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Sample records for babar silicon vertex

  1. The BaBar silicon vertex tracker

    International Nuclear Information System (INIS)

    Bozzi, C.; Carassiti, V.; Ramusino, A. Cotta; 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.; Pedrali-Noy, M.; Roe, N.A.; Zizka, G.; Roberts, D.; Barni, D.; Brenna, E.; Defendi, I.; Forti, A.; 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, P.; Cheng, C.; Kirkby, D.; Meyer, T.; Roat, C.; Bona, M.; Bianchi, F.; Daudo, F.; Girolamo, B. Di; Gamba, D.; Giraudo, G.; Grosso, P.; Romero, A.; Smol, A.; Trapani, P.; Zanin, D.; Bosisio, L.; Ricca, G. Della; 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.; Kroeger, 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 BaBar Silicon Vertex Tracker (SVT) is designed to provide the high-precision vertexing necessary for making measurements of CP violation at the SLAC B-Factory PEP-II. The instrument consists of five layers of double-sided silicon strip detectors and has been installed in the BaBar experiment and taking colliding beam data since May 1999. An overview of the design as well as performance and experience from the initial running will be presented

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

    International Nuclear Information System (INIS)

    Re, V.; Borean, C.; 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.; 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, P.; Cheng, C.; Kirkby, D.; Meyer, T.I.; Roat, C.; Bona, 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.; Kroeger, 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

  3. 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.

  4. The rad-hard readout system of the BaBar silicon vertex tracker

    Science.gov (United States)

    Re, V.; DeWitt, J.; Dow, S.; Frey, A.; Johnson, R. P.; Kroeger, W.; Kipnis, I.; Leona, A.; Luo, L.; Mandelli, E.; Manfredi, P. F.; Nyman, M.; Pedrali-Noy, M.; Poplevin, P.; Perazzo, A.; Roe, N.; Spencer, N.

    1998-02-01

    This paper discusses the behaviour of a prototype rad-hard version of the chip developed for the readout of the BaBar silicon vertex tracker. A previous version of the chip, implemented in the 0.8 μm HP rad-soft version has been thoroughly tested in the recent times. It featured outstanding noise characteristics and showed that the specifications assumed as target for the tracker readout were met to a very good extent. The next step was the realization of a chip prototype in the rad-hard process that will be employed in the actual chip production. Such a prototype is structurally and functionally identical to its rad-soft predecessor. However, the process parameters being different, and not fully mastered at the time of design, some deviations in the behaviour were to be expected. The reasons for such deviations have been identified and some of them were removed by acting on the points that were left accessible on the chip. Other required small circuit modifications that will not affect the production schedule. The tests done so far on the rad-hard chip have shown that the noise behaviour is very close to that of the rad-soft version, that is fully adequate for the vertex detector readout.

  5. The ARGUS silicon vertex detector

    International Nuclear Information System (INIS)

    Michel, E.; Ball, S.; Ehret, K.; Geyer, C.; Hesselbarth, J.; Hoelscher, A.; Hofmann, W.; Holzer, B.; Huepper, A.; Khan, S.; Knoepfle, K.T.; Seeger, M.; Spengler, J.; Brogle, M.; Horisberger, R.

    1994-01-01

    A silicon microstrip vertex detector has been built as an upgrade to the ARGUS detector for increased precision and efficiency in the reconstruction of decay vertices. This paper discusses the mechanical and electronic design of this device and presents first results from its successful test operation yielding an impact parameter resolution of about 18 μm. ((orig.))

  6. 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.

  7. The CDF Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Tkaczyk, S.; Carter, H.; Flaugher, B.

    1993-01-01

    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

  8. The CDF Silicon Vertex Trigger

    International Nuclear Information System (INIS)

    Dell'Orso, Mauro

    2006-01-01

    Motivations, design, performance and ongoing upgrade of the CDF Silicon Vertex Trigger are presented. The system provides CDF with a powerful tool for online tracking with offline quality in order to enhance the reach on B-physics and large P t -physics coupled to b quarks

  9. Belle II silicon vertex detector

    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, Università 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, Ti.; Baroncelli, To. [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, Università 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, Università 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, Università di Trieste, I-34127 Trieste (Italy); INFN Sezione di Trieste, I-34127 Trieste (Italy); and others

    2016-09-21

    The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by an inner tracking device comprising two layers of pixelated silicon detector and four layers of silicon vertex detector based on double-sided microstrip sensors. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector.

  10. The BELLE silicon vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Alimonti, G.; Aihara, H.; Alexander, J.; Asano, Y.; Bakich, A.; Bozek, A.; Banas, E.; Browder, T.; Dragic, J.; Fukunaga, C.; Gordon, A.; Guler, H.; Everton, C.; Heenan, E.; Haba, J.; Hazumi, M.; Hastings, N.; Hara, T.; Hojo, T.; Higuchi, T.; Iwai, G.; Ishino, H.; Jalocha, P.; Korotuschenko, K.; Kaneko, J.; Kapusta, P.; Kawasaki, T.; Lange, J.S.; Li, Y.; Marlow, D.; Moloney, G.; Moffitt, L.; Mori, S.; Matsubara, T.; Nakadaira, T.; Nakamura, T.; Natkaniec, Z.; Okuno, S.; Olsen, S.; Ostrowicz, W.; Palka, H.; Peak, L.S.; Ryuko, J.; Rozanska, M.; Sevior, M.; Shimada, J.; Sumisawa, K.; Stock, R.; Stanic, S.; Swain, S.; Taylor, G.; Takasaki, F.; Tajima, H.; Trabelsi, K.; Tamura, N.; Tanaka, J.; Tanaka, M. E-mail: tanakam@post.kek.jp; Takahashi, S.; Tomura, T.; Tsuboyama, T.; Tsujita, Y.; Varner, G.; Varvell, K.E.; Watanabe, Y.; Yamamoto, H.; Yamada, Y.; Yokoyama, M.; Zhao, H.; Zontar, D

    2000-10-11

    A silicon vertex detector has been developed for the BELLE experiment at the KEK B-factory to be used to determine the relative displacements of B-meson decay vertices for CP violation measurements. The device has been successfully installed and operated with high-luminosity beam conditions. The average strip yield is larger than 96%, including the preamplifier electronics yield and the detector is currently working stably with a signal-to-noise ratio of 17-40. The measured impact parameter resolution agrees with expectations based on Monte Carlo simulations, and the measured D{sup 0} lifetime is in good agreement with the particle data group's average of other measurements. Several B{yields}J/{psi}K events produced at the {upsilon}(4S) resonance have been detected and separate decay vertices have been found.

  11. 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

  12. The H1 silicon vertex detector

    International Nuclear Information System (INIS)

    Pitzl, D.; Behnke, O.; Biddulph, M.; Boesiger, K.; Eichler, R.; Erdmann, W.; Gabathuler, K.; Gassner, J.; Haynes, W.J..; Horisberger, R.; Kausch, M.; Lindstroem, M.; Niggli, H.; Noyes, G.; Pollet, P.; Steiner, S.; Streuli, S.; Szeker, K.; Truoel, P.

    2000-01-01

    The design, construction and performance of the H1 silicon vertex detector is described. It consists of two cylindrical layers of double-sided, double-metal silicon sensors read out by a custom designed analog pipeline chip. The analog signals are transmitted by optical fibres to a custom-designed ADC board and are reduced on PowerPC processors. Details of the design and construction are given and performance figures from the first data-taking periods are presented

  13. The CDF online silicon vertex tracker

    International Nuclear Information System (INIS)

    Ashmanskas, W.

    2001-01-01

    The CDF Online Silicon Vertex Tracker reconstructs 2-D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker. The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B s mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II

  14. The CDF online Silicon Vertex Tracker

    International Nuclear Information System (INIS)

    Ashmanskas, W.; Bardi, A.; Bari, M.; Belforte, S.; Berryhill, J.; Bogdan, M.; Carosi, R.; Cerri, A.; Chlachidze, G.; Culbertson, R.; Dell'Orso, M.; Donati, S.; Fiori, I.; Frisch, H.J.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Moneta, L.; Morsani, F.; Nakaya, T.; Passuello, D.; Punzi, G.; Rescigno, M.; Ristori, L.; Sanders, H.; Sarkar, S.; Semenov, A.; Shochet, M.; Speer, T.; Spinella, F.; Wu, X.; Yang, U.; Zanello, L.; Zanetti, A.M.

    2002-01-01

    The CDF Online Silicon Vertex Tracker (SVT) reconstructs 2D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker (XFT). The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B s mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II

  15. Construction of the CDF silicon vertex detector

    International Nuclear Information System (INIS)

    Skarha, J.; Barnett, B.; Boswell, C.; Snider, F.; Spies, A.; Tseng, J.; Vejcik, S.; Carter, H.; Flaugher, B.; Gonzales, B.; Hrycyk, M.; Nelson, C.; Segler, S.; Shaw, T.; Tkaczyk, S.; Turner, K.; Wesson, T.; Carithers, W.; Ely, R.; Haber, C.; Holland, S.; Kleinfelder, S.; Merrick, T.; Schneider, O.; Wester, W.; Wong, M.; Amidei, D.; Derwent, P.; Gold, M.; Matthews, J.; Bacchetta, N.; Bisello, D.; Busetto, G.; Castro, A.; Loreti, M.; Pescara, L.; Bedeschi, F.; Bolognesi, V.; Dell'Agnello, S.; Galeotti, S.; Mariotti, M.; Menzione, A.; Punzi, G.; Raffaelli, F.; Risotri, L.; Tartarelli, F.; Turini, N.; Wenzel, H.; Zetti, F.; Bailey, M.; Garfinkel, A.; Shaw, N.; Tipton, P.; Watts, G.

    1992-04-01

    Technical details and methods used in constructing the CDF silicon vertex detector are presented. This description includes a discussion of the foam-carbon fiber composite structure used to silicon microstrip detectors and the procedure for achievement of 5 μm detector alignment. The construction of the beryllium barrel structure, which houses the detector assemblies, is also described. In addition, the 10 μm placement accuracy of the detectors in the barrel structure is discussed and the detector cooling and mounting systems are described. 12 refs

  16. Silicon vertex tracker for RHIC PHENIX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Taketani, A [RIKEN, Nishina Ctr Accelerator Based Sci, Wako, Saitama, Japan; Cianciolo, Vince [ORNL; Enokizono, Akitomo [Oak Ridge National Laboratory (ORNL); PHENIX, Collaboration [The

    2010-01-01

    The PHENIX experiment at Relativistic Heavy Ion Collider will be equipped with Silicon Vertex tracker to enhance its physics capability. There are four layers of silicon sensor to reconstruct charged tracks with 50 {micro}m resolution of decay length measurement. The VTX surrounds the collision point. The inner two layers and the outer two layers are composed of 30 pixel ladders and 44 stripixel ladders, respectively. We have been developing these detectors and done a performance test with 120 GeV proton beam.

  17. 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.

  18. The Belle II Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Friedl, M.; Ackermann, K.; Aihara, H.; Aziz, T.; Bergauer, T.; Bozek, A.; Campbell, A.; Dingfelder, J.; Drasal, Z.; Frankenberger, A.; Gadow, K.; Gfall, I.; Haba, J.; Hara, K.; Hara, T.; Higuchi, T.; Himori, S.; Irmler, C.; Ishikawa, A.; Joo, C.

    2013-01-01

    The KEKB machine and the Belle experiment in Tsukuba (Japan) are now undergoing an upgrade, leading to an ultimate luminosity of 8×10 35 cm −2 s −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 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

  19. Silicon detectors for tracking and vertexing

    International Nuclear Information System (INIS)

    Nomerotski, Andrei

    2009-01-01

    This review covers recent developments in silicon detectors used for particle physics experiments for the tracking and vertexing systems. After a general introduction the main focus of the report is on new challenges for this field posed by requirements of the future generation machines. Technologies reviewed in more detail are column parallel CCDs, DEPFET, vertical integration of sensors and electronics and several others which allow fast readout and low mass design. Important system issues such as mechanical arrangements for the sensors and power distribution, which are critical for the low mass design, are also discussed.

