside an infinite tensor product of evaluation modules. This realization gives rise to simple descriptions of vertex operators and (up to a scalar function) their compositions.

  3. The baryon vertex with magnetic flux

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Bert [Departamento de Fisica Teorica y del Cosmos and Centro Andaluz de Fisica de Particulas Elementales, Universidad de Granada, 18071 Granada (Spain); Lozano, Yolanda [Departamento de Fisica, Universidad de Oviedo, Avda. Calvo Sotelo 18, 33007 Oviedo (Spain); Rodriguez-Gomez, Diego [Departamento de Fisica Teorica C-XI, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2006-11-15

    In this letter we generalise the baryon vertex configuration of AdS/CFT by adding a suitable instantonic magnetic field on its worldvolume, dissolving D-string charge. A careful analysis of the configuration shows that there is an upper bound on the number of dissolved strings. This could be a manifestation of the stringy exclusion principle. We provide a microscopical description of this configuration in terms of a dielectric effect for the dissolved strings.

  4. Silicon Technologies for the CLIC Vertex Detector

    CERN Document Server

    Spannagel, Simon

    2017-01-01

    CLIC is a proposed linear e$^+$e$^−$ collider designed to provide particle collisions at center-of-mass energies of up to 3 TeV. Precise measurements of the properties of the top quark and the Higgs boson, as well as searches for Beyond the Standard Model physics require a highly performant CLIC detector. In particular the vertex detector must provide a single point resolution of only a few micrometers while not exceeding the envisaged material budget of around 0.2%$~X_0$ per layer. Beam-beam interactions and beamstrahlung processes impose an additional requirement on the timestamping capabilities of the vertex detector of about 10 ns. These goals can only be met by using novel techniques in the sensor and ASIC design as well as in the detector construction. The R&D program for the CLIC vertex detector explores various technologies in order to meet these demands. The feasibility of planar sensors with a thickness of 50–150$~\\mu$m, including different active edge designs, are evaluated using Timepix3 A...

  5. Public Science with Real-Time Experiments

    Science.gov (United States)

    Lenardic, A.

    2013-12-01

    One of the best ways for professional scientists to engage in public outreach is to get outside of the university and/or lab walls and go out into the public. That is, go to public spaces to do some science experiments with the public - this includes students of all ages that constitute that public. Technological advance in portable measurement gear now allow one to do real, or near real, time experiments in outdoor, public spaces. We have been running a meta-experiment of this sort, aimed at the public display of science, for about a year now in Houston TX at the Lee and Joe Jamail Skatepark. The project goes under the title of Sk8Lab Houston and has introduced students of all ages to the power of scientific experimentation. We bring a portable science pack with us to the park. The pack has a range of wireless measurement gear that allow experiments to be done on the spot. Some of the experiments are designed by us but many are designed on by whoever suggests them to us that day. Over time the Sk8Lab scientists have built up a level of "trust" with the people who frequent the park (no one feels like we are gonna grade them at the park and they know that the learning is not on some regimented clock). This has broken down some learning walls and allowed for a more informal mode of exploration and a more genuine mode of experimentation (as compared to what often happens in class labs when students feel like they are just being forced to reproduce some known result). We will describe some of the test case experiments we have run and also discuss some of the trials, tribulations, and happy successes (many unplanned) along the way.

  6. A new efficient RLF-like algorithm for the vertex coloring problem

    Directory of Open Access Journals (Sweden)

    Adegbindin Mourchid

    2016-01-01

    Full Text Available The Recursive Largest First (RLF algorithm is one of the most popular greedy heuristics for the vertex coloring problem. It sequentially builds color classes on the basis of greedy choices. In particular, the first vertex placed in a color class C is one with a maximum number of uncolored neighbors, and the next vertices placed in C are chosen so that they have as many uncolored neighbors which cannot be placed in C. These greedy choices can have a significant impact on the performance of the algorithm, which explains why we propose alternative selection rules. Computational experiments on 63 difficult DIMACS instances show that the resulting new RLF-like algorithm, when compared with the standard RLF, allows to obtain a reduction of more than 50% of the gap between the number of colors used and the best known upper bound on the chromatic number. The new greedy algorithm even competes with basic metaheuristics for the vertex coloring problem.

  7. Impact vaporization: Late time phenomena from experiments

    Science.gov (United States)

    Schultz, P. H.; Gault, D. E.

    1987-01-01

    While simple airflow produced by the outward movement of the ejecta curtain can be scaled to large dimensions, the interaction between an impact-vaporized component and the ejecta curtain is more complicated. The goal of these experiments was to examine such interaction in a real system involving crater growth, ejection of material, two phased mixtures of gas and dust, and strong pressure gradients. The results will be complemented by theoretical studies at laboratory scales in order to separate the various parameters for planetary scale processes. These experiments prompt, however, the following conclusions that may have relevance at broader scales. First, under near vacuum or low atmospheric pressures, an expanding vapor cloud scours the surrounding surface in advance of arriving ejecta. Second, the effect of early-time vaporization is relatively unimportant at late-times. Third, the overpressure created within the crater cavity by significant vaporization results in increased cratering efficiency and larger aspect ratios.

  8. cellGPU: Massively parallel simulations of dynamic vertex models

    Science.gov (United States)

    Sussman, Daniel M.

    2017-10-01

    Vertex models represent confluent tissue by polygonal or polyhedral tilings of space, with the individual cells interacting via force laws that depend on both the geometry of the cells and the topology of the tessellation. This dependence on the connectivity of the cellular network introduces several complications to performing molecular-dynamics-like simulations of vertex models, and in particular makes parallelizing the simulations difficult. cellGPU addresses this difficulty and lays the foundation for massively parallelized, GPU-based simulations of these models. This article discusses its implementation for a pair of two-dimensional models, and compares the typical performance that can be expected between running cellGPU entirely on the CPU versus its performance when running on a range of commercial and server-grade graphics cards. By implementing the calculation of topological changes and forces on cells in a highly parallelizable fashion, cellGPU enables researchers to simulate time- and length-scales previously inaccessible via existing single-threaded CPU implementations. Program Files doi:http://dx.doi.org/10.17632/6j2cj29t3r.1 Licensing provisions: MIT Programming language: CUDA/C++ Nature of problem: Simulations of off-lattice "vertex models" of cells, in which the interaction forces depend on both the geometry and the topology of the cellular aggregate. Solution method: Highly parallelized GPU-accelerated dynamical simulations in which the force calculations and the topological features can be handled on either the CPU or GPU. Additional comments: The code is hosted at https://gitlab.com/dmsussman/cellGPU, with documentation additionally maintained at http://dmsussman.gitlab.io/cellGPUdocumentation

  9. Vertex finding performance studies for the Phase II CMS Level-1 Trigger

    CERN Document Server

    Udrescu, Silviu Marian

    2017-01-01

    At the HL-LHC, a significant increase in the luminosity delivered to CMS will result in a pileup per bunch crossing of 140-200. This provides a difficult environment to obtain reliable physics results and keep trigger rates manageable. In order to mitigate this problem, tracker information will be used, for the first time, at the Level-1 (L1) trigger. This will allow the primary vertex reconstruction at L1. In this report, an investigation into the vertex finding performance of a potential algorithm is presented. The vertex finding efficiency was measured as a function of several variables, such as the percentage of tracks associated to the primary vertex within the barrel and the pT of the tracks. The efficiency was found to not depend significantly on the pileup for the samples analyzed, however, a strong dependence was observed on the number of tracks associated with the primary vertex.

  10. The LHCb VELO (VErtex LOcator) and the LHCb VELO upgrade

    Science.gov (United States)

    Collins, P.; LHCb VELO Group; LHCb VELO Upgrade Group

    2013-01-01

    LHCb is a forward spectrometer experiment dedicated to the study of new physics in the decays of beauty and charm hadrons produced in proton collisions at the Large Hadron Collider (LHC) at CERN. The VErtex LOcator (VELO) is the silicon detector surrounding the LHCb interaction point. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO), and hence the detector is critical for both the trigger and the offline physics analyses. The sensors, which have an inner radius of ˜7 mm from the beam axis at the edge, and the first sensitive strips at a radius of ˜8.2 mm are exposed to maximum radiation doses of ˜0.6×1014 1 MeV neq/cm2 per integrated luminosity of fb-1. The performance of the VELO during the first two years of LHC running is described, together with the methods used to monitor radiation damage. The detector so far shows no significant performance degradation, however many interesting effects have been observed in the sensors, including a coupling of charge to the second metal routing line layer after irradiation. In 2018 the VELO will be upgraded together with the rest of the LHCb detector to a 40 MHz readout. The modules together with their front end electronics will be completely replaced with a radiation hard system capable of driving the signals out at the required rates. The current status of the R&D for the LHCb VELO Upgrade is outlined.

  11. B meson proper time measurements with the LHCb experiment impact on physics parameters and calibration methods

    CERN Document Server

    Balbi, G

    2007-01-01

    The LHCb (Large Hadron Collider beauty) experiment is one of the four experiments at the LHC, and is specifically dedicated to explore the B-meson dynamics. To this end, LHCb will exploit the large beauty production cross section, expected to be about 500 µb at 14 TeV p-p collisions. Differently from the B-factory case, the hadronization of the b-quarks at LHC will generate all the possible B-hadrons, remarkably the Bs and Bc mesons, where the present experimental knowledge is still rather poor. The number of b/b_bar pairs produced at the LHCb interaction point will be of the order of 10^12 per year, allowing for the search of extremely rare decays, with branching fractions at the level of 10^-9. In order to reduce the acquisition rate to a sustainable level (order of 2 kHz), maintaining at the same time a high efficiency on the signals of interest, LHCb is provided with an efficient and flexible trigger system. LHCb, by means of its vertex detector, will be able to reconstruct the proper time of decays wi...

  12. Imaging the LHC beams with silicon and scintillating fibre vertex detectors

    Science.gov (United States)

    Rihl, M.

    2017-02-01

    The LHCb Vertex Locator (VELO) is used to reconstruct beam-gas interaction vertices which allows one to obtain precise profiles of the LHC beams. In LHCb, this information is combined with the profile of the reconstructed beam-beam collisions and with the LHC beam currents to perform precise measurements of the luminosity. This beam-gas imaging (BGI) method also allows one to study the transverse beam shapes, beam positions and angles in real time. Therefore, a demonstrator beam-gas vertex detector (BGV) based on scintillating fibre modules has been built and installed in LHC Ring 2 at point 4.

  13. Track and vertex reconstruction of the ATLAS Inner Detector in the high multiplicity LHC environment

    CERN Document Server

    Wasicki, C; The ATLAS collaboration

    2012-01-01

    With an average number of up to 30 pile-up interactions per bunch crossing in 2012 data, the ATLAS Inner Detector at the LHC is performing in an environment beyond its design specifications. This has a significant impact on event reconstruction such as additional demands on CPU time and disk space as well as an increased probability to reconstruct fake tracks. Therefore the track and vertex reconstruction performance has been optimised in several high pile-up scenarios. Studies in data and simulation are presented which demonstrate that the performance of the Inner Detector track and vertex reconstruction is robust even in a high pile-up environment.

  14. Track and vertex reconstruction of the ATLAS Inner Detector in the high multiplicity LHC environment

    Science.gov (United States)

    Wasicki, Christoph

    2012-12-01

    With an average number of up to 30 pile-up interactions per bunch crossing in 2012 data, the ATLAS Inner Detector at the LHC is performing in an environment beyond its design specifications. This has a significant impact on event reconstruction such as additional demands on CPU time and disk space as well as an increased probability to reconstruct fake tracks. Therefore the track and vertex reconstruction performance has been optimised in several high pile-up scenarios (see [1]). Studies in data and simulation are presented which demonstrate that the performance of the Inner Detector track and vertex reconstruction is robust even in a high pile-up environment.

  15. Imaging the LHC beams with silicon and scintillating fibre vertex detectors

    CERN Document Server

    Rihl, M

    2016-01-01

    The LHCb Vertex Locator (VELO) is used to reconstruct beam–gas interaction vertices which allows one to obtain precise profiles of the LHC beams. In LHCb, this information is combined with the profile of the reconstructed beam–beam collisions and with the LHC beam currents to perform precise measurements of the luminosity. This beam–gas imaging (BGI) method also allows one to study the transverse beam shapes, beam positions and angles in real time. Therefore, a demonstrator beam–gas vertex detector (BGV) based on scintillating fibre modules has been built and installed in LHC Ring 2 at point 4.

  16. SPARTex: A Vertex-Centric Framework for RDF Data Analytics

    KAUST Repository

    Abdelaziz, Ibrahim

    2015-08-31

    A growing number of applications require combining SPARQL queries with generic graph search on RDF data. However, the lack of procedural capabilities in SPARQL makes it inappropriate for graph analytics. Moreover, RDF engines focus on SPARQL query evaluation whereas graph management frameworks perform only generic graph computations. In this work, we bridge the gap by introducing SPARTex, an RDF analytics framework based on the vertex-centric computation model. In SPARTex, user-defined vertex centric programs can be invoked from SPARQL as stored procedures. SPARTex allows the execution of a pipeline of graph algorithms without the need for multiple reads/writes of input data and intermediate results. We use a cost-based optimizer for minimizing the communication cost. SPARTex evaluates queries that combine SPARQL and generic graph computations orders of magnitude faster than existing RDF engines. We demonstrate a real system prototype of SPARTex running on a local cluster using real and synthetic datasets. SPARTex has a real-time graphical user interface that allows the participants to write regular SPARQL queries, use our proposed SPARQL extension to declaratively invoke graph algorithms or combine/pipeline both SPARQL querying and generic graph analytics.

  17. Vertex Separators for Partitioning a Graph

    Directory of Open Access Journals (Sweden)

    Cem Evrendilek

    2008-02-01

    Full Text Available Finite Element Method (FEM is a well known technique extensively studiedfor spatial and temporal modeling of environmental processes, weather predictioncomputations, and intelligent signal processing for wireless sensors. The need for hugecomputational power arising in such applications to simulate physical phenomenoncorrectly mandates the use of massively parallel computers to distribute the workloadevenly. In this study, a novel heuristic algorithm called Line Graph Bisection whichpartitions a graph via vertex separators so as to balance the workload amongst theprocessors and to minimize the communication overhead is proposed. The proposedalgorithm is proved to be computationally feasible and makes cost-effective parallelimplementations possible to speed up the solution process.

  18. The Mark II Vertex Drift Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.

    1989-03-01

    We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.

  19. From vertex operator algebras to conformal nets and back

    OpenAIRE

    Carpi, Sebastiano; Kawahigashi, Yasuyuki; Longo, Roberto; Weiner, Mihály

    2015-01-01

    We consider unitary simple vertex operator algebras whose vertex operators satisfy certain energy bounds and a strong form of locality and call them strongly local. We present a general procedure which associates to every strongly local vertex operator algebra V a conformal net A_V acting on the Hilbert space completion of V and prove that the isomorphism class of A_V does not depend on the choice of the scalar product on V. We show that the class of strongly local vertex operator algebras is...

  20. Propagation of the trip behavior in the VENUS vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Ohama, Taro; Yamada, Yoshikazu

    1995-03-01

    The high voltage system of the VENUS vertex chamber occasionally trips by a discharge somewhere among cathode electrodes during data taking. This trip behavior induces often additional trips at other electrodes such as the skin and the grid electrodes in the vertex chamber. This propagation mechanism of trips is so complicated in this system related with multi-electrodes. Although the vertex chamber is already installed inside the VENUS detector and consequently the discharge is not able to observe directly, a trial to estimate the propagation has been done using only the information which appears around the trip circuits and the power supply of the vertex chamber. (author).

  1. Human Performance on Hard Non-Euclidean Graph Problems: Vertex Cover

    Science.gov (United States)

    Carruthers, Sarah; Masson, Michael E. J.; Stege, Ulrike

    2012-01-01

    Recent studies on a computationally hard visual optimization problem, the Traveling Salesperson Problem (TSP), indicate that humans are capable of finding close to optimal solutions in near-linear time. The current study is a preliminary step in investigating human performance on another hard problem, the Minimum Vertex Cover Problem, in which…

  2. On non-Cayley vertex-transitive graphs and the Meta-Cayley graphs ...

    African Journals Online (AJOL)

    The pursuit to identify vertex-transitive non-Cayley graphs has been deliberate for some time now. In that vein, Alspach and Parsons [1] introduced metacirculant graphs. They are de ned on two cyclic groups with adjacency re-sembling twisting that is typically used in de ning semi-direct products of groups. In this sequel we ...

  3. The Construction of Spin Foam Vertex Amplitudes

    Directory of Open Access Journals (Sweden)

    Eugenio Bianchi

    2013-01-01

    Full Text Available Spin foam vertex amplitudes are the key ingredient of spin foam models for quantum gravity. These fall into the realm of discretized path integral, and can be seen as generalized lattice gauge theories. They can be seen as an attempt at a 4-dimensional generalization of the Ponzano-Regge model for 3d quantum gravity. We motivate and review the construction of the vertex amplitudes of recent spin foam models, giving two different and complementary perspectives of this construction. The first proceeds by extracting geometric configurations from a topological theory of the BF type, and can be seen to be in the tradition of the work of Barrett, Crane, Freidel and Krasnov. The second keeps closer contact to the structure of Loop Quantum Gravity and tries to identify an appropriate set of constraints to define a Lorentz-invariant interaction of its quanta of space. This approach is in the tradition of the work of Smolin, Markopoulous, Engle, Pereira, Rovelli and Livine.

  4. Performance of the CLAS12 Silicon Vertex Tracker modules

    Energy Technology Data Exchange (ETDEWEB)

    Antonioli, Mary Ann [JLAB; Boiarinov, Serguie; Bonneau, Peter R. [JLAB; Elouadrhiri, Latifa [JLAB; Eng, Brian J. [JLAB; Gotra, Yuri N. [JLAB; Kurbatov, Evgeny O. [Moscow State U.; Leffel, Mindy A. [JLAB; Mandal, Saptarshi [JLAB; McMullen, Marc E. [JLAB; Merkin, Mikhail M. [Moscow State U.; Raydo, Benjamin J. [JLAB; Teachey, Robert W, [JLAB; Tucker, Ross J. [Arizona State U.; Ungaro, Maurizio [JLAB; Yegneswaran, Amrit S. [JLAB; Ziegler, Veronique [JLAB

    2013-12-01

    For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156{micro}m, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements.

  5. A vertex similarity index for better personalized recommendation

    Science.gov (United States)

    Chen, Ling-Jiao; Zhang, Zi-Ke; Liu, Jin-Hu; Gao, Jian; Zhou, Tao

    2017-01-01

    Recommender systems benefit us in tackling the problem of information overload by predicting our potential choices among diverse niche objects. So far, a variety of personalized recommendation algorithms have been proposed and most of them are based on similarities, such as collaborative filtering and mass diffusion. Here, we propose a novel vertex similarity index named CosRA, which combines advantages of both the cosine index and the resource-allocation (RA) index. By applying the CosRA index to real recommender systems including MovieLens, Netflix and RYM, we show that the CosRA-based method has better performance in accuracy, diversity and novelty than some benchmark methods. Moreover, the CosRA index is free of parameters, which is a significant advantage in real applications. Further experiments show that the introduction of two turnable parameters cannot remarkably improve the overall performance of the CosRA index.

  6. Performance of the ALICE secondary vertex b-tagging algorithm

    CERN Document Server

    INSPIRE-00262232

    2016-11-04

    The identification of jets originating from beauty quarks in heavy-ion collisions is important to study the properties of the hot and dense matter produced in such collisions. A variety of algorithms for b-jet tagging was elaborated at the LHC experiments. They rely on the properties of B hadrons, i.e. their long lifetime, large mass and large multiplicity of decay products. In this work, the b-tagging algorithm based on displaced secondary-vertex topologies is described. We present Monte Carlo based performance studies of the algorithm for charged jets reconstructed with the ALICE tracking system in p-Pb collisions at $\\sqrt{s_\\text{NN}}$ = 5.02 TeV. The tagging efficiency, rejection rate and the correction of the smearing effects of non-ideal detector response are presented.

  7. The LHCb Vertex Locator (VELO) Pixel Detector Upgrade

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00536755

    2017-01-01

    The LHCb experiment is designed to perform high-precision measurements of CP violation and the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. There is a planned upgrade during Long Shutdown 2 (LS2), expected in 2019, which will allow the detector to run at higher luminosities by transforming the entire readout to a trigger-less system. This will include a substantial upgrade of the Vertex Locator (VELO), the silicon tracker that surrounds the LHCb interaction region. The VELO is moving from silicon strip technology to hybrid pixel sensors, where silicon sensors are bonded to VeloPix ASICs. Sensor prototypes have undergone rigorous testing using the Timepix3 Telescope at the SPS, CERN. The main components of the upgrade are summarised and testbeam results presented.

  8. Subgraphs in vertex neighborhoods of K-free graphs

    DEFF Research Database (Denmark)

    Bang-Jensen, J.; Brandt, Stephan

    2004-01-01

    In a K-free graph, the neighborhood of every vertex induces a K-free subgraph. The K-free graphs with the converse property that every induced K-free subgraph is contained in the neighborhood of a vertex are characterized, based on the characterization in the case r = 3 due to Pach [8]....

  9. Graphs with No Induced Five-Vertex Path or Antipath

    DEFF Research Database (Denmark)

    Chudnovsky, Maria; Esperet, Louis; Lemoine, Laetitia

    2017-01-01

    We prove that a graph G contains no induced five-vertex path and no induced complement of a five-vertex path if and only if G is obtained from 5-cycles and split graphs by repeatedly applying the following operations: substitution, split unification, and split unification in the complement, where...

  10. Vertex epidural haematoma manifesting with bilateral upper limb ...

    African Journals Online (AJOL)

    Vertex epidural haematomas (VEDH) are rare and difficulties are encountered in diagnosis and management. This is a case report of a patient with a vertex epidural haematoma who presented with signs of severe head injury with upper limb decerebrate posture. We discuss the challenges of radiological investigation and ...

  11. Capacitively coupled hybrid pixel assemblies for the CLIC vertex detector

    CERN Document Server

    AUTHOR|(SzGeCERN)734627; Benoit, Mathieu; Dannheim, Dominik; Dette, Karola; Hynds, Daniel; Kulis, Szymon; Peric, Ivan; Petric, Marko; Redford, Sophie; Sicking, Eva; Valerio, Pierpaolo

    2016-01-01

    The vertex detector at the proposed CLIC multi-TeV linear e+e- collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope with the expected high rate of beam-induced backgrounds. One of the options being considered is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel ASICs. A prototype of such an assembly, using two custom designed chips (CCPDv3 as active sensor glued to a CLICpix readout chip), has been characterised both in the lab and in beam tests at the CERN SPS using 120 GeV/c positively charged hadrons. Results of these characterisation studies are presented both for single and dual amplification stages in the active sensor. Pixel cross-coupling results are also presented, showing the sensitivity to placement precision and planarity of the glue layer.

  12. Greedy Local Search and Vertex Cover in Sparse Random Graphs

    DEFF Research Database (Denmark)

    Witt, Carsten

    2009-01-01

    finds an optimal cover in polynomial time with a probability arbitrarily close to 1. This behavior relies on the absence of a giant component. As an additional insight into the randomized search, it is shown that the heuristic fails badly also on graphs consisting of a single tree component of maximum......Recently, various randomized search heuristics have been studied for the solution of the minimum vertex cover problem, in particular for sparse random instances according to the G(n, c/n) model, where c > 0 is a constant. Methods from statistical physics suggest that the problem is easy if c .... This work starts with a rigorous explanation for this claim based on the refined analysis of the Karp-Sipser algorithm by Aronson et al. Subsequently, theoretical supplements are given to experimental studies of search heuristics on random graphs. For c search heuristic...

  13. Solving Vertex Cover Problem Using DNA Tile Assembly Model

    Directory of Open Access Journals (Sweden)

    Zhihua Chen

    2013-01-01

    Full Text Available DNA tile assembly models are a class of mathematically distributed and parallel biocomputing models in DNA tiles. In previous works, tile assembly models have been proved be Turing-universal; that is, the system can do what Turing machine can do. In this paper, we use tile systems to solve computational hard problem. Mathematically, we construct three tile subsystems, which can be combined together to solve vertex cover problem. As a result, each of the proposed tile subsystems consists of Θ(1 types of tiles, and the assembly process is executed in a parallel way (like DNA’s biological function in cells; thus the systems can generate the solution of the problem in linear time with respect to the size of the graph.

  14. Displaced vertex searches for sterile neutrinos at future lepton colliders

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805 München (Germany); Cazzato, Eros; Fischer, Oliver [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland)

    2016-12-02

    We investigate the sensitivity of future lepton colliders to displaced vertices from the decays of long-lived heavy (almost sterile) neutrinos with electroweak scale masses and detectable time of flight. As future lepton colliders we consider the FCC-ee, the CEPC, and the ILC, searching at the Z-pole and at the center-of-mass energies of 240, 350 and 500 GeV. For a realistic discussion of the detector response to the displaced vertex signal and the Standard Model background we consider the ILC’s Silicon Detector (SiD) as benchmark for the future lepton collider detectors. We find that displaced vertices constitute a powerful search channel for sterile neutrinos, sensitive to squared active-sterile mixing angles as small as 10{sup −11}.

  15. Artificial Spin-Ice and Vertex Models

    Science.gov (United States)

    Cugliandolo, Leticia F.

    2017-05-01

    In classical and quantum frustrated magnets the interactions in combination with the lattice structure impede the spins to order in optimal configurations at zero temperature. The theoretical interest in their classical realisations has been boosted by the artificial manufacture of materials with these properties, that are of flexible design. This note summarises work on the use of vertex models to study bidimensional spin-ices samples, done in collaboration with R. A. Borzi, M. V. Ferreyra, L. Foini, G. Gonnella, S. A. Grigera, P. Guruciaga, D. Levis, A. Pelizzola and M. Tarzia, in recent years. It is an invited contribution to a J. Stat. Mech. special issue dedicated to the memory of Leo P. Kadanoff.

  16. Interaction vertex for classical spinning particles

    Science.gov (United States)

    Rempel, Trevor; Freidel, Laurent

    2016-08-01

    We consider a model of the classical spinning particle in which the coadjoint orbits of the Poincaré group are parametrized by two pairs of canonically conjugate four-vectors, one representing the standard position and momentum variables, and the other encoding the spinning degrees of freedom. This "dual phase space model" is shown to be a consistent theory of both massive and massless particles and allows for coupling to background fields such as electromagnetism. The on-shell action is derived and shown to be a sum of two terms, one associated with motion in spacetime, and the other with motion in "spin space." Interactions between spinning particles are studied, and a necessary and sufficient condition for consistency of a three-point vertex is established.

  17. Development of fast and radiation hard Monolithic Active Pixel Sensors (MAPS) optimized for open charm meson detection with the CBM - vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Deveaux, Michael

    2008-03-20

    The work presented in this thesis addresses a key issue of the CBM experiment at FAIR, which aims to study charm production in heavy ion collisions at energies ranging from 10 to 40 AGeV. For the first time in this kinematical range, open charm mesons will be used as a probe of the nuclear fireball. Despite of their short decay length, which is typically in the order of few 100 {mu}m in the laboratory frame, those mesons will be identified by reconstructing their decay vertex. (orig.)

  18. Exact Solution of the Six-Vertex Model with Domain Wall Boundary Conditions. Disordered Phase

    CERN Document Server

    Bleher, P M

    2005-01-01

    The six-vertex model, or the square ice model, with domain wall boundary conditions (DWBC) has been introduced and solved for finite $N$ by Korepin and Izergin. The solution is based on the Yang-Baxter equations and it represents the free energy in terms of an $N\\times N$ Hankel determinant. Paul Zinn-Justin observed that the Izergin-Korepin formula can be re-expressed in terms of the partition function of a random matrix model with a nonpolynomial interaction. We use this observation to obtain the large $N$ asymptotics of the six-vertex model with DWBC in the disordered phase. The solution is based on the Riemann-Hilbert approach and the Deift-Zhou nonlinear steepest descent method. As was noticed by Kuperberg, the problem of enumeration of alternating sign matrices (the ASM problem) is a special case of the the six-vertex model. We compare the obtained exact solution of the six-vertex model with known exact results for the 1, 2, and 3 enumerations of ASMs, and also with the exact solution on the so-called f...

  19. The part-time doctoral student experience

    National Research Council Canada - National Science Library

    Gardner, Susan K; Gopaul, Bryan

    2012-01-01

    Although scholarly interest in doctoral education has increased dramatically over the last two decades, much of this attention has focused on the experiences of doctoral students who are enrolled full...

  20. Mesopic visual efficiency II: Reaction time experiments

    NARCIS (Netherlands)

    Walkey, H.; Orrevetelainen, P.; Barbur, J.; Halonen, L.; Goodman, T.; Alferdinck, J.W.A.M.; Freiding, A.; Szalmas, A.

    2007-01-01

    Reaction times are recorded to chromatic, mesopic stimuli to investigate mesopic reaction time spectral sensitivity. Measurements are made using three laboratory setups and a driving simulator. The chromatic stimuli have spectral distributions that range from quasi-monochromatic to broadband.

  1. Self-dual vertex operator superalgebras and superconformal field theory

    Science.gov (United States)

    Creutzig, Thomas; Duncan, John F. R.; Riedler, Wolfgang

    2018-01-01

    Recent work has related the equivariant elliptic genera of sigma models with K3 surface target to a vertex operator superalgebra that realizes moonshine for Conway’s group. Motivated by this we consider conditions under which a self-dual vertex operator superalgebra may be identified with the bulk Hilbert space of a superconformal field theory. After presenting a classification result for self-dual vertex operator superalgebras with central charge up to 12 we describe several examples of close relationships with bulk superconformal field theories, including those arising from sigma models for tori and K3 surfaces.

  2. The design and construction of the BaBar silicon vertex tracker

    CERN Document Server

    Bozzi, C; Ramusino, A C; Dittongo, S; Folegani, M; Piemontese, L; Abbott, B K; Breon, A B; Clark, A R; Dow, S; Fan, Q; Goozen, F; Hernikl, C; Karcher, A; Kerth, L T; Kipnis, I; Kluth, S; Lynch, G; Levi, M; Luft, P; Luo, L; Nyman, M A; Pedrali-Noy, M; Roe, N A; Zizka, G; Roberts, D; Barni, D; Brenna, E; Defendi, I; Forti, A C; Giugni, D; Lanni, F; Palombo, F; Vaniev, V; Leona, A; Mandelli, E; Manfredi, P F; Perazzo, A; Re, V; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bosi, F; Calderini, G; Carpinelli, M; Dutra, F; Forti, F; Gagliardi, D; Giorgi, M A; Lusiani, A; Mammini, P; Morganti, M; Morsani, F; Paoloni, E; Profeti, A; Rama, M; Rampino, G; Rizzo, G; Sandrelli, F; Simi, G; Triggiani, G; Tritto, S; Vitale, R; Burchat, Patricia R; Cheng, C; Kirkby, D; Meyer, T; Roat, C; Bóna, M; Bianchi, F; Daudo, F; Girolamo, B D; Gamba, D; Giraudo, G; Grosso, P; Romero, A; Smol, A; Trapani, P; Zanin, D; Bosisio, L; Della Ricca, G; Lanceri, L; Pompili, A; Poropat, P; Prest, M; Rastelli, C; Vallazza, E; Vuagnin, G; Hast, C; Potter, E P; Sharma, V; Burke, S; Callahan, D; Campagnari, C; Dahmes, B; Eppich, A; Hale, D; Hall, K; Hart, P; Kuznetsova, N; Kyre, S; Levy, S; Long, O; May, J; Richman, J; Verkerke, W; Witherell, M; Beringer, J; Eisner, A M; Frey, A; Grillo, A; Grothe, M; Johnson, R; Kröger, W; Lockman, W; Pulliam, T; Rowe, W; Schmitz, R; Seiden, A; Spencer, E; Turri, M; Wilder, M; Charles, E; Elmer, P; Nielsen, J; Orejudos, W; Scott, I; Walsh, J; Zobernig, H

    2000-01-01

    The Silicon Vertex Tracker (SVT) of the BaBar experiment at the PEP-II asymmetric B factory consists of five layers of double-sided, AC-coupled silicon strip detectors. The detectors are readout with a custom IC, capable of simultaneous acquisition, digitization and transmission of data. The SVT geometry is shown and the construction phases of its modules are described in detail, with emphasis on the bending procedures needed for the arch-modules of the outer layers.

  3. Measurement of the double-vertex reconstruction efficiency of the inclusive vertex finder with accidentally overlapping b-jets in ttbar events

    Energy Technology Data Exchange (ETDEWEB)

    Marchesini, Ivan; Nowatschin, Dominik; Ott, Jochen; Schmidt, Alexander; Tholen, Heiner [University of Hamburg (Germany)

    2015-07-01

    In LHC Run II, CMS b-tagging algorithms will employ a new core algorithm, named Inclusive Vertex Finder (IVF). The IVF is designed to perform decay vertex reconstruction of long-lived particles, such as B hadrons. Using only tracks from the silicon tracker, it does not depend on jet clustering and allows for higher reconstruction efficiency of decay vertices, which particularly applies to topologies with two or more decay vertices at low distance. Thus, the IVF will offer increased sensitivity for SM measurements (e.g. angular correlations), but also for the search of BSM physics (e.g. final states with boosted Higgs bosons decaying into b-quarks). For the first time, the dependence of the IVF reconstruction efficiency on the distance of vertices in the η-φ plane is investigated with a data-driven approach. We use a clean set of top quark pair events, selected from data recorded in 2012 in pp-collisions at 8 TeV with the CMS detector, and perform a template fit to a 2D-distribution of the masses of the vertices in an event. Correction factors are derived for the application to simulated events. We conclude that our technique will enable precise calibration of double vertexing with the IVF in the LHC Run II.

  4. Visualization in Real-Time Experiment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project will be to migrate some of the outputs from the WFF Mission Planning Lab (MPL) into a real-time visualization system.  The MPL is...

  5. An Efficient Local Search for the Feedback Vertex Set Problem

    Directory of Open Access Journals (Sweden)

    Zehui Shao

    2013-11-01

    Full Text Available Inspired by many deadlock detection applications, the feedback vertex set is defined as a set of vertices in an undirected graph, whose removal would result in a graph without cycle. The Feedback Vertex Set Problem, known to be NP-complete, is to search for a feedback vertex set with the minimal cardinality to benefit the deadlock recovery. To address the issue, this paper presents NewkLS FVS(LS, local search; FVS, feedback vertex set, a variable depth-based local search algorithm with a randomized scheme to optimize the efficiency and performance. Experimental simulations are conducted to compare the algorithm with recent metaheuristics, and the computational results show that the proposed algorithm can outperform the other state-of-art algorithms and generate satisfactory solutions for most DIMACSbenchmarks.

  6. Towards the Two-Loop Lcc Vertex in Landau Gauge

    Science.gov (United States)

    Cvetič, Gorazd; Kondrashuk, Igor; Kotikov, Anatoly; Schmidt, Ivan

    We are interested in the structure of the Lcc vertex in the Yang-Mills theory, where c is the ghost field and L the corresponding BRST auxiliary field. This vertex can give us information on other vertices, and the possible conformal structure of the theory should be reflected in the structure of this vertex. There are five two-loop contributions to the Lcc vertex in the Yang-Mills theory. We present here calculation of the first of the five contributions. The calculation has been performed in the position space. One main feature of the result is that it does not depend on any scale, ultraviolet or infrared. The result is expressed in terms of logarithms and Davydychev integral J(1, 1, 1) that are functions of the ratios of the intervals between points of effective fields in the position space. To perform the calculation we apply Gegenbauer polynomial technique and uniqueness method.

  7. Graph Theory. 2. Vertex Descriptors and Graph Coloring

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2002-12-01

    Full Text Available This original work presents the construction of a set of ten sequence matrices and their applications for ordering vertices in graphs. For every sequence matrix three ordering criteria are applied: lexicographic ordering, based on strings of numbers, corresponding to every vertex, extracted as rows from sequence matrices; ordering by the sum of path lengths from a given vertex; and ordering by the sum of paths, starting from a given vertex. We also examine a graph that has different orderings for the above criteria. We then proceed to demonstrate that every criterion induced its own partition of graph vertex. We propose the following theoretical result: both LAVS and LVDS criteria generate identical partitioning of vertices in any graph. Finally, a coloring of graph vertices according to introduced ordering criteria was proposed.

  8. First time rounding experiences for nonclinicians: the Cleveland Clinic experience.

    Science.gov (United States)

    Greenwald, Laura R; Nowacki, Amy S; Stoller, James K

    2015-01-01

    Clinical rounds serve several key objectives in academic medical centers: providing a forum for patient communication, clinical decision making, and teaching. Nonclinical colleagues ordinarily do not have the opportunity to round, and the idea of implementing a rounding program that includes nonclinical colleagues has received little attention to date. Reasoning that a rounding program with nonclinicians could enhance (1) understanding of the organization's clinical mission, (2) appreciation of caregivers' roles, and (3) engagement, the authors created such a program. From 2010 to 2013, 51 nonclinicians within the Cleveland Clinic Education Institute participated; 14 submitted written reflections, and 27 responded to a survey about their experience. Overall, 12 themes emerged that suggest an enhanced familiarity with the institution and increased engagement and alignment with its mission. Notably, the results align with a long-standing focus on organizational engagement and an observed increase in mean engagement scores since the program was implemented. © 2014 by the American College of Medical Quality.

  9. Quantum algorithms and mathematical formulations of biomolecular solutions of the vertex cover problem in the finite-dimensional hilbert space.

    Science.gov (United States)

    Chang, Weng-Long; Ren, Ting-Ting; Feng, Mang

    2015-01-01

    In this paper, it is shown that the proposed quantum algorithm for implementing Boolean circuits generated from the DNA-based algorithm solving the vertex-cover problem of any graph G with m edges and n vertices is the optimal quantum algorithm. Next, it is also demonstrated that mathematical solutions of the same biomolecular solutions are represented in terms of a unit vector in the finite-dimensional Hilbert space. Furthermore, for testing our theory, a nuclear magnetic resonance (NMR) experiment of three quantum bits to solve the simplest vertex-cover problem is completed.

  10. Mirror of the refined topological vertex from a matrix model

    CERN Document Server

    Eynard, B

    2011-01-01

    We find an explicit matrix model computing the refined topological vertex, starting from its representation in terms of plane partitions. We then find the spectral curve of that matrix model, and thus the mirror symmetry of the refined vertex. With the same method we also find a matrix model for the strip geometry, and we find its mirror curve. The fact that there is a matrix model shows that the refined topological string amplitudes also satisfy the remodeling the B-model construction.

  11. R&D Challenges of a CLIC Vertex Detector

    CERN Document Server

    van der Kraaij, E

    2010-01-01

    The Compact Linear Collider (CLIC) is a concept for an electron-positron collider with a center- of-mass energy of up to 3 TeV. Given the unprecedented experimental conditions at CLIC none of the technologies available today can fulfill all requirements set for the vertex detector. At the conference these conditions and the challenges they pose for the R&D of a CLIC vertex detector were presented.

  12. The vertex detector for the Lepton/Photon collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, J.P.; Boissevain, J.G.; Fox, D.; Hecke, H. van; Jacak, B.V.; Kapustinsky, J.S.; Leitch, M.J.; McGaughey, P.L.; Moss, J.M.; Sondheim, W.E. [Los Alamos National Lab., NM (United States)

    1991-12-31

    The conceptual design of the vertex detector for the Lepton/Photon Collaboration at RHIC is described, including simulations of its expected performance. The design consists of two con- centric layers of single-sided Si strips. The expected performance as a multiplicity detector and in measuring the pseudo-rapidity ({nu}) distribution is discussed as well as the expected vertex finding efficiency and accuracy. Various options which could be used to reduce the cost of the detector are also discussed.

  13. Vertex reconstruction framework and its implementation for CMS

    CERN Document Server

    Boccali, T; Prokofiev, K; Speer, T; Vanlaer, P; Waltenberger, W

    2003-01-01

    The class framework developed for vertex reconstruction in CMS is described. We emphasize how we proceed to develop a flexible, efficient and reliable piece of reconstruction software. We describe the decomposition of the algorithms into logical parts, the mathematical toolkit, and the way vertex reconstruction integrates into the CMS reconstruction project ORCA. We discuss the tools that we have developed for algorithm evaluation and optimization and for code release.

  14. Calculation of Wakefields for the New Design of the LHCb Vertex Locator

    CERN Document Server

    Wanzenberg, Rainer; CERN. Geneva. ATS Department

    2016-01-01

    The upgrade of the LHCb detector in the LHCb experiment was planned in 2011. The main purpose of the upgrade is an improvement of the functional abilities of the LHCb detector, such as the measurement and the collection of various characteristics of the particles produced by colliding protons. The new configuration of the LHCb detector will include an upgraded configuration of the LHCb VErtex LOcator (VELO) and a new design of the beam pipe for this detector. The wakefields for the new geometrical model of the beam pipe in the vertex locator have been calculated with the Wakefield Solver of the program CST STUDIO 2015. Preliminary results of the calculations are presented in this report.

  15. Performance, radiation damage effects and upgrade of the LHCB vertex locator

    Energy Technology Data Exchange (ETDEWEB)

    Capua, Stefano de, E-mail: stefano.decapua@hep.manchester.co.uk

    2013-12-21

    LHCb is a dedicated experiment to study new physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. Heavy hadrons are identified through their flight distance in the Vertex Locator (VELO), the retractable silicon-strip vertex detector surrounding the LHCb interaction point at only 8 mm from the beam during normal LHC operation. The VELO consists of a series of silicon micro-strip detectors and operates in an extreme and highly non-uniform radiation environment. The performance of the LHCb VELO during the first three years of LHC physics running and the primary results from radiation damage studies are presented. Plans for an upgraded detector by 2018 with a 40 MHz readout are also presented.