  20. Mechanical design of the CDF SVX II silicon vertex detector

    International Nuclear Information System (INIS)

    Skarha, J.E.

    1994-08-01

    A next generation silicon vertex detector is planned at CDF for the 1998 Tevatron collider run with the Main Injector. The SVX II silicon vertex detector will allow high luminosity data-taking, enable online triggering of secondary vertex production, and greatly increase the acceptance for heavy flavor physics at CDF. The design specifications, geometric layout, and early mechanical prototyping work for this detector are discussed

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

    International Nuclear Information System (INIS)

    Bozzi, C.; Carassiti, V.; 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.; Pedrali-Noy, M.; Roe, N.A.; Zizka, G.; Roberts, D.; Schieck, J.; Barni, D.; Brenna, E.; Defendi, I.; Forti, A.; 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, P.; Cheng, C.; Kirkby, D.; Meyer, T.; Roat, C.; Bona, 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.; Kroeger, 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 μm thickness with a readout strip pitch of 50-210 μm 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 on the so far accumulated damage are presented. The implications of test-irradiation results and possible future PEP-II luminosity upgrades on the radiation limited lifetime of the SVT are discussed

  2. 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.

  3. 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.

  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. SVT: an online silicon vertex tracker for the CDF upgrade

    International Nuclear Information System (INIS)

    Bardi, A.; Belforte, S.; Berryhill, J.

    1997-07-01

    The SVT is an online tracker for the CDF upgrade which will reconstruct 2D tracks using information from the Silicon VerteX detector (SVXII) and Central Outer Tracker (COT). The precision measurement of the track impact parameter will then be used to select and record large samples of B hadrons. We discuss the overall architecture, algorithms, and hardware implementation of the system

  6. Performance of the CDF Silicon VerteX detector

    International Nuclear Information System (INIS)

    Schneider, O.

    1992-11-01

    The current status of the online and offline performance of the CDF Silicon VerteX detector is presented. So far, at low radiation dose, the device delivers good quality data. After the latest alignment using collision data, a spatial resolution of 13 pm is achieved in the transverse plane, demonstrating that CDF has a powerful tool to detect b decay vertices

  7. 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.

  8. The CDF silicon vertex detector SVX and its upgrades

    International Nuclear Information System (INIS)

    Seidel, S.; Univ. of New Mexico, Albuquerque, NM

    1994-11-01

    The three generations of CDF silicon vertex detectors, SVX, SVX', and SVX II, are described. SVX, which operated during Tevatron run Ia, achieved 10.6 μm resolution in r - φ. SVX' is a radiation-hard device for run Ib with a similar but improved mechanical design and improved signal/noise. SVX II, which will be installed for run II, will track in three dimensions with radiation tolerance and electronics appropriate to a Main Injector environment

  9. 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.

  10. Silicon vertex detector upgrade in the ALPHA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Amole, C. [Department of Physics and Astronomy, York University, Toronto, ON, M3J 1P3 (Canada); Andresen, G.B. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Ashkezari, M.D. [Department of Physics, Simon Fraser University, Burnaby, BC, V5A 1S6 (Canada); Baquero-Ruiz, M. [Department of Physics, University of California at Berkeley, Berkeley, CA 94720-7300 (United States); Bertsche, W. [School of Physics and Astronomy, University of Manchester, M13 9PL Manchester (United Kingdom); The Cockcroft Institute, Daresbury Laboratory, WA4 4AD Warrington (United Kingdom); Burrows, C. [Department of Physics, College of Science, Swansea University, Swansea SA2 8PP (United Kingdom); Butler, E. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Capra, A. [Department of Physics and Astronomy, York University, Toronto, ON, M3J 1P3 (Canada); Cesar, C.L. [Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Chapman, S. [Department of Physics, University of California at Berkeley, Berkeley, CA 94720-7300 (United States); Charlton, M.; Deller, A.; Eriksson, S. [Department of Physics, College of Science, Swansea University, Swansea SA2 8PP (United Kingdom); Fajans, J. [Department of Physics, University of California at Berkeley, Berkeley, CA 94720-7300 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Friesen, T. [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Fujiwara, M.C. [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Gill, D.R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Gutierrez, A. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z4 (Canada); and others

    2013-12-21

    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.

  11. Fine pitch and low material readout bus in the Silicon Pixel Vertex Tracker for the PHENIX Vertex Tracker upgrade

    International Nuclear Information System (INIS)

    Fujiwara, Kohei

    2010-01-01

    The construction of the Silicon Pixel Detector is starting in spring 2009 as project of the RHIC-PHENIX Silicon Vertex Tracker (VTX) upgrade at the Brookhaven National Laboratory. For the construction, we have developed a fine pitch and low material readout bus as the backbone parts of the VTX. In this article, we report the development and production of the readout bus.

  12. The silicon vertex tracker for star and future applications of silicon drift detectors

    International Nuclear Information System (INIS)

    Bellwied, Rene

    2001-01-01

    The Silicon Vertex Tracker (SVT) for the STAR experiment at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory has recently been completed and installed. First data were taken in July 2001. The SVT is based on a novel semi-conductor technology called Silicon Drift Detectors. 216 large area (6 by 6 cm) Silicon wafers were employed to build a three barrel device capable of vertexing and tracking in a high occupancy environment. Its intrinsic radiation hardness, its operation at room temperature and its excellent position resolution (better than 20 micron) in two dimensions with a one dimensional detector readout, make this technology very robust and inexpensive and thus a viable alternative to CCD, Silicon pixel and Silicon strip detectors in a variety of applications from fundamental research in high-energy and nuclear physics to astrophysics to medical imaging. I will describe the development that led to the STAR-SVT, its performance and possible applications for the near future

  13. 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.

  14. The Belle II silicon vertex detector assembly and mechanics

    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, Università 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, Ti.; Baroncelli, To. [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, Università 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., E-mail: stefano.bettarini@pi.infn.it [Dipartimento di Fisica, Università 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, Università di Trieste, I-34127 Trieste (Italy); INFN Sezione di Trieste, I-34127 Trieste (Italy); and others

    2017-02-11

    The Belle II experiment at the asymmetric SuperKEKB collider in Japan will operate at an instantaneous luminosity approximately 50 times greater than its predecessor (Belle). The central feature of the experiment is a vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is CP violation asymmetry in the decays of beauty and charm hadrons, which hinges on a precise charged-track vertex determination and low-momentum track measurement. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the final SVD modules. Finally, some results from the latest test-beam are reported.

  15. The silicon vertex detector of the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, Markus, E-mail: friedl@hephy.a [Institute of High Energy Physics, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Bergauer, Thomas; Gfall, Immanuel; Irmler, Christian; Valentan, Manfred [Institute of High Energy Physics, Nikolsdorfergasse 18, A-1050 Vienna (Austria)

    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 8x10{sup 35} cm{sup -2} s{sup -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 and 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.

  16. The silicon vertex detector of the Belle II experiment

    International Nuclear Information System (INIS)

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

    2011-01-01

    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 8x10 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 and 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.

  17. System software design for the CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, S. (Fermi National Accelerator Lab., Batavia, IL (United States)); Bailey, M. (Purdue Univ., Lafayette, IN (United States))

    1991-11-01

    An automated system for testing and performance evaluation of the CDF Silicon Vertex Detector (SVX) data acquisition electronics is described. The SVX data acquisition chain includes the Fastbus Sequencer and the Rabbit Crate Controller and Digitizers. The Sequencer is a programmable device for which we developed a high level assembly language. Diagnostic, calibration and data acquisition programs have been developed. A distributed software package was developed in order to operate the modules. The package includes programs written in assembly and Fortran languages that are executed concurrently on the SVX Sequencer modules and either a microvax or an SSP. Test software was included to assist technical personnel during the production and maintenance of the modules. Details of the design of different components of the package are reported.

  18. System software design for the CDF Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Tkaczyk, S.; Bailey, M.

    1991-11-01

    An automated system for testing and performance evaluation of the CDF Silicon Vertex Detector (SVX) data acquisition electronics is described. The SVX data acquisition chain includes the Fastbus Sequencer and the Rabbit Crate Controller and Digitizers. The Sequencer is a programmable device for which we developed a high level assembly language. Diagnostic, calibration and data acquisition programs have been developed. A distributed software package was developed in order to operate the modules. The package includes programs written in assembly and Fortran languages that are executed concurrently on the SVX Sequencer modules and either a microvax or an SSP. Test software was included to assist technical personnel during the production and maintenance of the modules. Details of the design of different components of the package are reported

  19. CDF silicon vertex tracker: tevatron run II preliminary results

    International Nuclear Information System (INIS)

    Ashmanskas, W.; Belforte, S.; Budagov, Yu.

    2002-01-01

    The Online Silicon Vertex Tracker (SVT) is the unique new trigger processor dedicated to the 2-D reconstruction of charged particle trajectories at Level 2 of the CDF trigger. The SVT has been successfully built, installed and operated during the 2000 and 20001 CDF data taking runs. The performance of the SVT is already very close to the design. The SVT is able to find tracks and calculate their impact parameter with high precision (σ d = 35 μm). It is possible to correct the beam position offset and give the beam position feedback to accelerator in real time. In fact, the beam position is calculated online every few seconds with an accuracy of 1 to 5 μm. The beam position is continuously sent to the accelerator control. By using trigger tracks, parent particles such as K S 's and D 0 's are reconstructed, proving that the SVT is ready to be used for physics studies

  20. Silicon micro-vertex detector for Belle II

    International Nuclear Information System (INIS)

    Mohanty, Gagan

    2013-01-01

    The Belle experiment at the KEK B-factory is Japan provided the landmark experimental confirmation of CP violation mechanism within the standard model that led to the physics Nobel prize in 2008. In its second phase, called Belle II, it would seek for the holy-grail of new physics using rare decays of B and D mesons and tau leptons as a probe, in complimentary to the direct searches carried out with the LHC experiments. An important component of this upgrade is to replace the innermost subdetector, namely the silicon micro-vertex detector (SVD). The new SVD will, like the old one, consist of four layers of double-sided silicon strip detector, but made from 6âĂİ wafers and located at higher radii as a novel, two-layer DEPFET pixel detector will be inserted very dose to the beam- pipe. Starting with the physics motivation, we discuss the design concept, fabrication and the Indian contributions toward the Belle II SVD. (author)

  1. Characterisation of silicon detectors for the LHCb Vertex Locator Upgrade

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00401830

    The LHCb Vertex Locator must be upgraded in the next long shutdown of the LHC, starting at the end of 2018. This is due to the increased occupancy. The current silicon strip detector is being upgraded to a silicon pixel detector. The prototype sensors for this detector were tested thoroughly before a final design will be chosen. The testing was done with the Timepix3 Telescope, which was commissioned in the summer of 2014. The charge collected by the sensors and efficiency of the sensors were investigated. After maximum irradiation, of 8$\\times$10$^{15}$ 1 MeV n$_{eq}$/cm$^{2}$, the sensors must have a most probable value of collected charge of 6000 electrons before 1000 V or breakdown, whichever comes first. The sensors must also have a high efficiency at maximum irradiation of 8$\\times$10$^{15}$ 1 MeV n$_{eq}$/cm$^{2}$. All tested sensors reach these criteria. All sensors reach 6000 electrons between 600 V and 800 V and have a cluster finding efficiency of over 95\\% at the respective voltages. Overall, a 15...

  2. 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).

  3. 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 ...

  4. 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.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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 υ(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

  6. Proposed method of assembly for the BCD silicon strip vertex detector modules

    International Nuclear Information System (INIS)

    Lindenmeyer, C.

    1989-01-01

    The BCD Silicon strip Vertex Detector is constructed of 10 identical central region modules and 18 similar forward region modules. This memo describes a method of assembling these modules from individual silicon wafers. Each wafer is fitted with associated front end electronics and cables and has been tested to insure that only good wafers reach the final assembly stage. 5 figs

  7. Control and data acquisition electronics for the CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Turner, K.J.; Nelson, C.A.; Shaw, T.M.; Wesson, T.R.

    1991-11-01

    A control and data acquisition system has been designed for the CDF Silicon Vertex Detector (SVX) at Fermilab. The system controls the operation of the SVX Rev D integrated circuit (SVX IC) that is used to instrument a 46,000 microstrip silicon detector. The system consists of a Fastbus Sequencer, a Crate Controller and Digitizer modules. 11 refs., 6 figs., 3 tabs.

  8. Control and data acquisition electronics for the CDF silicon vertex detector

    International Nuclear Information System (INIS)

    urner, K.J.; Nelson, C.A.; Shaw, T.M.; Wesson, T.R.

    1992-01-01

    This paper reports on a control and data acquisition system that has been designed for the CDF Silicon Vertex Detector (SVX) at Fermilab. The system controls the operation of the SVX Rev D integrated circuit (SVX IC) that is used to instrument a 46,000 microstrip silicon detector. The system consists of a Fastbus Sequencer, a Crate Controller and Digitizer modules

  9. Control and data acquisition electronics for the CDF Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Turner, K.J.; Nelson, C.A.; Shaw, T.M.; Wesson, T.R.

    1991-11-01

    A control and data acquisition system has been designed for the CDF Silicon Vertex Detector (SVX) at Fermilab. The system controls the operation of the SVX Rev D integrated circuit (SVX IC) that is used to instrument a 46,000 microstrip silicon detector. The system consists of a Fastbus Sequencer, a Crate Controller and Digitizer modules. 11 refs., 6 figs., 3 tabs

  10. Assembly procedure for the silicon pixel ladder for PHENIX silicon vertex tracker

    International Nuclear Information System (INIS)

    Onuki, Y.; Akiba, Y.; En'yo, H.; Fujiwara, K.; Haki, Y.; Hashimoto, K.; Ichimiya, R.; Kasai, M.; Kawashima, M.; Kurita, K.; Kurosawa, M.; Mannel, E.J.; Nakano, K.; Pak, R.; Sekimoto, M.; Sondheim, W.E.; Taketani, A.; Togawa, M.; Yamamoto, Y.

    2009-01-01

    The silicon vertex tracker (VTX) will be installed in the summer of 2010 to enhance the physics capabilities of the Pioneering High Energy Nuclear Interaction eXperiment (PHENIX) experiment at Brookhaven National Laboratory. The VTX consists of two types of silicon detectors: a pixel detector and a strip detector. The pixel detector consists of 30 pixel ladders placed on the two inner cylindrical layers of the VTX. The ladders are required to be assembled with high precision, however, they should be assembled in both cost and time efficient manner. We have developed an assembly bench for the ladder with several assembly fixtures and a quality assurance (Q/A) system using a 3D measurement machine. We have also developed an assembly procedure for the ladder, including a method for dispensing adhesive uniformly and encapsulation of bonding wires. The developed procedures were adopted in the assembly of the first pixel ladder and satisfy the requirements.

  11. Development of new assembly techniques for a silicon micro-vertex detector unit using the flip-chip bonding method

    International Nuclear Information System (INIS)

    Saitoh, Y.; Takeuchi, H.; Mandai, M.; Kanazawa, H.; Yamanaka, J.; Miyahara, S.; Kamiya, M.; Fujita, Y.; Higashi, Y.; Ikeda, H.; Ikeda, M.; Koike, S.; Matsuda, T.; Ozaki, H.; Tanaka, M.; Tsuboyama, T.; Avrillon, S.; Okuno, S.; Haba, J.; Hanai, H.; Mori, S.; Yusa, K.; Fukunaga, C.

    1994-01-01

    Full-size models of a detector unit for a silicon micro-vertex detector were built for the KEK B factory. The Flip-Chip Bonding (FCB) method using a new type anisotropic conductive film was examined. The structure using the FCB method successfully provides a new architecture for the silicon micro-vertex detector unit. (orig.)

  12. The BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G

    2001-05-18

    BABAR, the detector for the SLAC PEP-II asymmetric e{sup +}e{sup -} B Factory operating at the {Upsilon}(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

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

    International Nuclear Information System (INIS)

    Bortoletto, D.

    1994-11-01

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

  14. Design and Tests of the Silicon Sensors for the ZEUS Micro Vertex Detector

    OpenAIRE

    Dannheim, D.; Koetz, U.; Coldewey, C.; Fretwurst, E.; Garfagnini, A.; Klanner, R.; Martens, J.; Koffeman, E.; Tiecke, H.; Carlin, R.

    2002-01-01

    To fully exploit the HERA-II upgrade,the ZEUS experiment has installed a Micro Vertex Detector (MVD) using n-type, single-sided, silicon micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 micrometers, with five intermediate strips (20 micrometer strip pitch). The designs of the silicon sensors and of the test structures used to verify the technological parameters, are presented. Results on the electrical measurements are discussed. A total of 1123 sen...

  15. Operation of the CDF Silicon Vertex Detector with colliding beams at Fermilab

    International Nuclear Information System (INIS)

    Bedeschi, F.; Bolognesi, V.; Dell'Agnello, S.; Galeotti, S.; Grieco, G.; Mariotti, M.; Menzione, A.; Punzi, G.; Raffaelli, F.; Ristori, L.; Tartarelli, F.; Turini, N.; Wenzel, H.; Zetti, F.; Bailey, M.W.; Garfinkel, A.F.; Kruse, M.C.; Shaw, N.M.; Carithers, W.C.; Ely, R.; Haber, C.; Holland, S.; Kleinfelder, S.; Merrick, T.; Schneider, O.; Wester, W.; Wong, M.; Yao, W.; Carter, H.; Flaugher, B.; Nelson, C.; Segler, S.; Shaw, T.; Tkaczyk, S.; Turner, K.; Wesson, T.R.; Barnett, B.; Boswell, C.; Skarha, J.; Snider, F.D.; Spies, A.; Tseng, J.; Vejcik, S.; Amidei, D.; Derwent, P.F.; Song, T.Y.; Dunn, A.; Gold, M.; Matthews, J.; Bacchetta, N.; Azzi, P.; Bisello, D.; Busetto, G.; Castro, A.; Loreti, M.; Pescara, L.; Tipton, P.; Watts, G.

    1992-10-01

    In this paper we briefly describe the main features of the CDF Silicon Vertex Detector (SVX) and discuss its performance during actual colliding beam operation at the Fermilab Tevatron. Details on S/N ratio, alignment, resolution and efficiency are given

  16. 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.

  17. The upgrade of the vertex detector to form the central part of the silicon tracker in DELPHI

    International Nuclear Information System (INIS)

    Brenner, R.

    1997-01-01

    The DELPHI vertex detector has undergone a final upgrade to meet the physics requirements at LEP200. The old vertex detector has been made longer by 24 cm and is now the barrel part of the silicon tracker with a very forward part at both ends. The configuration and first results on the stability and performance of the barrel part is reported. (orig.)

  18. A silicon pixel detector prototype for the CLIC vertex detector

    CERN Multimedia

    AUTHOR|(INSPIRE)INSPIRE-00714258

    2017-01-01

    A silicon pixel detector prototype for CLIC, currently under study for the innermost detector surrounding the collision point. The detector is made of a High-Voltage CMOS sensor (top) and a CLICpix2 readout chip (bottom) that are glued to each other. Both parts have a size of 3.3 x 4.0 $mm^2$ and consist of an array of 128 x 128 pixels of 25 x 25 $\\micro m^2$ size.

  19. Silicon Drift Detectors - A Novel Technology for Vertex Detectors

    Science.gov (United States)

    Lynn, D.

    1996-10-01

    Silicon Drift Detectors (SDD) are novel position sensing silicon detectors which operate in a manner analogous to gas drift detectors. Single SDD's were shown in the CERN NA45 experiment to permit excellent spatial resolution (pseudo-rapidity. Over the last three years we undertook a concentrated R+D effort to optimize the performance of the detector by minimizing the inactive area, the operating voltage and the data volume. We will present test results from several wafer prototypes. The charge produced by the passage of ionizing particles through the bulk of the detectors is collected on segmented anodes, with a pitch of 250 μm, on the far edges of the detector. The anodes are wire-bonded to a thick film multi-chip module which contains preamplifier/shaper chips and CMOS based switched capacitor arrays used as an analog memory pipeline. The ADC is located off-detector. The complete readout chain from the wafer to the DAQ will be presented. Finally we will show physics performance simulations based on the resolution achieved by the SVT prototypes.

  20. Operation and performance of the silicon vertex detector (SVX') at CDF

    International Nuclear Information System (INIS)

    Singh, P.P.

    1994-10-01

    The authors describe the operation and performance of the Silicon Vertex Detector (SVX'), which replaced the CDF SVX detector for run lb of the Fermilab Tevatron Collider. The new features of the SVX' include AC coupled readout, Field OXide Field Effect Transistor (FOXFET) biasing and radiation hard front end electronics. The authors expect the detector to survive beyond the 100 pb -1 of data taking anticipated for the present CDF physics run. Preliminary results from the collider data show that the detector has a resolution of about 12 μm. This provides a powerful tool to do top and bottom physics

  1. Radiation monitoring with CVD diamonds and PIN diodes at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Bruinsma, M. [University of California Irvine, Irvine, CA 92697 (United States); Burchat, P. [Stanford University, Stanford, CA 94305-4060 (United States); Curry, S. [University of California Irvine, Irvine, CA 92697 (United States)], E-mail: scurry@slac.stanford.edu; Edwards, A.J. [Stanford University, Stanford, CA 94305-4060 (United States); Kagan, H.; Kass, R. [Ohio State University, Columbus, OH 43210 (United States); Kirkby, D. [University of California Irvine, Irvine, CA 92697 (United States); Majewski, S.; Petersen, B.A. [Stanford University, Stanford, CA 94305-4060 (United States)

    2007-12-11

    The BaBar experiment at the Stanford Linear Accelerator Center has been using two polycrystalline chemical vapor deposition (pCVD) diamonds and 12 silicon PIN diodes for radiation monitoring and protection of the Silicon Vertex Tracker (SVT). We have used the pCVD diamonds for more than 3 years, and the PIN diodes for 7 years. We will describe the SVT and SVT radiation monitoring system as well as the operational difficulties and radiation damage effects on the PIN diodes and pCVD diamonds in a high-energy physics environment.

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

    International Nuclear Information System (INIS)

    Mours, B.

    1996-03-01

    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. 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) in 12 μm in the r.φ view and 12 μm in the z view. The design and construction of the entire detector system are discussed in detail and the experience gained in running the detector is 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. (orig.)

  3. Electronics and mechanics for the Silicon Vertex Detector of the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Irmler, C; Bergauer, T; Friedl, M; Gfall, I; Valentan, M, E-mail: irmler@hephy.oeaw.ac.a [Institute of High Energy Physics, Austrian Academy of Sciences, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria)

    2010-12-15

    A major upgrade of the KEK-B factory (Tsukuba, Japan), aiming at a peak luminosity of 8 x 10{sup 35}cm{sup -2}s{sup -1}, which is 40 times the present value, is foreseen until 2014. Consequently an upgrade of the Belle detector and in particular its Silicon Vertex Detector (SVD) is required. We will introduce the concept and prototypes of the full readout chain of the Belle II SVD. Its APV25 based front-end utilizes the Origami chip-on-sensor concept, while the back-end VME system provides online data processing as well as hit time finding using FPGAs. Furthermore, the design of the double-sided silicon detectors and the mechanics will be discussed.