  16. Power pulsing scheme for analog and digital electronics of the vertex detectors at CLIC

    CERN Document Server

    Blanchot, Georges

    2015-01-01

    The precision requirements of the vertex detector at CLIC impose strong limitations on the mass of such a detector (< 0.2% of a radiation length, Xo, per layer). To achieve such a low material budget, ultra-thin hybrid pixel detectors are foreseen, while the mass for cooling and services will be reduced by implementing a power pulsing scheme that takes advantage of the low duty cycle of the accelerator. The principal aim is to achieve significant power reduction without compromising the power integrity supplied to the front-end electronics. This report summarises the study of a power pulsing scheme to power the vertex barrel electronics of the future CLIC experiment. Its main goal is to describe in more detail what has been already presented in TWEPP conferences and other presentations. The report can therefore serve as an operator manual for future use and development of the system

  17. Studies of radiation hardness of MOS devices for application in a linear collider vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qingyu

    2008-10-17

    The proposed International Linear Collider (ILC) together with the Large Hadron Collider (LHC) at CERN serve as a combined tool to explore the mysteries of the universe: the former is a precision machine and the latter can be considered as a finding machine. The key component of the ILC is the vertex detector that should be placed as close as possible to the Interaction Point (IP) and has better radiation tolerance against the dominant electron-positron pair production background from beam-beam interactions. A new generation of MOS-type Depleted-Field-Effect Transistor (MOSDEPFET) active pixel detectors has been proposed and developed by Semiconductor Labor Munich for Physics and for extraterrestrial Physics in order to meet the requirements of the vertex detector at the ILC. Since all MOS devices are susceptible to ionizing radiation, the main topic is focused on the radiation hardness of detectors, by which a series of physical processes are analyzed: e.g. surface damage due to ionizing radiation as well as damage mechanisms and their associated radiation effects. As a consequence, the main part of this thesis consists of a large number of irradiation experiments and the corresponding discussions. Finally, radiation hardness of the detectors should be improved through a set of concluded experiences that are based on a series of analysis of the characteristic parameters using different measurement techniques. The feasibility of the MOSDEPFET-based vertex detector is, therefore, predicted at ILC. (orig.)

  18. Time while waiting: patients' experiences of scheduled surgery.

    Science.gov (United States)

    Carr, Tracey; Teucher, Ulrich C; Casson, Alan G

    2014-12-01

    Research on patients' experiences of wait time for scheduled surgery has centered predominantly on the relative tolerability of perceived wait time and impacts on quality of life. We explored patients' experiences of time while waiting for three types of surgery with varied wait times--hip or knee replacement, shoulder surgery, and cardiac surgery. Thirty-two patients were recruited by their surgeons. We asked participants about their perceptions of time while waiting in two separate interviews. Using interpretative phenomenological analysis (IPA), we discovered connections between participant suffering, meaningfulness of time, and agency over the waiting period and the lived duration of time experience. Our findings reveal that chronological duration is not necessarily the most relevant consideration in determining the quality of waiting experience. Those findings helped us create a conceptual framework for lived wait time. We suggest that clinicians and policy makers consider the complexity of wait time experience to enhance preoperative patient care. © The Author(s) 2014.

  19. Response time in online stated choice experiments

    DEFF Research Database (Denmark)

    Campbell, Danny; Mørkbak, Morten Raun; Olsen, Søren Bøye

    2017-01-01

    In this paper, we use paradata relating to the length of time respondents required in a self-administered online stated preference surveys. Although this issue has been previously explored, there is little guidance on how to identify and deal with ‘fast’ and ‘slow’ respondents. In this paper, we...... use scale-adjusted latent class models to address preference and variance heterogeneity and explore how class membership varies with response latency. To test our methodology, we use stated choice data collected via an online survey to establish German anglers’ preferences for fishing site attributes...

  20. Clinical experience with real-time ultrasound

    Science.gov (United States)

    Chimiak, William J.; Wolfman, Neil T.; Covitz, Wesley

    1995-05-01

    After testing the extended multimedia interface (EMMI) product which is an asynchronous transmission mode (ATM) user to network interface (UNI) of AT&T at the Society for Computer Applications in Radiology conference in Winston-Salem, the Department of Radiology together with AT&T are implementing a tele-ultrasound system to combine real- time ultrasound with the static imaging features of more traditional digital ultrasound systems. Our current ultrasound system archives digital images to an optical disk system. Static images are sent using our digital radiology systems. This could be transferring images from one digital imaging and communications (DICOM)-compliant machine to another, or the current image transfer methodologies. The prototype of a live ultrasound system using the EMMI demonstrated the feasibility of doing live ultrasound. We now are developing the scenarios using a mix of the two methodologies. Utilizing EMMI technology, radiologists at the BGSM review at a workstation both static images and real-time scanning done by a technologist on patients at a remote site in order to render on-line primary diagnosis. Our goal is to test the feasibility of operating an ultrasound laboratory at a remote site utilizing a trained technologist without the necessity of having a full-time radiologist at that site. Initial plans are for a radiologist to review an initial set of static images on a patient taken by the technologist. If further scanning is required, the EMMI is used to transmit real-time imaging and audio using the audio input of a standard microphone system and the National Television Standards Committee (NTSC) output of the ultrasound equipment from the remote site to the radiologist in the department review station. The EMMI digitally encodes this data and places it in an ATM format. This ATM data stream goes to the GCNS2000 and then to the other EMMI where the ATM data stream is decoded into the live studies and voice communication which are then

  1. Temporality and Time in Fascist Experience

    Directory of Open Access Journals (Sweden)

    Lorenzo Santoro

    2014-05-01

    Full Text Available The article deals with the theme of Temporality in Italian fascism, an argument that is significant in order to analyze its peculiar approach to mass culture, mass rites but also concerning the function of its elite culture. A number of fascist political leaders, intellectuals and agitators insisted in such argument as a fundamental element in the developing of the regime and the approaching of its most peculiar qualities such as new multifaceted   imperialism and the necessity to project a new Nation imbued of a new political and monolithic culture.  Fascism tried to gain a synthesis between very different cultural elements such as futurism, revolutionarism and classicism, romanità, which deserve a peculiar analysis able to deal with the complexity of mass society. For these reasons the essay proposes an articulated methodologically overview on the argument of Temporality in Historiography and social sciences. In fact it insists in analyzing. Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  2. The upgrade of the LHCb Vertex Locator (VELO)

    CERN Document Server

    van Beuzekom, M

    2014-01-01

    The upgrade of the LHCb experiment, planned for 2018, will enable the detector to run at a luminosity of 2 x 10$^{33}$ cm$^{-22}$s$^{-1}$ and explore New Physics effects in the beauty and charm sector with unprecedented precision. To achieve this, the entire readout will be transformed into a triggerless system operating at 40 MHz, where the event selection algorithms will be executed by high-level software in the CPU farm. The upgraded silicon vertex detector (VELO) must be lightweight, radiation hard, vacuum compatible, and has to drive data to the data acquisition system at speeds of up to 3 Tbit/s. This challenge will be met with a new VELO design based on hybrid pixel detectors, positioned to within 5 mm of the LHC colliding beams. The sensors have 55 x 55 $\\mu$m$^2$ square pixels and the VeloPix ASIC, which is being developed for the readout, is based on the Timepix/Medipix family of chips. The hottest ASIC will have to cope with integrated hit rates of up to 900 MHz which translates to a bandwidth of m...

  3. Readout, first- and second-level triggers of the new Belle silicon vertex detector

    Science.gov (United States)

    Friedl, M.; Abe, R.; Abe, T.; Aihara, H.; Asano, Y.; Aso, T.; Bakich, A.; Browder, T.; Chang, M. C.; Chao, Y.; Chen, K. F.; Chidzik, S.; Dalseno, J.; Dowd, R.; Dragic, J.; Everton, C. W.; Fernholz, R.; Fujii, H.; Gao, Z. W.; Gordon, A.; Guo, Y. N.; Haba, J.; Hara, K.; Hara, T.; Harada, Y.; Haruyama, T.; Hasuko, K.; Hayashi, K.; Hazumi, M.; Heenan, E. M.; Higuchi, T.; Hirai, H.; Hitomi, N.; Igarashi, A.; Igarashi, Y.; Ikeda, H.; Ishino, H.; Itoh, K.; Iwaida, S.; Kaneko, J.; Kapusta, P.; Karawatzki, R.; Kasami, K.; Kawai, H.; Kawasaki, T.; Kibayashi, A.; Koike, S.; Korpar, S.; Križan, P.; Kurashiro, H.; Kusaka, A.; Lesiak, T.; Limosani, A.; Lin, W. C.; Marlow, D.; Matsumoto, H.; Mikami, Y.; Miyake, H.; Moloney, G. R.; Mori, T.; Nakadaira, T.; Nakano, Y.; Natkaniec, Z.; Nozaki, S.; Ohkubo, R.; Ohno, F.; Okuno, S.; Onuki, Y.; Ostrowicz, W.; Ozaki, H.; Peak, L.; Pernicka, M.; Rosen, M.; Rozanska, M.; Sato, N.; Schmid, S.; Shibata, T.; Stamen, R.; Stanič, S.; Steininger, H.; Sumisawa, K.; Suzuki, J.; Tajima, H.; Tajima, O.; Takahashi, K.; Takasaki, F.; Tamura, N.; Tanaka, M.; Taylor, G. N.; Terazaki, H.; Tomura, T.; Trabelsi, K.; Trischuk, W.; Tsuboyama, T.; Uchida, K.; Ueno, K.; Ueno, K.; Uozaki, N.; Ushiroda, Y.; Vahsen, S.; Varner, G.; Varvell, K.; Velikzhanin, Y. S.; Wang, C. C.; Wang, M. Z.; Watanabe, M.; Watanabe, Y.; Yamada, Y.; Yamamoto, H.; Yamashita, Y.; Yamashita, Y.; Yamauchi, M.; Yanai, H.; Yang, R.; Yasu, Y.; Yokoyama, M.; Ziegler, T.; Žontar, D.

    2004-12-01

    A major upgrade of the Silicon Vertex Detector (SVD 2.0) of the Belle experiment at the KEKB factory was installed along with new front-end and back-end electronics systems during the summer shutdown period in 2003 to cope with higher particle rates, improve the track resolution and meet the increasing requirements of radiation tolerance. The SVD 2.0 detector modules are read out by VA1TA chips which provide "fast or" (hit) signals that are combined by the back-end FADCTF modules to coarse, but immediate level 0 track trigger signals at rates of several tens of a kHz. Moreover, the digitized detector signals are compared to threshold lookup tables in the FADCTFs to pass on hit information on a single strip basis to the subsequent level 1.5 trigger system, which reduces the rate below the kHz range. Both FADCTF and level 1.5 electronics make use of parallel real-time processing in Field Programmable Gate Arrays (FPGAs), while further data acquisition and event building is done by PC farms running Linux. The new readout system hardware is described and the first results obtained with cosmics are shown.

  4. Integration of the strip barrel staves of the PANDA micro vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Quagli, Tommaso; Brinkmann, Kai-Thomas; Schnell, Robert; Zaunick, Hans-Georg [II. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Giessen (Germany); Collaboration: PANDA-Collaboration

    2014-07-01

    PANDA is a key experiment of the future FAIR facility, under construction in Darmstadt, Germany. It will study the collisions between an antiproton beam and a fixed proton or nuclear target. The Micro Vertex Detector (MVD) is the innermost detector of the apparatus and is composed of four concentric barrels and six forward disks, instrumented with silicon hybrid pixel detectors and double-sided silicon microstrip detectors; its main task is the identification of primary and secondary vertices. The central requirements include high spatial and time resolution, trigger-less readout with high rate capability, good radiation tolerance and low material budget. Square and rectangular microstrip sensors will be used in the two outer barrels of the detector. The sensors and the front-end electronics will be arranged on linear staves, composed of a carbon support structure with an embedded active cooling system. A flexible multilayer bus will be used to route the signals on the stave towards the DAQ system. The design of the stave, its integration concept and some relevant hardware developments are presented.

  5. Students' Understanding of the Concept of Vertex of Quadratic Functions in Relation to Their Personal Meaning of the Concept of Vertex

    Science.gov (United States)

    Childers, Annie Burns; Vidakovic, Draga

    2014-01-01

    This paper explores sixty-six students' personal meaning and interpretation of the vertex of a quadratic function in relation to their understanding of quadratic functions in two different representations, algebraic and word problem. Several categories emerged from students' personal meaning of the vertex including vertex as maximum or minimum…

  6. Advanced monolithic active pixel sensors for tracking, vertexing and calorimetry with full CMOS capability

    Science.gov (United States)

    Stanitzki, M.; SPiDeR Collaboration, www. spider. ac. uk

    2011-09-01

    We present test results from the "TPAC" and "F ORTIS" sensors produced using the 180 nm CMOS INMAPS process. The TPAC sensor has a 50 μm pixel size with advanced in-pixel electronics. Although TPAC was developed for digital electromagnetic calorimetry, the technology can be readily extended to tracking and vertexing applications where highly granular pixels with in-pixel intelligence are required. By way of example, a variant of the TPAC sensor has been proposed for the Super B vertex detector. The F ORTIS sensor is a prototype with several pixel variants to study the performance of a four transistors (4T) architecture and is the first sensor of this type tested for particle physics applications. TPAC and F ORTIS sensors have been fabricated with some of the processing innovations available in INMAPS such as deep p-wells and high-resistivity epitaxial layers. The performance of these sensor variants has been measured both in the laboratory and at test beams and results showing significant improvements due to these innovations are presented. We have recently manufactured the "C HERWELL" sensor, building on the experience with both TPAC and F ORTIS and making use of the 4T approach. C HERWELL is designed for tracking and vertexing and has an integrated ADC and targets very low-noise performance. The principal features of C HERWELL are described.

  7. Measurement of the triple gluon vertex from double quark tagged 4-jet events

    CERN Document Server

    Abreu, P; Adye, T; Adzic, P; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andersson, P; Andreazza, A; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbi, M S; Barbiellini, Guido; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Bärring, O; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bizouard, M A; Bloch, D; Blume, M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Colomer, M; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahm, J; D'Almagne, B; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Di Diodato, A; Djannati, A; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Durand, J D; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Fichet, S; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Geryukov, L; Gokieli, R; Golob, B; Gonçalves, P; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Green, C; Grefrath, A; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Knoblauch, D; Kokkinias, P; Konoplyannikov, A K; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Mahon, J R; Maio, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Medbo, J; Meroni, C; Meyer, S; Meyer, W T; Myagkov, A; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Münich, K; Mulders, M; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Nikolenko, M; Niss, P; Nomerotski, A; Normand, Ainsley; Nygren, A; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Ortuno, S; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Paiano, S; Pain, R; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Piotto, E; Podobnik, T; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Roos, L; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sannino, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Serbelloni, L; Shellard, R C; Sheridan, A; Siegrist, P; Silvestre, R; Simonetto, F; Sissakian, A N; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sokolov, A; Solovyanov, O; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stapnes, Steinar; Stavitski, I; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chernyaev, E; Tegenfeldt, F; Terranova, F; Thomas, J; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Eldik, J; Van Lysebetten, A; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Wlodek, T; Yi, J; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

    1997-01-01

    The 4-jet events collected by the DELPHI experiment at LEP1 in 1992, 1993 and 1994 are analysed to determine the contribution of the triple-gluon vertex. Two of the four jets are tagged as jets from $b$- or $c$-quarks using lifetime and lepton transverse momentum information. The 4-jet contributions from double-gluon bremsstrahlung, the triple-gluon vertex, and secondary quark-antiquark pair production then yield significantly different two-dimensional distributions in the generalized Nachtmann Reiter angle %$\\Theta^{*}_{NR}$ versus the opening angle of the two secondary jets. These distributions are used to fit $C_A/C_F$, the ratio of the coupling strength of the triple-gluon vertex to that of gluon bremsstrahlung, and $N_C/N_A$, the ratio of the number of quark colours to the number of gluons, giving \\begin{center} $C_A/C_F=2.51 \\pm 0.28$ ~and~ $N_C/N_A=0.38 \\pm 0.10$ \\end{center} in agreement with the values expected from QCD: \\begin{center} $C_A/C_F = 9/4 = 2.25$ ~and~ $N_C/N_A = 3/8 = 0.375$. \\end{center...

  8. Error handling for the CDF Silicon Vertex Tracker

    CERN Document Server

    Belforte, S; Dell'Orso, Mauro; Donati, S; Galeotti, S; Giannetti, P; Morsani, F; Punzi, G; Ristori, L; Spinella, F; Zanetti, A M

    2000-01-01

    The SVT online tracker for the CDF upgrade reconstructs two- dimensional tracks using information from the Silicon Vertex detector (SVXII) and the Central Outer Tracker (COT). The SVT has an event rate of 100 kHz and a latency time of 10 mu s. The system is composed of 104 VME 9U digital boards (of 8 different types) and it is implemented as a data driven architecture. Each board runs on its own 30 MHz clock. Since the data output from the SVT (few Mbytes/sec) are a small fraction of the input data (200 Mbytes/sec), it is extremely difficult to track possible internal errors by using only the output stream. For this reason several diagnostic tools have been implemented: local error registers, error bits propagated through the data streams and the Spy Buffer system. Data flowing through each input and output stream of every board are continuously copied to memory banks named Spy Buffers which act as built in logic state analyzers hooked continuously to internal data streams. The contents of all buffers can be ...

  9. Error handling for the CDF online silicon vertex tracker

    CERN Document Server

    Bari, M; Cerri, A; Dell'Orso, Mauro; Donati, S; Galeotti, S; Giannetti, P; Morsani, F; Punzi, G; Ristori, L; Spinella, F; Zanetti, A M

    2001-01-01

    The online silicon vertex tracker (SVT) is composed of 104 VME 9U digital boards (of eight different types). Since the data output from the SVT (few MB/s) are a small fraction of the input data (200 MB/s), it is extremely difficult to track possible internal errors by using only the output stream. For this reason, several diagnostic tools have been implemented: local error registers, error bits propagated through the data streams, and the Spy Buffer system. Data flowing through each input and output stream of every board are continuously copied to memory banks named spy buffers, which act as built-in logic state analyzers hooked continuously to internal data streams. The contents of all buffers can be frozen at any time (e.g., on error detection) to take a snapshot of all data flowing through each SVT board. The spy buffers are coordinated at system level by the Spy Control Board. The architecture, design, and implementation of this system are described. (4 refs).

  10. From vertex detectors to inner trackers with CMOS pixel sensors

    CERN Document Server

    Besson, A.

    2017-01-01

    The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order of magnitude improvement on readout speed and improved radiation tolerance. This triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz 180 nm, for the design of a CPS well adapted for the new ALICE-ITS running conditions. This paper reports the R&D results for the conception of a CPS well adapted for the ALICE-ITS.

  11. Novel integrated CMOS pixel structures for vertex detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kleinfelder, Stuart; Bieser, Fred; Chen, Yandong; Gareus, Robin; Matis, Howard S.; Oldenburg, Markus; Retiere, Fabrice; Ritter, Hans Georg; Wieman, Howard H.; Yamamoto, Eugene

    2003-10-29

    Novel CMOS active pixel structures for vertex detector applications have been designed and tested. The overriding goal of this work is to increase the signal to noise ratio of the sensors and readout circuits. A large-area native epitaxial silicon photogate was designed with the aim of increasing the charge collected per struck pixel and to reduce charge diffusion to neighboring pixels. The photogate then transfers the charge to a low capacitance readout node to maintain a high charge to voltage conversion gain. Two techniques for noise reduction are also presented. The first is a per-pixel kT/C noise reduction circuit that produces results similar to traditional correlated double sampling (CDS). It has the advantage of requiring only one read, as compared to two for CDS, and no external storage or subtraction is needed. The technique reduced input-referred temporal noise by a factor of 2.5, to 12.8 e{sup -}. Finally, a column-level active reset technique is explored that suppresses kT/C noise during pixel reset. In tests, noise was reduced by a factor of 7.6 times, to an estimated 5.1 e{sup -} input-referred noise. The technique also dramatically reduces fixed pattern (pedestal) noise, by up to a factor of 21 in our tests. The latter feature may possibly reduce pixel-by-pixel pedestal differences to levels low enough to permit sparse data scan without per-pixel offset corrections.

  12. Tracking and Vertexing with the ATLAS Inner Detector in the LHC Run2 and Beyond

    CERN Document Server

    Swift, Stewart Patrick; The ATLAS collaboration

    2017-01-01

    Run-2 of the LHC has provided new challenges to track and vertex reconstruction with higher centre-of-mass energies and luminosity leading to increasingly high-multiplicity environments, boosted, and highly-collimated physics objects. To achieve this goal, ATLAS is equipped with the Inner Detector tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. In addition, the Insertable B-layer (IBL) is a fourth pixel layer, which was inserted at the centre of ATLAS during the first long shutdown of the LHC. An overview of the use of each of these subdetectors in track and vertex reconstruction, as well as the algorithmic approaches taken to the specific tasks of pattern recognition and track fitting, is given. The performance of the Inner Detector tracking and vertexing will be summarised. These include a factor of three reduction in the reconstruction time, optimisation for the expected conditions, ...

  13. TRACKING AND VERTEXING WITH THE ATLAS INNER DETECTOR IN THE LHC RUN2 AND BEYOND

    CERN Document Server

    Choi, Kyungeon; The ATLAS collaboration

    2017-01-01

    Run-2 of the LHC has provided new challenges to track and vertex reconstruction with higher centre-of-mass energies and luminosity leading to increasingly high-multiplicity environments, boosted, and highly-collimated physics objects. To achieve this goal, ATLAS is equipped with the Inner Detector tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. In addition, the Insertable B-layer (IBL) is a fourth pixel layer, which was inserted at the centre of ATLAS during the first long shutdown of the LHC. An overview of the use of each of these subdetectors in track and vertex reconstruction, as well as the algorithmic approaches taken to the specific tasks of pattern recognition and track fitting, is given. The performance of the Inner Detector tracking and vertexing will be summarised. These include a factor of three reduction in the reconstruction time, optimisation for the expected conditions, ...

  14. An imaging algorithm for vertex reconstruction for ATLAS Run-2

    CERN Document Server

    The ATLAS collaboration

    2015-01-01

    The reconstruction of vertices corresponding to proton--proton collisions in ATLAS is an essential element of event reconstruction used in many performance studies and physics analyses. During Run-1 of the LHC, ATLAS has employed an iterative approach to vertex finding. In order to improve the flexibility of the algorithm and ensure continued performance for very high numbers of simultaneous collisions in future LHC data taking, a new approach to seeding vertex finding is being developed inspired by image reconstruction techniques. This note provides a brief outline of how reconstructed tracks are used to create an image of likely vertex collisions in an event and presents some preliminary results of the performance of the algorithm in simulation approximating early Run-2 conditions.

  15. Bivariate C^1 quadratic finite elements and vertex splines

    Science.gov (United States)

    Chui, Charles K.; He, Tian Xiao

    1990-01-01

    Following work of Heindl and of Powell and Sabin, each triangle of an arbitrary (regular) triangulation Δ of a polygonal region Ω in {R^2} is subdivided into twelve triangles, using the three medians, yielding the refinement hat Δ of Δ , so that {C^1} quadratic finite elements can be constructed. In this paper, we derive the Bezier nets of these elements in terms of the parameters that describe function and first partial derivative values at the vertices and values of the normal derivatives at the midpoints of the edges of Δ . Consequently, bivariate {C^1} quadratic (generalized) vertex splines on Δ have an explicit formulation. Here, a generalized vertex spline is one which is a piecewise polynomial on the refined grid partition hat Δ and has support that contains at most one vertex of the original partition Δ in its interior. The collection of all {C^1} quadratic generalized vertex splines on Δ so constructed is shown to form a basis of S_2^1(hat Δ ) , the vector space of all functions on {C^1}(Ω ) whose restrictions to each triangular cell of the partition hat Δ are quadratic polynomials. A subspace with the basis given by appropriately chosen generalized vertex splines with exactly one vertex of Δ in the interior of their supports, that reproduces all quadratic polynomials, is identified, and hence, has approximation order three. Quasi-interpolation formulas using this subspace are obtained. In addition, a constructive procedure that yields a locally supported basis of yet another subspace with dimension given by the number of vertices of Δ , that has approximation order three, is given.

  16. Vertex-Detector R&D for CLIC

    CERN Document Server

    Dannheim, Dominik

    2014-03-19

    A detector concept based on hybrid planar pixel-detector technology is under development for the CLIC vertex detector. It comprises fast, low-power and small-pitch readout ASICs implemented in 65 nm CMOS technology (CLICpix) coupled to ultra-thin sensors via low-mass interconnects. The power dissipation of the readout chips is reduced by means of power pulsing, allowing for a cooling system based on forced gas flow. In this paper the CLIC vertex-detector requirements are reviewed and the current status of R&D on sensors, readout and detector integration is presented.

  17. A Gaussian-Sum Filter for Vertex Reconstruction

    CERN Document Server

    Speer, Thomas

    2005-01-01

    A vertex reconstruction algorithm that is based on the Gaussian-sum Filter (GSF) was developed and implemented in the framework of the CMS reconstruction program. While linear least-square estimators are optimal in case all observation errors are Gaussian distributed, the GSF offers a better treatment of non-Gaussian distributions of track parameter errors when these are modelled by Gaussian mixtures. The algorithm has been verified and evaluated with simulated data. The results are compared to the Kalman filter and to an adaptive vertex estimator.

  18. The Virasoro vertex algebra and factorization algebras on Riemann surfaces

    Science.gov (United States)

    Williams, Brian

    2017-12-01

    This paper focuses on the connection of holomorphic two-dimensional factorization algebras and vertex algebras which has been made precise in the forthcoming book of Costello-Gwilliam. We provide a construction of the Virasoro vertex algebra starting from a local Lie algebra on the complex plane. Moreover, we discuss an extension of this factorization algebra to a factorization algebra on the category of Riemann surfaces. The factorization homology of this factorization algebra is computed as the correlation functions. We provide an example of how the Virasoro factorization algebra implements conformal symmetry of the beta-gamma system using the method of effective BV quantization.

  19. Tracking and vertex reconstruction in modern emulsion experiments

    CERN Document Server

    Aoki, S

    2001-01-01

    The analysis procedure of nuclear emulsions has radically changed with the realisation of high speed, fully automated scanning systems. Nuclear emulsion can now be considered as an analog data storage device from which the automated scanning system retrieves the data.

  20. Tracking and vertex reconstruction in modern emulsion experiments

    Science.gov (United States)

    Aoki, Shigeki

    2001-11-01

    The analysis procedure of nuclear emulsions has radically changed with the realisation of high speed, fully automated scanning systems. Nuclear emulsion can now be considered as an analog data storage device from which the automated scanning system retrieves the data.

  1. JetFitter vertex reconstruction performance in the ATLAS experiment

    CERN Document Server

    Miu, Ovidiu

    2016-01-01

    The process of b-tagging relies on a combination of complementary algorithms in a multivariate approach designed to provide an effective discrimination against c- and light-flavour jets. The JetFitter algorithm is one of the three b-tagging algorithms aiming at reconstructing the full decay topology of a b-hadron. This report presents a brief analysis of the secondary vertices reconstruction performance of the JetFitter algorithm in simulated $pp$ collisions at the LHC running at $\\sqrt{s} = 13$ TeV centre-of-mass energy. Comparisons with other algorithms, in particular SV, are also presented in order to underline the relative strengths and weaknesses of the JetFitter algorithm. Improvements in the rejection of undesired tracks are proposed for a future JetFitter optimisation.

  2. TECHNICAL DESIGN REPORT OF THE FORWARD SILICON VERTEX (FVTX)

    Energy Technology Data Exchange (ETDEWEB)

    PHENIX EXPERIMENT; OBRIEN,E.; PAK, R.; DREES, K.A.; (PHENIX EXPERIMENT COLLABORATORS)

    2007-08-01

    The main goal of the RHIC heavy ion program is the discovery of the novel ultra-hot high-density state of matter predicted by the fundamental theory of strong interactions and created in collisions of heavy nuclei, the Quark-Gluon Plasma (QGP). From measurements of the large elliptic flow of light mesons and baryons and their large suppression at high transverse momentum pT that have been made at RHIC, there is evidence that new degrees of freedom, characteristic of a deconfined QCD medium, drive the dynamics of nucleus-nucleus collisions. It has been recognized, however, that the potential of light quarks and gluons to characterize the properties of the QGP medium is limited and the next phase of the RHIC program calls for the precise determination of its density, temperature, opacity and viscosity using qualitatively new probes, such as heavy quarks. We propose the construction of two Forward Silicon Vertex Trackers (FVTX) for the PHENIX experiment that will directly identify and distinguish charm and beauty decays within the acceptance of the muon spectrometers. The FVTX will provide this essential coverage over a range of forward and backward rapidities (1.2 < |y| < 2.4)--a rapidity range coverage which not only brings significantly larger acceptance to PHENIX but which is critical for separating cold nuclear matter effects from QGP effects and is critical for measuring the proton spin contributions over a significant fraction of the kinematic range of interest. In addition, the FVTX will provide greatly reduced background and improved mass resolution for dimuon events, culminating in the first measurements of the {upsilon}{prime} and Drell-Yan at RHIC. These same heavy flavor and dimuon measurements in p+p collisions will allow us to place significant constraints on the gluon and sea quark contributions to the proton's spin and to make fundamentally new tests of the Sivers function universality.

  3. Random matrices and the six-vertex model

    CERN Document Server

    Bleher, Pavel

    2013-01-01

    This book provides a detailed description of the Riemann-Hilbert approach (RH approach) to the asymptotic analysis of both continuous and discrete orthogonal polynomials, and applications to random matrix models as well as to the six-vertex model. The RH approach was an important ingredient in the proofs of universality in unitary matrix models. This book gives an introduction to the unitary matrix models and discusses bulk and edge universality. The six-vertex model is an exactly solvable two-dimensional model in statistical physics, and thanks to the Izergin-Korepin formula for the model with domain wall boundary conditions, its partition function matches that of a unitary matrix model with nonpolynomial interaction. The authors introduce in this book the six-vertex model and include a proof of the Izergin-Korepin formula. Using the RH approach, they explicitly calculate the leading and subleading terms in the thermodynamic asymptotic behavior of the partition function of the six-vertex model with domain wa...

  4. Galilean invariance and vertex renormalization in turbulence theory.

    Science.gov (United States)

    McComb, W D

    2005-03-01

    The Navier-Stokes equation is invariant under Galilean transformation of the instantaneous velocity field. However, the total velocity transformation is effected by transformation of the mean velocity alone. For a constant mean velocity, the equation of motion for the fluctuating velocity is automatically Galilean invariant in the comoving frame, and vertex renormalization is not constrained by this symmetry.

  5. R&D for the Vertexing at CLIC

    CERN Document Server

    Redford, S

    2015-01-01

    The Compact Linear Collider is a candidate to be the next high-energy particle physics collider. Using a novel acceleration technique, electrons and positrons would be brought into collision with a centre-of-mass energy of up to 3 TeV. Despite challenging levels of beam-induced background, this would provide a relatively clean environment in which to perform precision physics measurements. The vertex detector would be crucial in achieving this, and would need to provide accurate particle tracking information to facilitate secondary vertex reconstruction and jet flavour-tagging. With this goal in mind, current technological limits are being stretched to design a low occupancy, low mass and low-power dissipation vertex detector for CLIC. A concept comprising thin hybrid pixel detectors coupled to high- performance readout ASICs, power-pulsing and air-flow cooling is under development. In this paper, the CLIC vertex detector requirements are reviewed and the current status of R&D on sensors, readout, powerin...

  6. Preliminary studies for the LHCb vertex detector cooling system

    CERN Document Server

    Doets, M; Ferro-Luzzi, Massimiliano

    2000-01-01

    99-046 "We present some preliminary studies for the design of a cooling system for the LHCb silicon vertex detector. We consider the case of a cooling system using CO2 in the gas-liquid mixed phase as a coolant. Based on these considerations, we sketch a possible design."

  7. The Urban Function of the Infraordinary: Dry Cleaners as Social Vertexes

    DEFF Research Database (Denmark)

    Lunde Nielsen, Espen

    2015-01-01

    of social coexistence that has ‘a function that is separate from their practical use’ (Jorn 1954). A London dry cleaner serves as testing ground, employing critical spatial practices and creative writing as research tools. The dry cleaner does not simply clean clothes, but is a social vertex and physical...... interface through which (non-)events unfold, trajectories thickens and people of the neighbourhood coexists as familiar strangers (Milgram 2010; Paulos and Goodman 2004) through events in real-time and deposits over time. It is a semi-public space and an implosion of the external neighbourhood, partly...

  8. Domination parameters of a graph with added vertex

    Directory of Open Access Journals (Sweden)

    Maciej Zwierzchowski

    2004-01-01

    Full Text Available Let \\(G=(V,E\\ be a graph. A subset \\(D\\subseteq V\\ is a total dominating set of \\(G\\ if for every vertex \\(y\\in V\\ there is a vertex \\(x\\in D\\ with \\(xy\\in E\\. A subset \\(D\\subseteq V\\ is a strong dominating set of \\(G\\ if for every vertex \\(y\\in V-D\\ there is a vertex \\(x\\in D\\ with \\(xy\\in E\\ and \\(\\deg _{G}(x\\geq\\deg _{G}(y\\. The total domination number \\(\\gamma _{t}(G\\ (the strong domination number \\(\\gamma_{S}(G\\ is defined as the minimum cardinality of a total dominating set (a strong dominating set of \\(G\\. The concept of total domination was first defined by Cockayne, Dawes and Hedetniemi in 1980 [Cockayne E. J., Dawes R. M., Hedetniemi S. T.: Total domination in graphs. Networks 10 (1980, 211–219], while the strong domination was introduced by Sampathkumar and Pushpa Latha in 1996 [Pushpa Latha L., Sampathkumar E.: Strong weak domination and domination balance in a graph. Discrete Mathematics 161 (1996, 235–242]. By a subdivision of an edge \\(uv\\in E\\ we mean removing edge \\(uv\\, adding a new vertex \\(x\\, and adding edges \\(ux\\ and \\(vx\\. A graph obtained from \\(G\\ by subdivision an edge \\(uv\\in E\\ is denoted by \\(G\\oplus u_{x}v_{x}\\. The behaviour of the total domination number and the strong domination number of a graph \\(G\\oplus u_{x}v_{x}\\ is developed.

  9. Subjective Acceleration of Time Experience in Everyday Life across Adulthood

    Science.gov (United States)

    John, Dennis; Lang, Frieder R.

    2015-01-01

    Most people believe that time seems to pass more quickly as they age. Building on assumptions of socioemotional selectivity theory, we investigated whether awareness that one's future lifetime is limited is associated with one's experience of time during everyday activities across adulthood in 3 studies. In the first 2 studies (Study 1: N = 608;…

  10. Abnormal Time Experiences in Major Depression: An Empirical Qualitative Study.

    Science.gov (United States)

    Stanghellini, Giovanni; Ballerini, Massimo; Presenza, Simona; Mancini, Milena; Northoff, Georg; Cutting, John

    2017-01-01

    Phenomenological psychopathology, through theoretical and idiographic studies, conceptualizes major depressive disorder (MDD) as a disorder of time experience. Investigations on abnormal time experience (ATE) in MDD adopting methodologies requested by the standards of empirical sciences are still lacking. Our study aimed to provide a qualitative analysis, on an empirical ground and on a large scale, of narratives of temporal experiences of persons affected by MDD. We interviewed 550 consecutive patients affected by affective and schizophrenic disorders. Clinical files were analysed by means of consensual qualitative research. Out of 100 MDD patients, 96 reported at least 1 ATE. The principal categories of ATE are vital retardation - the experience of a stagnation of endogenous vital processes (37 patients), the experience of present and future dominated by the past (29 patients), and the experience of the slackening of the flow oftime (25 patients). A comparison with ATE in schizophrenia patients showed that in MDD, unlike in schizophrenia, there is no disarticulation of time experience (disorder of temporal synthesis) but rather a disorder of conation or inhibition of becoming. The interview style was not meant to make a quantitative assessment ("false negatives" cannot be excluded). Our findings confirm the relevance of distinctive features of ATE in MDD, support the hypothesis of an intrinsic disordered temporal structure in depressive symptoms, and may have direct implications in clinical practice, especially in relation to differential diagnosis, setting the boundaries between "true" and milder forms of depression, and neurobiological research. © 2016 S. Karger AG, Basel.

  11. The lived experience of part-time baccalaureate nursing faculty.

    Science.gov (United States)

    Gazza, Elizabeth A; Shellenbarger, Teresa

    2010-01-01

    Hiring part-time nursing faculty may impact students, faculty careers, and the institution. Yet, little has been studied, particularly in nursing, regarding the experiences of these faculty. This hermeneutic phenomenological study seeks to understand the lived experience of being a part-time faculty member in a baccalaureate nursing program. Through purposive and snowball sampling, nine nursing faculty in part-time positions in northeastern baccalaureate nursing programs participated in in-depth personal interviews. Four themes were uncovered during data analysis, including achieving the dream, a group divided, for the love of the students, and jump in and figure it out. Results of the study seem to indicate that the experience of being a part-time faculty differs in several ways from being a full-time faculty. Understanding part-time faculty experiences provides insight into faculty needs, issues, and concerns while facilitating the development of research-based recruitment and retention strategies. Recommendations for those involved in nursing education, including nursing faculty and administrators, are provided. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Analysis of an iterated local search algorithm for vertex cover in sparse random graphs

    DEFF Research Database (Denmark)

    Witt, Carsten

    2012-01-01

    finds an optimal cover in polynomial time with a probability arbitrarily close to 1. This behavior relies on the absence of a giant component. As an additional insight into the randomized search, it is shown that the heuristic fails badly also on graphs consisting of a single tree component of maximum......Recently, various randomized search heuristics have been studied for the solution of the minimum vertex cover problem, in particular for sparse random instances according to the G(n,c/n) model, where c>0 is a constant. Methods from statistical physics suggest that the problem is easy if c......search heuristics on random graphs. For csearch heuristic...

  13. Development of CMOS Pixel Sensors fully adapted to the ILD Vertex Detector Requirements

    CERN Document Server

    Winter, Marc; Besson, Auguste; Claus, Gilles; Dorokhov, Andrei; Goffe, Mathieu; Hu-Guo, Christine; Morel, Frederic; Valin, Isabelle; Voutsinas, Georgios; Zhang, Liang

    2012-01-01

    CMOS Pixel Sensors are making steady progress towards the specifications of the ILD vertex detector. Recent developments are summarised, which show that these devices are close to comply with all major requirements, in particular the read-out speed needed to cope with the beam related background. This achievement is grounded on the double- sided ladder concept, which allows combining signals generated by a single particle in two different sensors, one devoted to spatial resolution and the other to time stamp, both assembled on the same mechanical support. The status of the development is overviewed as well as the plans to finalise it using an advanced CMOS process.

  14. Internal alignement of the BABAR silicon vertex tracking detector

    CERN Document Server

    Brown, D; Roberts, D

    2007-01-01

    The BABAR Silicon Vertex Tracker (SVT ) is a five-layer double-sided silicon detector designed to provide precise measurements of the position and direction of primary tracks, and to fully reconstruct low-momentum tracks produced in e+e¡ collisions at the PEP-II asymmetric collider at Stanford Linear Accelerator Center. This paper describes the design, implementation, performance and validation of the local alignment procedure used to determine the relative positions and orientations of the 340 Silicon Vertex Trackerwafers. This procedure uses a tuned mix of lab-bench measurements and complementary in-situ experimental data to control systematic distortions. Wafer positions and orientations are determined by minimizing a Â2 computed using these data for each wafer individually, iterating to account for between-wafer correlations. A correction for aplanar distortions of the silicon wafers is measured and applied. The net effect of residual mis-alignments on relevant physical variables evaluated in special co...

  15. Vertex detectors: The state of the art and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Damerell, C.J.S. [Rutherford Appleton Laboratory, Didcot (United Kingdom)

    1997-01-01

    We review the current status of vertex detectors (tracking microscopes for the recognition of charm and bottom particle decays). The reasons why silicon has become the dominant detector medium are explained. Energy loss mechanisms are reviewed, as well as the physics and technology of semiconductor devices, emphasizing the areas of most relevance for detectors. The main design options (microstrips and pixel devices, both CCD`s and APS`s) are discussed, as well as the issue of radiation damage, which probably implies the need to change to detector media beyond silicon for some vertexing applications. Finally, the evolution of key performance parameters over the past 15 years is reviewed, and an attempt is made to extrapolate to the likely performance of detectors working at the energy frontier ten years from now.

  16. The secondary vertex finding algorithm with the ATLAS detector

    CERN Document Server

    Heer, Sebastian; The ATLAS collaboration

    2017-01-01

    A high performance identification of jets, produced via fragmentation of bottom quarks, is crucial for the ATLAS physics program. These jets can be identified by exploiting the presence of cascade decay vertices from bottom hadrons. A general vertex-finding algorithm is introduced and its ap- plication to the search for secondary vertices inside jets is described. Kinematic properties of the reconstructed vertices are used to construct several b-jet identification algorithms. The features and performance of the secondary vertex finding algorithm in a jet, as well as the performance of the jet tagging algorithms, are studied using simulated $pp$ -> $t\\bar{t}$ events at a centre-of-mass energy of 13 TeV.

  17. Worldline calculation of the three-gluon vertex

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadiniaz, N.; Schubert, C. [Dipartimento di Fisica, Universita di Bologna and INFN Sezione di Bologna Via Irnerio 46, I-40126 Bologna (Italy); Instituto de Fisica y Matematicas Universidad Michoacana de San Nicolas de Hidalgo Apdo. Postal 2-82 C.P. 58040, Morelia, Michoacan (Mexico)

    2012-10-23

    The three-gluon vertex is a basic object of interest in nonabelian gauge theory. At the one-loop level, it has been calculated and analyzed by a number of authors. Here we use the worldline formalism to unify the calculations of the scalar, spinor and gluon loop contributions to the one-loop vertex, leading to an extremely compact representation in terms of field strength tensors. We verify its equivalence with previously obtained representations, and explain the relation of its structure to the low-energy effective action. The sum rule found by Binger and Brodsky for the scalar, spinor and gluon loop contributions in the present approach relates to worldline supersymmetry.

  18. The N = 1 Triplet Vertex Operator Superalgebras: Twisted Sector

    Directory of Open Access Journals (Sweden)

    Drazen Adamovic

    2008-12-01

    Full Text Available We classify irreducible σ-twisted modules for the N = 1 super triplet vertex operator superalgebra SW(m introduced recently [Adamovic D., Milas A., Comm. Math. Phys., to appear, arXiv:0712.0379]. Irreducible graded dimensions of σ-twisted modules are also determined. These results, combined with our previous work in the untwisted case, show that the SL(2,Z-closure of the space spanned by irreducible characters, irreducible supercharacters and σ-twisted irreducible characters is (9m + 3-dimensional. We present strong evidence that this is also the (full space of generalized characters for SW(m. We are also able to relate irreducible SW(m characters to characters for the triplet vertex algebra W(2m + 1, studied in [Adamovic D., Milas A., Adv. Math. 217 (2008, 2664-2699, arXiv:0707.1857].

  19. On the zero crossing of the three-gluon vertex

    Directory of Open Access Journals (Sweden)

    A. Athenodorou

    2016-10-01

    Full Text Available We report on new results on the infrared behavior of the three-gluon vertex in quenched Quantum Chromodynamics, obtained from large-volume lattice simulations. The main focus of our study is the appearance of the characteristic infrared feature known as ‘zero crossing’, the origin of which is intimately connected with the nonperturbative masslessness of the Faddeev–Popov ghost. The appearance of this effect is clearly visible in one of the two kinematic configurations analyzed, and its theoretical origin is discussed in the framework of Schwinger–Dyson equations. The effective coupling in the momentum subtraction scheme that corresponds to the three-gluon vertex is constructed, revealing the vanishing of the effective interaction at the exact location of the zero crossing.

  20. On the zero crossing of the three-gluon vertex

    Energy Technology Data Exchange (ETDEWEB)

    Athenodorou, A. [Department of Physics, University of Cyprus, POB 20537, 1678 Nicosia (Cyprus); Binosi, D., E-mail: binosi@ectstar.eu [European Centre for Theoretical Studies in Nuclear Physics and Related Areas - ECT* and Fondazione Bruno Kessler, Villa Tambosi, Strada delle Tabarelle 286, I-38050 Villazzano (Italy); Boucaud, Ph. [Laboratoire de Physique Théorique (UMR8627), CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay (France); De Soto, F. [Dpto. Sistemas Físicos, Químicos y Naturales, Univ. Pablo de Olavide, 41013 Sevilla (Spain); Papavassiliou, J. [Department of Theoretical Physics and IFIC, University of Valencia-CSIC, E-46100, Valencia (Spain); Rodríguez-Quintero, J. [Department of Integrated Sciences, University of Huelva, E-21071 Huelva (Spain); Zafeiropoulos, S. [Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany)

    2016-10-10

    We report on new results on the infrared behavior of the three-gluon vertex in quenched Quantum Chromodynamics, obtained from large-volume lattice simulations. The main focus of our study is the appearance of the characteristic infrared feature known as ‘zero crossing’, the origin of which is intimately connected with the nonperturbative masslessness of the Faddeev–Popov ghost. The appearance of this effect is clearly visible in one of the two kinematic configurations analyzed, and its theoretical origin is discussed in the framework of Schwinger–Dyson equations. The effective coupling in the momentum subtraction scheme that corresponds to the three-gluon vertex is constructed, revealing the vanishing of the effective interaction at the exact location of the zero crossing.

  1. Time delay systems theory, numerics, applications, and experiments

    CERN Document Server

    Ersal, Tulga; Orosz, Gábor

    2017-01-01

    This volume collects contributions related to selected presentations from the 12th IFAC Workshop on Time Delay Systems, Ann Arbor, June 28-30, 2015. The included papers present novel techniques and new results of delayed dynamical systems. The topical spectrum covers control theory, numerical analysis, engineering and biological applications as well as experiments and case studies. The target audience primarily comprises research experts in the field of time delay systems, but the book may also be beneficial for graduate students alike. .

  2. The effect of radiation damage on the vertex detector efficiency

    CERN Document Server

    Cooke, O

    1997-01-01

    97-023 This note describes a brief study into the effects of the radiation damage on the vertex detectorperformance. The noise increases as the detector is irradiated. Fixing the fraction of noise clusters to 0.1% by adjusting the thresholds brings about a loss in efficiency with increased irradiation. This loss in efficiency is parameterized, and some effects on the B->pi+pi- channel are shown.

  3. A Gaussian-Sum Filter for Vertex Reconstruction

    OpenAIRE

    Frühwirth, R.; Speer, T

    2004-01-01

    A vertex reconstruction algorithm was developed based on the Gaussian-sum Filter and implemented in the framework of the CMS reconstruction program. While linear least-square estimators are optimal in case all observation errors are Gaussian distributed, a GSF offers a better treatment of non-Gaussian distributions of track parameter errors when these are modeled by Gaussian mixtures. Results are compared to the Kalman filter.

  4. A Gaussian-Sum Filter for Vertex Reconstruction

    CERN Document Server

    Frühwirth, R

    2005-01-01

    A vertex reconstruction algorithm was developed based on the Gaussian-sum filter (GSF) and implemented in the framework of the CMS reconstruction program. While linear least-square estimators are optimal in case all observation errors are Gaussian distributed, the GSF offers a better treatment of non-Gaussian distributions of track parameter errors when these are modelled by Gaussian mixtures. In addition, this ensures better protection against outliers and offers some robustness.

  5. Can experience overcome stereotypes in times of terror threat?

    Directory of Open Access Journals (Sweden)

    Mirya R. Holman

    2017-02-01

    Full Text Available Research on evaluations of leaders has frequently found that female leaders receive lower ratings in times of national security crisis. However, less is known about countervailing factors. We contend that partisanship and leadership experience in relevant domains are two factors that can counteract the negative effects of terrorist threat on evaluations of female political leaders. To test this expectation, we implemented a national study in 2012 containing terrorist threat and non-threat conditions, and then asked participants to evaluate political leaders. The results show that Republican leaders, including women, are unaffected by terrorist threat; in contrast, Democratic leaders are punished during times of terrorist threat, but this negative effect is smaller for then-Secretary of State Hillary Clinton compared to Nancy Pelosi, who lacks similar experience. In short, Republican partisanship is a strong countervailing factor, while leadership experience in national security more modestly countervails.

  6. Statistical aspects of quantitative real-time PCR experiment design

    Czech Academy of Sciences Publication Activity Database

    Kitchen, R.R.; Kubista, Mikael; Tichopád, Aleš

    2010-01-01

    Roč. 50, č. 4 (2010), s. 231-236 ISSN 1046-2023 R&D Projects: GA AV ČR IAA500520809 Institutional research plan: CEZ:AV0Z50520701 Keywords : Real-time PCR * Experiment design * Nested analysis of variance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.527, year: 2010

  7. First-time fathers' experiences of normal childbirth.

    Science.gov (United States)

    Ledenfors, Anna; Berterö, Carina

    2016-09-01

    To identify and describe first-time fathers' experiences of normal childbirth. A qualitative interview study using a thematic analysis for analysing the transcripts. purposeful sampling was used. Eight men were interviewed two to six months after experiencing childbirth. Participants were men who had become fathers for the first time. A county located in the middle of Sweden covering both urban and rural areas. The analysis resulted in one major theme - a transformative experience - with four sub-themes: preparing for childbirth, feeling vulnerable in a new situation, being confirmed as part of a unit, and meeting their child for the first time. The findings indicate that the needs of prospective fathers should be given more recognition during childbirth. The findings also show that the midwife is an important person for prospective fathers, both before and during the birth. The findings of the study show what affects first-time fathers' experiences of childbirth. By listening to fathers and recognising them as part of a unit with the woman giving birth, midwifes can support them and increase their participation. Thereby, they can find their role in an unfamiliar situation and thus have a positive experience of childbirth. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Single-molecule binding experiments on long time scales

    NARCIS (Netherlands)

    Elenko, Mark P.; Szostak, Jack W.; van Oijen, Antoine M.

    We describe an approach for performing single-molecule binding experiments on time scales from hours to days, allowing for the observation of slower kinetics than have been previously investigated by single-molecule techniques. Total internal reflection fluorescence microscopy is used to image the

  9. Organization mechanism and counting algorithm on vertex-cover solutions

    Science.gov (United States)

    Wei, Wei; Zhang, Renquan; Niu, Baolong; Guo, Binghui; Zheng, Zhiming

    2015-04-01

    Counting the solution number of combinational optimization problems is an important topic in the study of computational complexity, which is concerned with Vertex-Cover in this paper. First, we investigate organizations of Vertex-Cover solution spaces by the underlying connectivity of unfrozen vertices and provide facts on the global and local environment. Then, a Vertex-Cover Solution Number Counting Algorithm is proposed and its complexity analysis is provided, the results of which fit very well with the simulations and have a better performance than those by 1-RSB in the neighborhood of c = e for random graphs. Based on the algorithm, variation and fluctuation on the solution number the statistics are studied to reveal the evolution mechanism of the solution numbers. Furthermore, the marginal probability distributions on the solution space are investigated on both the random graph and scale-free graph to illustrate the different evolution characteristics of their solution spaces. Thus, doing solution number counting based on the graph expression of the solution space should be an alternative and meaningful way to study the hardness of NP-complete and #P-complete problems and the appropriate algorithm design can help to achieve better approximations of solving combinational optimization problems and the corresponding counting problems.

  10. Colour-independent partition functions in coloured vertex models

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O., E-mail: omar.foda@unimelb.edu.au [Dept. of Mathematics and Statistics, University of Melbourne, Parkville, VIC 3010 (Australia); Wheeler, M., E-mail: mwheeler@lpthe.jussieu.fr [Laboratoire de Physique Théorique et Hautes Energies, CNRS UMR 7589 (France); Université Pierre et Marie Curie – Paris 6, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2013-06-11

    We study lattice configurations related to S{sub n}, the scalar product of an off-shell state and an on-shell state in rational A{sub n} integrable vertex models, n∈{1,2}. The lattice lines are colourless and oriented. The state variables are n conserved colours that flow along the line orientations, but do not necessarily cover every bond in the lattice. Choosing boundary conditions such that the positions where the colours flow into the lattice are fixed, and where they flow out are summed over, we show that the partition functions of these configurations, with these boundary conditions, are n-independent. Our results extend to trigonometric A{sub n} models, and to all n. This n-independence explains, in vertex-model terms, results from recent studies of S{sub 2} (Caetano and Vieira, 2012, [1], Wheeler, (arXiv:1204.2089), [2]). Namely, 1.S{sub 2}, which depends on two sets of Bethe roots, {b_1} and {b_2}, and cannot (as far as we know) be expressed in single determinant form, degenerates in the limit {b_1}→∞, and/or {b_2}→∞, into a product of determinants, 2. Each of the latter determinants is an A{sub 1} vertex-model partition function.

  11. A fast algorithm for vertex-frequency representations of signals on graphs.

    Science.gov (United States)

    Jestrović, Iva; Coyle, James L; Sejdić, Ervin

    2017-02-01

    The windowed Fourier transform (short time Fourier transform) and the S-transform are widely used signal processing tools for extracting frequency information from non-stationary signals. Previously, the windowed Fourier transform had been adopted for signals on graphs and has been shown to be very useful for extracting vertex-frequency information from graphs. However, high computational complexity makes these algorithms impractical. We sought to develop a fast windowed graph Fourier transform and a fast graph S-transform requiring significantly shorter computation time. The proposed schemes have been tested with synthetic test graph signals and real graph signals derived from electroencephalography recordings made during swallowing. The results showed that the proposed schemes provide significantly lower computation time in comparison with the standard windowed graph Fourier transform and the fast graph S-transform. Also, the results showed that noise has no effect on the results of the algorithm for the fast windowed graph Fourier transform or on the graph S-transform. Finally, we showed that graphs can be reconstructed from the vertex-frequency representations obtained with the proposed algorithms.

  12. Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment

    Science.gov (United States)

    Glicksohn, Joseph; Berkovich-Ohana, Aviva; Mauro, Federica; Ben-Soussan, Tal D.

    2017-01-01

    The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min), followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP) task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log–log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as “the sensation of time disappeared,” their TP data could not be linearized using a log–log plot, hence indicating that for these

  13. Results on diamond timing detector for the TOTEM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bossini, E., E-mail: edoardo.bossini@pi.infn.it [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Rome (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (Italy)

    2016-07-11

    We describe the results and status of our R&D on diamond timing detectors for the TOTEM experiment at CERN. Tests with commercial devices have been done and here reported; the unsatisfactory results push us to design a new detector. We present test beams results and the front-end electronics, critical point of the design. Efficiency studies and timing performance dependence from detector capacitance will be also reported. - Highlights: • Diamond particles detector for precise Time Of Flight measurements. • Integrated very low-noise electronics. • Minimum Ionizing Particle detector. • Diamond detector development and characterization.

  14. Original electric-vertex formulation of the symmetric eight-vertex model on the square lattice is fully nonuniversal

    Science.gov (United States)

    Krčmár, Roman; Šamaj, Ladislav

    2018-01-01

    The partition function of the symmetric (zero electric field) eight-vertex model on a square lattice can be formulated either in the original "electric" vertex format or in an equivalent "magnetic" Ising-spin format. In this paper, both electric and magnetic versions of the model are studied numerically by using the corner transfer matrix renormalization-group method which provides reliable data. The emphasis is put on the calculation of four specific critical exponents, related by two scaling relations, and of the central charge. The numerical method is first tested in the magnetic format, the obtained dependencies of critical exponents on the model's parameters agree with Baxter's exact solution, and weak universality is confirmed within the accuracy of the method due to the finite size of the system. In particular, the critical exponents η and δ are constant as required by weak universality. On the other hand, in the electric format, analytic formulas based on the scaling relations are derived for the critical exponents ηe and δe which agree with our numerical data. These exponents depend on the model's parameters which is evidence for the full nonuniversality of the symmetric eight-vertex model in the original electric formulation.

  15. LHCb VErtex LOcator module characterisation and long term quality assurance tests

    CERN Document Server

    Bates, A; Doherty, F; Dumps, R; Dwyer, L; Gersabeck, M; Marinho, 1, F; Melone, J; Parkes, C; Saavedra, A; Tobin, M; Viret, S

    2009-01-01

    LHCb is the dedicated b-physics experiment of the LHC. Its vertex detector, the VErtex LOcator (VELO), will operate in a harsh radiation environment with limited access due to its proximity to the LHC beam. To ensure the long term operation and performance, every module was required to pass a set of quality assurance tests. These were specifically developed for the VELO modules to take into account their operational environment and assembly steps. Each VELO module was rigorously inspected, tested and thermally cycled in the Glasgow module burn-in procedures. This paper provides details of the burn-in procedures and summarises the main results that were found. Some of the major results presented in this paper are: the full characterisation of the leakage currents; identification of bad channels; and signal to noise measurements. A few minor problems were identified through visual inspections of the modules and the feedback into the production process proved critical. As a result of the electrical and thermal t...

  16. Vertex coloring of graphs via phase dynamics of coupled oscillatory networks.

    Science.gov (United States)

    Parihar, Abhinav; Shukla, Nikhil; Jerry, Matthew; Datta, Suman; Raychowdhury, Arijit

    2017-04-19

    While Boolean logic has been the backbone of digital information processing, there exist classes of computationally hard problems wherein this paradigm is fundamentally inefficient. Vertex coloring of graphs, belonging to the class of combinatorial optimization, represents one such problem. It is well studied for its applications in data sciences, life sciences, social sciences and technology, and hence, motivates alternate, more efficient non-Boolean pathways towards its solution. Here we demonstrate a coupled relaxation oscillator based dynamical system that exploits insulator-metal transition in Vanadium Dioxide (VO2) to efficiently solve vertex coloring of graphs. Pairwise coupled VO2 oscillator circuits have been analyzed before for basic computing operations, but using complex networks of VO2 oscillators, or any other oscillators, for more complex tasks have been challenging in theory as well as in experiments. The proposed VO2 oscillator network harnesses the natural analogue between optimization problems and energy minimization processes in highly parallel, interconnected dynamical systems to approximate optimal coloring of graphs. We further indicate a fundamental connection between spectral properties of linear dynamical systems and spectral algorithms for graph coloring. Our work not only elucidates a physics-based computing approach but also presents tantalizing opportunities for building customized analog co-processors for solving hard problems efficiently.

  17. LHCb: Performance and Radiation Damage Effects in the LHCb Vertex Locator

    CERN Multimedia

    Carvalho Akiba, K

    2014-01-01

    LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the LHC. Heavy hadrons are identified through their flight distance in the Vertex Locator (VELO), hence the detector is critical for both the trigger and offline physics analyses. The VELO is the retractable silicon-strip detector surrounding the LHCb interaction point. It is located only 7 mm from the LHC beam during normal LHC operation, once moved into its closed position for each LHC fill when stable beams are obtained. During insertion the detector is centred around the LHC beam by the online reconstruction of the primary vertex position. Both VELO halves comprise 21 silicon micro-strip modules each. A module is made of two n-on-n 300 $\\mu$m thick half-disc sensors with R-measuring and $\\phi$-measuring micro-strip geometry, mounted on a carbon fibre support paddle. The minimum pitch is approximately 40 $\\mu$m. The detector is also equipped with the only n-on-p sensors operating at the LHC. The detectors are operated in ...

  18. Adding timing to the VELO

    CERN Document Server

    Mitreska, Biljana

    2017-01-01

    The LHCb experiment is designed to perform high precision measurements of matter-antimatter asymmetries and searches for rare and forbidden decays, with the aim of discovering new and unexpected particles and forces. In 2030 the LHC beam intensity will increase by a factor of 50 compared to current operations. This means increased samples of the particles we need to study, but it also presents experimental challenges. In particular, with current technology it becomes impossible to differentiate the many (>50) separate proton-proton collisions which occur for each bunch crossing.\\\\ In this project a Monte Carlo simulation was developed to model the operation of a silicon pixel vertex detector surrounding the collision region at LHCb, under the conditions expected after 2030, after the second upgrade of the Vertex Locator(VELO).The main goal was studying the effect of adding '4D' detectors which save high-precision timing information, in addition to the usual three spatial coordinates, as charged particles pas...

  19. Thim's Experiment and Exact Rotational Space-Time Transformations

    CERN Document Server

    Hsu, Leonardo

    2014-01-01

    Thim measured the transverse Doppler shift using a system consisting of a stationary antenna and pickup, in addition to a number of intermediate antennas mounted on the rim of a rotating disk. No such shift was detected, although the experiment should have had enough sensitivity to measure it, as predicted by the Lorentz transformations. However, using the Lorentz transformations to analyze the results of experiments involving circular motion, while commonly done, is inappropriate because such an analysis involves non-inertial frames, which are outside the range of validity of special relativity. In this paper, we re-analyze Thim's experiment using exact rotational space-time transformations, finding that his null result is consistent with theoretical predictions.

  20. Space, body, time and relationship experiences of recess physical activity

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Andersen, Henriette Bondo; Tjørnhøj-Thomsen, Tine

    2016-01-01

    physically active. This study was conducted to explore the least physically active children's "lived experiences" within four existential lifeworlds linked to physical activity during recess: space, body, time, and relations. METHODS: The study builds on ethnographic fieldwork in a public school in Denmark...... using a combination of participatory photo interviews and participant observation. Thirty-seven grade five children (11-12 years old) were grouped in quartiles based on their objectively measured daily physical activity levels. Eight children in the lowest activity quartile (six girls) were selected...... to participate in the study. To avoid stigmatising and to make generalisations more reliable we further recruited eight children from the two highest activity quartiles (four girls) to participate. RESULTS: An analysis of the least physically active children's "lived experiences" of space, body, time...

  1. Time of flight measurement on the SOFIA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bail, A.; Taieb, J.; Chatillon, A.; Belier, G.; Laurent, B.; Pellereau, E. [CEA/DAM/DIF, Arpajon (France)

    2011-07-01

    The SOFIA experiment, which will be held at GSI (Darmstadt (Germany)) will allow to completely determine the mass and charge numbers of fragments produced in the fission reaction of radioactive actinides in reverse kinematics. Therefore, a dedicated setup has been developed for the Time of Flight measurement of relativistic heavy ions. The studies, which led to the choice of the adequate plastic scintillators and photomultipliers, are presented. Tests have been undertaken with the ELSA laser and electron beam facility. They shown that a suitable choice would be EJ-232 plastic scintillator for the ToF wall and EJ-232Q for the start detector and Hamamatsu H6533 and H10580 photomultipliers. This was confirmed by two test experiments realized at GSI with relativistic heavy ion beam ({sup 56}Fe and {sup 238}U), where a time of flight resolution better than 20 ps FWHM was reached. (authors)

  2. Art in time and space: context modulates the relation between art experience and viewing time.

    Science.gov (United States)

    Brieber, David; Nadal, Marcos; Leder, Helmut; Rosenberg, Raphael

    2014-01-01

    The experience of art emerges from the interaction of various cognitive and affective processes. The unfolding of these processes in time and their relation with viewing behavior, however, is still poorly understood. Here we examined the effect of context on the relation between the experience of art and viewing time, the most basic indicator of viewing behavior. Two groups of participants viewed an art exhibition in one of two contexts: one in the museum, the other in the laboratory. In both cases viewing time was recorded with a mobile eye tracking system. After freely viewing the exhibition, participants rated each artwork on liking, interest, understanding, and ambiguity scales. Our results show that participants in the museum context liked artworks more, found them more interesting, and viewed them longer than those in the laboratory. Analyses with mixed effects models revealed that aesthetic appreciation (compounding liking and interest), understanding, and ambiguity predicted viewing time for artworks and for their corresponding labels. The effect of aesthetic appreciation and ambiguity on viewing time was modulated by context: Whereas art appreciation tended to predict viewing time better in the laboratory than in museum context, the relation between ambiguity and viewing time was positive in the museum and negative in the laboratory context. Our results suggest that art museums foster an enduring and focused aesthetic experience and demonstrate that context modulates the relation between art experience and viewing behavior.

  3. Art in time and space: context modulates the relation between art experience and viewing time.

    Directory of Open Access Journals (Sweden)

    David Brieber

    Full Text Available The experience of art emerges from the interaction of various cognitive and affective processes. The unfolding of these processes in time and their relation with viewing behavior, however, is still poorly understood. Here we examined the effect of context on the relation between the experience of art and viewing time, the most basic indicator of viewing behavior. Two groups of participants viewed an art exhibition in one of two contexts: one in the museum, the other in the laboratory. In both cases viewing time was recorded with a mobile eye tracking system. After freely viewing the exhibition, participants rated each artwork on liking, interest, understanding, and ambiguity scales. Our results show that participants in the museum context liked artworks more, found them more interesting, and viewed them longer than those in the laboratory. Analyses with mixed effects models revealed that aesthetic appreciation (compounding liking and interest, understanding, and ambiguity predicted viewing time for artworks and for their corresponding labels. The effect of aesthetic appreciation and ambiguity on viewing time was modulated by context: Whereas art appreciation tended to predict viewing time better in the laboratory than in museum context, the relation between ambiguity and viewing time was positive in the museum and negative in the laboratory context. Our results suggest that art museums foster an enduring and focused aesthetic experience and demonstrate that context modulates the relation between art experience and viewing behavior.

  4. Art in Time and Space: Context Modulates the Relation between Art Experience and Viewing Time

    Science.gov (United States)

    Brieber, David; Nadal, Marcos; Leder, Helmut; Rosenberg, Raphael

    2014-01-01

    The experience of art emerges from the interaction of various cognitive and affective processes. The unfolding of these processes in time and their relation with viewing behavior, however, is still poorly understood. Here we examined the effect of context on the relation between the experience of art and viewing time, the most basic indicator of viewing behavior. Two groups of participants viewed an art exhibition in one of two contexts: one in the museum, the other in the laboratory. In both cases viewing time was recorded with a mobile eye tracking system. After freely viewing the exhibition, participants rated each artwork on liking, interest, understanding, and ambiguity scales. Our results show that participants in the museum context liked artworks more, found them more interesting, and viewed them longer than those in the laboratory. Analyses with mixed effects models revealed that aesthetic appreciation (compounding liking and interest), understanding, and ambiguity predicted viewing time for artworks and for their corresponding labels. The effect of aesthetic appreciation and ambiguity on viewing time was modulated by context: Whereas art appreciation tended to predict viewing time better in the laboratory than in museum context, the relation between ambiguity and viewing time was positive in the museum and negative in the laboratory context. Our results suggest that art museums foster an enduring and focused aesthetic experience and demonstrate that context modulates the relation between art experience and viewing behavior. PMID:24892829

  5. Journalism and change in time experience in Western society

    OpenAIRE

    Carlos Franciscato

    2011-01-01

    The purpose of this paper is to investigate the temporality produced by journalistic practice and the ways journalism has a privilege to build a specifi c type of social experience of the present time. This inquiry carries out a historical journey, but it is not our purpose to present a history of press in the sense of a history of institutions, particular genres and languages. Instead, this investigation develops a historical study in order to identify social temporal phenomena produced by jo...

  6. Spatial and vertex resolution studies on the ATLAS Pixel Detector based on Combined Testbeam 2004 data

    CERN Document Server

    Reisinger, Ingo; Klingenberg, Reiner

    2006-01-01

    This diploma thesis deals with spatial and vertex resolution studies on the ATLAS Pixel detector based on real data taken during the Combined Testbeam period 2004 (17th May - 15th November). For the Combined Testbeam a barrel segment of the ATLAS Detector was build up and tested under real experimental conditions. Several data sets, being recorded during that time, are reconstructed by the ATLAS control framework called ATHENA. The input information for the reconstruction of the particle tracks through the Pixel Detector are the so-called spacepoints. Their uncertainty affects the resolution of the reconstructed particle tracks and thus, also the accuracy of the vertex reconstruction. Since traversing particles deposite their charge mostly (but not compellingly) within more than one pixel, all pixels corresponding to one hit have to be grouped together to a cluster. To compute the spacepoint from the cluster information two different strategies can be performed. The first one is a digital clustering, w...

  7. Porting Large HPC Applications to GPU Clusters: The Codes GENE and VERTEX

    CERN Document Server

    Dannert, Tilman; Rampp, Markus

    2013-01-01

    We have developed GPU versions for two major high-performance-computing (HPC) applications originating from two different scientific domains. GENE is a plasma microturbulence code which is employed for simulations of nuclear fusion plasmas. VERTEX is a neutrino-radiation hydrodynamics code for "first principles"-simulations of core-collapse supernova explosions. The codes are considered state of the art in their respective scientific domains, both concerning their scientific scope and functionality as well as the achievable compute performance, in particular parallel scalability on all relevant HPC platforms. GENE and VERTEX were ported by us to HPC cluster architectures with two NVidia Kepler GPUs mounted in each node in addition to two Intel Xeon CPUs of the Sandy Bridge family. On such platforms we achieve up to twofold gains in the overall application performance in the sense of a reduction of the time to solution for a given setup with respect to a pure CPU cluster. The paper describes our basic porting ...

  8. Robust test method for time-course microarray experiments

    Directory of Open Access Journals (Sweden)

    George Stephen L

    2010-07-01

    Full Text Available Abstract Background In a time-course microarray experiment, the expression level for each gene is observed across a number of time-points in order to characterize the temporal trajectories of the gene-expression profiles. For many of these experiments, the scientific aim is the identification of genes for which the trajectories depend on an experimental or phenotypic factor. There is an extensive recent body of literature on statistical methodology for addressing this analytical problem. Most of the existing methods are based on estimating the time-course trajectories using parametric or non-parametric mean regression methods. The sensitivity of these regression methods to outliers, an issue that is well documented in the statistical literature, should be of concern when analyzing microarray data. Results In this paper, we propose a robust testing method for identifying genes whose expression time profiles depend on a factor. Furthermore, we propose a multiple testing procedure to adjust for multiplicity. Conclusions Through an extensive simulation study, we will illustrate the performance of our method. Finally, we will report the results from applying our method to a case study and discussing potential extensions.

  9. A vertex-centered and positivity-preserving scheme for anisotropic diffusion problems on arbitrary polygonal grids

    Science.gov (United States)

    Zhang, Xiaoping; Su, Shuai; Wu, Jiming

    2017-09-01

    We suggest a new positivity-preserving finite volume scheme for anisotropic diffusion problems on arbitrary polygonal grids. The scheme has vertex-centered, edge-midpoint and cell-centered unknowns. The vertex-centered unknowns are primary and have finite volume equations associated with them. The edge-midpoint and cell-centered unknowns are treated as auxiliary ones and are interpolated by the primary unknowns, which makes the final scheme a pure vertex-centered one. Unlike most existing positivity-preserving schemes, the construction of the scheme is based on a special nonlinear two-point flux approximation that has a fixed stencil and does not require the convex decomposition of the co-normal. In order to solve efficiently the nonlinear systems resulting from the nonlinear scheme, Picard method and its Anderson acceleration are discussed. Numerical experiments demonstrate the second-order accuracy and well positivity of the solution for heterogeneous and anisotropic problems on severely distorted grids. The high efficiency of the Anderson acceleration is also shown on reduction of the number of nonlinear iterations. Moreover, the proposed scheme does not have the so-called numerical heat-barrier issue suffered by most existing cell-centered and hybrid schemes. However, further improvements have to be made if the solution is very close to the machine precision and the mesh distortion is very severe.

  10. The forcing vertex detour monophonic number of a graph

    Directory of Open Access Journals (Sweden)

    P. Titus

    2016-04-01

    Full Text Available For any two vertices x and y in a connected graph G, an x–y path is a monophonic path if it contains no chord, and a longest x–y monophonic path is called an x–y detour monophonic path. For any vertex x in G, a set Sx⊆V(G is an x-detour monophonic set of G if each vertex v∈V(G lies on an x–y detour monophonic path for some element y in Sx. The minimum cardinality of an x-detour monophonic set of G is the x-detour monophonic number of G, denoted by dmx(G. A subset Tx of a minimum x-detour monophonic set Sx of G is an x-forcing subset for Sx if Sx is the unique minimum x-detour monophonic set containing Tx. An x-forcing subset for Sx of minimum cardinality is a minimum x-forcing subset of Sx. The forcing x-detour monophonic number of Sx, denoted by fdmx(Sx, is the cardinality of a minimum x-forcing subset for Sx. The forcing x-detour number of G is fdmx(G=min{fdmx(Sx}, where the minimum is taken over all minimum x-detour monophonic sets Sx in G. We determine bounds for it and find the same for some special classes of graphs. Also we show that for every pair s,t of integers with 2≤s≤t, there exists a connected graph G such that fdmx(G=s and dmx(G=t for some vertex x in G.

  11. W-symmetry, topological vertex and affine Yangian

    Energy Technology Data Exchange (ETDEWEB)

    Procházka, Tomáš [Arnold Sommerfeld Center for Theoretical Physics, Ludwig Maximilian University of Munich,Theresienstr. 37, D-80333 München (Germany); Institute of Physics AS CR,Na Slovance 2, Prague 8 (Czech Republic)

    2016-10-14

    We discuss the representation theory of the non-linear chiral algebra W{sub 1+∞} of Gaberdiel and Gopakumar and its connection to the Yangian of (u(1))-hat whose presentation was given by Tsymbaliuk. The characters of completely degenerate representations of W{sub 1+∞} are given by the topological vertex. The Yangian picture provides an infinite number of commuting charges which can be explicitly diagonalized in W{sub 1+∞} highest weight representations. Many properties that are difficult to study in the W{sub 1+∞} picture turn out to have a simple combinatorial interpretation, once translated to the Yangian picture.

  12. A new tool for constrained vertex fitting in ATLAS

    CERN Document Server

    Colijn, Auke Pieter; Limper, Maaike; Prokofiev, Kirill

    2009-01-01

    The precise reconstruction of trajectories of charged and neutral particles and their decay vertices is crucial for many physics analyses. Studying the tracking performance on well known benchmark channels helps to understand the properties of the ATLAS detector during the initial phase of the LHC. In order to exploit the correlations between reconstructed parameters of final state tracks having the same mother particle, a new tool for vertex fitting with possibility of simultaneous application of kinematic constraints has been developed. Using this tool on a benchmark channel such as J/psi to μ+μ− helps to correct shifts in the reconstructed curvature induced by systematic deformations of the detector.

  13. Vertex Normals and Face Curvatures of Triangle Meshes

    KAUST Repository

    Sun, Xiang

    2016-08-12

    This study contributes to the discrete differential geometry of triangle meshes, in combination with discrete line congruences associated with such meshes. In particular we discuss when a congruence defined by linear interpolation of vertex normals deserves to be called a ʼnormal’ congruence. Our main results are a discussion of various definitions of normality, a detailed study of the geometry of such congruences, and a concept of curvatures and shape operators associated with the faces of a triangle mesh. These curvatures are compatible with both normal congruences and the Steiner formula.

  14. 3D circuit integration for Vertex and other detectors

    Energy Technology Data Exchange (ETDEWEB)

    Yarema, Ray; /Fermilab

    2007-09-01

    High Energy Physics continues to push the technical boundaries for electronics. There is no area where this is truer than for vertex detectors. Lower mass and power along with higher resolution and radiation tolerance are driving forces. New technologies such as SOI CMOS detectors and three dimensional (3D) integrated circuits offer new opportunities to meet these challenges. The fundamentals for SOI CMOS detectors and 3D integrated circuits are discussed. Examples of each approach for physics applications are presented. Cost issues and ways to reduce development costs are discussed.

  15. Eight-Vertex Model of Two-Dimensional Domain Walls

    Science.gov (United States)

    Rys, Franz S.

    1983-09-01

    A statistical model of interacting linear domain walls (occurring, e.g., in monolayer adsorbates) is solved on the square lattice with use of exact and numerical results of an equivalent eight-vertex model. For attractive walls a commensurate and an incommensurate phase are separated by a first-order line for stiff walls and by a fluid phase for flexible walls. The phase boundaries with the fluid phase are Ising-like. For repulsive stiff walls an intermediate striped phase with a nonuniversal boundary occurs which vanishes for higher flexibilities. Moreover, disorder lines are located.

  16. Vertex Operators Arising from Jacobi-Trudi Identities

    Science.gov (United States)

    Jing, Naihuan; Rozhkovskaya, Natasha

    2016-09-01

    We give an interpretation of the boson-fermion correspondence as a direct consequence of the Jacobi-Trudi identity. This viewpoint enables us to construct from a generalized version of the Jacobi-Trudi identity the action of a Clifford algebra on the polynomial algebras that arrive as analogues of the algebra of symmetric functions. A generalized Giambelli identity is also proved to follow from that identity. As applications, we obtain explicit formulas for vertex operators corresponding to characters of the classical Lie algebras, shifted Schur functions, and generalized Schur symmetric functions associated to linear recurrence relations.

  17. Heat transfer function of the VENUS vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Ohama, T.; Ishihara, N.; Yamada, Y.

    1996-05-01

    In order to estimate the temperature distribution in the VENUS vertex chamber at TRISTAN, a heat transfer function has been derived from the temperature information of a beam pipe flange. The function obtained suggests that the temperature of the flange and that in the chamber gas are simply in proportional relation to the equivalent heat input. Consequently, it is possible to easily correct the velocity of drift electrons in the chamber gas on the basis of the temperature distribution patterns, which are calculated from the typical heat input. (author)

  18. Shock timing on the National Ignition Facility: First experiments

    Directory of Open Access Journals (Sweden)

    Celliers P.M.

    2013-11-01

    Full Text Available An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a re-entrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

  19. Shock timing on the National Ignition Facility: First Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Celliers, P M; Robey, H F; Boehly, T R; Alger, E; Azevedo, S; Berzins, L V; Bhandarkar, S D; Bowers, M W; Brereton, S J; Callahan, D; Castro, C; Chandrasekaran, H; Choate, C; Clark, D; Coffee, K R; Datte, P S; Dewald, E L; DiNicola, P; Dixit, S; Doeppner, T; Dzenitis, E; Edwards, M J; Eggert, J H; Fair, J; Farley, D R; Frieders, G; Gibson, C R; Giraldez, E; Haan, S; Haid, B; Hamza, A V; Haynam, C; Hicks, D G; Holunga, D M; Horner, J B; Jancaitis, K; Jones, O S; Kalantar, D; Kline, J L; Krauter, K G; Kroll, J J; LaFortune, K N; Pape, S L; Malsbury, T; Maypoles, E R; Milovich, J L; Moody, J D; Moreno, K; Munro, D H; Nikroo, A; Olson, R E; Parham, T; Pollaine, S; Radousky, H B; Ross, G F; Sater, J; Schneider, M B; Shaw, M; Smith, R F; Thomas, C A; Throop, A; Town, R J; Trummer, D; Van Wonterghem, B M; Walters, C F; Widmann, K; Widmayer, C; Young, B K; Atherton, L J; Collins, G W; Landen, O L; Lindl, J D; MacGowan, B J; Meyerhofer, D D; Moses, E I

    2011-10-24

    An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

  20. Time-symmetric electrodynamics and the Kocher-Commins experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pegg, D.T. (Rochester Univ., NY (USA). Dept. of Physics and Astronomy)

    1982-01-01

    A quantised version of Wheeler-Feynman time-symmetric absorber theory sheds new light on an old problem at present experiencing a revival of interest. Some photon correlation experiments, when interpreted in terms of quantum electrodynamics, lead to conceptual difficulties of the Einstein-Podolsky-Rosen type. The results imply that one has to abandon either the concept of strict causality, which would make conventional quantum electrodynamics self-inconsistent, or the concept of an objective reality independent of the observer, which has far-reaching philosophical consequences. In terms of absorber theory, on the other hand, there is no need to abandon objective reality and, in fact, such an experiment is directly interpretable as an example of the manifestation of the future on the past, which is the important distinguishing feature of absorber theory.

  1. Decision dynamics of departure times: Experiments and modeling

    Science.gov (United States)

    Sun, Xiaoyan; Han, Xiao; Bao, Jian-Zhang; Jiang, Rui; Jia, Bin; Yan, Xiaoyong; Zhang, Boyu; Wang, Wen-Xu; Gao, Zi-You

    2017-10-01

    A fundamental problem in traffic science is to understand user-choice behaviors that account for the emergence of complex traffic phenomena. Despite much effort devoted to theoretically exploring departure time choice behaviors, relatively large-scale and systematic experimental tests of theoretical predictions are still lacking. In this paper, we aim to offer a more comprehensive understanding of departure time choice behaviors in terms of a series of laboratory experiments under different traffic conditions and feedback information provided to commuters. In the experiment, the number of recruited players is much larger than the number of choices to better mimic the real scenario, in which a large number of commuters will depart simultaneously in a relatively small time window. Sufficient numbers of rounds are conducted to ensure the convergence of collective behavior. Experimental results demonstrate that collective behavior is close to the user equilibrium, regardless of different scales and traffic conditions. Moreover, the amount of feedback information has a negligible influence on collective behavior but has a relatively stronger effect on individual choice behaviors. Reinforcement learning and Fermi learning models are built to reproduce the experimental results and uncover the underlying mechanism. Simulation results are in good agreement with the experimentally observed collective behaviors.

  2. Factors Influencing Positive Birth Experiences of First-Time Mothers

    Directory of Open Access Journals (Sweden)

    Lena Nilsson

    2013-01-01

    Full Text Available Objectives. The objective of this study was to describe first-time mothers’ experiences and reflections of their first birth. Study Design. This study is a part of a larger study which was carried out in southwestern Sweden in 2008. A qualitative method with content analysis was chosen for this study. The unit of data was 14 written narratives from the first-time mothers. Results. The theme “To be empowered increases first-time mothers’ chances for a positive birth experience” crossed over into all the three categories: “To trust the body and to face the pain,” “Interaction between body and mind in giving birth,” and “Consistency of support.” Conclusion. In order to feel confident in their first childbirth, the women wanted to be confirmed and seen as unique individuals by the professionals and their partner. If professionals responded to the individual woman’s needs of support, the woman more often had a positive birth experience, even if the birth was protracted or with medical complications.

  3. Cycle killer... Qu'est-ce que c'est? On the Comparative Approximability of Hybridization Number and Directed Feedback Vertex Set

    NARCIS (Netherlands)

    Kelk, S.; van Iersel, L.J.J.; Lekic, N.; Linz, S.; Scornavacca, C.; Stougie, L.

    2012-01-01

    We show that the problem of computing the hybridization number of two rooted binary phylogenetic trees on the same set of taxa X has a constant factor polynomial-time approximation if and only if the problem of computing a minimum-size feedback vertex set in a directed graph (DFVS) has a constant

  4. Design of a current based readout chip and development of a DEPFET pixel prototype system for the ILC vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Trimpl, M.

    2005-12-15

    The future TeV-scale linear collider ILC (International Linear Collider) offers a large variety of precision measurements complementary to the discovery potential of the LHC (Large Hadron Collider). To fully exploit its physics potential, a vertex detector with unprecedented performance is needed. One proposed technology for the ILC vertex detector is the DEPFET active pixel sensor. The DEPFET sensor offers particle detection with in-pixel amplification by incorporating a field effect transistor into a fully depleted high-ohmic silicon substrate. The device provides an excellent signal-to-noise ratio and a good spatial resolution at the same time. To establish a very fast readout of a DEPFET pixel matrix with row rates of 20 MHz and more, the 128 channel CURO II ASIC has been designed and fabricated. The architecture of the chip is completely based on current mode techniques (SI) perfectly adapted to the current signal of the sensor. For the ILC vertex detector a prototype system with a 64 x 128 DEPFET pixel matrix read out by the CURO II chip has been developed. The design issues and the standalone performance of the readout chip as well as first results with the prototype system will be presented. (orig.)

  5. The design, construction and performance of the ALEPH silicon vertex detector

    CERN Document Server

    Mours, B; Jacobsen, R; Mattison, T S; Martin, E B; Menary, S R; Moneta, L; Redlinger, G; Focardi, E; Parrini, G; Scarlini, E; Walther, S; Carr, J; Coyle, P; Drinkard, J; Rousseau, D; Schwemling, P; Bauer, C; Becker, H; Brown, D; Cattaneo, Paolo Walter; Dietl, H; Hauff, D; Holl, P; Lauber, J; Lutz, Gerhard; Lütjens, G; Männer, W; Moser, H G; Schwarz, A S; Settles, Ronald; Seywerd, H C J; Strüder, L; Waltermann, G; Batignani, G; Bosi, F; Bosisio, L; Carpinelli, M; Ciocci-Marrocchesi, A; Dell'Orso, R; Forti, F; Giorgi, M A; Piccinini, S; Profeti, A; Rizzi, D; Rizzo, G; Tonelli, G; Triggiani, G; Vannini-Castaldi, C; Verdini, P G; Walsh, J; Lançon, E; Hansl-Kozanecka, Traudl; Litke, A M; McNeil, M A; Taylor, G; Wear, J; Sharma, V; Weber, F

    1996-01-01

    The ALEPH Silicon Vertex Detector is the first detector operating in a colliding beam environment that uses silicon strip detectors which provide readout on both sides and hence a three-- dimensional point measurement for the trajectory of charged particles. \\par The detector system was commissioned successfully at the $e^+e^-$ collider LEP at the research centre CERN, Switzerland, during the year 1991 while taking data at the $Z^0$ resonance. The achieved spatial resolution of the complete 73~728 channel device (intrinsic plus alignment) is $12 \\; \\mu m$ in the $r \\cdot \\phi$ view and $ 12 \\; \\mu m$ in the $z$ view. \\par The design and construction of the entire detector system are discussed in detail and the experience gained in running the detector will be described with special emphasis on the uses of this novel tracking device for the physics of short-lived heavy particles produced in the decays of the $Z^0$ resonance.

  6. Time-resolved pump-probe experiments at the LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Glownia, James; /SLAC /Stanford U., Appl. Phys. Dept.; Cryan, J.; /SLAC /Stanford U., Phys. Dept.; Andreasson, J.; /Uppsala U.; Belkacem, A.; /LBNL, Berkeley; Berrah, N.; /Western Michigan U.; Blaga, C.L.; /Ohio State U.; Bostedt, C.; Bozek, J.; /SLAC; DiMauro, L.F.; /Ohio State U.; Fang, L.; /Western Michigan U.; Frisch, J.; /SLAC; Gessner, O.; /LBNL; Guhr, M.; /SLAC; Hajdu, J.; /Uppsala U.; Hertlein, M.P.; /LBNL; Hoener, M.; /Western Michigan U. /LBNL; Huang, G.; Kornilov, O.; /LBNL; Marangos, J.P.; /Imperial Coll., London; March, A.M.; /Argonne; McFarland, B.K.; /SLAC /Stanford U., Phys. Dept. /SLAC /IRAMIS, Saclay /Stanford U., Phys. Dept. /Georgia Tech /Argonne /Kansas State U. /SLAC /Stanford U., Phys. Dept. /SLAC /Stanford U., Appl. Phys. Dept. /Stanford U., Appl. Phys. Dept. /SLAC /LBNL /Argonne /SLAC /SLAC /Stanford U., Appl. Phys. Dept. /Stanford U., Phys. Dept.