  4. The CDF silicon vertex trigger for B-mesons physics study

    International Nuclear Information System (INIS)

    Belforte, S.; Donati, S.; Ristori, L.; Spinella, F.; Budagov, Yu.; Chlachidze, G.; Glagolev, V.; Semenov, A.; Sisakyan, A.; Punzi, G.

    2001-01-01

    The CDF scientific program includes particularly the study of some key topics of the Standard Model: 1) constraint of the CKM matrix: CP violation in B sector (B 0 → π + π - ) and B s mixing (B s 0 → D s - π + , B s 0 → D s - π + π - π + ); 2) t-quark physics (t → Wb); and processes beyond the Standard Model - e.g., Higgs searching (MSSM) in the H → b bar b mode. All the above processes have the common feature - the presence of b-quarks (B-mesons). B hadrons of sufficiently high transverse momentum are characterized by a large mean value of distribution of the impact parameter with respect to the beam axis. That means events containing this kind of particles can be recognized and separated from non-long-lived background simply by cutting on the track's impact parameter. The upgraded CDF is equipped by the so-called Silicon Vertex Tracker (SVT), a unique electronic device for real time track reconstruction using the data from two CDF track detectors: the silicon strip vertex detector and drift chamber. The SVT is a level-2 trigger which within 10 μs reconstructs the tracks and obtains the transverse momentum (p t ), azimuthal angle (φ) and impact parameter (d) with 30 μm precision. The simulation studies show the background reduction by factor 1000 for B 0 π + π - by demand d > 100 μm for at least two tracks. This trigger is the first one of this sort ever used for hadron collider experiments: it enables to trigger on the secondary vertex, which opens the unique new opportunities in the heavy quark physics study. The basic logic, architecture and perspectives of SVT application are briefly described

  5. Study of gluing and wire bonding for the Belle II Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Kang, K.H.; Hara, K.; Higuchi, T.; Hyun, H.J.; Jeon, H.B.; Joo, C.W.; Kah, D.H.; Kim, H.J.; Mibe, T.; Onuki, Y.; Park, H.; Rao, K.K.; Sato, N.; Shimizu, N.; Tanida, K.; Tsuboyama, T.; Uozumi, S.

    2014-01-01

    This paper describes an investigation into gluing and wire bonding for assembling the Silicon Vertex Detector (SVD) for the Belle II experiment at KEK in Japan. Optimizing the gluing of the silicon microstrip sensors, the support frame, and the readout flex cables is important for achieving the required mechanical precision. The wire bonding between the sensors and the readout electronic chips also needs special care to maximize the physics capability of the SVD. The silicon sensors and signal fan out flex circuits (pitch adapters) are glued and connected using wire bonding. We determine that gluing quality is important for achieving good bonding efficiency. The standard deviation in the glue thickness for the best result is measured to be 3.11 μm. Optimal machine parameters for wire bonding are determined to be 70 mW power, 20 gf force, and 20 ms for the pitch adapter and 60 mW power, 20 gf force, and 20 ms for the silicon strip sensors; these parameters provide a pull force of (10.92±0.72) gf. With these settings, 75% of the pitch adapters and 25% of the strip sensors experience the neck-broken type of break

  6. Thermal simulations of the new design for the BELLE silicon vertex detector

    International Nuclear Information System (INIS)

    Dragic, J.

    2000-01-01

    Full text: The experienced imperfections of the BELLE silicon vertex detector, SVD1 motioned the design of a new detector, SVD2, which targets on improving the main weaknesses encountered in the old design. In this report we focus on tile thermal aspects of the SVD2 ladder, whereby sufficient cooling of the detector is necessary in order to minimise the detector leakage currents. It is estimated that reducing the temperature of the silicon detector from 25 deg C to 15 deg C would result in a 50% reduction in leak current. Further, cooling the detector would help minimize mechanical stresses from the thermal cycling. Our task is to ensure that the heat generated by the readout chips is conducted down the SVD hybrid unit effectively, such that the chip and the hybrid temperature does not overbear the SVD silicon sensor temperature. We considered the performance of two materials to act as a heat spreading plate which is glued between the two hybrids in order to improve the heat conductivity of the hybrid unit, namely Copper and Thermal Pyrolytic Graphite (TPG). The effects of other ladder components were also considered in order to enhance the cooling of the silicon detectors. Finite element analysis with ANSYS software was used to simulate the thermal conditions of the SVD2 hybrid unit, in accordance with the baseline design for the mechanical structure of the ladder. It was found that Cu was a preferred material as it achieved equivalent silicon sensor cooling (3.6 deg C above cooling point), while its mechanical properties rendered it a lot more practical. Suppressing, the thermal path via a rib support block, by increasing its thermal resistivity, as well as increasing thermal conductivity of the ribs in the hybrid region, were deemed essential in the effective cooling of the silicon sensors

  7. Thin pixel development for the SuperB silicon vertex tracker

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, G., E-mail: giuliana.rizzo@pi.infn.it [INFN-Pisa and Universita di Pisa (Italy); Avanzini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Ceccanti, M.; Cenci, R.; Cervelli, A.; Crescioli, F.; Dell' Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.A. [INFN-Pisa and Universita di Pisa (Italy); Lusiani, A. [Scuola Normale Superiore and INFN-Pisa (Italy); Gregucci, S.; Mammini, P.; Marchiori, G.; Massa, M.; Morsani, F.; Neri, N. [INFN-Pisa and Universita di Pisa (Italy); and others

    2011-09-11

    The high luminosity SuperB asymmetric e{sup +}e{sup -} collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 10{sup 36} cm{sup -2} s{sup -1} with moderate beam currents and a reduced center of mass boost with respect to earlier B-Factories. An improved vertex resolution is required for precise time-dependent measurements and the SuperB Silicon Vertex Tracker will be equipped with an innermost layer of small radius (about 1.5 cm), resolution of 10-15{mu}m in both coordinates, low material budget (<1% X0), and able to withstand a background rate of several tens of MHz/cm{sup 2}. The ambitious goal of designing a thin pixel device with these stringent requirements is being pursued with specific R and D programs on different technologies: hybrid pixels, CMOS MAPS and pixel sensors developed with vertical integration technology. The latest results on the various pixel options for the SuperB SVT will be presented.

  8. Development of a silicon tracking and vertex detection system for the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Heuser, Johann M.

    2007-01-01

    The compressed baryonic matter (CBM) experiment is a fixed-target heavy-ion spectrometer planned at the future international Facility for Antiproton and Ion Research (FAIR) at GSI. The CBM research program will explore the phase diagram of Quantum Chromo Dynamics (QCD) in the region of high baryon chemical potentials, in other words nuclear matter at extreme densities. Matter of such forms is believed to exist in the interior of neutron stars and in the cores of certain types of supernovae. In the laboratory, the dense nuclear medium is created in collisions of heavy-ion beams with nuclear targets. With beam intensities of up to 10 12 ions per pulse, beam energies up to 45 GeV/nucleon, and high availability the SIS-300 synchrotron of FAIR will offer unique opportunities for this research. The CBM detector will identify hadrons and leptons in nuclear collisions with up to 1000 charged particles at event rates up to 10 MHz. The experiment will be optimized in particular for the detection of rare probes, like hadronic decays of D mesons and leptonic decays of light vector mesons, that can yield information on the initial dense phase of the collisions. The challenge is to accomplish in this environment high-resolution charged particle tracking, momentum measurement and secondary vertex selection with a silicon tracking and vertex detection system, the central component of the CBM detector. The system requirements include a very low material budget, radiation tolerant sensors with high spatial resolution, and a fast readout compatible with high-level-only triggers. The paper discusses the concept of the silicon detection system, the optimization of its layout, and the R and D on micro-strip and pixel sensors as well as front-end electronics for the building blocks of the detector stations

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

    International Nuclear Information System (INIS)

    Kang, K.H.; Jeon, H.B.; Park, H.; Uozumi, S.; Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, T.; Basith, A.K.; Batignani, G.; Bauer, A.; Behera, P.K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.

    2016-01-01

    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.

  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. Design and tests of the silicon sensors for the ZEUS micro vertex detector

    International Nuclear Information System (INIS)

    Dannheim, D.; Koetz, U.; Coldewey, C.; Fretwurst, E.; Garfagnini, A.; Klanner, R.; Martens, J.; Koffeman, E.; Tiecke, H.; Carlin, R.

    2003-01-01

    To fully exploit the HERA-II upgrade, the ZEUS experiment has installed a Micro Vertex Detector (MVD) using n-type, single-sided, silicon μ-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 μm, with five intermediate strips (20 μm strip pitch). The designs of the silicon sensors and of the test structures used to verify the technological parameters, are presented. Results on the electrical measurements are discussed. A total of 1123 sensors with three different geometries have been produced by Hamamatsu Photonics K.K. Irradiation tests with reactor neutrons and 60 Co photons have been performed for a small sample of sensors. The results on neutron irradiation (with a fluence of 1x10 13 1 MeV equivalent neutrons/cm 2 ) are well described by empirical formulae for bulk damage. The 60 Co photons (with doses up to 2.9 kGy) show the presence of generation currents in the SiO 2 -Si interface, a large shift of the flatband voltage and a decrease of the hole mobility

  12. Production of high energy η' in B meson decays from BaBar experiment

    International Nuclear Information System (INIS)

    Hicheur, A.

    2003-04-01

    The work presented in this thesis relies on the analysis of data collected between october 1999 and July 2002 by the BaBar experiment at the PEP-II collider located at SLAC (Stanford, California). Electron-positron collisions at a center of mass energy equal to the Υ(4S) resonance mass are used for the production of B meson pairs. In July 2001, the BaBar collaboration published the first measurement of CP violation in the neutral B mesons system. Since then, the precision of the measurement has been continually being improved with the increasing data sample. Two devices are dedicated to the reconstruction of charged particles: the Silicon Vertex Tracker and the Drift Chamber. The Silicon Vertex Tracker is crucial for the reconstruction of the B meson decay vertex. Its motion with regard to the Drift Chamber needs a rolling calibration of the corresponding alignment parameters roughly every two hours. The relation between the Drift Chamber geometry and the alignment has been studied. Beside CP violation, Heavy Flavour Physics is an other important issue of BaBar research program. Rare decays are of particular interest as they are sensible to a new physics beyond the Standard Model. The production of high energy η' in B decays has been studied through the two main contributions, B→ η' X s coming from the rare decay b → sg*, and B-bar 0 → η'D 0 coming from the internal tree color suppressed decay b → cud. The improvement of the measurement of the process B → η'X-s and the first. observation of the decay B-bar 0 → η'D 0 have led to the conclusion that the η' production is dominated by the decay b → sg* and enables to constrain its quark content. (author)

  13. Mechanical and thermal behavior of a prototype support structure for a large silicon vertex detector (BCD)

    International Nuclear Information System (INIS)

    Mulderink, H.; Michels, N.; Joestlein, H.

    1989-01-01

    The Bottom Collider Detector (BCD) has been proposed as a device to study large numbers of events containing B mesons. To identify secondary vertices in hadronic events it will employ the most ambitious silicon strip tracking detector proposed to-date. This report will discuss results from measurements on a first mechanical/thermal model of the vertex detector support structure. The model that was built and used for the studies described here is made of brass. Brass was used because it is readily available and easily assembled by soft soldering, and, for appropriate thicknesses, it will behave similarly to the beryllium that will be used in the actual detector. The trough was built to full scale with the reinforcement webbing and the cooling channels in place. There were no detector modules in place. We plan, however, to install modules in the trough in the future. The purpose of the model was to address two concerns that have arisen about the proposed structure of the detector. The first is whether or not the trough will be stable enough. The trough must be very light in weight yet have a high degree of rigidity. Because of the 3m length of the detector there is question as to the stiffness of the proposed trough. The main concern is that there will sagging or movement of the trough in the middle region. The second problem is the heat load. There will be a great deal of heat generated by the electronics attached to the detector modules. So the question arises as to whether or not the silicon detectors can be kept cool enough so that when the actual experiment is run the readings will be valid. The heat may also induce motion by differential expansion of support components. 26 figs

  14. 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.

  15. Recent developments on CMOS MAPS for the SuperB Silicon Vertex Tracker

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, G., E-mail: rizzo@pi.infn.it [Università degli Studi di Pisa (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (Italy); Comott, D. [Università degli Studi di Bergamo (Italy); Manghisoni, M.; Re, V.; Traversi, G. [Università degli Studi di Bergamo (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pavia (Italy); Fabbri, L.; Gabrielli, A. [Università degli Studi di Bologna (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy); Giorgi, F.; Pellegrini, G.; Sbarra, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy); Semprini-Cesari, N.; Valentinetti, S.; Villa, M.; Zoccoli, A. [Università degli Studi di Bologna (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy); Berra, A.; Lietti, D.; Prest, M. [Università dell' Insubria, Como (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca (Italy); Bevan, A. [School of Physics and Astronomy, Queen Mary, University of London, London E1 4NS (United Kingdom); Wilson, F. [STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Beck, G. [School of Physics and Astronomy, Queen Mary, University of London, London E1 4NS (United Kingdom); and others

    2013-08-01

    In the design of the Silicon Vertex Tracker for the high luminosity SuperB collider, very challenging requirements are set by physics and background conditions on its innermost Layer0: small radius (about 1.5 cm), resolution of 10–15μm in both coordinates, low material budget <1%X{sub 0}, and the ability to withstand a background hit rate of several tens of MHz/cm{sup 2}. Thanks to an intense R and D program the development of Deep NWell CMOS MAPS (with the ST Microelectronics 130 nm process) has reached a good level of maturity and allowed for the first time the implementation of thin CMOS sensors with similar functionalities as in hybrid pixels, such as pixel-level sparsification and fast time stamping. Further MAPS performance improvements are currently under investigation with two different approaches: the INMAPS CMOS process, featuring a quadruple well and a high resistivity substrate, and 3D CMOS MAPS, realized with vertical integration technology. In both cases specific features of the processes chosen can improve charge collection efficiency, with respect to a standard DNW MAPS design, and allow to implement a more complex in-pixel logic in order to develop a faster readout architecture. Prototypes of MAPS matrix, suitable for application in the SuperB Layer0, have been realized with the INMAPS 180 nm process and the 130 nm Chartered/Tezzaron 3D process and results of their characterization will be presented in this paper.

  16. Advances in the development of pixel detector for the SuperB Silicon Vertex Tracker

    Energy Technology Data Exchange (ETDEWEB)

    Paoloni, E., E-mail: eugenio.paoloni@pi.infn.it [Università degli Studi di Pisa (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (Italy); Comotti, D. [Università degli Studi di Bergamo (Italy); Manghisoni, M.; Re, V.; Traversi, G. [Università degli Studi di Bergamo (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pavia (Italy); Fabbri, L.; Gabrielli, A. [Università degli Studi di Bologna (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy); Giorgi, F.; Pellegrini, G.; Sbarra, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy); Semprini-Cesari, N.; Valentinetti, S.; Villa, M.; Zoccoli, A. [Università degli Studi di Bologna (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy); Berra, A.; Lietti, D.; Prest, M. [Università dell' Insubria, Como (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca (Italy); Bevan, A. [School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom); Wilson, F. [STFC Rutherford Appleton Laboratory, Harwell, Oxford Didcot OX11 0QX (United Kingdom); Beck, G. [School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom); and others

    2013-12-11

    The latest advances in the design and characterization of several pixel sensors developed to satisfy the very demanding requirements of the innermost layer of the SuperB Silicon Vertex Tracker will be presented in this paper. The SuperB machine is an electron positron collider operating at the ϒ(4S) peak to be built in the very near future by the Cabibbo Lab consortium. A pixel detector based on extremely thin, radiation hard devices able to cope with rate in the tens of MHz/cm{sup 2} range will be the optimal solution for the upgrade of the inner layer of the SuperB tracking system. At present several options with different levels of maturity are being investigated to understand advantages and potential issues of the different technologies: thin hybrid pixels, Deep N-Well CMOS MAPS, INMAPS CMOS MAPS featuring a quadruple well and high resistivity substrates and CMOS MAPS realized with Vertical Integration technology. The newest results from beam test, the outcomes of the radiation damage studies and the laboratory characterization of the latest prototypes will be reported.

  17. Advances in the development of pixel detector for the SuperB Silicon Vertex Tracker

    International Nuclear Information System (INIS)

    Paoloni, E.; Comotti, D.; Manghisoni, M.; Re, V.; Traversi, G.; Fabbri, L.; Gabrielli, A.; Giorgi, F.; Pellegrini, G.; Sbarra, C.; Semprini-Cesari, N.; Valentinetti, S.; Villa, M.; Zoccoli, A.; Berra, A.; Lietti, D.; Prest, M.; Bevan, A.; Wilson, F.; Beck, G.

    2013-01-01

    The latest advances in the design and characterization of several pixel sensors developed to satisfy the very demanding requirements of the innermost layer of the SuperB Silicon Vertex Tracker will be presented in this paper. The SuperB machine is an electron positron collider operating at the ϒ(4S) peak to be built in the very near future by the Cabibbo Lab consortium. A pixel detector based on extremely thin, radiation hard devices able to cope with rate in the tens of MHz/cm 2 range will be the optimal solution for the upgrade of the inner layer of the SuperB tracking system. At present several options with different levels of maturity are being investigated to understand advantages and potential issues of the different technologies: thin hybrid pixels, Deep N-Well CMOS MAPS, INMAPS CMOS MAPS featuring a quadruple well and high resistivity substrates and CMOS MAPS realized with Vertical Integration technology. The newest results from beam test, the outcomes of the radiation damage studies and the laboratory characterization of the latest prototypes will be reported

  18. 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

  19. The Silicon Vertex Detector for b-tagging at Belle II

    International Nuclear Information System (INIS)

    Valentan, M.

    2013-01-01

    The Belle experiment at KEK (Tsukuba, Japan) was successfully operated from 1999 until 2010 and confirmed the theoretical predictions of CP violation. In order to increase the beam intensity, a major upgrade of the KEKB collider is foreseen until 2015. The final goal is to reach a luminosity of 8 x 10 35 cm -2 s -1 , which is about 40 times higher than the previous peak value. This also implies changes to the Belle detector and its innermost tracking subdetector, the SVD (Silicon Vertex Detector), in particular. The SVD will be completely replaced, as it had already operated close to its limits in the past. All other subsystems will also be upgraded. This leads to the new Belle II experiment. The aim of Belle II is to search for deviations from the Standard Model of particle physics by providing extremely precise measurements of rare particle decays, thus representing a complementary approach to the direct searches performed at high energy hadron colliders. The upgraded SuperKEKB machine will collide electrons and positrons at the center-of-mass energy of excited states of the Y-particle, which hereafter decays to a B meson and its anti-particle. The decay vertices of these mesons have to be precisely measured by the Belle II SVD, together with the PXD (PiXel Detector) and the CDC (Central Drift Chamber). This allows the measurement of time-dependent, mixing-induced CP asymmetry. In addition, the SVD measures vertex information in other decay channels involving D meson and tau lepton decays. Since the collision energy is quite low (around 10 GeV), the emerging particles have low momentum and are subject to strong multiple scattering when traversing material. Therefore, all sensors of the Belle II SVD have to be optimised in terms of material thickness, while preserving high signal yield and position measurement accuracy. This will be possible by the development of thin, double-sided silicon microstrip sensors. This PhD thesis includes the physics motivation for

  20. Recent progress in sensor- and mechanics-R and D for the Belle II Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Bergauer, T., E-mail: thomas.bergauer@oeaw.ac.at [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria); Doljeschi, P.; Frankenberger, A.; Friedl, M.; Gfall, I.; Irmler, C. [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria); Onuki, Y. [University of Tokyo, Department of Physics, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Smiljic, D. [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria); Tsuboyama, T. [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Valentan, M. [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria)

    2013-08-01

    The Belle experiment at the KEKB electron/positron collider in Tsukuba (Japan) was successfully running for more than ten years. A major update of the machine to SuperKEKB is now foreseen until 2015, aiming a peak luminosity which is 40 times the peak value of the previous system. This also requires a redesign of the Belle detector (leading to Belle II) and especially its Silicon Vertex Detector (SVD), which surrounds the beam pipe. The future Belle II SVD will consist of four layers of double-sided silicon strip sensors based on 6 in. silicon wafers. Three of the four layers will be equipped with trapezoidal sensors in the slanted forward region. Moreover, two inner layers with pixel detectors based on DEPFET technology will complement the SVD as innermost detector. Since the KEKB-factory operates at relatively low energy, material inside the active volume has to be minimized in order to reduce multiple scattering. This can be achieved by arranging the sensors in the so-called “Origami chip-on-sensor concept”, and a very light-weight mechanical support structure made from carbon fiber reinforced Airex foam. Moreover, CO{sub 2} cooling for the front-end chips will ensure high efficiency at minimum material budget. In this paper, an overview of the future Belle II SVD design will be given, covering the silicon sensors, the readout electronics and the mechanics. A strong emphasis will be given to our R and D work on double-sided sensors where different p-stop layouts for the n-side of the detectors were compared. Moreover, this paper gives updated numbers for the mechanical dimensions of the ladders and their radii.

  1. Recent progress in sensor- and mechanics-R and D for the Belle II Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Bergauer, T.; Doljeschi, P.; Frankenberger, A.; Friedl, M.; Gfall, I.; Irmler, C.; Onuki, Y.; Smiljic, D.; Tsuboyama, T.; Valentan, M.

    2013-01-01

    The Belle experiment at the KEKB electron/positron collider in Tsukuba (Japan) was successfully running for more than ten years. A major update of the machine to SuperKEKB is now foreseen until 2015, aiming a peak luminosity which is 40 times the peak value of the previous system. This also requires a redesign of the Belle detector (leading to Belle II) and especially its Silicon Vertex Detector (SVD), which surrounds the beam pipe. The future Belle II SVD will consist of four layers of double-sided silicon strip sensors based on 6 in. silicon wafers. Three of the four layers will be equipped with trapezoidal sensors in the slanted forward region. Moreover, two inner layers with pixel detectors based on DEPFET technology will complement the SVD as innermost detector. Since the KEKB-factory operates at relatively low energy, material inside the active volume has to be minimized in order to reduce multiple scattering. This can be achieved by arranging the sensors in the so-called “Origami chip-on-sensor concept”, and a very light-weight mechanical support structure made from carbon fiber reinforced Airex foam. Moreover, CO 2 cooling for the front-end chips will ensure high efficiency at minimum material budget. In this paper, an overview of the future Belle II SVD design will be given, covering the silicon sensors, the readout electronics and the mechanics. A strong emphasis will be given to our R and D work on double-sided sensors where different p-stop layouts for the n-side of the detectors were compared. Moreover, this paper gives updated numbers for the mechanical dimensions of the ladders and their radii

  2. CATS: a cellular automaton for tracking in silicon for the HERA-B vertex detector

    International Nuclear Information System (INIS)

    Abt, I.; Emeliyanov, D.; Kisel, I.; Masciocchi, S.