    2011-08-12

    The first time-resolved x-ray/optical pump-probe experiments at the SLAC Linac Coherent Light Source (LCLS) used a combination of feedback methods and post-analysis binning techniques to synchronize an ultrafast optical laser to the linac-based x-ray laser. Transient molecular nitrogen alignment revival features were resolved in time-dependent x-ray-induced fragmentation spectra. These alignment features were used to find the temporal overlap of the pump and probe pulses. The strong-field dissociation of x-ray generated quasi-bound molecular dications was used to establish the residual timing jitter. This analysis shows that the relative arrival time of the Ti:Sapphire laser and the x-ray pulses had a distribution with a standard deviation of approximately 120 fs. The largest contribution to the jitter noise spectrum was the locking of the laser oscillator to the reference RF of the accelerator, which suggests that simple technical improvements could reduce the jitter to better than 50 fs.

  7. Recent results with HV-CMOS and planar sensors for the CLIC vertex detector

    CERN Document Server

    AUTHOR|(SzGeCERN)734627

    2016-01-01

    The physics aims for the future multi-TeV e+e- Compact Linear Collider (CLIC) impose high precision requirements on the vertex detector which has to match the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of 3μm, 10 ns time stamping capabilities, low mass (⇠0.2% X0 per layer), low power dissipation and pulsed power operation. Recent results of test beam measurements and GEANT4 simulations for assemblies with Timepix3 ASICs and thin active-edge sensors are presented. The 65 nm CLICpix readout ASIC with 25μm pitch was bump bonded to planar silicon sensors and also capacitively coupled through a thin layer of glue to active HV-CMOS sensors. Test beam results for these two hybridisation concepts are presented.

  8. Real-time virtual EAST physical experiment system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dan, E-mail: lidan@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Xiao, B.J., E-mail: bjxiao@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui (China); Xia, J.Y., E-mail: jyxia@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Yang, Fei, E-mail: fyang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Department of Computer Science, Anhui Medical University, Hefei, Anhui (China)

    2014-05-15

    Graphical abstract: - Highlights: • 3D model of experimental advanced superconducting tokamak is established. • Interaction behavior is created that the users can get information from database. • The system integrates data acquisition, plasma shape visualization and simulation. • Browser-oriented system is web-based and more interactive, immersive and convenient. • The system provides the framework for virtual physical experimental environment. - Abstract: As a large fusion reaction device, experimental advanced superconducting tokamak (EAST)’s internal structure is complicated and not easily accessible. Moreover, various diagnostic systems and complicated configuration bring about the inconveniency to the scientists who are unfamiliar with the system but interested in the data. We propose a virtual system to display the 3D model of EAST facility and enable people to view its inner structure and get access to the information of its components in various view sights. We would also provide most of the diagnostic configuration details together with their signal names and physical properties. Compared to the previous ways of viewing information by reference to collected drawings and videos, virtual EAST system is more interactive and immersive. We constructed the browser-oriented virtual EAST physical experiment system, integrated real-time experiment data acquisition, plasma shape visualization and experiment result simulation in order to reproduce physical experiments in a web browser. This system used B/S (Browser/Server) structure in combination with the technology of virtual reality – VRML (Virtual Reality Modeling Language) and Java 3D. In order to avoid the bandwidth limit across internet, we balanced the rendering speed and the precision of the virtual model components. Any registered user can view the experimental information visually and efficiently by logining the system through a web browser. The establishment of the system provides the

  9. Real-Time Use of GPUs in NA62 Experiment

    CERN Document Server

    Pantaleo, F; Innocente, V; Lamanna, G; Sozzi, M

    2012-01-01

    We describe a pilot project for the use of GPUs in a real-time triggering application in the early trigger stages at the CERN NA62 experiment, and the results of the first field tests together with a prototype data acquisition (DAQ) system. This pilot project within NA62 aims at integrating GPUs into the central L0 trigger processor, and also to use them as fast online processors for computing trigger primitives. Several TDC-equipped sub-detectors with sub-nanosecond time resolution will participate in the first-level NA62 trigger (L0), fully integrated with the data-acquisition system, to reduce the readout rate of all sub-detectors to 1 MHz, using multiplicity information asynchronously computed over time frames of a few ns, both for positive sub-detectors and for vetos. The online use of GPUs would allow the computation of more complex trigger primitives already at this first trigger level. We describe the architectures of the proposed systems, focusing on measuring the performance (both throughput and l...

  10. On the Relation between Edge and Vertex Modelling in Shape Analysis

    DEFF Research Database (Denmark)

    Hobolth, Asger; Kent, John Thomas; Dryden, Ian L.

    2002-01-01

    circulant covariance matrix to model the edge transformation vector. This type of model is also feasible for the vertex transformation vector and in certain cases the free parameters of the two models match up in a simple way. A vertex model and an edge model are applied to a data set of sand particles...... to explore shape variability....

  11. Vertex epidural haematoma manifesting with bilateral upper limb decerebrate posture: case report.

    Science.gov (United States)

    Kiboi, J G; Muriithi, I M

    2009-06-01

    Vertex epidural haematomas (VEDH) are rare and difficulties are encountered in diagnosis and management. This is a case report of a patient with a vertex epidural haematoma who presented with signs of severe head injury with upper limb decerebrate posture. We discuss the challenges of radiological investigation and neurosurgical management of VEDH.

  12. Space, body, time and relationship experiences of recess physical activity

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Andersen, Henriette Bondo; Tjørnhøj-Thomsen, Tine

    2016-01-01

    the classroom as a space for physical activity, designing schoolyards with smaller secluded spaces and varied facilities, improving children's self-esteem and body image, e.g., during physical education, and creating teacher organised play activities during recess.......BACKGROUND: Increasing recess physical activity has been the aim of several interventions, as this setting can provide numerous physical activity opportunities. However, it is unclear if these interventions are equally effective for all children, or if they only appeal to children who are already...... physically active. This study was conducted to explore the least physically active children's "lived experiences" within four existential lifeworlds linked to physical activity during recess: space, body, time, and relations. METHODS: The study builds on ethnographic fieldwork in a public school in Denmark...

  13. Journalism and change in time experience in Western society

    Directory of Open Access Journals (Sweden)

    Carlos Franciscato

    2005-06-01

    Full Text Available The purpose of this paper is to investigate the temporality produced by journalistic practice and the ways journalism has a privilege to build a specifi c type of social experience of the present time. This inquiry carries out a historical journey, but it is not our purpose to present a history of press in the sense of a history of institutions, particular genres and languages. Instead, this investigation develops a historical study in order to identify social temporal phenomena produced by journalism, and to express them in the form of descriptive categories, which give regularity to a diversity of temporal phenomena: instantaneity, simultaneity, periodicity, novelty, and public disclosure. Besides, we consider this work a theoretical study that uses historical elements to analyze, through a sociological approach, fundamental aspects of a social constitution of journalistic temporality.

  14. First time mothers' experiences of breastfeeding their newborn.

    Science.gov (United States)

    Kronborg, Hanne; Harder, Ingegerd; Hall, Elisabeth O C

    2015-06-01

    Despite efforts to improve continued breastfeeding, the percentages of exclusively breastfeeding remain low. To help the breastfeeding mother and reshape professional practice, we need more knowledge of maternal experiences of breastfeeding in the first months. The objective was to explore mothers' early breastfeeding experiences. Qualitative content analysis was used to analyse data from 108 Danish first time mothers who had answered an open-ended question 6 months after birth. All the mothers started breastfeeding. We identified three overlapping phases presented as dominant themes: (1) on shaky ground, characterised by breastfeeding interwoven with mothering, painful breastfeeding, and conflicting advice, (2) searching for a foothold, characterised by reading the baby's cues, concerns about milk production, for or against breastfeeding, and looking for professional support, and (3) at ease with choice of feeding, characterised by a thriving baby, trust in breastfeeding capability, and approval of feeding preference. Together these themes and subthemes constituted the overall theme: being on a breastfeeding-bonding trajectory. Supporting the new breastfeeding mother should include facilitation of the transition to motherhood, learning to read the baby's cues, developing a sense of the right attachment at the breast, and building up the mother's confidence in her capability to care for the baby and produce a sufficient milk supply. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Time projection chambers for the T2K experiment

    Science.gov (United States)

    Karlen, Dean; T2K/TPC Collaboration

    2010-11-01

    The T2K experiment will study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large super-Kamiokande detector located 295 km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280 m downstream of the neutrino production target. A key element of the near detectors is the ND280 tracker consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The tracker will provide high statistics samples for studying charged current neutrino interaction rates and kinematics prior to oscillation, so as to better understand backgrounds in the far detector. The tracker is surrounded by the UA1/Nomad dipole magnet and the TPCs will measure the charge, momentum, particle type (through ionization energy loss in the gas) of particles passing through them. Novel features of these TPCs include the rectangular box design, constructed from composite panels, the use of bulk micromegas detectors for gas amplification, electronics readout based on a new ASIC, and a photoelectron calibration system. This paper describes the design and construction of the TPCs, the readout electronics, the gas handling system and shows the performance of a completed TPC as deduced from measurements with particle beams, cosmic rays, and the calibration system.

  16. Outcome of labour in nullipara at term with unengaged vertex.

    Science.gov (United States)

    Chaudhary, Saima; Farrukh, Rubina; Dar, Asma; Humayun, Shamsa

    2009-01-01

    Primigravidas with unengaged foetal head at term should be regarded as high risk cases. It is seen that nuglliparous women with the floating foetal head demonstrate higher rates of caesarean section than those with dipping or engaged head in early labour. These cases should be regarded as high risk and identified early and should be referred to a tertiary care centre where good facilities for operative delivery are available. The present study was undertaken to determine the outcome of labour in nulliparous women with unengaged head and compare it with those who present with engaged head at term as a case control study. The objective of the study was to enumerate the outcome of labour in nulliparous women presenting with unengaged head at term and compare it with those who present with engaged head in early active labour. It was a case control study, completed in 11 months, conducted in Department of Obstetrics and Gynaecology, Sir Ganga Ram Hospital, Lahore. 300 women were selected by convenience sampling. 150 nulliparous women who presented with unengaged head in early active labour were taken as cases, out which 2 women left against medical advice with their medical records so data was missing leaving 148 patients in this group. While 150 nulliparous women who presented with engaged head were taken as controls. C-section rates was significantly found to be more in unengaged group being 16.89%, compared with 5.33% in engaged group (p = 0.000). Most of C-sections were carried out due to failed progress of labour (48%). Patients with unengaged foetal head had significantly lower APGAR scores at 1 (p < 0.002) and 5 min (0.003) and higher mean birth weights (p = 0.002).Cases also had significantly longer 1st (p = 0.0001) and 2nd stage (p = 0.004) of labour. Engaged vertex at the onset of active labour is associated with a lower risk of caesarean delivery in nulliparous women. Patients with unengaged vertex are at higher risk for caesarean delivery due to arrest

  17. A quantum hybrid with a thin antenna at the vertex of a wedge

    Energy Technology Data Exchange (ETDEWEB)

    Carlone, Raffaele, E-mail: raffaele.carlone@unina.it [Università “Federico II” di Napoli, Dipartimento di Matematica e Applicazioni “R. Caccioppoli”, MSA, via Cinthia, I-80126, Napoli (Italy); Posilicano, Andrea, E-mail: andrea.posilicano@uninsubria.it [DiSAT, Università dell' Insubria, via Valleggio 11, I-22100, Como (Italy)

    2017-03-26

    We study the spectrum, resonances and scattering matrix of a quantum Hamiltonian on a “hybrid surface” consisting of a half-line attached by its endpoint to the vertex of a concave planar wedge. At the boundary of the wedge, outside the vertex, homogeneous Dirichlet conditions are imposed. The system is tunable by varying the measure of the angle at the vertex. - Highlights: • Spectral characterization of a quantum Hamiltonian on “hybrid surface” consisting of a halfline attached to the vertex of a concave planar wedge. • The system is tunable by varying the measure of the angle at the vertex. • Relation between the conduction properties inside the hybrid and formation of resonances. • Easy generalization of the results to more complicated structures.

  18. Selective attention and the auditory vertex potential. 2: Effects of signal intensity and masking noise

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1975-01-01

    A randomized sequence of tone bursts was delivered to subjects at short inter-stimulus intervals with the tones originating from one of three spatially and frequency specific channels. The subject's task was to count the tones in one of the three channels at a time, ignoring the other two, and press a button after each tenth tone. In different conditions, tones were given at high and low intensities and with or without a background white noise to mask the tones. The N sub 1 component of the auditory vertex potential was found to be larger in response to attended channel tones in relation to unattended tones. This selective enhancement of N sub 1 was minimal for loud tones presented without noise and increased markedly for the lower tone intensity and in noise added conditions.

  19. Performance of the ALICE secondary vertex b-tagging algorithm

    Science.gov (United States)

    Eyyubova, G.; Kramarik, L.

    2016-11-01

    The identification of jets originating from beauty quarks in heavy-ion collisions is important to study the properties of the hot and dense matter produced in such collisions. A variety of algorithms for b-jet tagging was elaborated at the LHC experments. They rely on the properties of B hadrons, i.e. their long lifetime, large mass and large multiplicity of decay products. In this work, the b-tagging algorithm based on displaced secondary-vertex topologies is described. We present Monte Carlo based performance studies of the algorithm for charged jets reconstructed with the ALICE tracking system in p-Pb collisions at √sNN = 5.02 TeV. The tagging efficiency, rejection rate and the correction of the smearing effects of non-ideal detector response are presented.

  20. Topological vertex, string amplitudes and spectral functions of hyperbolic geometry

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, M.E.X.; Rosa, T.O. [Universidade Federal Fluminense, Instituto de Fisica, Av. Gal. Milton Tavares de Souza, s/n, CEP 24210-346, Niteroi, RJ (Brazil); Luna, R.M. [Universidade Estadual de Londrina, Departamento de Fisica, Caixa Postal 6001, Londrina, Parana (Brazil)

    2014-05-15

    We discuss the homological aspects of the connection between quantum string generating function and the formal power series associated to the dimensions of chains and homologies of suitable Lie algebras. Our analysis can be considered as a new straightforward application of the machinery of modular forms and spectral functions (with values in the congruence subgroup of SL(2,Z)) to the partition functions of Lagrangian branes, refined vertex and open string partition functions, represented by means of formal power series that encode Lie algebra properties. The common feature in our examples lies in the modular properties of the characters of certain representations of the pertinent affine Lie algebras and in the role of Selberg-type spectral functions of a hyperbolic three-geometry associated with q-series in the computation of the string amplitudes. (orig.)

  1. Online psychophysics: reaction time effects in cognitive experiments.

    Science.gov (United States)

    Semmelmann, Kilian; Weigelt, Sarah

    2017-08-01

    Using the Internet to acquire behavioral data is currently on the rise. However, very basic questions regarding the feasibility of online psychophysics are still open. Here, we aimed to replicate five well-known paradigms in experimental psychology (Stroop, Flanker, visual search, masked priming, attentional blink) in three settings (classical "lab", "web-in-lab", "web") to account for possible changes in technology and environment. Lab and web-in-lab data were both acquired in an in-lab setting with lab using "Gold Standard" methods, while web-in-lab used web technology. This allowed for a direct comparison of potential differences in acquisition software. To account for additional environmental differences, the web technology experiments were published online to participate from home (setting web), thereby keeping the software and experimental design identical and only changing the environmental setting. Our main results are: First, we found an expected fixed additive timing offset when using web technology (M = 37 ms, SD = 8.14) and recording online (M = 87 ms, SD = 16.04) in comparison to lab data. Second, all task-specific effects were reproduced except for the priming paradigm, which couldn't be replicated in any setting. Third, there were no differences in error rates, which are independent of the timing offset. This finding further supports the assumption of data equality over all settings. Fourth, we found that browser type might be influencing absolute reaction times. Together, these results contribute to the slowly but steadily growing literature that online psychophysics is a suitable complement - or even substitute - to lab data acquisition.

  2. Real time digital control and controlled structures experiments

    Science.gov (United States)

    Rossi, Michael J.; Knowles, Gareth J.; Rauch, Frank

    1991-01-01

    Viewgraphs covering the following topics are given: controlled structures technology at Grumman Corporate Research Center, active and passive control technology, experiment plans, and vacuum chamber test experiment objectives and setup.

  3. Increasing Stability and Activity of Core-Shell Catalysts by Preferential Segregation of Oxide on Edges and Vertexes: Oxygen Reduction on Ti-Au@Pt/C.

    Science.gov (United States)

    Hu, Jue; Wu, Lijun; Kuttiyiel, Kurian A; Goodman, Kenneth R; Zhang, Chengxu; Zhu, Yimei; Vukmirovic, Miomir B; White, Michael G; Sasaki, Kotaro; Adzic, Radoslav R

    2016-07-27

    We describe a new class of core-shell nanoparticle catalysts having edges and vertexes covered by refractory metal oxide that preferentially segregates onto these catalyst sites. The monolayer shell is deposited on the oxide-free core atoms. The oxide on edges and vertexes induces high catalyst stability and activity. The catalyst and synthesis are exemplified by fabrication of Au nanoparticles doped by Ti atoms that segregate as oxide onto low-coordination sites of edges and vertexes. Pt monolayer shell deposited on Au sites has the mass and specific activities for the oxygen reduction reaction about 13 and 5 times higher than those of commercial Pt/C catalysts. The durability tests show no activity loss after 10 000 potential cycles from 0.6 to 1.0 V. The superior activity and durability of the Ti-Au@Pt catalyst originate from protective titanium oxide located at the most dissolution-prone edge and vertex sites and Au-supported active and stable Pt shell.

  4. The Time Projection Chamber of the HARP Experiment

    CERN Document Server

    Lundborg, A

    2002-01-01

    The hadron production experiment HARP aims to measure hadron collision cross sections with a 2-15 GeV particle beam and several targets. This energy regime is in a borderline zone between the low energy region dominated by resonance formation and the high energy domain where perturbative Quantum Chromo Dynamics is applicable. The emphasis of this master thesis is put on the HARP central tracker, the Time Projection Chamber (TPC). In the thesis work, Finite Element Method computations of the electric field in critical regions of the TPC have been performed to provide design input concerning the electrostatic configuration of the field cages and of the wire chamber. A first step in the chain of reconstruction of the information produced by the detector is the equalisation and monitoring of about 4000 analogue signals. An algorithm that processes the raw digitised signals, filters out electronics noise and extracts the pad gain from signal distributions has been produced and analysed for this purpose. The algori...

  5. Quark-gluon vertex dressing and meson masses beyond ladder-rainbow truncation

    Energy Technology Data Exchange (ETDEWEB)

    Hrayr Matevosyan; Anthony Thomas; Peter Tandy

    2007-04-01

    We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. With the more consistent vertex used here, the error in ladder-rainbow truncation for vector mesons is never more than 10% as the current quark mass is varied from the u/d region to the b region.

  6. A Vizing-like theorem for union vertex-distinguishing edge coloring

    OpenAIRE

    Bousquet, Nicolas; Dailly, Antoine; Duchene, Eric; Kheddouci, Hamamache; Parreau, Aline

    2016-01-01

    We introduce a variant of the vertex-distinguishing edge coloring problem, where each edge is assigned a subset of colors. The label of a vertex is the union of the sets of colors on edges incident to it. In this paper we investigate the problem of finding a coloring with the minimum number of colors where every pair of vertices receive distinct labels. Finding such a coloring generalizes several other well-known problems of vertex-distinguishing colorings in graphs. We show that for any grap...

  7. Heat input into the VENUS vertex chamber due to TRISTAN beams

    Energy Technology Data Exchange (ETDEWEB)

    Ohama, Taro.

    1994-04-01

    The VENUS vertex chamber is a drift chamber covering the interaction point of the VENUS detector to obtain precise vertex information at TRISTAN (e[sup +] e[sup -] collider). As a mixed gas of CO[sub 2] 92 % and C[sub 2]H[sub 6] 8 % is used for the chamber, the drift velocity of electron depends on the gas temperature in the chamber. In order to estimate the temperature of the chamber, a trial to obtain the pattern of heat input due to the beams to the vertex chamber has been done. (author).

  8. Automatised Data Quality Monitoring of the LHCb Vertex Locator

    CERN Multimedia

    Szumlak, Tomasz

    2016-01-01

    The LHCb Vertex Locator (VELO) is a silicon strip semiconductor detector operating at just 8mm distance to the LHC beams. Its 172,000 strips are read at a frequency of 1 MHz and processed by off-detector FPGAs followed by a PC cluster that reduces the event rate to about 10 kHz. During the second run of the LHC, which lasts from 2015 until 2018, the detector performance will undergo continued change due to radiation damage effects. This necessitates a detailed monitoring of the data quality to avoid adverse effects on the physics analysis performance. The VELO monitoring infrastructure has been re-designed compared to the first run of the LHC when it was based on manual checks. The new system is based around an automatic analysis framework, which monitors the performance of new data as well as long-term trends and flags issues whenever they arise. An unbiased subset of the detector data are processed about once per hour by monitoring algorithms. The new analysis framework then analyses the plots that are prod...

  9. Jet Vertex Charge Reconstruction Poster for LHCP 2015

    CERN Document Server

    Nektarijevic, Snezana; The ATLAS collaboration

    2015-01-01

    B-jet reconstruction algorithms used so far in ATLAS data analyses do not provide the b-jet charge information, which could potentially play a major role in reducing the combinatorial backgrounds in final states with multiple b-jets. This missing point is addressed by the newly developed JetVertexCharge (JVC) algorithm presented in this poster. Inspired by the decay chain of B-hadrons, the JVC algorithm provides a multi-variate b-jet charge estimate relying on tracks, displaced vertices and muons contained in the jet. In this algorithm, the established concept of estimating jet charge as a transverse momentum weighted sum of track charges is used to reconstruct the charge of the jet as whole, as well as the charges of up to two displaced vertices in the jet, using the corresponding sets of associated tracks. The charge of the associated muon is interpreted as the same-sign or opposite-sign relative to the b-jet charge, according to its transverse momentum and geometrical match to vertices. Jets are divided in...

  10. A dynamic cellular vertex model of growing epithelial tissues

    Science.gov (United States)

    Lin, Shao-Zhen; Li, Bo; Feng, Xi-Qiao

    2017-04-01

    Intercellular interactions play a significant role in a wide range of biological functions and processes at both the cellular and tissue scales, for example, embryogenesis, organogenesis, and cancer invasion. In this paper, a dynamic cellular vertex model is presented to study the morphomechanics of a growing epithelial monolayer. The regulating role of stresses in soft tissue growth is revealed. It is found that the cells originating from the same parent cell in the monolayer can orchestrate into clustering patterns as the tissue grows. Collective cell migration exhibits a feature of spatial correlation across multiple cells. Dynamic intercellular interactions can engender a variety of distinct tissue behaviors in a social context. Uniform cell proliferation may render high and heterogeneous residual compressive stresses, while stress-regulated proliferation can effectively release the stresses, reducing the stress heterogeneity in the tissue. The results highlight the critical role of mechanical factors in the growth and morphogenesis of epithelial tissues and help understand the development and invasion of epithelial tumors.

  11. Towards Petaflops Capability of the VERTEX Supernova Code

    CERN Document Server

    Marek, Andreas; Hanke, Florian; Janka, Hans-Thomas

    2014-01-01

    The VERTEX code is employed for multi-dimensional neutrino-radiation hydrodynamics simulations of core-collapse supernova explosions from first principles. The code is considered state-of-the-art in supernova research and it has been used for modeling for more than a decade, resulting in numerous scientific publications. The computational performance of the code, which is currently deployed on several high-performance computing (HPC) systems up to the Tier-0 class (e.g. in the framework of the European PRACE initiative and the German GAUSS program), however, has so far not been extensively documented. This paper presents a high-level overview of the relevant algorithms and parallelization strategies and outlines the technical challenges and achievements encountered along the evolution of the code from the gigaflops scale with the first, serial simulations in 2000, up to almost petaflops capabilities, as demonstrated lately on the SuperMUC system of the Leibniz Supercomputing Centre (LRZ). In particular, we sh...

  12. Effect of Heterogeneity of Vertex Activation on Epidemic Spreading in Temporal Networks

    Directory of Open Access Journals (Sweden)

    Yixin Zhu

    2014-01-01

    Full Text Available Development of sensor technologies and the prevalence of electronic communication services provide us with a huge amount of data on human communication behavior, including face-to-face conversations, e-mail exchanges, phone calls, message exchanges, and other types of interactions in various online forums. These indirect or direct interactions form potential bridges of the virus spread. For a long time, the study of virus spread is based on the aggregate static network. However, the interaction patterns containing diverse temporal properties may affect dynamic processes as much as the network topology does. Some empirical studies show that the activation time and duration of vertices and links are highly heterogeneous, which means intense activity may be followed by longer intervals of inactivity. We take heterogeneous distribution of the node interactivation time as the research background to build an asynchronous communication model. The two sides of the communication do not have to be active at the same time. One derives the threshold of virus spreading on the communication mode and analyzes the reason the heterogeneous distribution of the vertex interactivation time suppresses the spread of virus. At last, the analysis and results from the model are verified on the BA network.

  13. Response time patterns in a stated choice experiment

    DEFF Research Database (Denmark)

    Börjesson, Maria; Fosgerau, Mogens

    2015-01-01

    employed by the respondents when making their choices. We find clear signs of reference-dependence in response times in the form of a strong gain–loss asymmetry. Moreover, different patterns of response times for travel time and travel cost indicate that these attributes are processed in different ways...

  14. A "View from Nowhen" on Time Perception Experiments

    Science.gov (United States)

    Riemer, Martin; Trojan, Jorg; Kleinbohl, Dieter; Holzl, Rupert

    2012-01-01

    Systematic errors in time reproduction tasks have been interpreted as a misperception of time and therefore seem to contradict basic assumptions of pacemaker-accumulator models. Here we propose an alternative explanation of this phenomenon based on methodological constraints regarding the direction of time, which cannot be manipulated in…

  15. Almost all Almost Regular c-partite Tournaments with c ≥ 5 are Vertex Pancyclic

    DEFF Research Database (Denmark)

    Tewes, Meike; Volkmann, Lutz; Yeo, Anders

    2002-01-01

    ) indegree of D are denoted by + ( +) and - ( -), respectively. In addition, we define =min{ +, -} and =max{ +, -}. A digraph is regular when = and almost regular when - =c>=5, and that all, except possibly...... a finite number, regular 4-partite tournaments are vertex pancyclic. Clearly, in a regular multipartite tournament, each partite set has the same cardinality. As a supplement of Yeo's result we prove first that an almost regular c-partite tournament with c>=5 is vertex pancyclic, if all partite sets have...... the same cardinality. Second, we show that all almost regular c-partite tournaments are vertex pancyclic when c>=8, and third that all, except possibly a finite number, almost regular c-partite tournaments are vertex pancyclic when c>=5....

  16. The beam test measurements of the Belle II vertex detector modules

    Science.gov (United States)

    Bilka, T.

    2017-03-01

    The Belle II experiment designed to study CP Violation and Beyond Standard model physics at the decays of B-mesons is quickly approaching its first physics run with the SuperKEKB accelerator (Tsukuba, Japan) already under commissioning. To operate in the unique conditions of the Belle II experiment, its vertex detector (VXD) is a six layers silicon detector with two innermost layers of DEPFET active pixel modules and four layers of double-sided strip modules. A section of it will become a commissioning detector for the first collisions of the next-generation high luminosity B-factory. The same setup, from cooling services, mechanical support or sensors and front-end electronics to DAQ, including the software and alignment framework, is tested under an electron beam provided by DESY facilities. We present the basic characteristics of the pixel and strip modules and the setup under test, including software and alignment framework—as close to the final system as possible.

  17. Precision bottom physics program at sPHENIX with inner vertex detector upgrade

    Science.gov (United States)

    Li, Xuan; Sphenix Collaboration

    2017-09-01

    The planned sPHENIX experiment at RHIC aims to study the microscopic nature of strongly interacting matter ranging from nucleons to the quark-gluon plasma (QGP) with high precision measurements of jets and heavy flavor observables for a wide selection of nuclear collision systems. In particular, the bottom quark is expected to be produced in a hard scattering before the QGP creation in heavy ion collisions and experience the medium throughout its evolution. The observables of bottom quark tagged jets (b-jets), bottom hadrons and their correlations at sPHENIX cover a wide kinematic range of the bottom probes. The sPHENIX measurements are complementary to the studies at the LHC, experiencing less fraction of bottom production via gluon splitting and probing QGP of different properties. Such measurements are essential for our understanding of the bottom quark energy loss mechanisms and transport properties of the QGP medium. To achieve these goals, the sPHENIX collaboration proposed to utilize a state of the art silicon vertex detector based on the Monolithic-Active-Pixel-Sensor (MAPS) technology. The detector design, physics reach and the status of detector R&D will be presented.

  18. Studies for Online Selection of Beam-Gas Events with the LHCb Vertex Locator

    CERN Document Server

    Hopchev, Plamen; Ferro-Luzzi, M

    2008-01-01

    The start of the Large Hadron Collider (LHC) is scheduled for the Summer 2008. The accelerator is going to provide unprecedented amount of proton-proton colli- sions with a record center-of-mass energy. The total number of collisions produced in an interaction point is directly connected to a collider characteristic called `absolute luminosity'. The luminosity depends on a number of quantities like the number of particles in a bunch, the bunch size and the number of bunches in a beam. For precise measurements of Standard Model parameters and for the search of New Physics the LHC experiments count on precise knowledge on its luminosity. The absolute luminosity of LHC is going to be measured using various meth- ods, including the recently proposed beam-gas luminosity method. This method counts on the reconstruction of beam-gas vertices for measuring the beam shapes and overlap integral. The beam-gas luminosity method is going to be first tried in the LHCb experiment, making use of its excellent vertex resolutio...

  19. Study of the radiation induced effects in the LHCb Vertex Locator

    CERN Document Server

    Szumlak, Tomasz

    2016-01-01

    LHCb is a dedicated heavy-flavour physics experiment at the Large Hadron Collider at CERN. The VErtex LOcator (VELO) is a critical part of a LHCb tracking system, enabling the full topological reconstruction of beauty and charm mesons’ decays and providing essential input for the High Level Trigger (HLT) system used by the experiment to select events. The VELO comprises 42 modules made of two $n^{+}$-on-$n~300~\\mu$m thick half-disc silicon sensors with $R$- and ${\\mit\\Phi}$-measuring micro-strips, arranged in two retractable halves, operating only about 8 mm from the proton beams. In these paper, selected aspects of the VELO performance during the Run 1 data-taking period is shortly summarised along with the radiation damage studies. The track finding efficiency is typically greater than 98\\%. An impact parameter resolution of less than $35~\\mu$m is achieved for particles with transverse momentum greater than 1 GeV/$c$. An overview of all important performance parameters will be given. The VELO sensors have...

  20. Measurement of relative branching fractions for $D^{0}$ meson Cabibbo suppressed hadronic decays, from the CDF secondary vertex trigger sample at the Tevatron collider.

    Energy Technology Data Exchange (ETDEWEB)

    De Cecco, Sandro [Univ. of Rome (Italy)

    2003-01-01

    The analysis presented in this thesis are first strong evidences for both the new CDF Secondary Vertex Trigger ability in the on-line selection of heavy flavour hadronic decays in $p\\bar{p}$ interactions and for the $CDF$ potentials, in particular on charm physics. The result of the relative BR measurements for $D^0$ mesons two-body decays presented in this thesis is at this time competitive with best single measurement obtained by the CLEO experiment. Analysis and reconstruction tools developed for charm mesons are tuned and validated at a very refined level and constitute the framework for B mesons analysis in hadronic final states like $B_{s} → D_{s}\\pi$. As prospected in final sections, competitive measurements and limits on $D^0$ mixing and direct CP violation in $D^0$ mesons decays will be possible with the luminosity integrated in the future of $CDF$ operations. Also, studies on particle ID with $dE/dx$ and CDF Time-of-Flight, are presented and their validat ion on high statistic sample of charmed mesons will allow a precise knowledge of $CDF$ PID global performance. This will be of particular relevance for flavour tagging techniques and especially those based on Kaon tagging will benefit of this study. This point will be crucial, as underlined in final section for $B_s$ oscillation mixing frequency measurement at $CDF$.

  1. Statistical approach to tunneling time in attosecond experiments

    Science.gov (United States)

    Demir, Durmuş; Güner, Tuğrul

    2017-11-01

    Tunneling, transport of particles through classically forbidden regions, is a pure quantum phenomenon. It governs numerous phenomena ranging from single-molecule electronics to donor-acceptor transition reactions. The main problem is the absence of a universal method to compute tunneling time. This problem has been attacked in various ways in the literature. Here, in the present work, we show that a statistical approach to the problem, motivated by the imaginary nature of time in the forbidden regions, lead to a novel tunneling time formula which is real and subluminal (in contrast to various known time definitions implying superluminal tunneling). In addition to this, we show explicitly that the entropic time formula is in good agreement with the tunneling time measurements in laser-driven He ionization. Moreover, it sets an accurate range for long-range electron transfer reactions. The entropic time formula is general enough to extend to the photon and phonon tunneling phenomena.

  2. Twist Field as Three String Interaction Vertex in Light Cone String Field Theory

    OpenAIRE

    Kishimoto, Isao; Moriyama, Sanefumi; Teraguchi, Shunsuke

    2006-01-01

    It has been suggested that matrix string theory and light-cone string field theory are closely related. In this paper, we investigate the relation between the twist field, which represents string interactions in matrix string theory, and the three-string interaction vertex in light-cone string field theory carefully. We find that the three-string interaction vertex can reproduce some of the most important OPEs satisfied by the twist field.

  3. NLO Vertex for a Forward Jet plus a Rapidity Gap at High Energies

    CERN Document Server

    Hentschinski, Martin; Murdaca, Beatrice; Vera, Agustín Sabio

    2015-01-01

    We present the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the BFKL formalism at next-to-leading order (NLO). Real emission contributions are computed via Lipatov's effective action. The NLO jet vertex turns out to be finite within collinear factorization and allows, together with the NLO non-forward gluon Green's function, to perform NLO studies of jet production in diffractive events (e.g. Mueller-Tang dijets).

  4. Studies of the Triple PomeronVertex in perturbative QCD and its applications in phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Kutak, K.

    2006-12-15

    We study the properties of the Triple Pomeron Vertex in the perturbative QCD using the twist expansion method. Such analysis allows us to find the momenta configurations preferred by the vertex. When the momentum transfer is zero, the dominant contribution in the limit when N{sub c}{yields}{infinity} comes from anticollinear pole. This is in agreement with result obtained without expanding, but by direct averaging of the Triple Pomeron Vertex over angles. Resulting theta functions show that the anticollinear configuration is optimal for the vertex. In the finite N{sub c} case the collinear term also contributes. Using the Triple Pomeron Vertex we construct a pomeron loop and we also consider four gluon propagation between two Triple Pomeron Vertices. We apply the Triple Pomeron Vertex to construct the Hamiltonian from which we derive the Balitsky-Kovchegov equation for an unintegrated gluon density. In order to apply this equation to phenomenology, we apply the Kwiecinski-Martin-Stasto model for higher order corrections to a linear part of the Balitsky-Kovchegov equation. We introduce the definition of the saturation scale which reflects properties of this equation. Finally, we use it for computation of observables, such as the F{sub 2} structure function and diffractive Higgs boson production cross section. The impact of screening corrections on F{sub 2} is negligible, but those effects turn out to be significant for diffractive Higgs boson production at LHC.

  5. A Survey of Utility Experience with Real Time Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Barbose, Galen; Goldman, Charles; Neenan, Bernie

    2004-12-01

    While more than 70 utilities in the U.S. have offered voluntary RTP tariffs on either a pilot or permanent basis, most have operated in relative obscurity. To bring this broad base of experience to bear on policymakers current efforts to stimulate price responsive demand, we conducted a survey of 43 voluntary RTP tariffs offered in 2003. The survey involved telephone interviews with RTP program managers and other utility staff, as well as a review of regulatory documents, tariff sheets, program evaluations, and other publicly available sources. Based on this review of RTP program experience, we identify key trends related to: utilities motivations for implementing RTP, evolution of RTP tariff design, program participation, participant price response, and program outlook. We draw from these findings to discuss implications for policymakers that are currently considering voluntary RTP as a strategy for developing price responsive demand.

  6. Gain-of-function experiments: time for a real debate.

    Science.gov (United States)

    Duprex, W Paul; Fouchier, Ron A M; Imperiale, Michael J; Lipsitch, Marc; Relman, David A

    2015-01-01

    According to the WHO, dual use research of concern (DURC) is "life sciences research that is intended for benefit, but which might easily be misapplied to do harm". Recent studies, particularly those on influenza viruses, have led to renewed attention on DURC, as there is an ongoing debate over whether the benefits of gain-of-function (GOF) experiments that result in an increase in the transmission and/or pathogenicity of potential pandemic pathogens (PPPs) are outweighed by concerns over biosecurity and biosafety. In this Viewpoint article, proponents and opponents of GOF experiments discuss the benefits and risks associated with these studies, as well as the implications of the current debate for the scientific community and the general public, and suggest how the current discussion should move forward.

  7. Neural network real time event selection for the DIRAC experiment

    CERN Document Server

    Kokkas, P; Tauscher, Ludwig; Vlachos, S

    2001-01-01

    The neural network first level trigger for the DIRAC experiment at CERN is presented. Both the neural network algorithm used and its actual hardware implementation are described. The system uses the fast plastic scintillator information of the DIRAC spectrometer. In 210 ns it selects events with two particles having low relative momentum. Such events are selected with an efficiency of more than 0.94. The corresponding rate reduction for background events is a factor of 2.5. (10 refs).

  8. Optical Beam Timing Monitor Experiments at the Advanced Light Source

    OpenAIRE

    Byrd, John; De Santis, Stefano; Wilcox, Rusell; Yan, Yin

    2008-01-01

    We present the initial results of an experimental study of a beam timing monitor based on an optoelectronic technique. This technique uses the electrical signal from a beam position monitor to modulate the amplitude of a train of laser pulses, converting timing jitter into an amplitude jitter. This modulation is then measured with a photodetector and sampled by a fast ADC. This approach has already demonstrated sub-100 fs resolution and promises even better results. Additionally, we are ...

  9. Neutron Time-Of-Flight (n_TOF) experiment

    CERN Multimedia

    Brugger, M; Kaeppeler, F K; Jericha, E; Cortes rossell, G P; Riego perez, A; Baccomi, R; Laurent, B G; Griesmayer, E; Leeb, H; Dressler, M; Cano ott, D; Variale, V; Ventura, A; Carrillo de albornoz trillo, A; Lo meo, S; Andrzejewski, J J; Pavlik, A F; Kadi, Y; Zanni vlastou, R; Krticka, M; Weiss, C; Kokkoris, M; Praena rodriguez, A J; Cortes giraldo, M A; Perkowski, J; Losito, R; Audouin, L; Tagliente, G; Wallner, A; Woods, P J; Mengoni, A; Guerrero sanchez, C G; Tain enriquez, J L; Vlachoudis, V; Calviani, M; Reifarth, R; Mendoza cembranos, E; Quesada molina, J M; Babiano suarez, V; Schumann, M D; Tsinganis, A; Rauscher, T; Calvino tavares, F; Mingrone, F; Gonzalez romero, E M; Colonna, N; Negret, A L; Chiaveri, E; Milazzo, P M; De almeida carrapico, C A; Castelluccio, D M

    The neutron time-of-flight facility n_TOF at CERN, Switzerland, operational since 2001, delivers neutrons using the Proton Synchrotron (PS) 20 GeV/c proton beam impinging on a lead spallation target. The facility combines a very high instantaneous neutron flux, an excellent time of flight resolution due to the distance between the experimental area and the production target (185 meters), a low intrinsic background and a wide range of neutron energies, from thermal to GeV neutrons. These characteristics provide a unique possibility to perform neutron-induced capture and fission cross-section measurements for applications in nuclear astrophysics and in nuclear reactor technology.

  10. A bonding study toward the quality assurance of Belle-II silicon vertex detector modules

    Energy Technology Data Exchange (ETDEWEB)

    Kang, K.H.; Jeon, H.B. [RSRI, Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Park, H., E-mail: sunshine@knu.ac.kr [RSRI, Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Uozumi, S. [RSRI, Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, T. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technology Guwahati, Assam 781039 (India); and others

    2016-09-21

    A silicon vertex detector (SVD) for the Belle-II experiment comprises four layers of double-sided silicon strip detectors (DSSDs), assembled in a ladder-like structure. Each ladder module of the outermost SVD layer has four rectangular and one trapezoidal DSSDs supported by two carbon-fiber ribs. In order to achieve a good signal-to-noise ratio and minimize material budget, a novel chip-on-sensor “Origami” method has been employed for the three rectangular sensors that are sandwiched between the backward rectangular and forward (slanted) trapezoidal sensors. This paper describes the bonding procedures developed for making electrical connections between sensors and signal fan-out flex circuits (i.e., pitch adapters), and between pitch adapters and readout chips as well as the results in terms of the achieved bonding quality and pull force. - Highlights: • Gluing and wire binding for Belle-II SVD are studied. • Gluing robot and Origami module are used. • QA are satisfied in terms of the achieved bonding throughput and the pull force. • Result will be applied for L6 ladder assembly.

  11. JTAG boundary-scan of the Belle II pixel vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Leitl, Philipp [Max-Planck-Institut fuer Physik (Germany); Collaboration: Belle II-Collaboration

    2016-07-01

    For the upgrade of the Vertex Detector at the Belle II experiment, DEPFET sensors will be used. This new technology requires specific electronics for controlling and readout. Therefore three different kinds of Application-Specific Integrated Circuits (ASICs) are mounted very close to the sensors. Because of space limitations ball grid arrays (BGAs) are used for the contacts to the electronic circuitry. After the mounting process this results in a lack of physical access to the electrical connections. With Boundary-Scan tests, following the IEEE Std 1149.1, it is possible to regain access to the pins for interconnection tests. In this way a quality assurance (QA) is possible to verify that the integration was done correctly and that the circuitry and the electronics are working properly. The present user-friendly system is presented, including the description of additionally developed hardware as well as necessary adjustments to the netlist files and Boundary-Scan Description Language (BSDL) Files of the ASICs. Achieved measurement results from the so far produced detector modules are shown.