    2002-01-01

    The new track reconstruction program CATS developed for the Vertex Detector System of the HERA-B experiment at DESY is presented. It employs a cellular automaton for track searching and the Kalman filter for track fitting. This results in a very fast algorithm that combines highly efficient track recognition with accurate and reliable track parameter estimation. To reduce the computational cost of the fit an optimized numerical implementation of the Kalman filter is used. Alternative approaches to the track reconstruction in the VDS are also discussed. Since 1999, after extensive tests on simulated data, CATS has been employed to reconstruct experimental data collected in HERA-B. Results regarding tracking performance, the accuracy of track parameter estimates and CPU time consumption are presented

  3. Production of high energy {eta}' in B meson decays from BaBar experiment; Etude de la production de {eta}' de haute impulsion dans les desintegrations du meson B dans l'experience BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Hicheur, A

    2003-04-01

    The work presented in this thesis relies on the analysis of data collected between october 1999 and July 2002 by the BaBar experiment at the PEP-II collider located at SLAC (Stanford, California). Electron-positron collisions at a center of mass energy equal to the {upsilon}(4S) resonance mass are used for the production of B meson pairs. In July 2001, the BaBar collaboration published the first measurement of CP violation in the neutral B mesons system. Since then, the precision of the measurement has been continually being improved with the increasing data sample. Two devices are dedicated to the reconstruction of charged particles: the Silicon Vertex Tracker and the Drift Chamber. The Silicon Vertex Tracker is crucial for the reconstruction of the B meson decay vertex. Its motion with regard to the Drift Chamber needs a rolling calibration of the corresponding alignment parameters roughly every two hours. The relation between the Drift Chamber geometry and the alignment has been studied. Beside CP violation, Heavy Flavour Physics is an other important issue of BaBar research program. Rare decays are of particular interest as they are sensible to a new physics beyond the Standard Model. The production of high energy {eta}' in B decays has been studied through the two main contributions, B{yields} {eta}' X{sub s} coming from the rare decay b {yields} sg*, and B-bar{sup 0} {yields} {eta}'D{sup 0} coming from the internal tree color suppressed decay b {yields} cud. The improvement of the measurement of the process B {yields} {eta}'X-s and the first. observation of the decay B-bar{sup 0} {yields} {eta}'D{sup 0} have led to the conclusion that the {eta}' production is dominated by the decay b {yields} sg* and enables to constrain its quark content. (author)

  4. 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...

  5. Recent results of BABAR

    International Nuclear Information System (INIS)

    Bernard, D.

    2001-01-01

    The BABAR detector at SLAC's PEP-II storage ring has collected data amounting to about 30.4 fb -1 until june 2001. Results on CP violation, and in particular search for direct CP violation, and measurement of rare B decays are presented

  6. Evaluation of the data of the HERA-B vertex detector with regards to the physical properties of the applied silicon strip counters

    International Nuclear Information System (INIS)

    Wagner, W.

    1999-01-01

    The HERA-B experiment at the DESY laboratory in Hamburg is dedicated to measuring CP-violation in the decays of neutral B-mesons. The primary purpose of the experiment in the measurement of the CP-asymmetry in the decay channel B 0 → J/ψK S 0 . In order to identify the B-mesons and to determine the time-dependent asymmetry, the decay length anti Δ anti l of the B-mesons must be measured to an accuracy of σ Δl ≤ 500 μm. To achieve this aim, HERA-B has a vertex detector which is based on double-sided silicon strip detectors mounted in a Roman pot system. One important specification of the vertex detector is to allow independent tracking with an efficiency above 95%. Therefore, it is required to select hits on the strip detectors with an efficiency above 99% and optimize the suppression of noise. This thesis describes a detailed investigation of the behaviour of the silicon strip detectors used in the vertex detector. The first part presents measurements performed in the laboratory using a tunable infrared dye laser to simulate the passage of charged particles through the detector. This includes measurements of the charge division between adjacent readout strips and mapping of the detector depletion. The results of the measurements agree excellently with the predictions from a detailed model calculation carried out in this thesis. The second part of the thesis the analysis of data recorded with the HERA-B vertex detector during the commissioning run of spring 1999. The analysis focusses on the investigation of cluster shapes and cluster sizes. In particular, the dependence of these distributions from the selection cuts is analyzed. Additionally, the differences between the two detector designs used, p-spray and p-stop detectors with intermediate strip or without respectively, are worked out. The measured distributions agree very well with the predictions from a model calculation taking all relevant detector parameters into account. The results of the data

  7. Design and development of a vertex reconstruction for the CMS (Compact Muon Solenoid) data. Study of gaseous and silicon micro-strips detectors (MSGC)

    International Nuclear Information System (INIS)

    Moreau, St.

    2002-12-01

    The work presented in this thesis has contributed to the development of the Compact Muon Solenoid detector (CMS) that will be installed at the future Large Hadron Collider (LHC) which will start running in summer 2007. This report is organised in three parts: the study of gaseous detectors and silicon micro-strips detectors, and a development of a software for the reconstruction and analysis of CMS data in the framework of ORCA. First, the micro-strips gaseous detectors (MSGC) study was on the ultimate critical irradiation test before their substitution in the CMS tracker. This test showed a really small number of lost anodes and a stable signal to noise ratio. This test proved that the described MSGC fulfill all the requirements to be integrated in the CMS tracker. The following contribution described a study of silicon micro-strips detectors and its electronics exposed to a 40 MHz bunched LHC like beam. These tests indicated a good behaviour of the data acquisition and control system. The signal to noise ratio, the bunch crossing identification and the cluster finding efficiency had also be analysed. The last study concern the design and the development of an ORCA algorithm dedicates to secondary vertex reconstruction. This iterative algorithm aims to be use for b tagging. This part analyse also primary vertex reconstruction in events without and with pile up. (author)

  8. Recent BABAR Results

    Energy Technology Data Exchange (ETDEWEB)

    Eigen, Gerald [University of Bergen, Bergen (Norway). Dept. of Physics

    2015-04-29

    We present herein the most recent BABAR results on direct CP asymmetry measurements in B → Xsγ, on partial branching fraction and CP asymmetry measurements in B → Xs+-, on a search for B → π/ηℓ+- decays, on a search for lepton number violation in B+ → X-+ℓ'+ modes and a study of B0 →ωω and B0 → ωφ decays.

  9. Vertex detectors

    International Nuclear Information System (INIS)

    Lueth, V.

    1992-07-01

    The purpose of a vertex detector is to measure position and angles of charged particle tracks to sufficient precision so as to be able to separate tracks originating from decay vertices from those produced at the interaction vertex. Such measurements are interesting because they permit the detection of weakly decaying particles with lifetimes down to 10 -13 s, among them the τ lepton and charm and beauty hadrons. These two lectures are intended to introduce the reader to the different techniques for the detection of secondary vertices that have been developed over the past decades. The first lecture includes a brief introduction to the methods used to detect secondary vertices and to estimate particle lifetimes. It describes the traditional technologies, based on photographic recording in emulsions and on film of bubble chambers, and introduces fast electronic registration of signals derived from scintillating fibers, drift chambers and gaseous micro-strip chambers. The second lecture is devoted to solid state detectors. It begins with a brief introduction into semiconductor devices, and then describes the application of large arrays of strip and pixel diodes for charged particle tracking. These lectures can only serve as an introduction the topic of vertex detectors. Time and space do not allow for an in-depth coverage of many of the interesting aspects of vertex detector design and operation

  10. The BaBar Mini

    International Nuclear Information System (INIS)

    Brown, David N.

    2003-01-01

    BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

  11. The BaBar mini

    International Nuclear Information System (INIS)

    Brown, David N.; BaBar Collaboration

    2003-01-01

    BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

  12. The First Year of the BABAR Experiment at PEP-II

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Barbara

    2000-12-18

    The BABAR detector, situated at the SLAC PEP-II asymmetric e{sup +}e{sup -} collider, has been recording data at energies on and around the {Upsilon}(4S) resonance since May 1999. In this paper, we briefly describe the PEP-II B Factory and the BABAR detector. The performance presently achieved by the experiment in the areas of tracking, vertexing, calorimetry and particle identification is reviewed. Analysis concepts that are used in the various papers submitted to this conference are also discussed.

  13. Charm Decays at BABAR

    International Nuclear Information System (INIS)

    Charles, M.

    2004-01-01

    The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D 0 → l + l - are presented and new upper limits on these processes are established. Second, a measurement of the branching fraction of the isospin-violating hadronic decay D* s (2112) + → D s + π 0 relative to the radiative decay D* s (2112) + → D s + γ is made. Third, the decays of D* sJ (2317) + and D sJ (2460) + mesons are studied and ratios of branching fractions are measured. Fourth, Cabibbo-suppressed decays of the Λ c + are examined and their branching fractions measured relative to Cabibbo-allowed modes. Fifth, the Χ c 0 is studied through its decays to Χ - π + and (Omega) - K + ; in addition to measuring the ratio of branching fractions for Χ c 0 produced from the c(bar c) continuum, the uncorrected momentum spectrum is measured, providing clear confirmation of Χ c 0 production in B decays

  14. A time-based front-end ASIC for the silicon micro strip sensors of the P-bar ANDA Micro Vertex Detector

    International Nuclear Information System (INIS)

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

    2016-01-01

    The P-bar ANDA (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 ( P-bar ANDA 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

  15. 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.

  16. Silicon PIN diode hybrid arrays for charged particle detection: Building blocks for vertex detectors at the SSC

    International Nuclear Information System (INIS)

    Kramer, G.; Gaalema, S.; Shapiro, S.L.; Dunwoodie, W.M.; Arens, J.F.; Jernigan, J.G.

    1989-05-01

    Two-dimensional arrays of solid state detectors have long been used in visible and infrared systems. Hybrid arrays with separately optimized detector and readout substrates have been extensively developed for infrared sensors. The characteristics and use of these infrared readout chips with silicon PIN diode arrays produced by MICRON SEMICONDUCTOR for detecting high-energy particles are reported. Some of these arrays have been produced in formats as large as 512 /times/ 512 pixels; others have been radiation hardened to total dose levels beyond 1 Mrad. Data generation rates of 380 megasamples/second have been achieved. Analog and digital signal transmission and processing techniques have also been developed to accept and reduce these high data rates. 9 refs., 15 figs., 2 tabs

  17. Measurements of hadronic B decays to excited-charm mesons, observation of a new charm resonance and construction of a silicon vertex detector for CLEO II.V

    Science.gov (United States)

    Nelson, Timothy Knight

    We describe measurements of the branching ratiosmath> B(B --->D*+p- p-total) =(29.2+/-4.5+/-3.8+/-3.1) ×10-4 B(B- --> D*+p- p -non- res)=( 9.7+/-3.6+/-1.5+/-1.9)× 10- 4 B(B---> D1(2420) 0p-) B(D1( 2420)0--> D*+p- )= (6.9+1.8-1.4 +/-1.1+/-0.4)× 10-4 B(B---> D01( j= / )p- ) B(D01 (j= /) -->D* +p-) = ( 10.6+/-1.9+/-1.7+/-2.3)× 10-4 B(B---> D*2( 2460)0p- )B(D *2( 2460)0--> D*+p- )= (3.1+/- 0.84+/-0.46+/-0.28)×10 -4, using data collected by the CLEO II detector. These measurements provide the first observation of the D01(j=/) with a mass and width of 2.461+0.053- 0.049GeV and 290+110 - 91MeV respectively. The mixing angles between the partial waves and strong phase shifts among the resonances are also measured assuming one possible parameterization of the amplitude. A method allowing full reconstruction of the signal without reconstruction of the D meson in the final state is used. The measurements are extracted using an four-dimensional, unbinned, maximum- likelihood fit to the distributions of the D*+p- mass and the decay angles. The primary element of the CLEO II.V upgrade was the installation of a three-layer Silicon Vertexing Detector. The design and construction of this detector are described in detail.