  12. Preparing meals under time stress. The experience of working mothers.

    Science.gov (United States)

    Beshara, Monica; Hutchinson, Amanda; Wilson, Carlene

    2010-12-01

    The present study quantitatively explored the effects of mothers' perceived time pressure, as well as meal-related variables including mothers' convenience orientation and meal preparation confidence, on the healthiness of evening meals served to school-aged children (5-18 years old) over a 7-day period. A sample of 120 employed mothers, who identified themselves as the chief meal-preparers in their households, completed a brief, self-report, meal-related questionnaire. Results revealed that mothers' perceived time pressure did not significantly predict meal healthiness. Mothers' confidence in their ability to prepare a healthy meal was the only unique, significant predictor of a healthy evening meal. Mothers who were more confident in their ability to prepare a healthy meal served healthier evening meals than those who were less confident. In addition, mothers' perceived time pressure and convenience orientation were negatively related to healthy meal preparation confidence. Results suggest that mothers' perceived time pressure and convenience orientation, may indirectly compromise meal healthiness, by decreasing mothers' meal preparation confidence. Practical and theoretical implications of the study's findings are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Development of monolithic pixel detector with SOI technology for the ILC vertex detector

    Science.gov (United States)

    Yamada, M.; Ono, S.; Tsuboyama, T.; Arai, Y.; Haba, J.; Ikegami, Y.; Kurachi, I.; Togawa, M.; Mori, T.; Aoyagi, W.; Endo, S.; Hara, K.; Honda, S.; Sekigawa, D.

    2018-01-01

    We have been developing a monolithic pixel sensor for the International Linear Collider (ILC) vertex detector with the 0.2 μm FD-SOI CMOS process by LAPIS Semiconductor Co., Ltd. We aim to achieve a 3 μm single-point resolution required for the ILC with a 20×20 μm2 pixel. Beam bunch crossing at the ILC occurs every 554 ns in 1-msec-long bunch trains with an interval of 200 ms. Each pixel must record the charge and time stamp of a hit to identify a collision bunch for event reconstruction. Necessary functions include the amplifier, comparator, shift register, analog memory and time stamp implementation in each pixel, and column ADC and Zero-suppression logic on the chip. We tested the first prototype sensor, SOFIST ver.1, with a 120 GeV proton beam at the Fermilab Test Beam Facility in January 2017. SOFIST ver.1 has a charge sensitive amplifier and two analog memories in each pixel, and an 8-bit Wilkinson-type ADC is implemented for each column on the chip. We measured the residual of the hit position to the reconstructed track. The standard deviation of the residual distribution fitted by a Gaussian is better than 3 μm.

  14. Differences in brain networks during consecutive swallows detected using an optimized vertex-frequency algorithm.

    Science.gov (United States)

    Jestrović, Iva; Coyle, James L; Sejdić, Ervin

    2017-03-06

    Patients with dysphagia can have higher risks of aspiration after repetitive swallowing activity due to the "fatigue effect". However, it is still unknown how consecutive swallows affect brain activity. Therefore, we sought to investigate differences in swallowing brain networks formed during consecutive swallows using a signal processing on graph approach. Data were collected from 55 healthy people using electroencephalography (EEG) signals. Participants performed dry swallows (i.e., saliva swallows) and wet swallows (i.e., water, nectar-thick, and honey thick swallows). After standard pre-processing of the EEG time series, brain networks were formed using the time-frequency-based synchrony measure, while signals on graphs were formed as a line graph of the brain networks. For calculating the vertex frequency information from the signals on graphs, the proposed algorithm was based on the optimized window size for calculating the windowed graph Fourier transform and the graph S-transform. The proposed algorithms were tested using synthetic signals and showed improved energy concentration in comparison to the original algorithm. When applied to EEG swallowing data, the optimized windowed graph Fourier transform and the optimized graph S-transform showed that differences exist in brain activity between consecutive swallows. In addition, the results showed higher differences between consecutive swallows for thicker liquids. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Colt: an experiment in wormhole run-time reconfiguration

    Science.gov (United States)

    Bittner, Ray; Athanas, Peter M.; Musgrove, Mark

    1996-10-01

    Wormhole run-time reconfiguration (RTR) is an attempt to create a refined computing paradigm for high performance computational tasks. By combining concepts from field programmable gate array (FPGA) technologies with data flow computing, the Colt/Stallion architecture achieves high utilization of hardware resources, and facilitates rapid run-time reconfiguration. Targeted mainly at DSP-type operations, the Colt integrated circuit -- a prototype wormhole RTR device -- compares favorably to contemporary DSP alternatives in terms of silicon area consumed per unit computation and in computing performance. Although emphasis has been placed on signal processing applications, general purpose computation has not been overlooked. Colt is a prototype that defines an architecture not only at the chip level but also in terms of an overall system design. As this system is realized, the concept of wormhole RTR will be applied to numerical computation and DSP applications including those common to image processing, communications systems, digital filters, acoustic processing, real-time control systems and simulation acceleration.

  16. A vertex model of Drosophila ventral furrow formation.

    Directory of Open Access Journals (Sweden)

    Philipp Spahn

    Full Text Available Ventral furrow formation in Drosophila is an outstanding model system to study the mechanisms involved in large-scale tissue rearrangements. Ventral cells accumulate myosin at their apical sides and, while being tightly coupled to each other via apical adherens junctions, execute actomyosin contractions that lead to reduction of their apical cell surface. Thereby, a band of constricted cells along the ventral epithelium emerges which will form a tissue indentation along the ventral midline (the ventral furrow. Here we adopt a 2D vertex model to simulate ventral furrow formation in a surface view allowing easy comparison with confocal live-recordings. We show that in order to reproduce furrow morphology seen in vivo, a gradient of contractility must be assumed in the ventral epithelium which renders cells more contractile the closer they lie to the ventral midline. The model predicts previous experimental findings, such as the gain of eccentric morphology of constricting cells and an incremental fashion of apical cell area reduction. Analysis of the model suggests that this incremental area reduction is caused by the dynamical interplay of cell elasticity and stochastic contractility as well as by the opposing forces from contracting neighbour cells. We underpin results from the model through in vivo analysis of ventral furrow formation in wildtype and twi mutant embryos. Our results show that ventral furrow formation can be accomplished as a "tug-of-war" between stochastically contracting, mechanically coupled cells and may require less rigorous regulation than previously thought.For the developmental biologist it is a fascinating question how cells can coordinate major tissue movements during embryonic development. The so-called ventral furrow of the Drosophila embryo is a well-studied example of such a process when cells from a ventral band, spanning nearly the entire length of the embryo, undergo dramatic shape change by contracting their

  17. Automatised data quality monitoring of the LHCb Vertex Locator

    Science.gov (United States)

    Bel, L.; Crocombe, A. Ch.; Gersabeck, M.; Pearce, A.; Majewski, M.; Szumlak, T.

    2017-10-01

    The LHCb Vertex Locator (VELO) is a silicon strip semiconductor detector operating at just 8mm distance to the LHC beams. Its 172,000 strips are read at a frequency of 1.1 MHz and processed by off-detector FPGAs followed by a PC cluster that reduces the event rate to about 10 kHz. During the second run of the LHC, which lasts from 2015 until 2018, the detector performance will undergo continued change due to radiation damage effects. This necessitates a detailed monitoring of the data quality to avoid adverse effects on the physics analysis performance. The VELO monitoring infrastructure has been re-designed compared to the first run of the LHC when it was based on manual checks. The new system is based around an automatic analysis framework, which monitors the performance of new data as well as long-term trends and using dedicated algorithms flags issues whenever they arise. The new analysis framework then analyses the plots that are produced by these algorithms. One of its tasks is to perform custom comparisons between the newly processed data and that from reference runs. The most-likely scenario in which this analysis would identify an issue is the parameters of the readout electronics no longer being optimal and requiring retuning. The data of the monitoring plots can be reduced further, e.g. by evaluating averages, and these quantities are input to long-term trending. This is used to detect slow variation of quantities, which are not detectable by the comparison of two nearby runs. Such gradual change is what is expected due to radiation damage effects. It is essential to detect these changes early such that measures can be taken, e.g. adjustments of the operating voltage, to prevent any impact on the quality of high-level quantities and thus on physics analyses. The plots as well as the analysis results and trends are made available through graphical user interfaces (GUIs). These GUIs are dynamically configured by a single configuration that determines the

  18. NH3-promoted ligand lability in eleven-vertex rhodathiaboranes.

    Science.gov (United States)

    Calvo, Beatriz; Roy, Beatriz; Macías, Ramón; Artigas, Maria Jose; Lahoz, Fernando J; Oro, Luis A

    2014-12-01

    The reaction of the 11-vertex rhodathiaborane, [8,8-(PPh3)2-nido-8,7-RhSB9H10] (1), with NH3 affords inmediately the adduct, [8,8,8-(NH3)(PPh3)2-nido-8,7-RhSB9H10] (4). The NH3-Rh interaction induces the labilization of the PPh3 ligands leading to the dissociation product, [8,8-(NH3)(PPh3)-nido-8,7-RhSB9H10] (5), which can then react with another molecule of NH3 to give [8,8,8-(NH3)2(PPh3)-nido-8,7-RhSB9H10] (6). These clusters have been characterized in situ by multielement NMR spectroscopy at different temeperatures. The variable temperature behavior of the system demonstrates that the intermediates 4-6 are in equilibrium, involving ligand exchange processes. On the basis of low intensity signals present in the (1)H NMR spectra of the reaction mixture, some species are tentatively proposed to be the bis- and tris-NH3 ligated clusters, [8,8-(NH3)2-nido-8,7-RhSB9H10] (7) and [8,8,8-(NH3)3-nido-8,7-RhSB9H10] (8). After evaporation of the solvent and the excess of NH3, the system containing species 4-8 regenerates the starting reactant, 1, thus closing a stoichiometric cycle of ammonia addition and loss. After 40 h at room temperature, the reaction of 1 with NH3 gives the hydridorhodathiaborane, [8,8,8-(H)(PPh3)2-nido-8,7-RhSB9H9] (2), as a single product. The reported rhodathiaboranes show reversible H3N-promoted ligand lability, which implies weak Rh-N interactions, leading to a rare case of metal complexes that circumvent "classical" Werner chemistry.

  19. Law of large numbers for the SIR model with random vertex weights on Erdős-Rényi graph

    Science.gov (United States)

    Xue, Xiaofeng

    2017-11-01

    In this paper we are concerned with the SIR model with random vertex weights on Erdős-Rényi graph G(n , p) . The Erdős-Rényi graph G(n , p) is generated from the complete graph Cn with n vertices through independently deleting each edge with probability (1 - p) . We assign i. i. d. copies of a positive r. v. ρ on each vertex as the vertex weights. For the SIR model, each vertex is in one of the three states 'susceptible', 'infective' and 'removed'. An infective vertex infects a given susceptible neighbor at rate proportional to the production of the weights of these two vertices. An infective vertex becomes removed at a constant rate. A removed vertex will never be infected again. We assume that at t = 0 there is no removed vertex and the number of infective vertices follows a Bernoulli distribution B(n , θ) . Our main result is a law of large numbers of the model. We give two deterministic functions HS(ψt) ,HV(ψt) for t ≥ 0 and show that for any t ≥ 0, HS(ψt) is the limit proportion of susceptible vertices and HV(ψt) is the limit of the mean capability of an infective vertex to infect a given susceptible neighbor at moment t as n grows to infinity.

  20. The Part-Time Student's Experience 1996-2007: An Issue of Identity and Marginalisation?

    Science.gov (United States)

    Williams, James; Kane, David

    2010-01-01

    Part-time study is one of the foci of the widening participation agenda in the UK. The experiences of part-time students, however, have received remarkably little attention from scholars, especially in a comparative context. This paper explores existing historical data going back over a decade to identify the main themes of part-time experience at…

  1. The Experience of Childhood as Hanami: Celebrating Special Moments in Time

    Science.gov (United States)

    Sullivan, Ginny; Banning, Wendy

    2010-01-01

    Cherry blossoms last only a very short time, a matter of days, and in Japan that time is special. People in Japan temporarily abandon their work, drop other commitments, and travel long distances to participate in time-honored rituals which enable them to explore, appreciate, and experience the ephemeral beauty of the event, an experience they…

  2. Minimum Vertex-type Sequence Indexing for Clusters on Square Lattice.

    Science.gov (United States)

    Liao, Longguang; Zhao, Yu-Jun; Cao, Zexian; Yang, Xiao-Bao

    2017-03-24

    An effective indexing scheme for clusters that enables fast structure comparison and congruence check is desperately desirable in the field of mathematics, artificial intelligence, materials science, etc. Here we introduce the concept of minimum vertex-type sequence for the indexing of clusters on square lattice, which contains a series of integers each labeling the vertex type of an atom. The minimum vertex-type sequence is orientation independent, and it builds a one-to-one correspondence with the cluster. By using minimum vertex-type sequence for structural comparison and congruence check, only one type of data is involved, and the largest amount of data to be compared is n pairs, n is the cluster size. In comparison with traditional coordinate-based methods and distance-matrix methods, the minimum vertex-type sequence indexing scheme has many other remarkable advantages. Furthermore, this indexing scheme can be easily generalized to clusters on other high-symmetry lattices. Our work can facilitate cluster indexing and searching in various situations, it may inspire the search of other practical indexing schemes for handling clusters of large sizes.

  3. Test-beam measurements and simulation studies of thin pixel sensors for the CLIC vertex detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00574329; Dannheim, Dominik

    The multi-$TeV$ $e^{+}e^{-}$ Compact Linear Collider (CLIC) is one of the options for a future high-energy collider for the post-LHC era. It would allow for searches of new physics and simultaneously offer the possibility for precision measurements of standard model processes. The physics goals and experimental conditions at CLIC set high precision requirements on the vertex detector made of pixel detectors: a high pointing resolution of 3 $\\mu m$, very low mass of 0.2% $X_{0}$ per layer, 10 ns time stamping capability and low power dissipation of 50 mW/$cm^{2}$ compatible with air-flow cooling. In this thesis, hybrid assemblies with thin active-edge planar sensors are characterised through calibrations, laboratory and test-beam measurements. Prototypes containing 50 $\\mu m$ to 150 $\\mu m$ thin planar silicon sensors bump-bonded to Timepix3 readout ASICs with 55 $\\mu m$ pitch are characterised in test beams at the CERN SPS in view of their detection efficiency and single-point resolution. A digitiser for AllP...

  4. Characterisation of capacitively coupled HV/HR-CMOS sensor chips for the CLIC vertex detector

    CERN Document Server

    AUTHOR|(SzGeCERN)756402

    2017-01-01

    The capacitive coupling between an active sensor and a readout ASIC has been considered in the framework of the CLIC vertex detector study. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is a High-Voltage CMOS sensor chip produced in a commercial 180 nm HV-CMOS process for this purpose. The sensor was designed to be connected to the CLICpix2 readout chip. It therefore matches the dimensions of the readout chip, featuring a matrix of 128 × 128 square pixels with 25 μm pitch. The sensor chip has been produced with the standard value for the substrate resistivity (∼ 20 Ωcm) and it has been characterised in standalone testing mode, before receiving and testing capacitively coupled assemblies. The standalone measurement results show a rise time of ∼ 20 ns for a power consumption of 5 μW/pixel. Production of the C3PD HV-CMOS sensor chip with higher substrate resistivity wafers (∼ 20, 80, 200 and 1000 Ωcm) is foreseen. The expected benefits of the higher substrate resistivity will be studied using...

  5. Characterisation of capacitively coupled HV/HR-CMOS sensor chips for the CLIC vertex detector

    Science.gov (United States)

    Kremastiotis, I.

    2017-12-01

    The capacitive coupling between an active sensor and a readout ASIC has been considered in the framework of the CLIC vertex detector study. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is a High-Voltage CMOS sensor chip produced in a commercial 180 nm HV-CMOS process for this purpose. The sensor was designed to be connected to the CLICpix2 readout chip. It therefore matches the dimensions of the readout chip, featuring a matrix of 128×128 square pixels with 25μm pitch. The sensor chip has been produced with the standard value for the substrate resistivity (~20 Ωcm) and it has been characterised in standalone testing mode, before receiving and testing capacitively coupled assemblies. The standalone measurement results show a rise time of ~20 ns for a power consumption of 5μW/pixel. Production of the C3PD HV-CMOS sensor chip with higher substrate resistivity wafers (~20, 80, 200 and 1000 Ωcm) is foreseen. The expected benefits of the higher substrate resistivity will be studied using future assemblies with the readout chip.

  6. Prototype system for proton beam range measurement based on gamma electron vertex imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Han Rim [Neutron Utilization Technology Division, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057 (Korea, Republic of); Kim, Sung Hun; Park, Jong Hoon [Department of Nuclear Engineering, Hanyang University, Seongdong-gu, Seoul 04763 (Korea, Republic of); Jung, Won Gyun [Heavy-ion Clinical Research Division, Korean Institute of Radiological & Medical Sciences, Seoul 01812 (Korea, Republic of); Lim, Hansang [Department of Electronics Convergence Engineering, Kwangwoon University, Seoul 01897 (Korea, Republic of); Kim, Chan Hyeong, E-mail: chkim@hanyang.ac.kr [Department of Nuclear Engineering, Hanyang University, Seongdong-gu, Seoul 04763 (Korea, Republic of)

    2017-06-11

    In proton therapy, for both therapeutic effectiveness and patient safety, it is very important to accurately measure the proton dose distribution, especially the range of the proton beam. For this purpose, recently we proposed a new imaging method named gamma electron vertex imaging (GEVI), in which the prompt gammas emitting from the nuclear reactions of the proton beam in the patient are converted to electrons, and then the converted electrons are tracked to determine the vertices of the prompt gammas, thereby producing a 2D image of the vertices. In the present study, we developed a prototype GEVI system, including dedicated signal processing and data acquisition systems, which consists of a beryllium plate (= electron converter) to convert the prompt gammas to electrons, two double-sided silicon strip detectors (= hodoscopes) to determine the trajectories of those converted electrons, and a plastic scintillation detector (= calorimeter) to measure their kinetic energies. The system uses triple coincidence logic and multiple energy windows to select only the events from prompt gammas. The detectors of the prototype GEVI system were evaluated for electronic noise level, energy resolution, and time resolution. Finally, the imaging capability of the GEVI system was tested by imaging a {sup 90}Sr beta source, a {sup 60}Co gamma source, and a 45-MeV proton beam in a PMMA phantom. The overall results of the present study generally show that the prototype GEVI system can image the vertices of the prompt gammas produced by the proton nuclear interactions.

  7. A Full-Time Dilemma: Examining the Experiences of Part-Time Faculty

    Science.gov (United States)

    Kimmel, Krista M.; Fairchild, Jennifer L.

    2017-01-01

    Part-time faculty now account for more than half of all faculty in American colleges and universities. Existing scholarship primarily has focused on the teaching effectiveness of part-time faculty. In this exploratory study, the authors employ a qualitative approach to examine the perspectives of part-time faculty members at a public, regional…

  8. "PYOGENIC LIVER ABSCESS IN CHILDREN: A LONG TIME HOSPITAL EXPERIENCE"

    Directory of Open Access Journals (Sweden)

    G. Khotaii

    2004-05-01

    Full Text Available Consensus regarding management of pyogenic liver abscess (PLA among children is yet to emerge, and documentation on these subjects is scanty. Eighteen cases of PLA admitted at Children’s Medical Center in Tehran, Iran, over a 15 year period were analyzed to document the clinical profile and to evaluate the management of PLA among children. Records of all patients were reviewed for presenting signs and symptoms, any associated condition, investigative results, management, and follow–up findings. The overall rate of PLA was 48.9 per 100,000 pediatric admissions in our hospital. Moderate to severe malnutrition was present in five (27.8% and ascariasis in seven (38.9% children. Common presentations were fever (100%, abdominal pain (76.9%, and tender hepatomegaly (83.3%. Fourteen patients (77.8% had solitary liver abscess. Organism was isolated in 11 cases (63.3%, and staphylococcus aureus was the commonest isolate (66.7%.Twelve cases were managed conservatively with antibiotics alone, of these only two (16.7% required drainage later. Percutaneous aspiration was also undertaken in four additional (22.2% cases and open drainage in two (11.1%, at presentation. The overall mortality rate was 11.1%. Time taken for complete resolution ranged from 10 to 40 days. Altogether, we conclude that any child presenting with fever, abdominal pain, and tender hepatomegaly should be subjected to ultrasound scan for early detection of PLA. It seems that a combination of cloxacillin and gentamicin or a third generation cephalosporine and gentamicin, especially in infants, is a satistactory initial coverage. Therapeutic drainage is not an obligation in all cases of PLA. When required, percutaneous needle aspiration is safe and effective. Resolution and significant reduction in mortality has been made possible by early detection and appropriate antibiotic therapy.

  9. Measurement of the Charm and Beauty Structure Functions using the H1 Vertex Detector at HERA

    CERN Document Server

    Aaron, FD; Alexa, C; Alimujiang, K; Andreev, V; Antunovic, B; Asmone, A; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; de Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D -J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, Samvel; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jonsson, L; Jung, Andreas Werner; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H -U; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schoeffel, L; Schoning, A; Schultz-Coulon, H -C; Sefkow, F; Shaw-West, R N; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F; Zus, R

    2010-01-01

    Inclusive charm and beauty cross sections are measured in e-p and e+p neutral current collisions at HERA in the kinematic region of photon virtuality 5vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are combined with previous data and compared to QCD predictions.

  10. Measurement of the charm and beauty structure functions using the H1 vertex detector at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, F.D. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Bucharest Univ. (Romania). Faculty of Physics; Aldaya Martin, M. [DESY, Hamburg (Germany); Alexa, C. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (RO)] (and others)

    2009-06-15

    Inclusive charm and beauty cross sections are measured in e{sup -}p and e{sup +}p neutral current collisions at HERA in the kinematic region of photon virtuality 5{<=}Q{sup 2}{<=}2000 GeV{sup 2} and Bjorken scaling variable 0.0002{<=}x{<=}0.05. The data were collected with the H1 detector in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb{sup -1}. The numbers of charm and beauty events are determined using variables reconstructed by the H1 vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are combined with previous data and compared to QCD predictions. (orig.)

  11. Development and validation of a model for the response of the Belle II vertex detector

    CERN Document Server

    Schwenker, Benjamin

    The future super flavour factory SuperKEKB with its detector system Belle II offers precision physics measurements to test the Standard Model or probe undiscovered phenomena. The physics goals of Belle II require a very precise detection of the decay point, or vertex, of B mesons from their low momentum decay products. A novel, two layer vertex detector composed of very thin, high resolution silicon pixel detectors based on Depleted Field Effect Transistors (DEPFET) is in production for Belle II. A realistic and experimentally validated simulation for DEPFET pixel detectors is a crucial tool to optimize the resolution of the vertex detector well before construction. In this thesis, a detailed detector simulation for the response of thin DEPFET pixel detectors to charged particles is presented. The detector simulation provides a description of the straggling of particles in silicon, the drift, diffusion and collection of the signal and the response of the read-out electronics. The model yields a precise predic...

  12. Centration on the cornea vertex normal during hyperopic refractive photoablation using videokeratoscopy.

    Science.gov (United States)

    de Ortueta, Diego; Schreyger, Frank D

    2007-02-01

    To evaluate a method for centering the ablation in standard hyperopic LASIK using an excimer laser with a video-based eye tracker system. Results of 52 consecutive hyperopic eyes treated with the ESIRIS excimer laser were retrospectively reviewed. Ablation was shifted from the pupil center to the vertex normal of the cornea using pupillary offset measured with the Keratron Scout videokeratoscope. Outcomes were assessed 3 months postoperatively. All eyes preoperatively had a nasally oriented vertex normal in relation to the pupil center. Three months postoperatively a refractive outcome of < 0.50 diopters of spherical equivalent was achieved in 94% (49/52) of eyes. No eye lost more than one line of best spectacle-corrected visual acuity. Standard hyperopic LASIK with the ESIRIS laser system leads to good predictable efficacy and safety results when the ablation center is shifted to the cornea vertex normal based on videokeratoscopy data.

  13. ATLAS strategy for primary vertex reconstruction during Run-2 of the LHC

    CERN Document Server

    Borissov, Guennadi; The ATLAS collaboration; Grimm, Kathryn; Pagan Griso, Simone; Pedersen, Lars Egholm; Prokofiev, Kirill; Rudolph, Matthew Scott; Wharton, Andrew Mark

    2015-01-01

    The reconstruction of vertices corresponding to proton--proton collisions in ATLAS is an essential element of event reconstruction used in many performance studies and physics analyses. During Run-1 of the LHC, ATLAS has employed an iterative approach to vertex finding. In order to improve the flexibility of the algorithm and ensure continued performance for very high numbers of simultaneous collisions in Run-2 of the LHC and beyond, a new approach to seeding vertex finding has been developed inspired by image reconstruction techniques. This note provides a brief outline of how reconstructed tracks are used to create an image of likely vertex collisions in an event, describes the implementation in the ATLAS software, and presents some preliminary results of the performance of the algorithm in simulation approximating early Run-2 conditions.

  14. Study of the vertex trigger performance on test-beam data

    CERN Document Server

    Teubert, F

    1999-01-01

    99-030 The performance of the Level-1 vertex trigger algorithm on test-beam data collected with a prototype of the VDET detector is presented. The effect of the detectors misalignment on the Level-1 vertex trigger performance is shown to be a critical issue if the relative position is not controlled better than $100~\\mu$m. The Primary vertex resolution on the longitudinal direction obtained on the test-beam for 2D-tracks ($270~\\mu$m), translates into a resolution close to $80~\\mu$m for the statistics of an LHC event in good agreement with expectations. The discriminating power between B-events and Minimum Bias events is studied using a sample of ``artificial'' events built from events interacting at different targets separated by 1~cm. The results are very encouraging showing the feasibility to trigger on low multiplicity displaced vertices.

  15. ATLAS strategy for primary vertex reconstruction during Run-2 of the LHC

    Science.gov (United States)

    Borissov, G.; Casper, D.; Grimm, K.; Pagan Griso, S.; Egholm Pedersen, L.; Prokofiev, K.; Rudolph, M.; Wharton, A.

    2015-12-01

    The reconstruction of vertices corresponding to proton-proton collisions in ATLAS is an essential element of event reconstruction used in many performance studies and physics analyses. During Run-1 of the LHC, ATLAS has employed an iterative approach to vertex finding. In order to improve the flexibility of the algorithm and ensure continued performance for very high numbers of simultaneous collisions in Run-2 of the LHC and beyond, a new approach to seeding vertex finding has been developed inspired by image reconstruction techniques. This note provides a brief outline of how reconstructed tracks are used to create an image of likely vertex collisions in an event, describes the implementation in the ATLAS software, and presents some preliminary results of the performance of the algorithm in simulation approximating early Run-2 conditions.

  16. A vertex centred Finite Volume Jameson-Schmidt-Turkel (JST) algorithm for a mixed conservation formulation in solid dynamics

    Science.gov (United States)

    Aguirre, Miquel; Gil, Antonio J.; Bonet, Javier; Arranz Carreño, Aurelio

    2014-02-01

    A vertex centred Finite Volume algorithm is presented for the numerical simulation of fast transient dynamics problems involving large deformations. A mixed formulation based upon the use of the linear momentum, the deformation gradient tensor and the total energy as conservation variables is discretised in space using linear triangles and tetrahedra in two-dimensional and three-dimensional computations, respectively. The scheme is implemented using central differences for the evaluation of the interface fluxes in conjunction with the Jameson-Schmidt-Turkel (JST) artificial dissipation term. The discretisation in time is performed by using a Total Variational Diminishing (TVD) two-stage Runge-Kutta time integrator. The JST algorithm is adapted in order to ensure the preservation of linear and angular momenta. The framework results in a low order computationally efficient solver for solid dynamics, which proves to be very competitive in nearly incompressible scenarios and bending dominated applications.

  17. Finite-difference time-domain analysis of time-resolved terahertz spectroscopy experiments

    DEFF Research Database (Denmark)

    Larsen, Casper; Cooke, David G.; Jepsen, Peter Uhd

    2011-01-01

    probe pulse and can be determined solely by the pump pulse duration. Our method is found to reproduce complicated two-dimensional transient conductivity maps exceedingly well, demonstrating the power of the time-domain numerical method for extracting ultrafast and dynamic transport parameters from time...

  18. The missing gauge conditions for the dual fermion emission vertex and their consequences

    CERN Document Server

    Brink, L; Rebbi, C; Scherk, J

    1973-01-01

    The authors find that the dual vertex for emitting a ground state fermion of mass m converts between generalized mesonic G gauges and generalized fermionic F gauges. These generalized gauges consist of infinite linear combinations of F's and G's which are, roughly speaking, square roots of Virasoro gauges and exhibit partial reflection and transmission behaviour at the vertex. One of these Ward identities allows us to re-express the amplitude for fermion re- emission in the F/sub 2/ representation where the limit m=0 is well defined. If m=0 and d=10 certain meson channels are saturated by physical (ghost free) states. (12 refs).

  19. The SuperB Silicon Vertex Tracker and 3D vertical integration

    CERN Document Server

    Re, Valerio

    2011-01-01

    The construction of the SuperB high luminosity collider was approved and funded by the Italian government in 2011. The performance specifications set by the target luminosity of this machine (> 10^36 cm^-2 s^-1) ask for the development of a Silicon Vertex Tracker with high resolution, high tolerance to radiation and excellent capability of handling high data rates. This paper reviews the R&D activity that is being carried out for the SuperB SVT. Special emphasis is given to the option of exploiting 3D vertical integration to build advanced pixel sensors and readout electronics that are able to comply with SuperB vertexing requirements.

  20. Further results for the two-loop Lcc vertex in the Landau gauge

    OpenAIRE

    Cvetic, Gorazd; Kondrashuk, Igor

    2007-01-01

    In the previous paper hep-th/0604112 we calculated the first of the five planar two-loop diagrams for the Lcc vertex of the general non-Abelian Yang-Mills theory, the vertex which allows us in principle to obtain all other vertices via the Slavnov-Taylor identity. The integrand of this first diagram has a simple Lorentz structure. In this letter we present the result for the second diagram, whose integrand has a complicated Lorentz structure. The calculation is performed in the D-dimensional ...

  1. Algebraic arctic curves in the domain-wall six-vertex model

    Energy Technology Data Exchange (ETDEWEB)

    Colomo, F [INFN, Sezione di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Noferini, V [Department of Mathematics, University of Pisa, Largo Bruno Pontecorvo 5, 56127 Pisa (Italy); Pronko, A G, E-mail: colomo@fi.infn.it, E-mail: noferini@mail.dm.unipi.it, E-mail: agp@pdmi.ras.ru [Department of Physics, University of Wuppertal, 42097 Wuppertal (Germany)

    2011-05-13

    The arctic curve, i.e. the spatial curve separating ordered (or 'frozen') and disordered (or 'temperate) regions, of the six-vertex model with domain-wall boundary conditions is discussed for the root-of-unity vertex weights. In these cases, the curve is described by algebraic equations which can be worked out explicitly from the parametric solution for this curve. Some interesting examples are discussed in detail. The upper bound on the maximal degree of the equation in a generic root-of-unity case is obtained.

  2. Digital signal processors in the LHCb level-1 vertex trigger system

    CERN Document Server

    Bouianov, O

    1999-01-01

    99-002 The note discusses the use of Analog Devices' SHARC Digital Signal Processors for the Level-1 Vertex Trigger system implementation. It presents a short overview of current and future Analog Devices' floating-point DSP architectures, multiprocessor system architectures and a survey of available standard DSP board-level components and software for multiprocessor applications. A possible solution for mapping the vertex trigger algorithm on the scaleable DSP multiprocessor is discussed with analysis of its implementation using standard DSP multiprocessor components.

  3. Row Transfer Matrix Functional Relations for Baxter's Eight-Vertex and Six-Vertex Models with Open Boundaries Via More General Reflection Matrices

    OpenAIRE

    Zhou, Yu-kui

    1995-01-01

    The functional relations of the transfer matrices of fusion hierachies for six- and eight-vertex models with open boundary conditions have been presented in this paper. We have shown the su($2$) fusion rule for the models with more general reflection boundary conditions, which are represented by off-diagonal reflection matrices. Also we have discussed some physics properties which are determined by the functional relations. Finally the intertwining relation between the reflection $K$ matrices...

  4. Exploring the Impact of Work Experience on Part-Time Students' Academic Success in Malaysian Polytechnics

    Science.gov (United States)

    Ibrahim, Norhayati; Freeman, Steven A.; Shelley, Mack C.

    2012-01-01

    The study explored the influence of work experience on adult part-time students' academic success as defined by their cumulative grade point average. The sample consisted of 614 part-time students from four polytechnic institutions in Malaysia. The study identified six factors to measure the perceived influence of work experiences--positive…

  5. Electron and phonon dispersions of the two-dimensional Holstein model: effects of vertex and non-local corrections

    CERN Document Server

    Hague, J P

    2003-01-01

    I apply the newly developed dynamical cluster approximation (DCA) to the calculation of the electron and phonon dispersions in the two-dimensional Holstein model. In contrast to previous work, the DCA enables the effects of spatial fluctuations (non-local corrections) to be examined. Approximations neglecting and incorporating lowest-order vertex corrections are investigated. I calculate the phonon density of states, the renormalized phonon dispersion, the electron dispersion and electron spectral functions. I demonstrate how vertex corrections stabilize the solution, stopping a catastrophic softening of the (pi, pi) phonon mode. A kink in the electron dispersion is found in the normal state along the (zeta, zeta) symmetry direction in both the vertex- and non-vertex-corrected theories for low phonon frequencies, corresponding directly to the renormalized phonon frequency at the (pi, 0) point. This kink is accompanied by a sudden drop in the quasi-particle lifetime. Vertex and non-local corrections enhance th...

  6. Design and standalone characterisation of a capacitively coupled HV-CMOS sensor chip for the CLIC vertex detector

    Science.gov (United States)

    Kremastiotis, I.; Ballabriga, R.; Campbell, M.; Dannheim, D.; Fiergolski, A.; Hynds, D.; Kulis, S.; Peric, I.

    2017-09-01

    The concept of capacitive coupling between sensors and readout chips is under study for the vertex detector at the proposed high-energy CLIC electron positron collider. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is an active High-Voltage CMOS sensor, designed to be capacitively coupled to the CLICpix2 readout chip. The chip is implemented in a commercial 180 nm HV-CMOS process and contains a matrix of 128×128 square pixels with 25μm pitch. First prototypes have been produced with a standard resistivity of ~20 Ωcm for the substrate and tested in standalone mode. The results show a rise time of ~20 ns, charge gain of 190 mV/ke- and ~40 e- RMS noise for a power consumption of 4.8μW/pixel. The main design aspects, as well as standalone measurement results, are presented.

  7. Mixed-Hybrid and Vertex-Discontinuous-Galerkin Finite Element Modeling of Multiphase Compositional Flow on 3D Unstructured Grids

    CERN Document Server

    Moortgat, Joachim

    2016-01-01

    Problems of interest in hydrogeology and hydrocarbon resources involve complex heterogeneous geological formations. Such domains are most accurately represented in reservoir simulations by unstructured computational grids. Finite element methods accurately describe flow on unstructured meshes with complex geometries, and their flexible formulation allows implementation on different grid types. In this work, we consider for the first time the challenging problem of fully compositional three-phase flow in 3D unstructured grids, discretized by any combination of tetrahedra, prisms, and hexahedra. We employ a mass conserving mixed hybrid finite element (MHFE) method to solve for the pressure and flux fields. The transport equations are approximated with a higher-order vertex-based discontinuous Galerkin (DG) discretization. We show that this approach outperforms a face-based implementation of the same polynomial order. These methods are well suited for heterogeneous and fractured reservoirs, because they provide ...

  8. Convergence of the Stochastic Six-Vertex Model to the ASEP

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Amol, E-mail: amolaggarwal@g.harvard.edu [Harvard University Cambridge (United States)

    2017-06-15

    In this note we establish the convergence of the stochastic six-vertex model to the one-dimensional asymmetric simple exclusion process, under a certain limit regime recently predicted by Borodin-Corwin-Gorin. This convergence holds for arbitrary initial data.

  9. Triangle strings: Structures for augmentation of vertex-disjoint triangle sets

    NARCIS (Netherlands)

    Zhang, Zan-Bo; Zhang, X.

    2014-01-01

    Vertex-disjoint triangle sets (triangle sets for short) have been studied extensively. Many theoretical and computational results have been obtained. While the maximum triangle set problem can be viewed as the generalization of the maximum matching problem, there seems to be no parallel result to

  10. Virtual Network Embedding: A Hybrid Vertex Mapping Solution for Dynamic Resource Allocation

    Directory of Open Access Journals (Sweden)

    Adil Razzaq

    2012-01-01

    Full Text Available Virtual network embedding (VNE is a key area in network virtualization, and the overall purpose of VNE is to map virtual networks onto an underlying physical network referred to as a substrate. Typically, the virtual networks have certain demands, such as resource requirements, that need to be satisfied by the mapping process. A virtual network (VN can be described in terms of vertices (nodes and edges (links with certain resource requirements, and, to embed a VN, substrate resources are assigned to these vertices and edges. Substrate networks have finite resources and utilizing them efficiently is an important objective for a VNE method. This paper analyzes two existing vertex mapping approaches—one which only considers if enough node resources are available for the current VN mapping and one which considers to what degree a node already is utilized by existing VN embeddings before doing the vertex mapping. The paper also proposes a new vertex mapping approach which minimizes complete exhaustion of substrate nodes while still providing good overall resource utilization. Experimental results are presented to show under what circumstances the proposed vertex mapping approach can provide superior VN embedding properties compared to the other approaches.

  11. Selective attention and the auditory vertex potential. 1: Effects of stimulus delivery rate

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1975-01-01

    Enhancement of the auditory vertex potentials with selective attention to dichotically presented tone pips was found to be critically sensitive to the range of inter-stimulus intervals in use. Only at the shortest intervals was a clear-cut enhancement of the latency component to stimuli observed for the attended ear.

  12. A direct digital control of the temperature for the VENUS vertex chamber at TRISTAN

    Energy Technology Data Exchange (ETDEWEB)

    Ohama, T. (National Laboratory for High Energy Physics, KEK, Tsukuba, Ibaraki 305 (Japan)); Ishihara, N. (National Laboratory for High Energy Physics, KEK, Tsukuba, Ibaraki 305 (Japan)); Utsumi, M. (National Laboratory for High Energy Physics, KEK, Tsukuba, Ibaraki 305 (Japan)); Yamada, Y. (National Laboratory for High Energy Physics, KEK, Tsukuba, Ibaraki 305 (Japan))

    1994-12-01

    A trial to introduce a DDC (direct digital control) system has been carried out in order to stabilize the temperature of the VENUS vertex chamber so as to obtain a spatial resolution of better than 50 [mu]m. The temperature is controlled to within 0.1 C in the gas near to the chamber endplates. ((orig.))

  13. Study of a DEPFET vertex detector and of supersymmetric smuons at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xun

    2009-01-21

    This thesis is devoted to the study of the performance of a pixel vertex detector based on DEPFET technology at the International Linear Collider (ILC). The ILC is the proposed next generation e{sup +}e{sup -} collider to explore the physics at the Terascale. At the ILC with its well-defined initial state of collisions, possible discoveries at the Large Hadron Collider can be verified and studied more accurately. It is expected that the precision measurements of the ILC will answer many fundamental questions about the universe, such as the generation of particle masses and the origin of electroweak spontaneous symmetry breaking. The ambitious physics goals present challenges to the ILC detectors. Several detector concepts have been proposed in recent years. A crucial device for all these concepts is the pixel vertex detector. It provides precise impact parameter information of charged particles, jet flavor tagging and improves overall tracking efficiency. To meet the requirements of the ILC environment, the vertex detector will be arranged in a concentric multi-layer array around the interaction point to cover as large a solid angle as possible. Endcap disks are considered in some designs. Silicon pixel sensor technologies must be employed to provide excellent point resolution. The DEPFET technology, which integrates the first level of amplification into a depleted silicon bulk, is one of the promising candidates. The DEPFET sensor is very sensitive with a high signal-to-noise ratio. Power consumption is minimized due to the internal storage of signal charges. The good radiation tolerance makes it capable of working close to the interaction point. In this thesis, we discuss the detailed simulation of the DEPFET vertex detector, following the general vertex detector layout proposed by the TESLA collaboration. The simulation is used to evaluate the impact parameter resolution. We also discuss the DEPFET test beam analysis on two-track resolution. The whole analysis

  14. Estimating the number of endmembers in hyperspectral imagery using accumulated convex hull vertex and similarity measure

    Science.gov (United States)

    Wu, Kang-Pei; Teng, Hong-Chao; Wu, Jee-Cheng

    2017-10-01

    The key to successful spectral un-mixing is indicating number of endmembers and their corresponding spectral signatures. Nevertheless, correctly estimate the number of end members without a priori knowledge is a very hard task because pixels in a hyperspectral image are always contain a mixture of the several reflected spectra. Currently, Noise Whitened Harsanyi, Farrand, and Chang (NWHFC) and hyperspectral signal subspace identification by minimum error (HySime) are two well-known methods for estimating the number of endmembers. However, in practice, because NWHFC requires fixing the false-alarm probability and HySime needs estimate noise of each spectral band, these two methods may not only ignore small objects but also can't identify endmembers. In this paper, assuming endmembers in a hyperspectral image can be modeled by convex geometry. We propose a threestage process to estimate the number of endmembers. At the first stage, principal component (PC) is used to transform original image to low-dimensional components for speeding up algorithm execution. At second stage, successive volume maximization (SVMAX) is used to obtain vertex using convex properties. At the third stage, spectral angle mapper (SAM) is used to compute similarity measures among vertex, and minimum SAM value represents vertex separation. Repeat the second and third stages by increasing transformed component dimensions until reach a predefined criteria. The number of endmembers of the image is the vertex with maximum of the vertex separations Finally, the proposed method is applied to synthetic and real AVIRIS and HYDICE hyperspectral data sets for estimating the number of endmembers. The results demonstrate that the proposed method can be used to estimate more reasonable and precise number of endmembers than the two published methods.

  15. a Cell Vertex Algorithm for the Incompressible Navier-Stokes Equations on Non-Orthogonal Grids

    Science.gov (United States)

    Jessee, J. P.; Fiveland, W. A.