  18. Design and development of a vertex reconstruction for the CMS (Compact Muon Solenoid) data. Study of gaseous and silicon micro-strips detectors (MSGC); Conception d'un algorithme de reconstruction de vertex pour les donnees de CMS. Etude de detecteurs gazeux (MSGC) et silicium a micropistes

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, St

    2002-12-01

    The work presented in this thesis has contributed to the development of the Compact Muon Solenoid detector (CMS) that will be installed at the future Large Hadron Collider (LHC) which will start running in summer 2007. This report is organised in three parts: the study of gaseous detectors and silicon micro-strips detectors, and a development of a software for the reconstruction and analysis of CMS data in the framework of ORCA. First, the micro-strips gaseous detectors (MSGC) study was on the ultimate critical irradiation test before their substitution in the CMS tracker. This test showed a really small number of lost anodes and a stable signal to noise ratio. This test proved that the described MSGC fulfill all the requirements to be integrated in the CMS tracker. The following contribution described a study of silicon micro-strips detectors and its electronics exposed to a 40 MHz bunched LHC like beam. These tests indicated a good behaviour of the data acquisition and control system. The signal to noise ratio, the bunch crossing identification and the cluster finding efficiency had also be analysed. The last study concern the design and the development of an ORCA algorithm dedicates to secondary vertex reconstruction. This iterative algorithm aims to be use for b tagging. This part analyse also primary vertex reconstruction in events without and with pile up. (author)

  19. Vertex reconstruction in CMS

    International Nuclear Information System (INIS)

    Chabanat, E.; D'Hondt, J.; Estre, N.; Fruehwirth, R.; Prokofiev, K.; Speer, T.; Vanlaer, P.; Waltenberger, W.

    2005-01-01

    Due to 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-squares methods, robustifications of the classical algorithms 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

  20. 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.

  1. BaBar Physics Book

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Helen

    1998-11-04

    This book presents the results of a year-long workshop devoted to a review of the physics opportunities of the BABAR experiment at the PEP-II B Factory, at the Stanford Linear Accelerator Center laboratory. The workshop brought together a number of theorists with experimentalists from the BABAR Collaboration. Each chapter represents the contribution of a working group and presents both a theoretical summary of the relevant topics and the results of related simulation studies. The working group convenors, listed below, were teams that included both theorists and experimentalists. The book represents the status of work around the beginning of 1998. Both the state of the theory and of the experiment's simulation and analysis tools continue to advance. The results presented here are thus not a final view of what the experiment can achieve, but represent an interim study. The studies are more detailed and comprehensive than those made at the time of the Technical Design Report, but still lack many features that will be needed for the real data analysis. The book is intended as a guide to the work that still needs to be done, and as a detailed introduction which will assist new members, joining the Collaboration, and, we hope, other researchers in the field.

  2. BaBar Data Aquisition

    CERN Document Server

    Scott, I; Grosso, P; Hamilton, R T; Huffer, M E; O'Grady, C; Russell, J J

    1998-01-01

    The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by analysing the decays of a very large sample of B and Bbar mesons produced at the high luminosity PEP-11 accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detector subsystems. Data from the front end electronics is read into commercial VME processors via a custom "personality card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data are read out via a non-blocking network switch to a farm of commercial UNIX processors. Careful design of the core data acquisition code has enabled us to sustain events rates in excess of 20 kHz while maintaini...

  3. BaBar Physics Book

    International Nuclear Information System (INIS)

    Quinn, Helen

    1998-01-01

    This book presents the results of a year-long workshop devoted to a review of the physics opportunities of the BABAR experiment at the PEP-II B Factory, at the Stanford Linear Accelerator Center laboratory. The workshop brought together a number of theorists with experimentalists from the BABAR Collaboration. Each chapter represents the contribution of a working group and presents both a theoretical summary of the relevant topics and the results of related simulation studies. The working group convenors, listed below, were teams that included both theorists and experimentalists. The book represents the status of work around the beginning of 1998. Both the state of the theory and of the experiment's simulation and analysis tools continue to advance. The results presented here are thus not a final view of what the experiment can achieve, but represent an interim study. The studies are more detailed and comprehensive than those made at the time of the Technical Design Report, but still lack many features that will be needed for the real data analysis. The book is intended as a guide to the work that still needs to be done, and as a detailed introduction which will assist new members, joining the Collaboration, and, we hope, other researchers in the field

  4. Tracking and vertexing with the ATLAS detector at the LHC

    International Nuclear Information System (INIS)

    Hirsch, F.

    2011-01-01

    The Inner Detector of the ATLAS experiment at the Large Hadron Collider at CERN contains three tracking systems: The silicon Pixel Detector, the Silicon Microstrip Tracker and the Transition Radiation Tracker. In combination these detectors provide excellent track and vertex reconstruction efficiencies and resolutions. This paper describes studies which show the performance of track and vertex reconstruction on data collected at 7 TeV center-of-mass energy.

  5. BABAR

    DEFF Research Database (Denmark)

    Andersson, Per; Köpsén, Susanne; Gross, Marin

    This report presents the results from a comparative study of the qualification of adult educators in the Nordic-Baltic region. The study involved Denmark, Estonia and Sweden. The rationale behind the study is a growing interest in adult education resulting from a focus on lifelong learning in the...

  6. Using Grid for the BABAR Experiment

    International Nuclear Information System (INIS)

    Bozzi, C.

    2005-01-01

    The BaBar experiment has been taking data since 1999. In 2001 the computing group started to evaluate the possibility to evolve toward a distributed computing model in a grid environment. We built a prototype system, based on the European Data Grid (EDG), to submit full-scale analysis and Monte Carlo simulation jobs. Computing elements, storage elements, and worker nodes have been installed at SLAC and at various European sites. A BaBar virtual organization (VO) and a test replica catalog (RC) are maintained in Manchester, U.K., and the experiment is using three EDG testbed resource brokers in the U.K. and in Italy. First analysis tests were performed under the assumption that a standard BaBar software release was available at the grid target sites, using RC to register information about the executable and the produced n-tuples. Hundreds of analysis jobs accessing either Objectivity or Root data files ran on the grid. We tested the Monte Carlo production using a farm of the INFN-grid testbed customized to install an Objectivity database and run BaBar simulation software. First simulation production tests were performed using standard Job Description Language commands and the output files were written on the closest storage element. A package that can be officially distributed to grid sites not specifically customized for BaBar has been prepared. We are studying the possibility to add a user friendly interface to access grid services for BaBar

  7. 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.

  8. 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...

  9. The design and performance of the ZEUS micro vertex detector

    International Nuclear Information System (INIS)

    Polini, A.; Brock, I.; Goers, S.

    2007-08-01

    In order to extend the tracking acceptance, to improve the primary and secondary vertex reconstruction and thus enhancing the tagging capabilities for short lived particles, the ZEUS experiment at the HERA Collider at DESY installed a silicon strip vertex detector. The barrel part of the detector is a 63 cm long cylinder with silicon sensors arranged around an elliptical beampipe. The forward part consists of four circular shaped disks. In total just over 200k channels are read out using 2.9 m 2 of silicon. In this report a detailed overview of the design and construction of the detector is given and the performance of the completed system is reviewed. (orig.)

  10. The LHCb VERTEX LOCATOR performance and VERTEX LOCATOR upgrade

    International Nuclear Information System (INIS)

    Rodríguez Pérez, P

    2012-01-01

    LHCb is an experiment dedicated to the study of new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The Vertex Locator (VELO) is the silicon detector surrounding the LHCb interaction point. The detector operates in a severe and highly non-uniform radiation environment. The small pitch and analogue readout result in a best single hit precision of 4 μm. The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a trigger-less system operating at 40 MHz event rate. The vertex detector will have to cope with radiation levels up to 10 16 1 MeVn eq /cm 2 , more than an order of magnitude higher than those expected at the current experiment. A solution is under development with a pixel detector, based on the Timepix/Medipix family of chips with 55 x 55 μm pixels. In addition a micro-strip solution is also under development, with finer pitch, higher granularity and lower mass than the current detector. The current status of the VELO will be described together with recent testbeam results.

  11. Vertical integration technologies for vertex detectors

    International Nuclear Information System (INIS)

    Ratti, L.

    2011-01-01

    This work is focused on the use of vertical integration (3D) technologies in the design of hybrid or monolithic pixel detectors in view of applications to silicon vertex trackers (SVTs) at the future high luminosity colliders. After a short introduction on the specifications of next-generation SVTs, the paper will discuss the general features of 3D microelectronic processes and the benefits they can provide to the design of pixel detectors for high energy physics experiments.

  12. Performance of the babar-dirc

    International Nuclear Information System (INIS)

    Schwiening, Jochen; Babar-DIRC Collaboration

    2005-01-01

    A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for Detection of Internally Reflected Cherenkov (Light). This paper describes the performance of the DIRC during the first 5 years of operation

  13. The BaBar electromagnetic calorimeter

    CERN Document Server

    Lewandowski, B

    2002-01-01

    The BaBar electromagnetic calorimeter is a hermetic, total-absorption array of CsI(Tl)-crystals, operated at the asymmetric e sup - e sup + -collider PEP-II at SLAC. The design and the status of the performance as of February 2002 is presented.

  14. Rare B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Datta, M

    2005-03-14

    The authors present recent results on rare B meson decays based on data taken by the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} collider. Included in this report are measurements of branching fractions and other quantities of interest for several hadronic, radiative, electroweak, and purely leptonic decays of B mesons.

  15. Measurement of the angle alpha at BABAR

    International Nuclear Information System (INIS)

    Perez, A.

    2009-01-01

    The authors present recent measurements of the CKM angle α using data collected by the BABAR detector at the PEP-II asymmetric-energy e + e - collider at the SLAC National Accelerator Laboratory, operating at the Υ(4S) resonance. They present constraints on α from B → ππ, B → ρρ and B → ρπ decays.

  16. The BaBar Light Pulser System

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P

    2004-03-18

    The BABAR experiment and the PEP-II e{sup +}e{sup -} collider at SLAC in California started taking data in May 1999. The aim of the experiment is to study CP violation in the B meson system. A central part of the BABAR detector is the CsI(Tl) electromagnetic calorimeter. To make precision measurements with a calorimeter in a high luminosity environment requires that the crystals are well calibrated and continually monitored for radiation damage. However, this should not impact the total integrated luminosity. To achieve this goal a fiber-optic light pulser system was designed. The light sources chosen were xenon flash lamps. A novel light distribution method was developed using an array of graded index microlenses. Initial results from performance studies are presented.

  17. CORBA Evaluations for the BABAR Online System

    International Nuclear Information System (INIS)

    Glanzman, Thomas

    1998-01-01

    The Common Object Request Broker Architecture (CORBA) is a software system to deal with distributed object computing. The release of CORBA version 2, and real implementations from numerous vendors (both freeware and payware) have made its use very attractive for interprocess and interprocessor communication within an object-oriented software system. A number of object request brokers (ORBs) were evaluated for possible use within the BABAR Online system. Given an expectation for a reasonable level of performance within the Online system, it was essential to characterize the behavior and test the response of these products prior to their adoption. This paper summarizes the results of a systematic performance study of six ORB products. The products tested include: Visibroker, Orbix, DAIS, Omnibroker, OmniORB2, and TAO. Performance results of ORB products, including a test of TCP/IP sockets, are compared. These tests resulted in the adoption of the TAO ORB for use within the BABAR Online system

  18. The BaBar Data Acquisition System

    CERN Document Server

    Scott, I; Grosso, P; Huffer, M E; O'Grady, C; Russell, J J

    1999-01-01

    The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by ana-lyzing the decays of a very large sample of B and B(Bar) mesons produced at the high luminosity PEP-II accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detec-tor subsystems. Data from the front end electronics is read into commercial VME processors via a custom "Personality Card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data is read out via a non-blocking network switch to a farm of commercial UNIX processors. The current implementation of the BaBar data acquisition sys-tem has been shown to sustain a Level 1 trigger rate of 1.3...