    1996-08-01

    The steady, incompressible Navier-Stokes (N-S) equations are discretized using a cell vertex, finite volume method. Quadrilateral and hexahedral meshes are used to represent two- and three-dimensional geometries respectively. The dependent variables include the Cartesian components of velocity and pressure. Advective fluxes are calculated using bounded, high-resolution schemes with a deferred correction procedure to maintain a compact stencil. This treatment insures bounded, non-oscillatory solutions while maintaining low numerical diffusion. The mass and momentum equations are solved with the projection method on a non-staggered grid. The coupling of the pressure and velocity fields is achieved using the Rhie and Chow interpolation scheme modified to provide solutions independent of time steps or relaxation factors. An algebraic multigrid solver is used for the solution of the implicit, linearized equations.A number of test cases are anlaysed and presented. The standard benchmark cases include a lid-driven cavity, flow through a gradual expansion and laminar flow in a three-dimensional curved duct. Predictions are compared with data, results of other workers and with predictions from a structured, cell-centred, control volume algorithm whenever applicable. Sensitivity of results to the advection differencing scheme is investigated by applying a number of higher-order flux limiters: the MINMOD, MUSCL, OSHER, CLAM and SMART schemes. As expected, studies indicate that higher-order schemes largely mitigate the diffusion effects of first-order schemes but also shown no clear preference among the higher-order schemes themselves with respect to accuracy. The effect of the deferred correction procedure on global convergence is discussed.

  16. Time-integrated CP violation measurements in the B mesons system at the LHCb experiment

    CERN Document Server

    Cardinale, R

    2016-01-01

    Time-integrated CP violation measurements in the B meson system provide information for testing the CKM picture of CP violation in the Standard Model. A review of recent results from the LHCb experiment is presented.

  17. QRTEngine: An easy solution for running online reaction time experiments using Qualtrics

    NARCIS (Netherlands)

    Barnhoorn, Jonathan Sebastiaan; Haasnoot, Erwin; Bocanegra, Bruno R.; van Steenbergen, Henk

    2015-01-01

    Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this

  18. Liquid Argon Time Projection Chambers for Dark Matter and Neutrino Experiments

    OpenAIRE

    Manenti, L

    2016-01-01

    This thesis illustrates the contribution of the author to experiments using liquid argon Time Projection Chambers (LAr TPCs), a technology already widely used, that is becoming the dominating detection technique in dark matter (DM) and neutrino searches.

  19. Parental Experiences of the "Time Together" Home Visiting Intervention: An Attachment Theory Perspective

    Science.gov (United States)

    Butcher, Rebecca L.; Gersch, Irvine S.

    2014-01-01

    This paper reports the results of research into parental experiences of the Somerset (UK) "Time Together" home visiting intervention, with regards to its impact on the parent-child relationship. The research was carried out using an Attachment Theory lens in order to understand the qualitative experiences of seven parents of children in…

  20. Becoming Professionally Qualified: The School-Based Mentoring Experiences of Part-Time PGCE Students

    Science.gov (United States)

    Mukeredzi, Tabitha Grace; Mthiyane, Nonhlanhla; Bertram, Carol

    2015-01-01

    This paper reports on a study which explored the mentoring experiences of professionally unqualified practicing teachers enrolled in a part-time Post Graduate Certificate in Education (PGCE) programme at the University of KwaZulu-Natal. The study sought to understand the mentoring experiences these students received from their teacher mentors, who…

  1. Development of an automatic scanning system for nuclear emulsion analysis in the OPERA experiment and study of neutrino interactions location; Developpement d'un systeme ultra rapide pour le scan des emulsions nucleaires d'OPERA et etude sur la localistion des vertex de l'interaction des neutrinos a l'aide de ce systeme

    Energy Technology Data Exchange (ETDEWEB)

    Arrabito, L

    2007-10-15

    Following Super Kamiokande and K2K experiments, Opera (Oscillation Project with Emulsion tracking Apparatus), aims to confirm neutrino oscillation in the atmospheric sector. Taking advantage of a technique already employed in Chorus and in Donut, the Emulsion Cloud Chamber (ECC), Opera will be able to observe the {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillation, through the {nu}{sub {tau}} appearance in a pure {nu}{sub {mu}} beam. The Opera experiment, with its {approx} 100000 m{sup 2} of nuclear emulsions, needs a very fast automatic scanning system. Optical and mechanics components have been customized in order to achieve a speed of about 20 cm{sup 2}/hour per emulsion layer (44 {mu}m thick), while keeping a sub-micro-metric resolution. The first part of this thesis was dedicated to the optimization of 4 scanning systems at the French scanning station, based in Lyon. An experimental study on a dry objective scanning system has also been realized. The obtained results show that the performances of dry scanning are similar with respect to the traditional oil scanning, so that it can be successfully used for Opera. The second part of this work was devoted to the study of the neutrino interaction location and reconstruction strategy actually used in Opera. A dedicated test beam was performed at CERN in order to simulate Opera conditions. The obtained results definitely confirm that the proposed strategy is well adapted for tau search. (author)

  2. Time accuracy requirements for fusion experiments: A case study at ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Raupp, Gerhard, E-mail: gerhard.raupp@ipp.mpg.d [Max-Planck-Institut fuer Plasmaphysik, EURTATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Behler, Karl; Eixenberger, Horst [Max-Planck-Institut fuer Plasmaphysik, EURTATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Fitzek, Michael [Unlimited Computer Systems, D-82393 Iffeldorf (Germany); Kollotzek, Horst; Lohs, Andreas [Max-Planck-Institut fuer Plasmaphysik, EURTATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Lueddecke, Klaus [Unlimited Computer Systems, D-82393 Iffeldorf (Germany); Mueller, Peter; Merkel, Roland; Neu, Gregor; Schacht, Joerg; Schramm, Gerold; Treutterer, Wolfgang; Zasche, Dieter; Zehetbauer, Thomas [Max-Planck-Institut fuer Plasmaphysik, EURTATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2010-07-15

    To manage and operate a fusion device and measure meaningful data an accurate and stable time is needed. As a benchmark, we suggest to consider time accuracy as sufficient if it is better than typical data errors or process timescales. This allows to distinguish application domains and chose appropriate time distribution methods. For ASDEX Upgrade a standard NTP method provides Unix time for project and operation management tasks, and a dedicated time system generates and distributes a precise experiment time for physics applications. Applying the benchmark to ASDEX Upgrade shows that physics measurements tagged with experiment time meet the requirements, while correlation of NTP tagged operation data with physics data tagged with experiment time remains problematic. Closer coupling of the two initially free running time systems with daily re-sets was an efficient and satisfactory improvement. For ultimate accuracy and seamless integration, however, continuous adjustment of the experiment time clock frequency to NTP is needed, within frequency variation limits given by the benchmark.

  3. The time-varying shortest path problem with fuzzy transit costs and speedup

    Directory of Open Access Journals (Sweden)

    Rezapour Hassan

    2016-08-01

    Full Text Available In this paper, we focus on the time-varying shortest path problem, where the transit costs are fuzzy numbers. Moreover, we consider this problem in which the transit time can be shortened at a fuzzy speedup cost. Speedup may also be a better decision to find the shortest path from a source vertex to a specified vertex.

  4. "It's about Improving My Practice": The Learner Experience of Real-Time Coaching

    Science.gov (United States)

    Sharplin, Erica J.; Stahl, Garth; Kehrwald, Ben

    2016-01-01

    This article reports on pre-service teachers' experience of the Real-Time Coaching model, an innovative technology-based approach to teacher training. The Real-Time Coaching model uses multiple feedback cycles via wireless technology to develop within pre-service teachers the specific skills and mindset toward continual improvement. Results of…

  5. Hard real-time closed-loop electrophysiology with the Real-Time eXperiment Interface (RTXI.

    Directory of Open Access Journals (Sweden)

    Yogi A Patel

    2017-05-01

    Full Text Available The ability to experimentally perturb biological systems has traditionally been limited to static pre-programmed or operator-controlled protocols. In contrast, real-time control allows dynamic probing of biological systems with perturbations that are computed on-the-fly during experimentation. Real-time control applications for biological research are available; however, these systems are costly and often restrict the flexibility and customization of experimental protocols. The Real-Time eXperiment Interface (RTXI is an open source software platform for achieving hard real-time data acquisition and closed-loop control in biological experiments while retaining the flexibility needed for experimental settings. RTXI has enabled users to implement complex custom closed-loop protocols in single cell, cell network, animal, and human electrophysiology studies. RTXI is also used as a free and open source, customizable electrophysiology platform in open-loop studies requiring online data acquisition, processing, and visualization. RTXI is easy to install, can be used with an extensive range of external experimentation and data acquisition hardware, and includes standard modules for implementing common electrophysiology protocols.

  6. Vertex Reconstructing Neural Network at the ZEUS Central Tracking Detector

    CERN Document Server

    Dror, G; Dror, Gideon; Etzion, Erez

    2001-01-01

    An unconventional solution for finding the location of event creation is presented. It is based on two feed-forward neural networks with fixed architecture, whose parameters are chosen so as to reach a high accuracy. The interaction point location is a parameter that can be used to select events of interest from the very high rate of events created at the current experiments in High Energy Physics. The system suggested here is tested on simulated data sets of the ZEUS Central Tracking Detector, and is shown to perform better than conventional algorithms.

  7. TCAD simulations of High-Voltage-CMOS Pixel structures for the CLIC vertex detector

    CERN Document Server

    Buckland, Matthew Daniel

    2016-01-01

    The requirements for precision physics and the experimental conditions at CLIC result in stringent constraints for the vertex detector. Capacitively coupled active pixel sensors with 25 μm pitch implemented in a commercial 180 nm High-Voltage CMOS (HV-CMOS) process are currently under study as a candidate technology for the CLIC vertex detector. Laboratory calibration measurements and beam tests with prototypes are complemented by detailed TCAD and electronic circuit simulations, aiming for a comprehensive understanding of the signal formation in the HV-CMOS sensors and subsequent readout stages. In this note 2D and 3D TCAD simulation results of the prototype sensor, the Capacitively Coupled Pixel Detector version three (CCPDv3), will be presented. These include the electric field distribution, leakage current, well capacitance, transient response to minimum ionising particles and charge-collection.

  8. Study on Vertex Interval Determination for Consistent Calculation of Coastline Length

    Science.gov (United States)

    Woo, H. S.; Kwon, K. S.; Kim, B. G.

    2017-09-01

    Coastline extraction and decision have important implications for efficient land management and national policy formulation. However, coastlines extracted without certain criteria are difficult to obtain consistent results for the same region, and therefore, have a lot of restrictions on land management and application. For example, in some South Korea coastlines surveyed in this study, it was confirmed that there is a large difference in coastline lengths calculated for the same area depending on how the vertex interval is set. In this study, we propose and discuss the guidelines to enable consistent and accurate coastline extraction for the same area. The consistency of coastline output can be ensured only by the coastline calculation method using vertex interval criterion considering regional and coastline characteristics. This research content is expected to contribute to efficient land management and national policy establishment and progress.

  9. Active Vertex Model for cell-resolution description of epithelial tissue mechanics.

    Science.gov (United States)

    Barton, Daniel L; Henkes, Silke; Weijer, Cornelis J; Sknepnek, Rastko

    2017-06-01

    We introduce an Active Vertex Model (AVM) for cell-resolution studies of the mechanics of confluent epithelial tissues consisting of tens of thousands of cells, with a level of detail inaccessible to similar methods. The AVM combines the Vertex Model for confluent epithelial tissues with active matter dynamics. This introduces a natural description of the cell motion and accounts for motion patterns observed on multiple scales. Furthermore, cell contacts are generated dynamically from positions of cell centres. This not only enables efficient numerical implementation, but provides a natural description of the T1 transition events responsible for local tissue rearrangements. The AVM also includes cell alignment, cell-specific mechanical properties, cell growth, division and apoptosis. In addition, the AVM introduces a flexible, dynamically changing boundary of the epithelial sheet allowing for studies of phenomena such as the fingering instability or wound healing. We illustrate these capabilities with a number of case studies.

  10. Phase-space networks of the six-vertex model under different boundary conditions.

    Science.gov (United States)

    Han, Yilong

    2010-04-01

    The six-vertex model is mapped to three-dimensional sphere stacks and different boundary conditions corresponding to different containers. The shape of the container provides a qualitative visualization of the boundary effect. Based on the sphere-stacking picture, we map the phase spaces of the six-vertex models to discrete networks. A node in the network represents a state of the system, and an edge between two nodes represents a zero-energy spin flip, which corresponds to adding or removing a sphere. The network analysis shows that the phase spaces of systems with different boundary conditions share some common features. We derived a few formulas for the number and the sizes of the disconnected phase-space subnetworks under the periodic boundary conditions. The sphere stacking provides new challenges in combinatorics and may cast light on some two-dimensional models.

  11. New graph classes characterized by weak vertex separators and two-pairs

    Directory of Open Access Journals (Sweden)

    Terry A. McKee

    2017-04-01

    Full Text Available A set of vertices whose deletion from a graph would increase the distance between two remaining vertices is called a weak vertex separator of the graph. Two vertices form a two-pair if all chordless paths between them have length 2. I prove that every inclusion-minimal weak vertex separator of every induced subgraph of a graph G induces a complete subgraph if and only if nonadjacent vertices of induced C4 subgraphs of G always form two-pairs of G; moreover, this is also true when “complete” and C4 are replaced with “edgeless” and K4−e (≅K1,1,2. The first of the resulting new graph classes generalizes chordal graphs, and the second generalizes unichord-free graphs; they both generalize distance-hereditary graphs and geodetic graphs.

  12. S-matrix, vertex operators and correlation functions of Liouville theory

    Energy Technology Data Exchange (ETDEWEB)

    Jorjadze, G. [Razmadze Mathematical Institute, M. Aleksidze 1, Tbilisi, Georgia (United States)

    2004-06-01

    We investigate the S-matrix of Liouville theory on the basis of exact relation between exponentials of the in- and out-fields. The vertex operators for negative integer exponentials are constructed by regularising procedure. Their vacuum matrix elements are calculated using Dotsenko-Fateev integrals. The result is continued analytically to the generic case. The obtained correlation function coincides with the suggested 3-point function of Dorn and Otto for positive exponentials only. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  13. The Effect of the Vertex Angles of Wedged Indenters on Deformation during Nanoindentation

    Directory of Open Access Journals (Sweden)

    Xiaowen Hu

    2017-12-01

    Full Text Available In order to study the effect of the angle of wedged indenters during nanoindentation, indenters with half vertex angles of 60°, 70° and 80° are used for the simulations of nanoindentation on FCC aluminum (Al bulk material by the multiscale quasicontinuum method (QC. The load-displacement responses, the strain energy-displacement responses, and hardness of Al bulk material are obtained. Besides, atomic configurations for each loading situation are presented. We analyze the drop points in the load-displacement responses, which correspond to the changes of microstructure in the bulk material. From the atom images, the generation of partial dislocations as well as the nucleation and the emission of perfect dislocations have been observed with wedged indenters of half vertex angles of 60° and 70°, but not 80°. The stacking faults move beneath the indenter along the direction [ 1 1 ¯ 0 ] . The microstructures of residual displacements are also discussed. In addition, hardness of the Al bulk material is different in simulations with wedged indenters of half vertex angles of 60° and 70°, and critical hardness in the simulation with the 70° indenter is bigger than that with the 60° indenter. The size effect of hardness in plastic wedged nanoindentation is observed. There are fewer abrupt drops in the strain energy-displacement response than in the load-displacement response, and the abrupt drops in strain energy-displacement response reflect the nucleation of perfect dislocations or extended dislocations rather than partial dislocations. The wedged indenter with half vertex angle of 70° is recommended for investigating dislocations during nanoindentation.

  14. The LHCb Vertex Locator Replacement Detector - Electrical and Thermal Performance Studies

    CERN Document Server

    Hennessy, K

    2013-01-01

    This document describes the characterisation of the performance of the replacement detector for the LHCb Vertex Locator. Tests were performed at CERN on the fully assembled detector halves. Included are results of tests of the (i) intrinsic noise on the sensors, (ii) their IV curves, (iii) thermal performance and (iv) various tests associated with the Beetle readout ASIC. A comparison to the current detector is also given.

  15. Chemical Applications of Topology and Group Theory. 20. Eight-Vertex Polyhedra and Their Rearrangements.

    Science.gov (United States)

    1985-10-14

    Geometriae Dedicata 1975, 3, 469. *(6) Lipscomb, W. N. Science 1966, 153, 373. (7) King, R. B. J. Am. Chem. Soc. 1969, 91, 7211. * (8) Hoard, J. L...polyhedra given in Table 1 of Federico, P.J. Geometriae Dedicata 1975, 3, 469. The vertex index v7 v6v5 v4 v3 and the symmetry point group are given in

  16. Classification of eight-vertex solutions of the colored Yang-Baxter equation

    CERN Document Server

    Wang, S

    1997-01-01

    In this paper all eight-vertex type solutions of the colored Yang-Baxter equation dependent on spectral as well as color parameter are given. It is proved that they are composed of three groups of basic solutions, three groups of their degenerate forms and two groups of trivial solutions up to five solution transformations. Moreover, all non-trivial solutions can be classified into two types called Baxter and Free-Fermion type.

  17. Combining Vertex-centric Graph Processing with SPARQL for Large-scale RDF Data Analytics

    KAUST Repository

    Abdelaziz, Ibrahim

    2017-06-27

    Modern applications, such as drug repositioning, require sophisticated analytics on RDF graphs that combine structural queries with generic graph computations. Existing systems support either declarative SPARQL queries, or generic graph processing, but not both. We bridge the gap by introducing Spartex, a versatile framework for complex RDF analytics. Spartex extends SPARQL to support programs that combine seamlessly generic graph algorithms (e.g., PageRank, Shortest Paths, etc.) with SPARQL queries. Spartex builds on existing vertex-centric graph processing frameworks, such as Graphlab or Pregel. It implements a generic SPARQL operator as a vertex-centric program that interprets SPARQL queries and executes them efficiently using a built-in optimizer. In addition, any graph algorithm implemented in the underlying vertex-centric framework, can be executed in Spartex. We present various scenarios where our framework simplifies significantly the implementation of complex RDF data analytics programs. We demonstrate that Spartex scales to datasets with billions of edges, and show that our core SPARQL engine is at least as fast as the state-of-the-art specialized RDF engines. For complex analytical tasks that combine generic graph processing with SPARQL, Spartex is at least an order of magnitude faster than existing alternatives.

  18. An asynchronous data-driven readout prototype for CEPC vertex detector

    Science.gov (United States)

    Yang, Ping; Sun, Xiangming; Huang, Guangming; Xiao, Le; Gao, Chaosong; Huang, Xing; Zhou, Wei; Ren, Weiping; Li, Yashu; Liu, Jianchao; You, Bihui; Zhang, Li

    2017-12-01

    The Circular Electron Positron Collider (CEPC) is proposed as a Higgs boson and/or Z boson factory for high-precision measurements on the Higgs boson. The precision of secondary vertex impact parameter plays an important role in such measurements which typically rely on flavor-tagging. Thus silicon CMOS Pixel Sensors (CPS) are the most promising technology candidate for a CEPC vertex detector, which can most likely feature a high position resolution, a low power consumption and a fast readout simultaneously. For the R&D of the CEPC vertex detector, we have developed a prototype MIC4 in the Towerjazz 180 nm CMOS Image Sensor (CIS) process. We have proposed and implemented a new architecture of asynchronous zero-suppression data-driven readout inside the matrix combined with a binary front-end inside the pixel. The matrix contains 128 rows and 64 columns with a small pixel pitch of 25 μm. The readout architecture has implemented the traditional OR-gate chain inside a super pixel combined with a priority arbiter tree between the super pixels, only reading out relevant pixels. The MIC4 architecture will be introduced in more detail in this paper. It will be taped out in May and will be characterized when the chip comes back.

  19. Study for online range monitoring with the interaction vertex imaging method

    Science.gov (United States)

    Finck, Ch; Karakaya, Y.; Reithinger, V.; Rescigno, R.; Baudot, J.; Constanzo, J.; Juliani, D.; Krimmer, J.; Rinaldi, I.; Rousseau, M.; Testa, E.; Vanstalle, M.; Ray, C.

    2017-12-01

    Ion beam therapy enables a highly accurate dose conformation delivery to the tumor due to the finite range of charged ions in matter (i.e. Bragg peak (BP)). Consequently, the dose profile is very sensitive to patients anatomical changes as well as minor mispositioning, and so it requires improved dose control techniques. Proton interaction vertex imaging (IVI) could offer an online range control in carbon ion therapy. In this paper, a statistical method was used to study the sensitivity of the IVI technique on experimental data obtained from the Heidelberg Ion-Beam Therapy Center. The vertices of secondary protons were reconstructed with pixelized silicon detectors. The statistical study used the χ2 test of the reconstructed vertex distributions for a given displacement of the BP position as a function of the impinging carbon ions. Different phantom configurations were used with or without bone equivalent tissue and air inserts. The inflection points in the fall-off region of the longitudinal vertex distribution were computed using different methods, while the relation with the BP position was established. In the present setup, the resolution of the BP position was about 4–5 mm in the homogeneous phantom under clinical conditions (106 incident carbon ions). Our results show that the IVI method could therefore monitor the BP position with a promising resolution in clinical conditions.

  20. Vertex Algebras W(p)Am and W(p)Dm and Constant Term Identities

    Science.gov (United States)

    Adamović, Dražen; Lin, Xianzu; Milas, Antun

    2015-03-01

    We consider AD-type orbifolds of the triplet vertex algebras W(p) extending the well-known c=1 orbifolds of lattice vertex algebras. We study the structure of Zhu's algebras A(W(p)^{A_m}) and A(W(p)^{D_m}), where A_m and D_m are cyclic and dihedral groups, respectively. A combinatorial algorithm for classification of irreducible W(p)^Γ-modules is developed, which relies on a family of constant term identities and properties of certain polynomials based on constant terms. All these properties can be checked for small values of m and p with a computer software. As a result, we argue that if certain constant term properties hold, the irreducible modules constructed in [Commun. Contemp. Math. 15 (2013), 1350028, 30 pages; Internat. J. Math. 25 (2014), 1450001, 34 pages] provide a complete list of irreducible W(p)^{A_m} and W(p)^{D_m}-modules. This paper is a continuation of our previous work on the ADE subalgebras of the triplet vertex algebra W(p).

  1. A model-based detector of vertex waves and K complexes in sleep electroencephalogram.

    Science.gov (United States)

    Da Rosa, A C; Kemp, B; Paiva, T; Lopes da Silva, F H; Kamphuisen, H A

    1991-01-01

    A model of sleep phasic events such as vertex waves, K complexes, delta waves and sleep spindles is proposed. It consists of feedback loops that are driven by white noise (simulating tonic delta and sigma activity) and by isolated random impulses, simulating vertex waves or K complexes, depending on the background tonic activity. A model-based method for the detection of sleep phasic events was implemented in a personal computer. Its performance was investigated using simulated and real whole-night EEG signals. The method was able to detect K complexes and vertex waves in a reliable way in spite of their variable shapes and in the presence of a variety of background activities. The detector appears to have superior performance to those so far reported in the literature. The performance of the detector was also compared to that of an electroencephalographer using normal sleep EEG records of 8 h duration from 6 subjects. The performance was satisfactory both in terms of accuracy and reliability. The problem of detecting K complexes in stages 3 and 4 of sleep is discussed.

  2. Real time control of satellite tracking station operation for millimeter wave experiments and associated data processing

    Science.gov (United States)

    Kauffman, S. R.; Stutzman, W. L.

    1977-01-01

    Real time control, data collection, and data reduction of an earth-satellite millimeter wave system are discussed. Experiment control and data processing requirements are considered with attention to signal data acquisition, weather data acquisition, support and control functions, task classifications, the fundamental data acquisition procedure, and the computer-experiment interface. The general analysis is applied to a description of the Communications Technology Satellite system and its hardware.

  3. Enactive cinema paves way for understanding complex real-time social interaction in neuroimaging experiments

    OpenAIRE

    Tikka, Pia; Väljamäe, Aleksander; de Borst, Aline W.; Pugliese, Roberto; Ravaja, Niklas; Kaipainen, Mauri; Takala, Tapio

    2012-01-01

    We outline general theoretical and practical implications of what we promote as enactive cinema for the neuroscientific study of online socio-emotional interaction. In a real-time functional magnetic resonance imaging (rt-fMRI) setting, participants are immersed in cinematic experiences that simulate social situations. While viewing, their physiological reactions—including brain responses—are tracked, representing implicit and unconscious experiences of the on-going social situations. These r...

  4. Tracking, Vertexing and data handling strategy for the LHCb upgrade

    CERN Document Server

    Seyfert, Paul

    2017-01-01

    For Run III (2021 onwards) of the LHC, LHCb will take data at an instantaneous luminosity of $2 \\times 10^{33} \\mathrm{cm}^{-2} \\mathrm{s}^{-1}$, five times higher than in Run II (2015-2018). To cope with the harsher data taking conditions, the LHCb collaboration will upgrade the DAQ system and install a purely software based trigger, in addition to various detector upgrades. The high readout rate contributes to the challenge of reconstructing and selecting events in real time. Special emphasis in this contribution will be put on the need for fast track reconstruction in the software trigger. The modified detector infrastructure will be able to face this challenge and the necessary changes to the reconstruction sequence are discussed. A novel strategy is presented which distributes and maximises the bandwidth among the different physics channels using a genetic algorithm. The data processing chain includes a re-design of the event scheduling, introduction of concurrent processing, optimisations in processor ...

  5. Nano-Hertz Gravitational Waves Searches with Interferometric Pulsar Timing Experiments

    CERN Document Server

    Tinto, Massimo

    2011-01-01

    We estimate the sensitivity to nano-Hertz gravitational waves of pulsar timing experiments in which two highly-stable millisecond pulsars are tracked simultaneously with two neighboring radio telescopes that are referenced to the same time-keeping subsystem (i.e. "the clock"). By taking the difference of the two time-of-arrival residual data streams we can exactly cancel the clock noise in the combined data set, thereby enhancing the sensitivity to gravitational waves. We estimate that, in the band ($10^{-9} - 10^{-8}$) Hz, this "interferometric" pulsar timing technique can potentially improve the sensitivity to gravitational radiation by almost two orders of magnitude over that of single-telescopes. Interferometric pulsar timing experiments could be performed with neighboring pairs of antennas of the forthcoming large arraying projects.

  6. Out-of-Time Beam Extinction in the MU2E Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Prebys, E. J. [Fermilab; Werkema, S. [Fermilab

    2015-06-01

    The Mu2e Experiment at Fermilab will search for the conversion of a muon to an electron in the field of an atomic nucleus with unprecedented sensitivity. The experiment requires a beam consisting of proton bunches 250 ns FW long, separated by 1.7 $\\mu$ sec, with no out-of-time protons at the $10^{10}$ fractional level. Satisfying this "extinction" requirement is very challenging. The formation of the bunches is expected to result in an extinction on the order of $10^5$. The remaining extinction will be accomplished by a system of resonant magnets and collimators, configured such that only in-time beam is delivered to the experiment. Our simulations show that the total extinction achievable by the system is on the order of $10^{12}$, with an efficiency for transmitting in-time beam of 99.6%.

  7. The time between intention and action affect the experience of action

    Directory of Open Access Journals (Sweden)

    Mikkel C. Vinding

    2015-06-01

    Full Text Available We present a study investigating how the delay between the intention to act and the following action, influenced the experience of action. In experiments investigating sense of agency and experience of action, the contrast is most often between voluntary and involuntary actions. It is rarely asked whether different types of intentions influence the experience of action differently. To investigate this we distinguished between proximal intentions (i.e. intentions for immediate actions and delayed intentions (i.e. intentions with a temporal delay between intention and action. The distinction was implemented in an intentional binding paradigm, by varying the delay between the time where participants formed the intention to act and the time at which they performed the action. The results showed that delayed intentions were followed by a stronger binding effect for the tone following the action compared to proximal intentions. The actions were reported to have occurred earlier for delayed intentions than for proximal intentions. This effect was independent of the binding effect usually found in intentional binding experiments. This suggests that two perceptual shifts occurred in the contrast between delayed intentions and proximal intentions: The first being the binding effect, the second a general shift in the perceived time of action. Neither the stronger binding effect for tone, nor the earlier reports of action, differed across delays for delayed intentions. The results imply that delayed intentions and proximal intentions have a different impact on the experience of action.

  8. A course-based research experience: how benefits change with increased investment in instructional time.

    Science.gov (United States)

    Shaffer, Christopher D; Alvarez, Consuelo J; Bednarski, April E; Dunbar, David; Goodman, Anya L; Reinke, Catherine; Rosenwald, Anne G; Wolyniak, Michael J; Bailey, Cheryl; Barnard, Daron; Bazinet, Christopher; Beach, Dale L; Bedard, James E J; Bhalla, Satish; Braverman, John; Burg, Martin; Chandrasekaran, Vidya; Chung, Hui-Min; Clase, Kari; Dejong, Randall J; Diangelo, Justin R; Du, Chunguang; Eckdahl, Todd T; Eisler, Heather; Emerson, Julia A; Frary, Amy; Frohlich, Donald; Gosser, Yuying; Govind, Shubha; Haberman, Adam; Hark, Amy T; Hauser, Charles; Hoogewerf, Arlene; Hoopes, Laura L M; Howell, Carina E; Johnson, Diana; Jones, Christopher J; Kadlec, Lisa; Kaehler, Marian; Silver Key, S Catherine; Kleinschmit, Adam; Kokan, Nighat P; Kopp, Olga; Kuleck, Gary; Leatherman, Judith; Lopilato, Jane; Mackinnon, Christy; Martinez-Cruzado, Juan Carlos; McNeil, Gerard; Mel, Stephanie; Mistry, Hemlata; Nagengast, Alexis; Overvoorde, Paul; Paetkau, Don W; Parrish, Susan; Peterson, Celeste N; Preuss, Mary; Reed, Laura K; Revie, Dennis; Robic, Srebrenka; Roecklein-Canfield, Jennifer; Rubin, Michael R; Saville, Kenneth; Schroeder, Stephanie; Sharif, Karim; Shaw, Mary; Skuse, Gary; Smith, Christopher D; Smith, Mary A; Smith, Sheryl T; Spana, Eric; Spratt, Mary; Sreenivasan, Aparna; Stamm, Joyce; Szauter, Paul; Thompson, Jeffrey S; Wawersik, Matthew; Youngblom, James; Zhou, Leming; Mardis, Elaine R; Buhler, Jeremy; Leung, Wilson; Lopatto, David; Elgin, Sarah C R

    2014-01-01

    There is widespread agreement that science, technology, engineering, and mathematics programs should provide undergraduates with research experience. Practical issues and limited resources, however, make this a challenge. We have developed a bioinformatics project that provides a course-based research experience for students at a diverse group of schools and offers the opportunity to tailor this experience to local curriculum and institution-specific student needs. We assessed both attitude and knowledge gains, looking for insights into how students respond given this wide range of curricular and institutional variables. While different approaches all appear to result in learning gains, we find that a significant investment of course time is required to enable students to show gains commensurate to a summer research experience. An alumni survey revealed that time spent on a research project is also a significant factor in the value former students assign to the experience one or more years later. We conclude: 1) implementation of a bioinformatics project within the biology curriculum provides a mechanism for successfully engaging large numbers of students in undergraduate research; 2) benefits to students are achievable at a wide variety of academic institutions; and 3) successful implementation of course-based research experiences requires significant investment of instructional time for students to gain full benefit.

  9. The time between intention and action affects the experience of action.

    Science.gov (United States)

    Vinding, Mikkel C; Jensen, Mads; Overgaard, Morten

    2015-01-01

    We present a study investigating how the delay between the intention to act and the following action, influenced the experience of action. In experiments investigating sense of agency and experience of action, the contrast is most often between voluntary and involuntary actions. It is rarely asked whether different types of intentions influence the experience of action differently. To investigate this we distinguished between proximal intentions (i.e., intentions for immediate actions) and delayed intentions (i.e., intentions with a temporal delay between intention and action). The distinction was implemented in an intentional binding paradigm, by varying the delay between the time where participants formed the intention to act and the time at which they performed the action. The results showed that delayed intentions were followed by a stronger binding effect for the tone following the action compared to proximal intentions. The actions were reported to have occurred earlier for delayed intentions than for proximal intentions. This effect was independent of the binding effect usually found in intentional binding experiments. This suggests that two perceptual shifts occurred in the contrast between delayed intentions and proximal intentions: The first being the binding effect, the second a general shift in the perceived time of action. Neither the stronger binding effect for tone, nor the earlier reports of action, differed across delays for delayed intentions. The results imply that delayed intentions and proximal intentions have a different impact on the experience of action.

  10. Application verification research of cloud computing technology in the field of real time aerospace experiment

    Science.gov (United States)

    Wan, Junwei; Chen, Hongyan; Zhao, Jing

    2017-08-01

    According to the requirements of real-time, reliability and safety for aerospace experiment, the single center cloud computing technology application verification platform is constructed. At the IAAS level, the feasibility of the cloud computing technology be applied to the field of aerospace experiment is tested and verified. Based on the analysis of the test results, a preliminary conclusion is obtained: Cloud computing platform can be applied to the aerospace experiment computing intensive business. For I/O intensive business, it is recommended to use the traditional physical machine.

  11. Accumulating advantages over time: Family experiences and social class inequality in academic achievement.

    Science.gov (United States)

    Potter, Daniel; Roksa, Josipa

    2013-07-01

    Children from different family backgrounds enter schooling with different levels of academic skills, and those differences grow over time. What explains this growing inequality? While the social reproduction tradition has argued that family contexts are central to producing class gaps in academic achievement, recent quantitative studies have found that family experiences explain only a small portion of those inequalities. We propose that resolving this inconsistency requires developing a new measure of family experiences that captures the continuity of exposure over time and thus more closely reflects the logic of the social reproduction tradition. Results using data from the Early Childhood Longitudinal Study - Kindergarten cohort (ECLS-K) show that, consistent with previous quantitative research, time-specific measures of family experiences have little explanatory power. However, cumulative family experiences account for most of the growing inequality in academic achievement between children from different social class backgrounds over time. These findings support claims from the social reproduction tradition, and contribute more broadly to the understanding of how family experiences contribute to social inequality. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. An initial experience with 85 consecutive robotic-assisted rectal dissections: improved operating times and lower costs with experience.

    Science.gov (United States)

    Byrn, John C; Hrabe, Jennifer E; Charlton, Mary E

    2014-11-01

    Data are limited about the robotic platform in rectal dissections, and its use may be perceived as prohibitively expensive or difficult to learn. We report our experience with the initial robotic-assisted rectal dissections performed by a single surgeon, assessing learning curve and cost. Following IRB approval, a retrospective chart review was conducted of the first 85 robotic-assisted rectal dissections performed by a single surgeon between 9/1/2010 and 12/31/2012. Patient demographic, clinicopathologic, procedure, and outcome data were gathered. Cost data were obtained from the University HealthSystem Consortium (UHC) database. The first 43 cases (Time 1) were compared to the next 42 cases (Time 2) using multivariate linear and logistic regression models. Indications for surgery were cancer for 51 patients (60 %), inflammatory bowel disease for 18 (21 %), and rectal prolapse for 16 (19 %). The most common procedures were low anterior resection (n = 25, 29 %) and abdominoperineal resection (n = 21, 25 %). The patient body mass index (BMI) was statistically different between the two patient groups (Time 1, 26.1 kg/m(2) vs. Time 2, 29.4 kg/m(2), p = 0.02). Complication and conversion rates did not differ between the groups. Mean operating time was significantly shorter for Time 2 (267 min vs. 224 min, p = 0.049) and remained significant in multivariate analysis. Though not reaching statistical significance, the mean observed direct hospital cost decreased ($17,349 for Time 1 vs. $13,680 for Time 2, p = 0.2). The observed/expected cost ratio significantly decreased (1.47 for Time 1 vs. 1.05 for Time 2, p = 0.007) but did not remain statistically significant in multivariate analyses. Over the series, we demonstrated a significant improvement in operating times. Though not statistically significant, direct hospital costs trended down over time. Studies of larger patient groups are needed to confirm these findings and to correlate them with procedure volume to better

  13. Time-stamping system for nuclear physics experiments at RIKEN RIBF

    Science.gov (United States)

    Baba, H.; Ichihara, T.; Ohnishi, T.; Takeuchi, S.; Yoshida, K.; Watanabe, Y.; Ota, S.; Shimoura, S.; Yoshinaga, K.

    2015-03-01

    A time-stamping system for nuclear physics experiments has been introduced at the RIKEN Radioactive Isotope Beam Factory. Individual trigger signals can be applied for separate data acquisition (DAQ) systems. After the measurements are complete, separately taken data are merged based on the time-stamp information. In a typical experiment, coincidence trigger signals are formed from multiple detectors to take desired events only. The time-stamping system allows the use of minimum bias triggers. Since coincidence conditions are given by software, a variety of physics events can be flexibly identified. The live time for a DAQ system is important when attempting to determine reaction cross-sections. However, the combined live time for separate DAQ systems is not clearly known because it depends not only on the DAQ dead time but also on the coincidence conditions. Using the proposed time-stamping system, all trigger timings can be acquired, so that the combined live time can be easily determined. The combined live time is also estimated using Monte Carlo simulations, and the results are compared with the directly measured values in order to assess the accuracy of the simulation.

  14. Handling of time-critical Conditions Data in the CMS experiment - Experience of the first year of data taking

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Data management for a wide category of non-event data plays a critical role in the operation of the CMS experiment. The processing chain (data taking-reconstruction-analysis) relies in the prompt availability of specific, time dependent data describing the state of the various detectors and their calibration parameters, which are treated separately from event data. The Condition Database system is the infrastructure established to handle these data and to make sure that they are available to both offline and online workflows. The Condition Data layout is designed such that the payload data (the Condition) is associated to an Interval Of Validity (IOV). The IOV allows accessing selectively the sets corresponding to specific intervals of time, run number or luminosity section. Both payloads and IOVs are stored in a cluster of relational database servers (Oracle) using an object-relational access approach. The strict requirements of security and isolation of the CMS online systems are imposing a redundant archit...

  15. The relation between the experience of time and psychological distress in patients with hematological malignancies.

    Science.gov (United States)

    Wittmann, Marc; Vollmer, Tanja; Schweiger, Claudia; Hiddemann, Wolfgang

    2006-12-01

    The experience of time is strongly related to our momentary mood states. Patients with a life-threatening illness experience an extreme change in mood and suffer from psychological distress that can develop into clinically relevant psychiatric disorders, like anxiety and depression. The aim of this study was to investigate the associations among the subjective perception of time, psychological distress, and quality of life in patients with hematological malignancies. Eighty-eight inpatients with hematological malignancies rated how fast time passes subjectively on a visual analog scale and prospectively estimated a time span of 13 min. The Hospital Anxiety and Depression Scale (HADS) self-report measures of health-related quality of life (FACT-G) and spiritual well-being (FACIT-Sp) were employed to assess psychological distress and quality of life. Those patients who reported a lower quality of life, less spiritual well-being, and more anxiety experienced a slower passage of subjective time and overestimated the 13-min time interval. Our interpretation of the results is that patients with a life-threatening illness who show symptoms of psychological distress draw attention away from meaningful thoughts and actions and, thus, experience time as passing more slowly. An altered sense of time can be a sign of mental suffering, which should be addressed within psycho-oncological interventions. As this is the first study to demonstrate this relation in cancer patients, further research is needed to investigate the experience of time and its relation to meaning as an issue in clinical diagnostics.

  16. Overestimation of the subjective experience of time in social anxiety: Effects of facial expression, gaze direction and time course

    Directory of Open Access Journals (Sweden)

    Kenta eIshikawa

    2016-04-01

    Full Text Available It is known that threatening stimuli increase emotional arousal, resulting in overestimating the subjective experience of passing time. Moreover, facial expressions and gaze direction interact to create socially threatening situations in people with social anxiety. The present study investigated the effect of social anxiety on the perceived duration of observing emotional faces with a direct or an averted gaze. Participants were divided into high, medium and low social anxiety groups based on social anxiety inventory scores. Participants then performed a temporal bisection task. Participants with high social anxiety provided larger overestimates for neutral faces with an averted gaze than those with low social anxiety in the second half of the task, whereas these differences were not found for angry face with direct and averted gaze. These results suggest that people with social anxiety perceive the duration of threatening situations as being longer than true durations based on objectively measured time.

  17. "Time for dialysis as time to live": experiences of time in everyday life of the Swedish next of kin of hemodialysis patients.

    Science.gov (United States)

    Ziegert, Kristina; Fridlund, Bengt; Lidell, Evy

    2009-03-01

    The aim of this study was to explore the content of time in everyday life as experienced by the next of kin of patients on hemodialysis in Sweden. Chronic renal disease often requires hemodialysis, which is a time-consuming treatment that makes it necessary to carefully plan everyday life and involves the next of kin to a large degree. This study used a descriptive design with a content analysis approach. The analysis of the data from the twenty interviews revealed the experiences of time in the everyday lives of the next of kin of a patient on hemodialysis. The content of time in everyday life can be described as follows: fragmented time, vacuous time, and uninterrupted time. The findings show how everyday life time for the next of kin is minimized and that the common life space is contracted. The next of kin must be provided with supervision in order to provide them with more of their own time in everyday life, which can benefit their health.

  18. Time characteristics of detectors based on silicon photomultipliers for the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Somov, A. S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Somov, S. V. [National Research Nuclear Univ., Moscow (Russia); Tolstukhin, I. A. [National Research Nuclear Univ., Moscow (Russia); Indiana Univ., Bloomington, IN (United States)

    2017-06-16

    Here, silicon photomultipliers (SiPMs) are used in detectors of the GlueX experiment devoted to studying the nature of confinement. These detectors are operable at counting rates as high as 2 MHz with a time resolution (FWHM) of approximately 0.3 ns and a number of excited pixels of up to 104. For SiPMs that operate under these conditions, the measured dependences of the recovery time and the time resolution are presented as functions of the number of excited pixels and the excitation frequency. Using a picosecond laser, the time resolution has been measured for an array of 4 × 4 SiPMs, which was specially developed for the experiment.

  19. Limit-experience of time in Zoé Valdés's Querido primer novio

    Directory of Open Access Journals (Sweden)

    Olivia Torijano Navarrete

    2013-12-01

    Full Text Available Zoé Valdés, a Cuban writer currently living in exile in France, wrote Dear First Love, a story narrated by multiple narrator-characters, including Time itself. In this book, the time in which the characters and objects exist is transient, however, it is possible to determine the moment of enunciation and in this way discover that the story is a myth created within that fiction. This emerges from the discordancy between actual time and mythical time, a subject much discussed by Paul Ricoeur. The protagonist of the novel travels backin time by means of her memory, while at the same time goes on an actual journey to rescue the beloved of his memories. Such limit-experiences are associated with the axial moment, since without the latter it is not possible to understand the chronological succession of events: one cannot tell what came first or what comes next. Limit-experiences occur when monumental time in the novel coincides with the chronological time of the characters. When trying to explain this situation, it becomes clear that the character develops his orher life and actions at their own pace within their world, and thus time may have a different meaning for each of the characters.

  20. Operational Experience, Improvements, and Performance of the CDF Run II Silicon Vertex Detector

    CERN Document Server

    Aaltonen, T; Boveia, A.; Brau, B.; Bolla, G; Bortoletto, D; Calancha, C; Carron, S.; Cihangir, S.; Corbo, M.; Clark, D.; Di Ruzza, B.; Eusebi, R.; Fernandez, J.P.; Freeman, J.C.; Garcia, J.E.; Garcia-Sciveres, M.; Gonzalez, O.; Grinstein, S.; Hartz, M.; Herndon, M.; Hill, C.; Hocker, A.; Husemann, U.; Incandela, J.; Issever, C.; Jindariani, S.; Junk, T.R.; Knoepfel, K.; Lewis, J.D.; Martinez-Ballarin, R.; Mathis, M.; Mattson, M.; Merkel, P; Mondragon, M.N.; Moore, R.; Mumford, J.R.; Nahn, S.; Nielsen, J.; Nelson, T.K.; Pavlicek, V.; Pursley, J.; Redondo, I.; Roser, R.; Schultz, K.; Spalding, J.; Stancari, M.; Stanitzki, M.; Stuart, D.; Sukhanov, A.; Tesarek, R.; Treptow, K.; Wallny, R.; Worm, S.

    2013-01-01

    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, an...

  1. Development of vertexing and lifetime triggers and a study of Bs mixing using hadronic decays at D0

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Christopher P. [Imperial College, London (United Kingdom)

    2005-03-01

    The D0 detector underwent a major upgrade to maximize its ability to fully exploit Run II at the Fermilab Tevatron, the world's highest energy collider. The upgrade included a completely new central tracking system with an outer scintillating fiber tracker and an inner silicon vertex detector all within a 2T superconducting solenoid. This thesis describes the development of high level trigger algorithms including vertexing, impact parameter significance and invariant mass, that utilize tracks from these detectors. One of the main physics goals of Run II is the observation of Bs oscillations. This measurement, which cannot be performed at the B factories, will significantly constrain the ''unitarity triangle'' associated with Cp violation and so probe the Standard Model of particle physics. Furthermore this is an interesting measurement as the study of mixing in meson systems has a long history for revealing new physics. The second part of this thesis presents a study of the hadronic decay Bs → Dsπ. This important mode provides the best proper time resolution for Bs mixing and is reconstructed for the first time at D0. Projections on the sensitivity to Bs oscillations are then presented.

  2. High-Order Space-time Discontinuous Galerkin Cell Vertex Scheme toward Compressible Navier Stokes Equations

    Science.gov (United States)

    2012-06-25

    and right: p3 solution. 20 Figure 12: Subsonic flow around NACA0012 airfoil. Left: pressure field. Right: Mach number field. 5.2 Flow around NACA0012 ...Airfoil The second example is a subsonic flow with Mach 0.63, AoA = 2 around the NACA0012 airfoil with curved boundary. The mesh contains 1536

  3. Efficient data analysis and travel time picking methods for crosshole GPR experiments

    DEFF Research Database (Denmark)

    Keskinen, Johanna; Moreau, Julien; Nielsen, Lars

    2013-01-01

    High-resolution GPR crosshole experiments are conducted to resolve fine-scale anisotropy of chalk. Chalk plays important roles in groundwater production onshore Denmark and in hydrocarbon exploration in the North Sea, and chalk has previously been studied extensively with geological and geophysical...... methods. Future time-lapse GPR studies of different types of chalk aim at characterizing the flow characteristics of these economically important lithologies. In the framework of the current study, we have collected new crosshole GPR data from a site located in a former quarry in Eastern Denmark, where...... crosshole GPR experiments have been previously carried out. Time-lapse GPR crosshole experiments involve the interpretation of large datasets organised in terms of transmitter or receiver gathers and hence call for efficient and robust data inspection and picking of first arrivals. To this end, we have...

  4. nodeGame: Real-time, synchronous, online experiments in the browser.

    Science.gov (United States)

    Balietti, Stefano

    2017-10-01

    nodeGame is a free, open-source JavaScript/ HTML5 framework for conducting synchronous experiments online and in the lab directly in the browser window. It is specifically designed to support behavioral research along three dimensions: (i) larger group sizes, (ii) real-time (but also discrete time) experiments, and (iii) batches of simultaneous experiments. nodeGame has a modular source code, and defines an API (application programming interface) through which experimenters can create new strategic environments and configure the platform. With zero-install, nodeGame can run on a great variety of devices, from desktop computers to laptops, smartphones, and tablets. The current version of the software is 3.0, and extensive documentation is available on the wiki pages at http://nodegame.org .

  5. The experiences of first-time mothers with colic infants who seek ...

    African Journals Online (AJOL)

    The purpose of this study was to describe the experiences of first-time mothers with colic infants. The research design was qualitative, exploratory, descriptive and contextual. Data were collected by means of in-depth, semistructured, phenomenological interviews and a descriptive analysis was done. The results show that ...

  6. Time-of-Flight Experiments in Molecular Motion and Electron-Atom Collision Kinematics

    Science.gov (United States)

    Donnelly, Denis P.; And Others

    1971-01-01

    Describes a set of experiments for an undergraduate laboratory which demonstrates the relationship between velocity, mass, and temperature in a gas. The experimental method involves time-of-flight measurements on atoms excited to metastable states by electron impact. Effects resulting from recoil in the electron-atom collision can also be…

  7. Integrating Evidence-Based Practice into a Therapeutic Exercise Course: Real-Time Patient Experience

    Science.gov (United States)

    Popp, Jennifer K.

    2014-01-01

    Athletic training students need real-time patient experiences in order to transfer the knowledge and skills learned in the classroom into clinical practice. The objective is to present a description of an assignment that could be incorporated into a therapeutic exercise course giving the student an opportunity to evaluate a patient, design a…

  8. FAMINES, FIGHTS AND DEPRIVATION: THE NEOREALIST EXPERIENCE OR THE PORTUGUESE TIME DOCUMENTATION

    Directory of Open Access Journals (Sweden)

    Michele Dull Sampaio Beraldo Matter

    2014-04-01

    Full Text Available This article examines different images related to the food in literary texts and paintings of portuguese Neorealism in its configuration of missing - hunger - and its ideological conception - the hunger for freedom and dignity - thematic experience that gives inherently see the relationship of humans with their time and with his fellow man.

  9. Agreement and Null Subjects in German L2 Development: New Evidence from Reaction-Time Experiments.

    Science.gov (United States)

    Clahsen, Harald; Hong, Upyong

    1995-01-01

    Reports on reaction time experiments investigating subject-verb agreement and null subjects in 33 Korean learners of German and a control group of 20 German native speakers. Results found that the two phenomena do not covary in the Korean learners, indicating that properties of agreement and null subjects are acquired separately from one another.…

  10. Pre-Service Post Graduate Teachers' First Time Experience with Constructivist Learning Environment (CLE) Using MOODLE

    Science.gov (United States)

    Boopathiraj, C.; Chellamani, K.

    2015-01-01

    The aim of this study is to enlighten and discuss Post Graduate student teachers' first time experiences and their level of satisfaction with the use of Moodle Learning Management System (LMS) during their "Research Methods in Education" course offered online. This study investigated 30 pre-service Post Graduate student teachers' to…

  11. Time as a Medium of Reward in Three Social Preference Experiments

    NARCIS (Netherlands)

    Noussair, C.N.; Stoop, J.T.R.

    2012-01-01

    Abstract: We report results from three well-known experimental paradigms, where we use time, rather than money, as the salient component of subjects’ incentives. The three experiments, commonly employed to study social preferences, are the dictator game, the ultimatum game and the trust game. All

  12. Study of S1 detector' time resolution at NA61/SHINE experiment

    CERN Document Server

    Balkova, Yuliia

    2017-01-01

    This document presents the final report on my project at CERN Summer Student Programme. The aim of the work was to determine time resolution of S1 (scintillation) detector at NA61/SHINE experiment's beamline and how it depends on readout voltage, beam size and beam position.

  13. First-time mothers' breast-feeding maintenance: role of experiences and changes in maternal perceptions.

    Science.gov (United States)

    Schafer, Ellen J; Campo, Shelly; Colaizy, Tarah T; Mulder, Pamela J; Breheny, Patrick; Ashida, Sato

    2017-12-01

    Breast-feeding initiation rates have increased in the USA; however, maintenance of breast-feeding for recommended durations is low. The objective of the present study was to identify factors that may facilitate breast-feeding for longer durations among first-time mothers, including physiological and social experiences and changes in maternal perceptions. Survival analysis and linear regression methods were used to explore the relationship between experiences and breast-feeding duration, and the possible mediating effect of changes in maternal perceptions. Secondary data from the Infant Feeding Practices Study II, conducted in the USA between 2005 and 2007. Data from 762 first-time mothers who ever breast-fed were analysed. Experiencing trouble with baby's latch, problems with milk flow/supply and painful breast-feeding were significantly associated with breast-feeding duration (64, 26 and 36 % shorter duration, respectively). Meanwhile, positive changes in perception with respect to breast-feeding self-efficacy, opinion about infant feeding and belief about breast milk were associated with 16-27 % longer duration. Furthermore, changes in perception were observed to partially mediate the impact of physiological experiences on breast-feeding duration. Perceptions of breast-feeding self-efficacy, beliefs and opinions can change over time and are influenced by breast-feeding experiences. The combined effect of experience and perception plays a key role in influencing breast-feeding duration. Future research should explore interventions to maintain or improve these perceptions while accounting for physiological experiences to support breast-feeding for recommended durations among first-time mothers.

  14. Do psychotherapists improve with time and experience? A longitudinal analysis of outcomes in a clinical setting.

    Science.gov (United States)

    Goldberg, Simon B; Rousmaniere, Tony; Miller, Scott D; Whipple, Jason; Nielsen, Stevan Lars; Hoyt, William T; Wampold, Bruce E

    2016-01-01

    Psychotherapy researchers have long questioned whether increased therapist experience is linked to improved outcomes. Despite numerous cross-sectional studies examining this question, no large-scale longitudinal study has assessed within-therapist changes in outcomes over time. The present study examined changes in psychotherapists' outcomes over time using a large, longitudinal, naturalistic psychotherapy data set. The sample included 6,591 patients seen in individual psychotherapy by 170 therapists who had on average 4.73 years of data in the data set (range = 0.44 to 17.93 years). Patient-level outcomes were examined using the Outcome Questionnaire-45 and a standardized metric of change (prepost d). Two-level multilevel models (patients nested within therapist) were used to examine the relationship between therapist experience and patient prepost d and early termination. Experience was examined both as chronological time and cumulative patients seen. Therapists achieved outcomes comparable with benchmarks from clinical trials. However, a very small but statistically significant change in outcome was detected indicating that on the whole, therapists' patient prepost d tended to diminish as experience (time or cases) increases. This small reduction remained when controlling for several patient-level, caseload-level, and therapist-level characteristics, as well as when excluding several types of outliers. Further, therapists were shown to vary significantly across time, with some therapists showing improvement despite the overall tendency for outcomes to decline. In contrast, therapists showed lower rates of early termination as experience increased. Implications of these findings for the development of expertise in psychotherapy are explored. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Performance of Track and Vertex Reconstruction and B-Tagging Studies with ATLAS in pp Collisions at $\\sqrt{s}=7 TeV$

    CERN Document Server

    Fleckner, J

    2010-01-01

    First 7 TeV proton-proton collisions produced by the Large Hadron Collider at CERN have been recorded by the ATLAS experiments in 2010. The ability to accurately and efficiently reconstruct the trajectories of charged particles produced in these collisions is a critical component in the measurements that will be presented at this conference. This talk will present results on the performance of tracking and vertexreconstruction using the ATLAS tracking systems. Various methods are employed by the two experiments for determining the efficiency of track reconstruction using the first data collected by the detectors. Furthermore, the methods to control the track momentum scale and related systematic uncertainties will be discussed. Finally, the reconstruction of known particle decays is presented as important tool to understand the tracking and vertexing performance, as well as the particle identification capabilities. The identification of b-quark jets is an important tool for the physics programs of the ATLAS e...

  16. A direct test of time-reversal symmetry in the neutral K meson system with KS → πℓν and KL → 3π0 at KLOE-2

    Directory of Open Access Journals (Sweden)

    Gajos Aleksander

    2014-01-01

    Full Text Available Quantum entanglement of K and B mesons allows for a direct experimental test of time-reversal symmetry independent of CP violation. The T symmetry can be probed by exchange of initial and final states in the reversible transitions between flavor and CP- definite states of the mesons which are only connected by the T conjugation. While such a test was successfully performed by the BaBar experiment with neutral B mesons, the KLOE-2 detector can probe T -violation in the neutral kaons system by investigating the process with KS → π±l∓νl and KL → 3π0 decays. Analysis of the latter is facilitated by a novel reconstruction method for the vertex of KL → 3π0 decay which only involves neutral particles. Details of this new vertex reconstruction technique are presented as well as prospects for conducting the direct T symmetry test at the KLOE-2 experiment.

  17. A Multi-Threading Algorithm to Detect and Remove Cycles in Vertex- and Arc-Weighted Digraph

    Directory of Open Access Journals (Sweden)

    Huanqing Cui

    2017-10-01

    Full Text Available A graph is a very important structure to describe many applications in the real world. In many applications, such as dependency graphs and debt graphs, it is an important problem to find and remove cycles to make these graphs be cycle-free. The common algorithm often leads to an out-of-memory exception in commodity personal computer, and it cannot leverage the advantage of multicore computers. This paper introduces a new problem, cycle detection and removal with vertex priority. It proposes a multithreading iterative algorithm to solve this problem for large-scale graphs on personal computers. The algorithm includes three main steps: simplification to decrease the scale of graph, calculation of strongly connected components, and cycle detection and removal according to a pre-defined priority in parallel. This algorithm avoids the out-of-memory exception by simplification and iteration, and it leverages the advantage of multicore computers by multithreading parallelism. Five different versions of the proposed algorithm are compared by experiments, and the results show that the parallel iterative algorithm outperforms the others, and simplification can effectively improve the algorithm's performance.

  18. Assessing the monitor warm-up time required before a psychological experiment can begin

    Directory of Open Access Journals (Sweden)

    Poth, Christian H.

    2017-10-01

    Full Text Available Visual experiments in psychology, psychophysics, and cognitive neuroscience require precise control over stimulus characteristics, such as luminance and contrast. In such experiments, stimuli are most often presented using computer monitors. These monitors bear an often neglected and rarely reported source of experimental confounds and uncontrolled variation: they take a warm-up time in which their luminance systematically changes until a stable level is eventually reached. Here we demonstrate this problem by measuring luminance over time for five different monitors. Results indicate that not only the warm-up time but also the course that the warm-up takes can vary greatly between different monitors. To address this problem, we propose a simple method of approximating a monitor\\IeC {\\textquoteright }s warm-up time, which takes into account theoretical considerations of the specific experiment. On this basis, we suggest a standardized experimental procedure and a standardized way of reporting its results to enable experimenters to control for monitor warm-up time.

  19. THE ORGANIZATION OF SPACE AND EDUCATION SCHOOL-TIME: ANALYSIS OF AN INTEGRAL EDUCATION EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Marília Andrade Torales Campos

    2016-07-01

    Full Text Available This article proposes a reflection upon the public policies in education with regard to the experiences on full-time education – more specifically, on the process of extension and use of school-educational time, carried out in Apucarana/PR. The choice of this research object is justified by the emergence of a new political-economic reality in the country, which imposes the need to rethink school and its social functions. Thus, from the analyzed experience, the emergence of a new concept of school was noticed. This concept is based on a communitarian structure, or on learning communities, and it transcends the classic teacher-student dichotomy, including new learning-teaching individuals. In order to understand the data, it is important to rethink the meaning of time and space, not only in school, but also in families and communities from the social context.

  20. Solutions without Space-Time Separation for ADS Experiments: Overview on Developments and Applications

    Directory of Open Access Journals (Sweden)

    B. Merk

    2012-01-01

    Full Text Available The different analytical solutions without space-time separation foreseen for the analysis of ADS experiments are described. The SC3A experiment in the YALINA-Booster facility is described and investigated. For this investigation the very special configuration of YALINA-Booster is analyzed based on HELIOS calculations. The results for the time dependent diffusion and the time dependent P1 equation are compared with the experimental results for the SC3A configuration. A comparison is given for the deviation between the analytical solution and the experimental results versus the different transport approximations. To improve the representation to the special configuration of YALINA- Booster, a new analytical solution for two energy groups with two sources (central external and boundary source has been developed starting form the Green's function solution. Very good agreement has been found for these improved analytical solutions.

  1. Ives-Stilwell Time Dilation Li+ ESR Darmstadt Experiment and Neo-Lorentz Relativity

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2015-01-01

    Full Text Available Botermann et al in Test of Time Dilation Using Stored Li + Ions as Clocks at Relativis- tic Speed , Physical Review Letters , 2014, 113, 120405, reported results from an Ives- Stilwell-type time dilation experiment using Li + ions at speed 0.338c in the ESR storage ring at Darmstadt, and concluded that the data verifies the Special Relativity time dila- tion e ect. However numerous other experiments have shown that it is only neo-Lorentz Relativity that accounts for all data, and all detect a 3-space speed V 470 km / s essen- tially from the south. Here we show that the ESR data confirms both Special Relativity and neo-Lorentz Relativity, but that a proposed di erent re-analysis of the ESR data should enable a test that could distinguish between these two theories.

  2. The effect of time fractality on the transition coefficients: Historical Stern-Gerlach experiment revisited

    Energy Technology Data Exchange (ETDEWEB)

    Sirin, Hueseyin, E-mail: huseyin.sirin@ege.edu.t [Department of Physics, Science Faculty, Ege University, 35100 Bornova, Izmir (Turkey); Bueyuekkilic, Fevzi; Ertik, Hueseyin; Demirhan, Dogan [Department of Physics, Science Faculty, Ege University, 35100 Bornova, Izmir (Turkey)

    2011-01-15

    Research highlights: The influence of time discreteness on the transition coefficients of quantum systems. Time fractional Schroedinger Equation. Time fractional transition coefficients of historical Stern-Gerlach experiment. - Abstract: In this article, the influence of time discreteness on the transition coefficients is investigated within the framework of time fractional development of quantum systems which has been developed recently by the present authors . In this formalism, fractional mathematics which is a powerful tool to study the non-Markovian and non-Gaussian properties of physical processes is used in order to obtain time fractional evolution operator and transition probability. They are given in terms of Mittag-Leffler function which plays an important role in the mathematical structure as well as the physical interpretation of the phenomena under investigation. In order to place the presented formalism on a concrete basis, historical Stern-Gerlach experiment has been revisited with the purpose of studying transition coefficients which have a non-Markovian feature. The effect of the time fractionalization has been clearly illustrated in the figures via fractional derivative order {alpha}.

  3. Timing is everything: the experience of parental cancer for young adult daughters--a pilot study.

    Science.gov (United States)

    Puterman, Jenny; Cadell, Susan

    2008-01-01

    Parental cancer during young adulthood is unexpected and potentially disruptive to the developmental goals of this period. This study explores how young adult women experience a parent's cancer diagnosis and treatment. The sample included five participants, aged 20 to 32, who had a parent receiving cancer treatment. The interactive interview format, derived from an autoethnographic approach, allowed the first author (J. P.) to include her own experiences of her mother's cancer in the data. Analysis of the transcribed interviews revealed a number of themes including time, hope and spirituality, the meaning of cancer, relationships, family and coping. Time, an overriding theme in the interviews, is the focus of this article. Sub-themes under time include (1) unexpected timing, (2) uncertainty/waiting, (3) being present, (4) concerns for future, (5) acceleration of time, (6) illness progression and (7) holidays. This research revealed that a daughter's perception of time was altered by her parent's illness, and it also highlighted the significance of parental illness during young adulthood. Practitioners working with this population should be aware of issues related to timing so that daughters can be supported in coping with their parents' illnesses, and in achieving the developmental goals of this transitional phase of the life course.

  4. The Real Time Mission Monitor: A Situational Awareness Tool For Managing Experiment Assets

    Science.gov (United States)

    Blakeslee, Richard; Hall, John; Goodman, Michael; Parker, Philip; Freudinger, Larry; He, Matt

    2007-01-01

    The NASA Real Time Mission Monitor (RTMM) is a situational awareness tool that integrates satellite, airborne and surface data sets; weather information; model and forecast outputs; and vehicle state data (e.g., aircraft navigation, satellite tracks and instrument field-of-views) for field experiment management RTMM optimizes science and logistic decision-making during field experiments by presenting timely data and graphics to the users to improve real time situational awareness of the experiment's assets. The RTMM is proven in the field as it supported program managers, scientists, and aircraft personnel during the NASA African Monsoon Multidisciplinary Analyses experiment during summer 2006 in Cape Verde, Africa. The integration and delivery of this information is made possible through data acquisition systems, network communication links and network server resources built and managed by collaborators at NASA Dryden Flight Research Center (DFRC) and Marshall Space Flight Center (MSFC). RTMM is evolving towards a more flexible and dynamic combination of sensor ingest, network computing, and decision-making activities through the use of a service oriented architecture based on community standards and protocols.

  5. OGUMI-A new mobile application to conduct common-pool resource experiments in continuous time.

    Science.gov (United States)

    Brandt, Gunnar; Kulesz, Micaela M; Nissen, Dennis; Merico, Agostino

    2017-01-01

    OGUMI is an Android-based open source mobile application for conducting Common-Pool Resource Experiments, Choice Experiments, and Questionnaires in the field, in the laboratory, and online. A main feature of OGUMI is its capacity to capture real-time changes in human behaviour in response to a dynamically varying resource. OGUMI is simple (for example, likewise other existing software, it does not require expertise in behavioural game theory), stable, and extremely flexible with respect to the user-resource model running in the background. Here we present the motivation for the development of OGUMI and we discuss its main features with an example application.

  6. The Time Reversal Experiment with Kaons (TREK) at J-PARC

    Science.gov (United States)

    Kohl, Michael

    2009-08-01

    The Time Reversal Experiment with Kaons (TREK) at J-PARC aims to find CP violation beyond the Standard Model in the semi-leptonic Kμ3+ decay mode by measuring the T-violating transverse polarization PT of outgoing muons. TREK makes use of the intense kaon beam at J-PARC stopped in a target and employs an optimized setup with excellent control of systematic uncertainties. The sensitivity at J-PARC is improved by a factor of 20 compared to the current uncertainty for PT, well in the predicted range of various New Physics models. An overview of the planned experiment and current status will be presented.

  7. Development of a level-1 trigger and timing system for the Double Chooz neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Reinhold, Bernd

    2009-02-25

    The measurement of the mixing angle {theta}{sub 13} is the goal of several running and planned experiments. The experiments are either accelerator based (super)beam experiments (e.g. MINOS, T2K, Nova) or reactor anti-neutrino disappearance experiments (e.g. Daya Bay, RENO or Double Chooz). In order to measure or constrain {theta}{sub 13} with the Double Chooz experiment the overall systematic errors have to be controlled at the one-percent or sub-percent level. The limitation of the systematic errors is achieved through various means and techniques. E.g. the experiment consists of two identical detectors at different baselines, which allow to make a differential anti-neutrino flux measurement, where basically only relative normalisation errors remain. The requirements on the systematic errors put also strong constraints on the quality of all components and materials used for both detectors, most prominently on the stability and radiopurity of the scintillator, the photomultiplier tubes, the vessels containing the detector liquids and the shielding against ambient radioactivity. The readout electronics, trigger and data acquisition system have to operate reliably as an integrated and highly efficient whole over several years. The trigger is provided by the Level-1 Trigger and Timing System, which is the subject of this thesis. It has to provide a highly efficient trigger (at the 0.1% level) for neutrino-induced events as well as for several types of background events. Its decision is realized in hardware and based on energy depositions in the muon veto and the target region. The Level-1 Trigger and Timing System furthermore provides a common System Clock and an absolute timestamp for each event. The Level-1 Trigger and Timing System consists of two types of VME modules, several Trigger Boards and a Trigger Master Board, which have been custom-designed and developed in the electronics workshop of our institute for this experiment and purpose, starting in 2005. In

  8. Optimisation of selection criteria of $t$-channel single-top-quark events at $\\sqrt s$ = 13 TeV for studies of anomalous couplings in the $Wtb$ vertex.

    CERN Document Server

    AUTHOR|(CDS)2138011; Escobar Ibáñez, Carlos

    The top-quark is the heaviest known fundamental particle and probing its couplings with the other fundamental particles may open a window to physics beyond the Standard Model. Single top-quark production provides a unique way to study the coupling between the top-quark, the W-boson and the b-quark, since it involves the $Wtb$ vertex in both production and decay. The $Wtb$ vertex structure has been explored through the measurement of top-quark and W-boson polarisation observables using $t$-channel single top-quark events produced in proton-proton collisions during LHC Run I. The most recent limits on anomalous couplings in the $Wtb$ vertex from the ATLAS and CMS experiments are reviewed. Comprehensive studies of the $t$-channel selection requirements have been performed using Monte Carlo samples of signal and background events produced at $\\sqrt{s}$ = 13 TeV and normalised to an integrated luminosity of 36.1 ${\\rm pb}^{-1}$ . Starting from events containing one isolated lepton, large missing transverse momentu...

  9. Performance study of GPUs in real-time trigger applications for HEP experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ketchum, W.; /Chicago U.; Amerio, S.; /INFN, Padua; Bastieri, D.; Bauce, M.; /INFN, Padua /Padua U.; Catastini, P.; /Fermilab; Gelain, S.; /Padua U.; Hahn, K.; /Fermilab; Kim, Y.K.; /Fermilab /Chicago U.; Liu, T.; /Fermilab; Lucchesi, D.; /INFN, Padua /Padua U.; Urso, G.

    2011-06-01

    Graphical Processing Units (GPUs) have evolved into highly parallel, multi-threaded, multicore powerful processors with high memory bandwidth. GPUs are used in a variety of intensive computing applications. The combination of highly parallel architecture and high memory bandwidth makes GPUs a potentially promising technology for effective real-time processing for High Energy Physics (HEP) experiments. However, not much is known of their performance in real-time applications that require low latency, such as the trigger for HEP experiments. We describe an R and D project with the goal to study the performance of GPU technology for possible low latency applications, performing basic operations as well as some more advanced HEP lower-level trigger algorithms (such as fast tracking or jet finding). We present some preliminary results on timing measurements, comparing the performance of a CPU versus a GPU with NVIDIA's CUDA general-purpose parallel computing architecture, carried out at CDF's Level-2 trigger test stand. These studies will provide performance benchmarks for future studies to investigate the potential and limitations of GPUs for real-time applications in HEP experiments.

  10. Presentation and response timing accuracy in Adobe Flash and HTML5/JavaScript Web experiments.

    Science.gov (United States)

    Reimers, Stian; Stewart, Neil

    2015-06-01

    Web-based research is becoming ubiquitous in the behavioral sciences, facilitated by convenient, readily available participant pools and relatively straightforward ways of running experiments: most recently, through the development of the HTML5 standard. Although in most studies participants give untimed responses, there is a growing interest in being able to record response times online. Existing data on the accuracy and cross-machine variability of online timing measures are limited, and generally they have compared behavioral data gathered on the Web with similar data gathered in the lab. For this article, we took a more direct approach, examining two ways of running experiments online-Adobe Flash and HTML5 with CSS3 and JavaScript-across 19 different computer systems. We used specialist hardware to measure stimulus display durations and to generate precise response times to visual stimuli in order to assess measurement accuracy, examining effects of duration, browser, and system-to-system variability (such as across different Windows versions), as well as effects of processing power and graphics capability. We found that (a) Flash and JavaScript's presentation and response time measurement accuracy are similar; (b) within-system variability is generally small, even in low-powered machines under high load; (c) the variability of measured response times across systems is somewhat larger; and (d) browser type and system hardware appear to have relatively small effects on measured response times. Modeling of the effects of this technical variability suggests that for most within- and between-subjects experiments, Flash and JavaScript can both be used to accurately detect differences in response times across conditions. Concerns are, however, noted about using some correlational or longitudinal designs online.

  11. Design and construction of a Vertex Chamber and measurement of the average B-Hadron lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, H.N.

    1987-10-01

    Four parameters describe the mixing of the three quark generations in the Standard Model of the weak charged current interaction. These four parameters are experimental inputs to the model. A measurement of the mean lifetime of hadrons containing b-quarks, or B-Hadrons, constrains the magnitudes of two of these parameters. Measurement of the B-Hadron lifetime requires a device that can measure the locations of the stable particles that result from B-Hadron decay. This device must function reliably in an inaccessible location, and survive high radiation levels. We describe the design and construction of such a device, a gaseous drift chamber. Tubes of 6.9 mm diameter, having aluminized mylar walls of 100 ..mu..m thickness are utilized in this Vertex Chamber. It achieves a spatial resolution of 45 ..mu..m, and a resolution in extrapolation to the B-Hadron decay location of 87 ..mu..m. Its inner layer is 4.6 cm from e/sup +/e/sup -/ colliding beams. The Vertex Chamber is situated within the MAC detector at PEP. We have analyzed botht he 94 pb/sup -1/ of integrated luminosity accumulated at ..sqrt..s = 29 GeV with the Vertex Chamber in place as well as the 210 pb/sup -1/ accumulated previously. We require a lepton with large momentum transverse to the event thrust axis to obtain a sample of events enriched in B-Hadron decays. The distribution of signed impact parameters of all tracks in these events is used to measure the B-Hadron flight distance, and hence lifetime. 106 refs., 79 figs., 20 tabs.

  12. The high energy behavior of QCD. The effective action and the triple-Pomeron-vertex

    Energy Technology Data Exchange (ETDEWEB)

    Hentschinski, Martin

    2009-07-15

    We study integrations over light-cone momenta in the high energy effective action of QCD. After a brief review of the effective action, we arrive on a regularization mechanism from matching of effective action diagrams with QCD diagrams, which we apply to a re-derivation of the reggeized gluon and of the BFKL-equation. We study consequences of the proposed regularization on the analytic structure of 2{yields}3 and 2{yields}4 production amplitudes in the Multi-Regge-Kinematics. We derive a certain part of the 1-loop corrections to the production vertex and demonstrate that they yield the on-set of corrections demanded by the Steinmann-relations. The Reggeon-Particle-2-Reggeon vertex is determined and applied to the construction of various signature configurations of the production amplitudes. We extend the proposed regularization method to states of three and four reggeized gluons and propose a supplement to the effective Lagrangian. We derive vertices for the 1-3 and 2-4 reggeized-gluon-transition inside the elastic amplitude and verify that signature conservation is obeyed. Integral equations for the state of three and four reggeized gluons are formulated and shown to be in accordance with a result by Bartels and Wuesthoff. In a second part we investigate the high-energy behavior of QCD for different surface topologies of color graphs. After a brief review of the planar limit (bootstrap and gluon reggeization) and of the cylinder topology (BFKL) we investigate the 3{yields}3 scattering in the triple Regge limit which belongs to the pair-of-pants topology. We re-derive the triple Pomeron vertex function and show that it belongs to a specific set of graphs in color space which we identify as the analog of the Mandelstam diagram. We then extend the study to the high-energy behavior of N=4 SYM where we find a new class of color graphs not present in QCD. (orig.)

  13. Watching the clock: keeping time during pregnancy, birth, and postpartum experiences.

    Science.gov (United States)

    Simonds, Wendy

    2002-08-01

    In this paper, I analyze how different didactic discourses surrounding pregnancy, birth, and postpartum care portray time in procreative events. I investigate advice regarding procreative experiences offered to women by a variety of ''experts", and offered by experts to each other, examining literature which demonstrates the wide range of didactic approaches to procreative events that are accessible in US culture, from masculinist medical orthodoxy--the dominant perspective--to the naturalist/feminist midwifery model, with self-help literature reflecting the influence of both ends of this spectrum as well as of consumer-oriented health activism. I explore how the conceptualization of time in the medical discourse contributes to the overpowering or disempowering of procreating women, and how the self-help and midwifery approaches respond to the medical model--ranging on a continuum from reification to refutation. Obstetrics works on women's bodies to make them stay on time and on course; this quest becomes more obsessively time-focused over time. In contrast, the midwifery discourse centers on women active in time, rather than against it. Self-help book authors line up somewhere in the middle, mostly taking medical management of procreative time for granted and occasionally try to show women ways in which we can buy time or bide our time against medicine.

  14. The STAR silicon vertex tracker: a large area silicon drift detector

    CERN Document Server

    Lynn, D; Beuttenmüller, Rolf H; Caines, H; Chen, W; Dimassimo, D; Dyke, H; Elliot, D; Eremin, V; Grau, M; Hoffmann, G W; Humanic, T; Ilyashenko, Yu S; Kotov, I; Kraner, H W; Kuczewski, P; Leonhardt, B; Li, Z; Liaw, C J; Lo Curto, G; Middelkamp, P; Minor, R; Munhoz, M; Ott, G; Pandey, S U; Pruneau, C A; Rykov, V L; Schambach, J; Sedlmeir, J; Soja, B; Sugarbaker, E R; Takahashi, J; Wilson, K; Wilson, R

    2000-01-01

    The Solenoidal Tracker At RHIC-Silicon Vertex Tracker (STAR-SVT) is a three barrel microvertex detector based upon silicon drift detector technology. As designed for the STAR-SVT, silicon drift detectors (SDDs) are capable of providing unambiguous two-dimensional hit position measurements with resolutions on the order of 20 mu m in each coordinate. Achievement of such resolutions, particularly in the drift direction coordinate, depends upon certain characteristics of silicon and drift detector geometry that are uniquely critical for silicon drift detectors hit measurements. Here we describe features of the design of the STAR-SVT SDDs and the front-end electronics that are motivated by such characteristics.

  15. A facility for long term evaluation and quality assurance of LHCb Vertex Detector modules

    CERN Document Server

    Marinho, F; Dimattia, R; Doherty, F; Dumps, R; Gersabeck, M; Melone, J; Parkes, C; Saavedra, A; Tobin, M

    2007-01-01

    This note describes the facility developed for long term evaluation and quality assurance of the LHCb Vertex Detector modules, known as the 'Glasgow Burn-in System'. This facility was developed to ensure that the modules conform to stringent quality levels. The system was able to uncover any weaknesses that could be introduced during the manufacturing and assembly of the components or during the transport of the modules to CERN. The system consisted of: a high resolution microscope for visual inspections; and a burn-in system to operate cooled modules in vacuum. The main components of the burn-in system were a vacuum system, a cooling system and a DAQ system.

  16. Development of an ASIC for CCD readout at the vertex detectors of the intrenational linear collider

    CERN Document Server

    Murray, P; Stefanov, K D; Woolliscroft, T

    2007-01-01

    The Linear Collider Flavour Identification Collaboration is developing sensors and readout electronics suitable for the International Linear Collider vertex detector. In order to achieve high data rates the proposed detector utilises column parallel CCDs, each read out by a custom designed ASIC. The prototype chip (CPR2) has 250 channels of electronics, each with a preamplifier, 5-bit flash ADC, data sparsification logic for identification of significant data clusters, and local memory for storage of data awaiting readout. CPR2 also has hierarchical 2-level data multiplexing and intermediate data memory, enabling readout of the sparsified data via the 5-bit data output bus.

  17. Experimental tests on the air cooling of the CLIC vertex detector

    CERN Document Server

    Duarte Ramos, Fernando; Nuiry, Francois-Xavier

    2016-01-01

    The strict requirements in terms of material budget for the inner region of the CLIC detector concept require the use of a dry gas for the cooling of the respective sensors. This, in conjunction with the compactness of the inner volumes, poses several challenges for the design of a cooling system that is able to fulfil the required detector specifications. This note summarizes the results obtained from experimental tests on the air cooling of the CLIC vertex detector as well as their comparison with the corresponding computational fluid dynamics simulations.

  18. Effective-range parameters and vertex constants for Λ-nuclear systems

    Science.gov (United States)

    Rakityansky, S. A.; Gopane, I. M.

    For a wide range of the core-nuclei (6 ≤ A ≤ 207), the scattering lengths, effective radii, and the other effective-range parameters (up to the order ˜ k8) for the angular momentum ℓ = 0, 1, 2 are calculated within a two-body ΛA-model. For the same hypernuclear systems, the S-matrix residues as well as the corresponding Nuclear-Vertex and Asymptotic-Normalization constants (NVC’s and ANC’s) for the bound states are also found.

  19. The Depfet Active Pixel Sensor as Vertex Detector for the Ilc

    Science.gov (United States)

    Moser, H.-G.; Andricek, L.; Fischer, P.; Giesen, F.; Harter, M.; Karagounis, M.; Kohrs, R.; Krüger, H.; Lutz, G.; Peric, I.; Reuen, L.; Richter, R. H.; Sandow, C.; Strüder, L.; Treis, J.; Trimpl, M.; Wermes, N.; Wölfel, S.

    2006-04-01

    For the International Linear Collider a vertex detector with unprecedented performance is needed. The DEPFET, which integrates a MOSFET into the high resistivity detector substrate offers such performance: large signal/noise, small pixel size, thin detectors, low power consumption, high readout speed and radiation tolerance. This paper presents the concept of the DEPFET and results of a complete prototype system with dedicated control and readout electronics. Measurements of the radiation hardness will be presented and the technology to achieve thin detectors (50 μm) will be discussed.

  20. Time Structure of Particle Production in the Merit High-Power Target Experiment

    CERN Document Server

    Efthymiopoulos, I; Palm, M; Lettry, J; Haug, F; Pereira, H; Pernegger, H; Steerenberg, R; Grudiev, A; Kirk, H G; Park, H; Tsang, T; Mokhov, N; Striganov, S; Carroll, A J; Graves, V B; Spampinato, P T; McDonald, K T; Bennett, J R J; Caretta, O; Loveridge, P

    2010-01-01

    The MERIT experiment is a proof-of-principle test of a target system for high power proton beam to be used as front-end for a neutrino factory complex or amuon collider. The experiment took data in autumn 2007 with the fast extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of about 30 × 1012 protons per pulse. We report results from the portion of the MERIT experiment in which separated beam pulses were delivered to a free mercury jet target with time intervals between pulses varying from 2 to 700 μs. The analysis is based on the responses of particle detectors placed along side and downstream of the target.

  1. The Idea of a Stochastic Space-Time: Theory and Experiments

    Science.gov (United States)

    Consoli, Maurizio; Pluchino, Alessandro

    Basic foundational aspects of both quantum physics and relativity suggest that space-time may have the fundamental stochastic nature of a turbulent fluid. After reviewing the basic theoretical motivations, we have compared this picture with the phenomenological pattern observed in the ether-drift experiments. To this end, we have performed numerical simulations in which the parameters of the oscopic Earth's cosmic motion are only used to fix the limiting boundaries for a microscopic velocity field which has instead an intrinsic stochastic nature. In this framework, both classical and modern experiments become consistent with the type of cosmic Earth's motion which today is used to describe the CMB anisotropy. The need for confirmations with a new generation of dedicated experiments is finally emphasized.

  2. A highly efficient neutron time-of-flight detector for inertial confinement fusion experiments

    Science.gov (United States)

    Izumi, N.; Yamaguchi, K.; Yamagajo, T.; Nakano, T.; Kasai, T.; Urano, T.; Azechi, H.; Nakai, S.; Iida, T.

    1999-01-01

    We have developed the highly efficient neutron detector system MANDALA for the inertial-confinement-fusion experiment. The MANDALA system consists of 842 elements plastic scintillation detectors and data acquisition electronics. The detection level is the yield of 1.2×105 for 2.5 MeV and 1×105 for 14.1 MeV neutrons (with 100 detected hits). We have calibrated the intrinsic detection efficiencies of the detector elements using a neutron generator facility. Timing calibration and integrity test of the system were also carried out with a 60Co γ ray source. MANDALA system was applied to the implosion experiments at the GEKKO XII laser facility. The integrity test was carried out by implosion experiments.

  3. [Time-Resolved XEOL Experiment System on BL14W1 at SSRF].

    Science.gov (United States)

    Zhang, Zhao-hong; Jiang, Zheng; Xue, Song; Zheng, Li-fang

    2015-08-01

    A novel time-resolved X-ray excited optical luminescence (TRXEOL) experiment system was developed for X ray absorption fine structure spectroscopy(XAFS) beamline at Shanghai Synchrotron Radiation Facility (SSRF). The TRXEOL system is composed of three parts: timing system, spectrometer system and nuclear instrument module (NIM) system. These three systems were integrated to measure and record the optical luminescence from the sample excited by the synchrotron X-ray pulses, according to the time-correlated single photon counting methodology. It's the first time in the domestic synchrotron radiation facilities to achieve TRXEOL experiment using the synchrotron X-ray pulses and the time structure of the storage ring. In this work, a SSRF-self-developed timing system was used, which is based on the Field programmable Gate Array and the high-speed serial communication technology. The timing system can provide trigger pulse synchronized with the X-ray pulse. The timing jitter is about 6 ps, and the timing delay resolution is 5 ps. The NIM system is the core of the TRXEOL experiment system, it has three main modules: the Constant Fraction Discriminator (CFD), the Time to Amplitude Converter (TAC) and the Multi-Channel Analyzer (MCA). During one excitation circle, the spectrometer and the Photomultiplier Tube detector translate the induced luminescence of the sample excited by a single X-ray pulse into electrical pulse. The CFD module eliminates the timing walk larger than 50 ps induced by the amplitude of the electrical pulse. The TAC module calculates the time interval between the timing trigger pulse and the luminescence electrical pulse, and converts the interval into proportional amplitude of voltage. After plenty of circles, the MCA module gets the luminescence decay curve by recording and analyzing the voltage signals. And the data acquisition system gets the TRXEOL spectra by scanning the spectrometer and acquiring the frequency of the voltage pulses from the TAC

  4. Initial experience with the CDF SVT trigger

    CERN Document Server

    Ashmanskas, B; Bardi, A; Bari, M; Baumgart, M; Belforte, S; Berryhill, J W; Bogdan, M; Carosi, R; Cerri, A; Chlachidze, G; Culberston, R; Dell'Orso, Mauro; Donati, S; Fiori, I; Frisch, H; Galeotti, S; Giannetti, P; Glagolev, V; Léger, A; Liu, Y; Meschi, E; Moneta, L; Morsani, F; Nakaya, T; Punzi, G; Rescigno, M; Ristori, L; Sanders, H; Sarkar, S; Semenov, A; Shochet, M; Speer, T; Spinella, F; Vataga, H; Wu, X; Yang, U; Zanello, L; Zanetti, A M

    2003-01-01

    The Collider Detector at Fermilab (CDF) Silicon Vertex Tracker (SVT) is a device that works inside the CDF Level 2 trigger to find and fit tracks in real time using the central silicon vertex detector information. SVT starts from tracks found by the Level 1 central chamber fast trigger and adds the silicon information to compute transverse track parameters with offline quality in about 15 mu s. The CDF SVT is fully installed and functional and has been exercised with real data during the spring and summer 2001. It is a complex digital device of more than 100 VME boards that performs a dramatic data reduction (only about one event in a thousand is accepted by the trigger). Diagnosing rare failures poses a special challenge and SVT internal data flow is monitored by dedicated hardware and software. This paper briefly covers the SVT architecture and design and reports on the SVT building/commissioning experience (hardware and software) and on the first results from the initial running.

  5. Initial experience with the CDF SVT trigger

    Science.gov (United States)

    Ashmanskas, B.; Barchiesi, A.; Bardi, A.; Bari, M.; Baumgart, M.; Belforte, Stefano; Berryhill, J.; Bogdan, M.; Carosi, R.; Cerri, A.; Chlachidze, G.; Culberston, R.; Dell'Orso, M.; Donati, S.; Fiori, I.; Frisch, H.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Leger, A.; Liu, Y.; Meschi, E.; Moneta, L.; Morsani, F.; Nakaya, T.; Punzi, G.; Rescigno, M.; Ristori, L.; Sanders, H.; Sarkar, S.; Semenov, A.; Shochet, M.; Speer, T.; Spinella, F.; Vataga, H.; Wu, X.; Yang, U.; Zanello, L.; Zanetti, A. M.

    2003-03-01

    The Collider Detector at Fermilab (CDF) Silicon Vertex Tracker (SVT) is a device that works inside the CDF Level 2 trigger to find and fit tracks in real time using the central silicon vertex detector information. SVT starts from tracks found by the Level 1 central chamber fast trigger and adds the silicon information to compute transverse track parameters with offline quality in about 15 μs. The CDF SVT is fully installed and functional and has been exercised with real data during the spring and summer 2001. It is a complex digital device of more than 100 VME boards that performs a dramatic data reduction (only about one event in a thousand is accepted by the trigger). Diagnosing rare failures poses a special challenge and SVT internal data flow is monitored by dedicated hardware and software. This paper briefly covers the SVT architecture and design and reports on the SVT building/commissioning experience (hardware and software) and on the first results from the initial running.

  6. A 41 ps ASIC time-to-digital converter for physics experiments

    Science.gov (United States)

    Russo, Stefano; Petra, Nicola; De Caro, Davide; Barbarino, Giancarlo; Strollo, Antonio G. M.

    2011-12-01

    We present a novel Time-to-Digital (TDC) converter for physics experiments. Proposed TDC is based on a synchronous counter and an asynchronous fine interpolator. The fine part of the measurement is obtained using NORA inverters that provide improved resolution. A prototype IC was fabricated in 180 nm CMOS technology. Experimental measurements show that proposed TDC features 41 ps resolution associated with 0.35LSB differential non-linearity, 0.77LSB integral non-linearity and a negligible single shot precision. The whole dynamic range is equal to 18 μs. The proposed TDC is designed using a flash architecture that reduces dead time. Data reported in the paper show that our design is well suited for present and future particle physics experiments.

  7. Optical detection system using time structure of UVSOR for combined laser-SR experiments

    CERN Document Server

    Azuma, J; Tsujibayashi, T; Itoh, M; Watanabe, M; Arimoto, O; Nakanishi, S; Itoh, H; Kamada, M

    2001-01-01

    A new TAC-MCA detection system has been developed for combined laser-SR spectroscopy such as two-photon excitation or pump-probe experiments in the VUV region. In order to improve the signal to noise ratio, the time structure under partial-filling operation of UVSOR is utilized together with this detection system. In our experiment, where the two-photon excitation efficiency of laser and SR is more important than the time resolution, a pulse stretching technique using optical fiber is applied to the output pulse of a CW mode-locked Ti : sapphire laser. The usefulness of the present system is successfully demonstrated by observing luminescence signals from the two-photon-excited core state in BaF sub 2 crystals.

  8. The relationship between voice climate and patients' experience of timely care in primary care clinics.

    Science.gov (United States)

    Nembhard, Ingrid M; Yuan, Christina T; Shabanova, Veronika; Cleary, Paul D

    2015-01-01

    Aspects of the patient care experience, despite being central to quality care, are often problematic. In particular, patients frequently report problems with timeliness of care. As yet, research offers little insight on setting characteristics that contribute to patients' experience of timely care. The aims of this study were to assess the relationship between organizational climate and patients' reports of timely care in primary care clinics and to broadly examine the link between staff's work environment and patient care experiences. We test hypotheses about the relationship between voice climate--staff feeling safe to speak up about issues--and reported timeliness of care, consistency in reported voice climate across professions, and how climate differences for various professions relate to timely care. We conducted a cross-sectional study of employees (n = 1,121) and patients (n = 8,164) affiliated with 37 clinics participating in a statewide reporting initiative. Employees were surveyed about clinics' voice climate, and patients were surveyed about the timeliness of care. Hypotheses were tested using analysis of variance and generalized estimating equations. Clinical and administrative staff (e.g., nurses and office assistants) reported clinics' climates to be significantly less supportive of voice than did clinical leaders (e.g., physicians). The greater the difference in reported support for voice between professional groups, the less patients reported experiencing timely care in three respects: obtaining an appointment, seeing the doctor within 15 minutes of appointment time, and receiving test results. In clinics where staff reported climates supportive of voice, patients indicated receiving more timely care. Clinical leaders' reports of voice climate had no relationship to reported timeliness of care. Our findings suggest the importance of clinics developing a strong climate for voice, particularly for clinical and administrative staff, to support better

  9. Electron and phonon dispersions of the two-dimensional Holstein model: effects of vertex and non-local corrections

    Energy Technology Data Exchange (ETDEWEB)

    Hague, J P [Max-Planck Institut fuer Physik Komplexer Systeme, Dresden (Germany)

    2003-05-07

    I apply the newly developed dynamical cluster approximation (DCA) to the calculation of the electron and phonon dispersions in the two-dimensional Holstein model. In contrast to previous work, the DCA enables the effects of spatial fluctuations (non-local corrections) to be examined. Approximations neglecting and incorporating lowest-order vertex corrections are investigated. I calculate the phonon density of states, the renormalized phonon dispersion, the electron dispersion and electron spectral functions. I demonstrate how vertex corrections stabilize the solution, stopping a catastrophic softening of the ({pi}, {pi}) phonon mode. A kink in the electron dispersion is found in the normal state along the ({zeta}, {zeta}) symmetry direction in both the vertex- and non-vertex-corrected theories for low phonon frequencies, corresponding directly to the renormalized phonon frequency at the ({pi}, 0) point. This kink is accompanied by a sudden drop in the quasi-particle lifetime. Vertex and non-local corrections enhance the effects at large bare phonon frequencies.

  10. The influence of time of day on decision fatigue in online food choice experiments

    DEFF Research Database (Denmark)

    Olsen, Søren Bøye; Meyerhoff, Jürgen; Mørkbak, Morten Raun

    2017-01-01

    though time of day related fatigue effects are well known in the psychology literature. The purpose of this paper is to hypothesize that variations in the time of day when respondents answer an online food choice experiment will translate into observable fatigue effects in the food choices. Design....../methodology/approach: An empirical SCE concerning food choices is conducted using a web-based questionnaire for interviews in a pre-recruited online panel of consumers. Timestamps collected during the online interviews provide knowledge about the time of day at which each respondent has answered the survey. This information...... is linked with knowledge from a food sociology survey on typical meal times as well as biophysical research linking food intake to blood sugar and mental energy in order to generate a proxy variable for each respondent’s level of mental energy when answering the food choice tasks in the questionnaire...

  11. The gendered effects of labour market experiences on marriage timing in Egypt

    Directory of Open Access Journals (Sweden)

    Rania Salem

    2016-08-01

    Full Text Available Background: In Egypt, the 'social problem' of delayed marriage is typically attributed to the difficult labour market conditions and high marriage costs faced by young people, particularly men. However, emerging evidence indicates that Egyptian women's employment experiences may also influence marriage timing. Objective: This paper investigates gender differences in the determinants of marriage timing, including employment history, job characteristics, education, and urban residence. It tests a number of hypotheses based on existing claims in the literature on marriage timing. Methods: Data from two waves of the nationally representative Egypt Labour Market Panel Survey are used to carry out proportional hazard analyses. Characteristics of never-married respondents at wave one in 1998 are used to predict the risk of marriage by wave two in 2006. Results: The results indicate that, to some extent, never-married men who have favourable labour market experiences marry earlier. The same experiences bear no association with women's marriage timing. For men, being employed and having a public sector job are important economic prerequisites for marriage. Conclusions: Evidence indicates that Egyptian men with favourable labour market experiences attract a spouse and establish an independent household faster than others. The male breadwinner ideal is therefore a powerful force in dictating who marries when in Egypt today. I also contend that previous studies may have overstated the delaying effects of education and urban residence on marriage, particularly for women. Finally, I offer four contextual factors that must be taken into account when predicting whether existing theories will hold in a given setting.

  12. Journalism and change in the experience of time in Western societies

    OpenAIRE

    Carlos Franciscato

    2015-01-01

    The purpose of this paper is to investigate the temporality produced by journalistic practice and the ways journalism has a privilege to build a specific type of social experience of the present time. This inquiry carries out a historical journey, but it is not our purpose to present a history of press in the sense of a history of institutions, particular genres and languages. Instead, this investigation develops a historical study in order to identify social temporal phenomena produced by jo...

  13. Analysis of test-beam data with hybrid pixel detector prototypes for the Compact LInear Collider (CLIC) vertex detectors

    CERN Document Server

    Pequegnot, Anne-Laure

    2013-01-01

    The LHC is currently the most powerful accelerator in the world. This proton-proton collider is now stoppped to increase significantly its luminosity and energy, which would provide a larger discovery potential in 2014 and beyond. A high-energy $e^{+}e^{-}$ collider, such as CLIC, is an option to complement and to extend the LHC physics programme. Indeed, a lepton collider gives access to additional physics processes, beyond those observable at the LHC, and therefore provides new discovery potential. It can also provide complementary and/or more precise information about new physics uncovered at the LHC. Many essential features of a detector are required to deliver the full physics potential of this CLIC machine. In this present report, I present my work on the vertex detector R\\&D for this future linear collider, which aims at developping highly granular and ultra-thin position sensitive detection devices with very low power consumption and fast time-stamping capability. We tested here thin silicon pixel...

  14. The influence of prior experience and expected timing on vibrotactile discrimination

    Science.gov (United States)

    Karim, Muhsin; Harris, Justin A.; Langdon, Angela; Breakspear, Michael

    2013-01-01

    Vibrotactile discrimination tasks involve perceptual judgements on stimulus pairs separated by a brief interstimulus interval (ISI). Despite their apparent simplicity, decision making during these tasks is biased by prior experience in a manner that is not well understood. A striking example is when participants perform well on trials where the first stimulus is closer to the mean of the stimulus-set than the second stimulus, and perform comparatively poorly when the first stimulus is further from the stimulus mean. This “time-order effect” suggests that participants implicitly encode the mean of the stimulus-set and use this internal standard to bias decisions on any given trial. For relatively short ISIs, the magnitude of the time-order effect typically increases with the distance of the first stimulus from the global mean. Working from the premise that the time-order effect reflects the loss of precision in working memory representations, we predicted that the influence of the time-order effect, and this superimposed “distance” effect, would monotonically increase for trials with longer ISIs. However, by varying the ISI across four intervals (300, 600, 1200, and 2400 ms) we instead found a complex, non-linear dependence of the time-order effect on both the ISI and the distance, with the time-order effect being paradoxically stronger at short ISIs. We also found that this relationship depended strongly on participants' prior experience of the ISI (from previous task titration). The time-order effect not only depends on participants' expectations concerning the distribution of stimuli, but also on the expected timing of the trials. PMID:24399927

  15. Nucleation kinetics of paracetamol-ethanol solutions from induction time experiments using Lasentec FBRM ®

    Science.gov (United States)

    Mitchell, Niall A.; Frawley, Patrick J.; Ó'Ciardhá, Clifford T.

    2011-04-01

    A study of the nucleation kinetics for cooling crystallisation of paracetamol-ethanol solutions in a batch reactor is described in this paper. Induction time experiments were conducted in order to estimate the nucleation kinetics of the system. Measured induction times can be affected by numerous process parameters, such as concentration, agitation rate and solution hydrodynamics. The theoretical approach of Kubota (2008) [14] was employed to estimate the nucleation kinetics, where the induction time is assumed to correspond to the time required for the number density of grown crystals to reach a fixed value. The induction time was observed to be independent of the solution temperature. This is suggested from Kubota's theory, in agreement with previous work and serves to further validate the induction time theory of Kubota. In this investigation, induction times were observed to decrease significantly with increased levels of agitation. Furthermore, the presence of wall baffles in the reaction vessel was also found to significantly reduce the measured induction times for the solution system.

  16. [Associations between adverse childhood experiences with early puberty timing and possible gender difference].

    Science.gov (United States)

    Liu, Yang; Sun, Ying; Tao, Fangbiao; Tong, Shilu

    2015-04-01

    To explore the association of adverse childhood events with early puberty timing and possible gender differences. Data was gathered through questionnaires, physical and secondary sexual characteristics, examination with breast stage in girls and testicular volume in boys measured under informed consent among children in grade 3 to grade 5 from a large-scale primary school. Information regarding adverse childhood experiences (ACEs), time of screening and physical activity was included in the questionnaire. Age limits on secondary sexual characteristics for defining early puberty established under the "China Puberty Research Collaboration Project" were used to classify early puberty timing. Body mass index was calculated and used to classify both overweight and obesity, in each gender. Among the 1 744 children aged 8.2-12.2 years old (957 boys), the prevalence rates of early puberty timing among boys and girls were 7.5% and 14.6%, respectively, with gender differences (χ² = 11.671, P early puberty. Results from multivariate logistic regression analysis showed that family life events were associated with a higher risk of early puberty timing in boys (odds ratio: 2.531, 95% CI: 1.276-5.020) while experience related to physical abuse appeared a risk factor of early puberty timing in girls (odds ratio: 2.453, 95% CI: 1.588-3.788). Physical abuse and adverse family life events seemed to be associated with early puberty timing, suggesting further longitudinal study should be carried out to understand the nature of these findings and gender differences.

  17. Geometry Survey of the Time-of-Flight Neutron-Elastic Scattering (Antonella) Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Oshinowo, Babatunde O. [Fermilab; Izraelevitch, Federico [Buenos Aires U.

    2016-10-17

    The Antonella experiment is a measurement of the ionization efficiency of nuclear recoils in silicon at low energies [1]. It is a neutron elastic scattering experiment motivated by the search for dark matter particles. In this experiment, a proton beam hits a lithium target and neutrons are produced. The neutron shower passes through a collimator that produces a neutron beam. The beam illuminates a silicon detector. With a certain probability, a neutron interacts with a silicon nucleus of the detector producing elastic scattering. After the interaction, a fraction of the neutron energy is transferred to the silicon nucleus which acquires kinetic energy and recoils. This kinetic energy is then dissipated in the detector producing ionization and thermal energy. The ionization produced is measured with the silicon detector electronics. On the other hand, the neutron is scattered out of the beam. A neutron-detector array (made of scintillator bars) registers the neutron arrival time and the scattering angle to reconstruct the kinematics of the neutron-nucleus interaction with the time-of-flight technique [2]. In the reconstruction equations, the energy of the nuclear recoil is a function of the scattering angle with respect to the beam direction, the time-of-flight of the neutron and the geometric distances between components of the setup (neutron-production target, silicon detector, scintillator bars). This paper summarizes the survey of the different components of the experiment that made possible the off-line analysis of the collected data. Measurements were made with the API Radian Laser Tracker and I-360 Probe Wireless. The survey was completed at the University of Notre Dame, Indiana, USA in February 2015.

  18. GPU-based Real-time Triggering in the NA62 Experiment

    CERN Document Server

    INSPIRE-00646837; Cretaro, P.; Di Lorenzo, S.; Fantechi, R.; Fiorini, M.; Frezza, O.; Lamanna, G.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Neri, I.; Paolucci, P.S.; Pastorelli, E.; Piandani, R.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Vicini, P.

    2016-01-01

    Over the last few years the GPGPU (General-Purpose computing on Graphics Processing Units) paradigm represented a remarkable development in the world of computing. Computing for High-Energy Physics is no exception: several works have demonstrated the effectiveness of the integration of GPU-based systems in high level trigger of different experiments. On the other hand the use of GPUs in the low level trigger systems, characterized by stringent real-time constraints, such as tight time budget and high throughput, poses several challenges. In this paper we focus on the low level trigger in the CERN NA62 experiment, investigating the use of real-time computing on GPUs in this synchronous system. Our approach aimed at harvesting the GPU computing power to build in real-time refined physics-related trigger primitives for the RICH detector, as the the knowledge of Cerenkov rings parameters allows to build stringent conditions for data selection at trigger level. Latencies of all components of the trigger chain have...

  19. Further results for the two-loop Lcc vertex in the Landau gauge

    Science.gov (United States)

    Cvetic, Gorazd; Kondrashuk, Igor

    2008-02-01

    In the previous paper hep-th/0604112 we calculated the first of the five planar two-loop diagrams for the Lcc vertex of the general non-Abelian Yang-Mills theory, the vertex which allows us in principle to obtain all other vertices via the Slavnov-Taylor identity. The integrand of this first diagram has a simple Lorentz structure. In this letter we present the result for the second diagram, whose integrand has a complicated Lorentz structure. The calculation is performed in the D-dimensional Euclidean position space. We initially perform one of the two integrations in the position space and then reduce the Lorentz structure to D-dimensional scalar single integrals. Some of the latter are then calculated by the uniqueness method, others by the Gegenbauer polynomial technique. The result is independent of the ultraviolet and the infrared scale. It is expressed in terms of the squares of spacetime intervals between points of the effective fields in the position space—it includes simple powers of these intervals, as well as logarithms and polylogarithms thereof, with some of the latter appearing within the Davydychev integral J(1, 1, 1). Concerning the rest of diagrams, we present the result for the contributions correponding to third, fourth and fifth diagrams without giving the details of calculation. The full result for the Lcc correlator of the effective action at the planar two-loop level is written explicitly for maximally supersymmetric Yang-Mills theory.

  20. A two-level fanout system for the CDF silicon vertex tracker

    Energy Technology Data Exchange (ETDEWEB)

    A. Bardi et al.

    2001-11-02

    The Fanout system is part of the Silicon Vertex Tracker, a new trigger processor designed to reconstruct charged particle trajectories at Level 2 of the CDF trigger, with a latency of 10 {micro}s and an event rate up to 100 kHz. The core of SVT is organized as 12 identical slices, which process in parallel the data from the 12 independent azimuthal wedges of the Silicon Vertex Detector (SVXII). Each SVT slice links the digitized pulse heights found within one SVXII wedge to the tracks reconstructed by the Level 1 fast track finder (XFT) in the corresponding 30{sup o} angular region of the Central Outer Tracker. Since the XFT tracks are transmitted to SVT as a single data stream, their distribution to the proper SVT slices requires dedicated fanout logic. The Fanout system has been implemented as a multi-board project running on a common 20 MHz clock. Track fanout is performed in two steps by one ''Fanout A'' and two ''Fanout B'' boards. The architecture, design, and implementation of this system are described.

  1. The NLO jet vertex in the small-cone approximation for kt and cone algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Colferai, D.; Niccoli, A. [Dipartimento di Fisica e Astronomia, Università di Firenze and INFN, Sezione di Firenze, 50019 Sesto Fiorentino (Italy)

    2015-04-15

    We determine the jet vertex for Mueller-Navelet jets and forward jets in the small-cone approximation for two particular choices of jet algoritms: the kt algorithm and the cone algorithm. These choices are motivated by the extensive use of such algorithms in the phenomenology of jets. The differences with the original calculations of the small-cone jet vertex by Ivanov and Papa, which is found to be equivalent to a formerly algorithm proposed by Furman, are shown at both analytic and numerical level, and turn out to be sizeable. A detailed numerical study of the error introduced by the small-cone approximation is also presented, for various observables of phenomenological interest. For values of the jet “radius” R=0.5, the use of the small-cone approximation amounts to an error of about 5% at the level of cross section, while it reduces to less than 2% for ratios of distributions such as those involved in the measure of the azimuthal decorrelation of dijets.

  2. Three dimensional natural convection analysis in the VENUS vertex chamber at TRISTAN

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Isamu [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

    1997-03-01

    The trace of elementary particles produced by collision of electrons and positrons was determined by VENUS Vertex Chamber. To measure the accurate trace, the correct temperature of gases in the chamber had to be estimated under the various conditions of incident electrons and positrons. There dimensional natural convection analysis was carried out in this paper in order to solve the above problem. The change of temperature of gas and structure materials of Vertex Chamber was analyzed for 160 min by ZEPHYRUS (three dimensional Navier-Stokes code). The results of analysis made clear that the internal mixture gases in Macor showed the characters of horizontal annular natural convection flow by heating the inner skin and cooling the outer skin. The temperature of gas space increased up to 25degC at inner skin. Stratification phenomena of temperature was observed in the lower part of section. The difference of temperature between upper and lower part was 0.6degC (at 60min) and 0.4degC (at 160min) which had tendency to decrease. (S.Y.)

  3. Serum androgens and prostate-specific antigen levels in androgenetic alopecia: is there a difference between frontal and vertex baldness?

    Science.gov (United States)

    Lis-Święty, A; Arasiewicz, H; Ranosz-Janicka, I; Brzezińska-Wcisło, L

    2017-12-13

    Androgenetic alopecia (AGA) seems to be a marker of increased risk of prostate cancer (PCa). We sought to investigate potential pathophysiological differences between frontal and vertex balding that might have the impact on the incidence of PCa. Serum concentrations of testosterone (T), dihydrotestosterone (DHT) and prostate-specific antigen (PSA) were measured in 88 subjects with AGA. We have examined sixty patients with frontal baldness and 28 patients with vertex baldness. The subgroups did not differ significantly in age, BMI and as regards age of AGA onset, duration of AGA and comorbidities. The mean value of DHT in serum of the men with vertex baldness was higher than those in the men with frontal baldness with statistical significance (P baldness may signal higher exposures to circulating DHT. Serum PSA level cannot serve as surrogate diagnostic marker of increased androgenic activity in men with AGA. © 2017 European Academy of Dermatology and Venereology.

  4. [Part-time medical specialist training; experiences with job-sharing for trainee internists].

    Science.gov (United States)

    Bevers, K; Nauta, S; Stuyt, P M

    2004-02-14

    Due to various factors such as social changes, an increasing number of couples with two incomes, and a growing proportion of female doctors, there has been a growing demand for part-time work in recent years. This is also true for resident physicians. Objections such as a discontinuity in care and the decline in the quality of education frequently prevent resident physicians from working part-time. Over the past two years, the University Medical Centre Nijmegen, the Netherlands, has experimented with job-sharing on clinical wards for resident physicians in internal medicine. This approach works well in practice, as long as a number of conditions, including the proper transfer of medical information and good communication, are satisfied. Job-sharing is one means of satisfying the growing demand for part-time work among resident physicians and specialists.

  5. NATO Advanced Research Workshop on Time-Dependent Quantum Molecular Dynamics : Theory and Experiment

    CERN Document Server

    Lathouwers, L

    1992-01-01

    From March 30th to April 3rd, 1992, a NATO Advanced Research workshop entitled "Time Dependent Quantum Molecular Dynamics: Theory and Experiment" was held at Snowbird, Utah. The organizing committee consisted of J. BROECKHOVE (Antwerp, Belgium), L. CEDERBAUM (Heidelberg, Germany), L. LATHOUWERS (Antwerp, Belgium), N. OHRN (Gainesville, Florida) and J. SIMONS (Salt Lake City, Utah). Fifty-two participants from eleven different countries attended the meeting at which thirty-three talks and one poster session were held. Twenty-eight participants submitted contributions to the proceedings of the meeting, which are reproduced in this volume. The workshop brought together experts in different areas 0 f molecular quantum dynamics, all adhering to the time dependent approach. The aim was to discuss and compare methods and applications. The ~amiliarityo~ the aUdience with the concepts o~ time dependent approaches greatly facilitated topical discussions and probing towards new applications. A broad area of subject matt...

  6. Timing effects on first marriage: twentieth-century experience in England and Wales and the USA.

    Science.gov (United States)

    Schoen, Robert; Canudas-Romo, Vladimir

    2005-07-01

    Recent substantial declines in first marriage in Western countries have been accompanied by increases in the average age at first marriage. Since the period proportion ever marrying, PEM, is sensitive to cohort tempo changes, the recent fall in the PEM may simply reflect cohort delays in marriage. The importance of timing factors is examined in the light of twentieth-century experience of first marriage in England and Wales and the USA. Using a variant of the Timing Index developed in research on fertility, we measure cohort timing effects for marriage and calculate an adjusted PEM. After examining twentieth-century trends in nuptiality for men and women, we find substantial tempo effects on the period PEM. Adjusted PEM values show a real decline in marriage for cohorts, but that decline is considerably smaller than the one shown by the unadjusted figures. This is especially true for England and Wales, where the decline in marriage was much greater.

  7. Real-Time Strategy Video Game Experience and Visual Perceptual Learning.

    Science.gov (United States)

    Kim, Yong-Hwan; Kang, Dong-Wha; Kim, Dongho; Kim, Hye-Jin; Sasaki, Yuka; Watanabe, Takeo

    2015-07-22

    Visual perceptual learning (VPL) is defined as long-term improvement in performance on a visual-perception task after visual experiences or training. Early studies have found that VPL is highly specific for the trained feature and location, suggesting that VPL is associated with changes in the early visual cortex. However, the generality of visual skills enhancement attributable to action video-game experience suggests that VPL can result from improvement in higher cognitive skills. If so, experience in real-time strategy (RTS) video-game play, which may heavily involve cognitive skills, may also facilitate VPL. To test this hypothesis, we compared VPL between RTS video-game players (VGPs) and non-VGPs (NVGPs) and elucidated underlying structural and functional neural mechanisms. Healthy young human subjects underwent six training sessions on a texture discrimination task. Diffusion-tensor and functional magnetic resonance imaging were performed before and after training. VGPs performed better than NVGPs in the early phase of training. White-matter connectivity between the right external capsule and visual cortex and neuronal activity in the right inferior frontal gyrus (IFG) and anterior cingulate cortex (ACC) were greater in VGPs than NVGPs and were significantly correlated with RTS video-game experience. In both VGPs and NVGPs, there was task-related neuronal activity in the right IFG, ACC, and striatum, which was strengthened after training. These results indicate that RTS video-game experience, associated with changes in higher-order cognitive functions and connectivity between visual and cognitive areas, facilitates VPL in early phases of training. The results support the hypothesis that VPL can occur without involvement of only visual areas. Significance statement: Although early studies found that visual perceptual learning (VPL) is associated with involvement of the visual cortex, generality of visual skills enhancement by action video-game experience

  8. Postpartum experiences of first-time fathers in a Tanzanian suburb: a qualitative interview study.

    Science.gov (United States)

    Mbekenga, Columba K; Lugina, Helen I; Christensson, Kyllike; Olsson, Pia

    2011-04-01

    to explore postpartum experiences of first-time fathers in a multicultural, low-income, suburban Tanzanian setting. individual qualitative interviews with ten first-time fathers, four to ten weeks post partum in Ilala suburb, Dar es Salaam, Tanzania. these first-time fathers enjoyed fatherhood and revealed a sincere concern for the well-being of the mother and infant during the postpartum period. They described themselves as active in mother and infant care and household chores; however, they were limited by breadwinning responsibilities. The families were supported by relatives or laypersons. The mothers' and infants' nutrition had high priority but poverty was an obstacle. Timing of resumption of sex after childbirth was problematic as traditions prescribed abstinence while the woman is breast feeding. The risk of contracting HIV to the family was a concern. Reproductive and child health care often excluded fathers and gave unclear information. these new fathers struggled to gain confidence and experience while engaging in family matters during post partum. Changing gender roles in the suburban Tanzanian society in general and their personal experiences of transition to fatherhood both facilitated and made the postpartum period problematic. The health sector does not respond with respect to fathers' concerns for family health and needs for support. these findings call for programmes on gender relations, which are supporting constructive masculinities and facilitate new fathers' active participation and responsibilities in parenting, family health and their relations with their partners. Such programmes should not only target people in childbearing age but also their potential support persons. Health workers should welcome fathers and discuss strategies for good family health during post partum. Counselling couples together could facilitate their support for each other in optimising health post partum. Copyright © 2009 Elsevier Ltd. All rights reserved.

  9. Insertable system for fast turnaround time microwave experiments in a dilution refrigerator.

    Science.gov (United States)

    Ong, Florian R; Orgiazzi, Jean-Luc; de Waard, Arlette; Frossati, Giorgio; Lupascu, Adrian

    2012-09-01

    Microwave experiments in dilution refrigerators are a central tool in the field of superconducting quantum circuits and other research areas. This type of experiments relied so far on attaching a device to the mixing chamber of a dilution refrigerator. The minimum turnaround time in this case is a few days as required by cooling down and warming up the entire refrigerator. We developed a new approach, in which a suitable sample holder is attached to a cold-insertable probe and brought in contact with transmission lines permanently mounted inside the cryostat. The total turnaround time is 8 h if the target temperature is 80 mK. The lowest attainable temperature is 30 mK. Our system can accommodate up to six transmission lines, with a measurement bandwidth tested from zero frequency to 12 GHz. This bandwidth is limited by low-pass components in the setup; we expect the intrinsic bandwidth to be at least 18 GHz. We present our setup, discuss the experimental procedure, and give examples of experiments enabled by this system. This new measurement method will have a major impact on systematic ultra-low temperature studies using microwave signals, including those requiring quantum coherence.

  10. Analysis of Current-mode Detectors For Resonance Detection In Neutron Optics Time Reversal Symmetry Experiment

    Science.gov (United States)

    Forbes, Grant; Noptrex Collaboration

    2017-09-01

    One of the most promising explanations for the observed matter-antimatter asymmetry in our universe is the search for new sources of time-reversal (T) symmetry violation. The current amount of violation seen in the kaon and B-meson systems is not sufficient to describe this asymmetry. The Neutron Optics Time Reversal Experiment Collaboration (NOPTREX) is a null test for T violation in polarized neutron transmission through a polarized 139La target. Due to the high neutron flux needed for this experiment, as well as the ability to effectively subtract background noise, a current-mode neutron detector that can resolve resonances at epithermal energies has been proposed. In order to ascertain if this detector design would meet the requirements for the eventual NOPTREX experiment, prototypical detectors were tested at the NOBORU beam at the Japan Proton Accelerator Research Complex (JPARC) facility. Resonances in In and Ta were measured and the collected data was analyzed. This presentation will describe the analysis process and the efficacy of the detectors will be discussed. Department of Energy under Contract DE-SC0008107, UGRAS Scholarship.

  11. Enactive cinema paves way for understanding complex real-time social interaction in neuroimaging experiments.

    Science.gov (United States)

    Tikka, Pia; Väljamäe, Aleksander; de Borst, Aline W; Pugliese, Roberto; Ravaja, Niklas; Kaipainen, Mauri; Takala, Tapio

    2012-01-01

    We outline general theoretical and practical implications of what we promote as enactive cinema for the neuroscientific study of online socio-emotional interaction. In a real-time functional magnetic resonance imaging (rt-fMRI) setting, participants are immersed in cinematic experiences that simulate social situations. While viewing, their physiological reactions-including brain responses-are tracked, representing implicit and unconscious experiences of the on-going social situations. These reactions, in turn, are analyzed in real-time and fed back to modify the cinematic sequences they are viewing while being scanned. Due to the engaging cinematic content, the proposed setting focuses on living-by in terms of shared psycho-physiological epiphenomena of experience rather than active coping in terms of goal-oriented motor actions. It constitutes a means to parametrically modify stimuli that depict social situations and their broader environmental contexts. As an alternative to studying the variation of brain responses as a function of a priori fixed stimuli, this method can be applied to survey the range of stimuli that evoke similar responses across participants at particular brain regions of interest.

  12. Enactive cinema paves way towards understanding complex real-time social interaction in neuroimaging experiments

    Directory of Open Access Journals (Sweden)

    Pia eTikka

    2012-11-01

    Full Text Available We outline general theoretical and practical implications of what we promote as enactive cinema for the neuroscientific study of online socio-emotional interaction. In a real-time functional magnetic resonance imaging (rt-fMRI setting, participants are immersed in cinematic experiences that simulate social situations. While viewing, their physiological reactions - including brain responses - are tracked, representing implicit and unconscious experiences of the on-going social situations. These reactions, in turn, are analysed in real-time and fed back to modify the cinematic sequences they are viewing while being scanned. Due to the engaging cinematic content, the proposed setting focuses on living-by in terms of shared psycho-physiological epiphenomena of experience rather than active coping in terms of goal-oriented motor actions. It constitutes a means to parametrically modify stimuli that depict social situations and their broader environmental contexts. As an alternative to studying the variation of brain responses as a function of a priori fixed stimuli, this method can be applied to survey the range of stimuli that evoke similar responses across participants at particular brain regions of interest.

  13. Enactive cinema paves way for understanding complex real-time social interaction in neuroimaging experiments

    Science.gov (United States)

    Tikka, Pia; Väljamäe, Aleksander; de Borst, Aline W.; Pugliese, Roberto; Ravaja, Niklas; Kaipainen, Mauri; Takala, Tapio

    2012-01-01

    We outline general theoretical and practical implications of what we promote as enactive cinema for the neuroscientific study of online socio-emotional interaction. In a real-time functional magnetic resonance imaging (rt-fMRI) setting, participants are immersed in cinematic experiences that simulate social situations. While viewing, their physiological reactions—including brain responses—are tracked, representing implicit and unconscious experiences of the on-going social situations. These reactions, in turn, are analyzed in real-time and fed back to modify the cinematic sequences they are viewing while being scanned. Due to the engaging cinematic content, the proposed setting focuses on living-by in terms of shared psycho-physiological epiphenomena of experience rather than active coping in terms of goal-oriented motor actions. It constitutes a means to parametrically modify stimuli that depict social situations and their broader environmental contexts. As an alternative to studying the variation of brain responses as a function of a priori fixed stimuli, this method can be applied to survey the range of stimuli that evoke similar responses across participants at particular brain regions of interest. PMID:23125829

  14. Experiences from Implementing a Mobile Multiplayer Real-Time Game for Wireless Networks with High Latency

    Directory of Open Access Journals (Sweden)

    Alf Inge Wang

    2009-01-01

    Full Text Available This paper describes results and experiences from designing, implementing, and testing a multiplayer real-time game over mobile networks with high latency. The paper reports on network latency and bandwidth measurements from playing the game live over GPRS, EDGE, UMTS, and WLAN using the TCP and the UDP protocols. These measurements describe the practical constraints of various wireless networks and protocols when used for mobile multiplayer game purposes. Further, the paper reports on experiences from implementing various approaches to minimize issues related to high latency. Specifically, the paper focuses on a discussion about how much of the game should run locally on the client versus on the server to minimize the load on the mobile device and obtain sufficient consistency in the game. The game was designed to reveal all kinds of implementation issues of mobile network multiplayer games. The goal of the game is for a player to push other players around and into traps where they loose their lives. The game relies heavily on collision detection between the players and game objects. The paper presents experiences from experimenting with various approaches that can be used to handle such collisions, and highlights the advantages and disadvantages of the various approaches.

  15. Cold starting of fluorescent lamps - part II: experiments on glow times and electrode damaging

    Science.gov (United States)

    Langer, Reinhard; Paul, Irina; Hilscher, Achim; Horn, Siegfried; Tidecks, Reinhard

    2017-01-01

    In the present work we present experiments on cold start and the resulting electrode damaging (reducing lamp life) of AC driven fluorescent lamps. The crucial parameter is the glow time, determined from time resolved measurements of lamp voltage and current. The relation between the energy consumed during glow phase and the glow time is studied. It turns out that there is no common threshold of energy until the glow-to-arc transition takes place, but strong energy input into the lamp yields short glow times. The transient behaviour from the glow to the arc regime is investigated and the stable operation points of the arc discharge are determined, yielding an arc discharge voltage-current characteristics of the lamp type investigated. The electrode damage is investigated as a function of the open source voltage and the ballast resistance. Subsequent cold starts lead to an increase of the glow time due to electrode damaging, i.e., the electrode damage accumulates. Different regeneration procedures and their effectiveness are compared. Regeneration burning turns out to be more effective than heating up the electrode. A criterion for avoiding high electrode damage is obtained, indicating that the average power during glow time should exceed 20 W.

  16. Barrel time-of-flight detector for the PANDA experiment at FAIR

    Science.gov (United States)

    Gruber, L.; Brunner, S. E.; Marton, J.; Orth, H.; Suzuki, K.; Panda Tof Group

    2016-07-01

    The barrel time-of-flight detector for the PANDA experiment at FAIR is foreseen as a Scintillator Tile (SciTil) Hodoscope based on several thousand small plastic scintillator tiles read-out with directly attached Silicon Photomultipliers (SiPMs). The main tasks of the system are an accurate determination of the time origin of particle tracks to avoid event mixing at high collision rates, relative time-of-flight measurements as well as particle identification in the low momentum regime. The main requirements are the use of a minimum material amount and a time resolution of σ < 100 ps. We have performed extensive optimization studies and prototype tests to prove the feasibility of the SciTil design and finalize the R&D phase. In a 2.7 GeV/c proton beam at Forschungszentrum Jülich a time resolution of about 80 ps has been achieved using SiPMs from KETEK and Hamamatsu with an active area of 3 × 3mm2. Employing the Digital Photon Counter from Philips a time resolution of about 30 ps has been reached.

  17. Exploring the Sexual Development Experiences of Black Bisexual Male Adolescents Over Time.

    Science.gov (United States)

    Morgan, Anthony; Saunders, Brianna; Dodge, Brian; Harper, Gary; Arrington Sanders, Renata

    2018-01-03

    Scant research has sought to explore the development of dimensions of sexual orientation among Black bisexual male adolescents (BBMA). Understanding how sexual attractions, behaviors, and identities evolve among BBMA over time is crucial to understanding the most appropriate support strategies to provide during this developmental period. We sought to understand and describe the sexual orientation development experiences in a sample of BBMA over the course of 1 year. We further sought to understand the sociocontextual factors that may play a role during this development process. Fifteen BBMA, aged 15-19 years, were interviewed about sexual debut experiences (baseline) and were re-interviewed three times over a 1-year period about sexual attractions, behaviors, and identity at each follow-up point. A three-person team used inductive open coding to analyze each participant's data set. The mean Kinsey scale score for the sample was 2.93 (SD = 1.2) most closely translating to "heterosexual/gay-equally." A case study analysis was used to identify themes related to sexual attractions, behavior, and identity over time, within and across participants. Among the sample of young men, two unique groups were identified based on self-reported sexual identity and experiences of same- and other-sex sexual attractions and behaviors over time. The first group consisted of seven young men who consistently described their sexual identity as bisexual from baseline to the final follow-up. These young men also described similar experiences related to same- and other-sex sexual and romantic attractions and more consistently described same- and other-sex sexual behaviors. The second group consisted of eight young men that described changing sexual identity and same- and other-sex sexual romantic attractions over time. Participants described sociocontextual factors such as religion, masculinity, and homophobia played during their development. Findings from this study underscore the

  18. An open source/real-time atomic force microscope architecture to perform customizable force spectroscopy experiments.

    Science.gov (United States)

    Materassi, Donatello; Baschieri, Paolo; Tiribilli, Bruno; Zuccheri, Giampaolo; Samorì, Bruno

    2009-08-01

    We describe the realization of an atomic force microscope architecture designed to perform customizable experiments in a flexible and automatic way. Novel technological contributions are given by the software implementation platform (RTAI-LINUX), which is free and open source, and from a functional point of view, by the implementation of hard real-time control algorithms. Some other technical solutions such as a new way to estimate the optical lever constant are described as well. The adoption of this architecture provides many degrees of freedom in the device behavior and, furthermore, allows one to obtain a flexible experimental instrument at a relatively low cost. In particular, we show how such a system has been employed to obtain measures in sophisticated single-molecule force spectroscopy experiments [Fernandez and Li, Science 303, 1674 (2004)]. Experimental results on proteins already studied using the same methodologies are provided in order to show the reliability of the measure system.

  19. Fluence measurement at the neutron time of flight experiment at CERN

    CERN Document Server

    Weiss, Christina; Jericha, Erwin

    At the neutron time of flight facility n_TOF at CERN a new spallation target was installed in 2008. In 2008 and 2009 the commissioning of the new target took place. During the summer 2009 a fission chamber of the Physikalisch Technische Bundesanstalt (PTB) Braunschweig was used for the neutron fluence measurement. The evaluation of the data recorded with this detector is the primary topic of this thesis. Additionally a neutron transmission experiment with air has been performed at the TRIGA Mark II reactor of the Atomic Institute of the Austrian Universities (ATI). The experiment was implemented to clarify a question about the scattering cross section of molecular gas which could not be answered clearly via the literature. This problem came up during the evaluations for n_TOF.

  20. Signal-to-noise analysis of time-dependent greenhouse warming experiments

    Science.gov (United States)

    Santer, Benjamin D.; Brüggemann, Wolfgang; Cubasch, Ulrich; Hasselmann, Klaus; Höck, Heinke; Maier-Reimer, Ernst; Mikolajewica, Uwe

    1994-03-01

    Results from a control integration and time-dependent greenhouse warming experiments performed with a coupled ocean-atmosphere model are analysed in terms of their signal-to-noise properties. The aim is to illustrate techniques for efficient description of the space-time evolution of signals and noise and to identify potentially useful components of a multivariate greenhouse-gas “fingerprint”. The three 100-year experiments analysed here simulate the response of the climate system to a step-function doubling of CO2 and to the time-dependent greenhouse-gas increases specified in Scenarios A (“Business as Usual”) and D (“Draconian Measures”) of the Intergovernmental Panel on Climate Change (IPCC). If signal and noise patterns are highly similar, the separation of the signal from the natural variability noise is difficult. We use the pattern correlation between the dominant Empirical Orthogonal Functions (EOFs) of the control run and the Scenario A experiment as a measure of the similarity of signal and noise patterns. The EOF 1 patterns of signal and noise are least similar for near-surface temperature and the vertical structure of zonal winds, and are most similar for sea level pressure (SLP). The dominant signal and noise modes of precipitable water and stratospheric/tropospheric temperature contrasts show considerable pattern similarity. Despite the differences in forcing history, a highly similar EOF 1 surface temperature response pattern is found in all three greenhouse warming experiments. A large part of this similarity is due to a common land-sea contrast component of the signal. To determine the degree to which the signal is contaminated by the natural variability (and/or drift) of the control run, we project the Scenario A data onto EOFs 1 and 2 of the control. Signal contamination by the EOF 1 and 2 modes of the noise is lowest for near-surface temperature, a situation favorable for detection. The signals for precipitable water, SLP, and the