  19. Vertex routing models

    International Nuclear Information System (INIS)

    Markovic, D; Gros, C

    2009-01-01

    A class of models describing the flow of information within networks via routing processes is proposed and investigated, concentrating on the effects of memory traces on the global properties. The long-term flow of information is governed by cyclic attractors, allowing to define a measure for the information centrality of a vertex given by the number of attractors passing through this vertex. We find the number of vertices having a nonzero information centrality to be extensive/subextensive for models with/without a memory trace in the thermodynamic limit. We evaluate the distribution of the number of cycles, of the cycle length and of the maximal basins of attraction, finding a complete scaling collapse in the thermodynamic limit for the latter. Possible implications of our results for the information flow in social networks are discussed.

  20. Jet Vertex Charge Reconstruction

    CERN Document Server

    Nektarijevic, Snezana; The ATLAS collaboration

    2015-01-01

    A newly developed algorithm called the jet vertex charge tagger, aimed at identifying the sign of the charge of jets containing $b$-hadrons, referred to as $b$-jets, is presented. In addition to the well established track-based jet charge determination, this algorithm introduces the so-called \\emph{jet vertex charge} reconstruction, which exploits the charge information associated to the displaced vertices within the jet. Furthermore, the charge of a soft muon contained in the jet is taken into account when available. All available information is combined into a multivariate discriminator. The algorithm has been developed on jets matched to generator level $b$-hadrons provided by $t\\bar{t}$ events simulated at $\\sqrt{s}$=13~TeV using the full ATLAS detector simulation and reconstruction.

  1. The ARGUS vertex trigger

    International Nuclear Information System (INIS)

    Koch, N.; Kolander, M.; Kolanoski, H.; Siegmund, T.; Bergter, J.; Eckstein, P.; Schubert, K.R.; Waldi, R.; Imhof, M.; Ressing, D.; Weiss, U.; Weseler, S.

    1995-09-01

    A fast second level trigger has been developed for the ARGUS experiment which recognizes tracks originating from the interaction region. The processor compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks stored in random access memories. The masks which are fully defined in three dimensions are able to reject tracks originating in the wall of the narrow beampipe of 10.5 mm radius. (orig.)

  2. Biricodar. Vertex Pharmaceuticals.

    Science.gov (United States)

    Dey, Saibal

    2002-05-01

    Vertex is developing biricodar as a chemosensitizing agent designed to restore the effectiveness of chemotherapeutic agents in tumor multidrug resistance. By November 1998, phase II trials had commenced for biricodar, in combination with chemotherapy, for five common cancer indications: breast, ovarian, soft-tissue sarcomas, small cell lung cancer and prostate cancer. Phase II trials were ongoing in January 2002. By March 2000, Vertex was the sole developer of biricodar, as an agreement made in 1996 with BioChem Pharma (now Shire Pharmaceuticals), for the development and marketing of biricodar in Canada was terminated. Biricodar is the free base compound, which also has a citrate salt analog known as VX-710-3. Vertex has published three patents, WO-09615101, WO-09636630 and WO-09736869, disclosing derivatives of biricodar that are claimed for the treatment of multidrug resistant protein and P-glycoprotein-mediated multidrug resistant tumors. In January 2002, a Banc of America analyst report forecast that biricodar had a 30% chance of reaching the market with a launch date in the second half of 2005, with peak sales estimated at $250 million.

  3. Developments in solid state vertex detectors

    International Nuclear Information System (INIS)

    Damerell, C.J.S.

    1984-12-01

    Since the discovery of the J/psi in November 1974, there has been a strong interest in the physics of particles containing higher-flavour quarks (charm, bottom, top, ...). High precision vertex detectors can be used to identify the decay products of parent particles which have lifetimes of the order 10 -13 s. The paper surveys the progress which is being made in developing silicon detectors with the necessary tracking precision (< approx. 5 μm) to be used for this purpose in fixed target experiments and also in colliders such as SLC and LEP. (author)

  4. Vertex algebras and algebraic curves

    CERN Document Server

    Frenkel, Edward

    2004-01-01

    Vertex algebras are algebraic objects that encapsulate the concept of operator product expansion from two-dimensional conformal field theory. Vertex algebras are fast becoming ubiquitous in many areas of modern mathematics, with applications to representation theory, algebraic geometry, the theory of finite groups, modular functions, topology, integrable systems, and combinatorics. This book is an introduction to the theory of vertex algebras with a particular emphasis on the relationship with the geometry of algebraic curves. The notion of a vertex algebra is introduced in a coordinate-independent way, so that vertex operators become well defined on arbitrary smooth algebraic curves, possibly equipped with additional data, such as a vector bundle. Vertex algebras then appear as the algebraic objects encoding the geometric structure of various moduli spaces associated with algebraic curves. Therefore they may be used to give a geometric interpretation of various questions of representation theory. The book co...

  5. Hadronic Physics Studies at BaBar

    International Nuclear Information System (INIS)

    Stroili, R.

    2006-01-01

    A new resonance Y(4260) with a mass of 4259 ± 8 -6 +2 MeV/c 2 and J PC = 1 -- , discovered by the BaBar experiment shows peculiar behavior in his decay mode. The Λ c + baryon mass has been measured, using its decays to ΛK S 0 K + and Σ 0 K S 0 K + , and its value is 2286.46 ± 0.14 MeV/c 2 , the precision is greatly improved w.r.t. PDG value. Ξ c 0 and (Omega) c 0 decays and production have been studied with results greatly improved w.r.t. PDG

  6. Managing the BABAR Object Oriented Database

    International Nuclear Information System (INIS)

    Hasan, Adil

    2002-01-01

    The BaBar experiment stores its data in an Object Oriented federated database supplied by Objectivity/DB(tm). This database is currently 350TB in size and is expected to increase considerably as the experiment matures. Management of this database requires careful planning and specialized tools in order to make the data available to physicists in an efficient and timely manner. We discuss the operational issues and management tools that were developed during the previous run to deal with this vast quantity of data at SLAC

  7. Strong Interactions Physics at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Pioppi, M.

    2005-03-14

    Recent results obtained by BABAR experiment and related to strong interactions physics are presented, with particular attention to the extraction of the first four hadronic-mass moments and the first three lepton-energy moments in semileptonic decays. From a simultaneous fit to the moments, the CKM element |V{sub cb}|, the inclusive B {yields} X{sub c}lv and other heavy quark parameters are derived. The second topic is the ambiguity-free measurement of cos(2{beta}) in B {yields} J/{Psi}K* decays. With approximately 88 million of B{bar B} pairs, negative solutions for cos(2{beta}) are excluded at 89%.

  8. The design and performance of the ZEUS micro vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Polini, A. [Bologna Univ. (Italy)]|[INFN Bologna (Italy); Brock, I.; Goers, S. [Bonn Univ. (DE). Physikalisches Institut] (and others)

    2007-08-15

    In order to extend the tracking acceptance, to improve the primary and secondary vertex reconstruction and thus enhancing the tagging capabilities for short lived particles, the ZEUS experiment at the HERA Collider at DESY installed a silicon strip vertex detector. The barrel part of the detector is a 63 cm long cylinder with silicon sensors arranged around an elliptical beampipe. The forward part consists of four circular shaped disks. In total just over 200k channels are read out using 2.9 m{sup 2} of silicon. In this report a detailed overview of the design and construction of the detector is given and the performance of the completed system is reviewed. (orig.)

  9. Preliminary studies for the LHCb vertex detector vacuum system

    CERN Document Server

    Doets, M; Van Bakel, N; Van den Brand, J F J; van den Brand, Jo

    2000-01-01

    We lay down some general considerations which will serve as a starting point for design studies of a realistic LHCb vertex detector vacuum system. Based on these considerations, we propose a design strategy and identify issues to be further studied. In particular we try to outline some boundary conditions imposed by LHC and LHCb on the vacuum system. We discuss two possibilities for the LHCb vertex detector vacuum system. The preferred strategy uses a differentially pumped vacuum system with the silicon detectors separated from the beam line vacuum. Some estimations on static vacuum pressures and gas flows are presented.

  10. 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...

  11. The three-photon vertex

    International Nuclear Information System (INIS)

    Delbourgo, R.

    1976-01-01

    Owing to weak interactions, the three-photon vertex is non-zero. From gauge invariance and symmetry requirements, it is proved that the C = -1P = - 1 vertex amplitudes are at least of order q 7 in the limit of soft photon momentum q and that if any two photons are placed on mass shell the form factors vanish identically. (author)

  12. Results in Charm Physics from BABAR Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pompili, A

    2004-06-03

    Recent measurements in the charm sector at BABAR are reviewed. The scope of the presentation includes the observation of two new narrow mesons in the D{sub s}{sup +}{pi}{sup 0} and D{sub s}{sup +}{pi}{sup 0}{gamma} final states as well as the measurement of D{sup 0}-{bar D}{sup 0} mixing parameters by means of two methods: using the doubly-Cabibbo-suppressed D{sup 0} decay to K{sup +}{pi}{sup -} and using the ratios of lifetimes extracted from samples of D{sup 0} mesons decaying to K{sup -} {pi}{sup +}, K{sup -}K{sup +}, and {pi}{sup -}{pi}{sup +}.

  13. BABAR Experiment Status and Recent Results

    Energy Technology Data Exchange (ETDEWEB)

    De Nardo, G.

    2004-10-04

    The BaBar detector at SLAC PEP-II asymmetric B-Factory has collected between 1999 and 2002 a data sample of 88 millions {Upsilon}(4S) {yields} B{bar B} decays. We present here recent measurements of branching fractions and time-dependent CP-violating asymmetries of neutral B mesons decays to several CP eigenstates. We present the results on the decays to (c{bar c}) K{sub S}{sup 0}/K{sub L}{sup 0}, which are related in the Standard Model to the angle {beta} of the Unitarity Triangle of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Moreover we present the branching fractions and the CP-asymmetries of charmless two body decays related to the angle {alpha}.

  14. Track and Vertex Reconstruction in the ATLAS Experiment

    CERN Document Server

    Lacuesta, V; The ATLAS collaboration

    2012-01-01

    The track and vertex reconstruction algorithms of the ATLAS Inner Detector have demonstrated excellent performance in the early data from the LHC. However, the rapidly increas- ing number of interactions per bunch crossing introduces new challenges both in computational aspects and physics performance. The combination of both silicon and gas based detectors provides high precision impact parameter and momentum measurement of charged particles, with high efficiency and small fake rate. Vertex reconstruction is used to identify with high efficiency the hard scattering process and to measure the amount of pile-up interactions, both aspects are cru- cial for many physics analyses. The performance of track and vertex reconstruction efficiency and resolution achieved in the 2011 and 2012 data-taking period are presented.

  15. Track and Vertex Reconstruction in the ATLAS Experiment

    CERN Document Server

    Lacuesta, V; The ATLAS collaboration

    2012-01-01

    The track and vertex reconstruction algorithms of the ATLAS Inner Detector have demonstrated excellent performance in the early data from the LHC. However, the rapidly increas- ing number of interactions per bunch crossing introduces new challenges both in computational aspects and physics performance. The combination of both silicon and gas based detectors pro- vides high precision impact parameter and momentum measurement of charged particles, with high efficiency and small fake rate. Vertex reconstruction is used to identify with high efficiency the hard scattering process and to measure the amount of pile-up interactions, both aspects are cru- cial for many physics analyses. The performance of track and vertex reconstruction efficiency and resolution achieved in the 2011 and 2012 data-taking period are presented.

  16. Track and vertex reconstruction in the ATLAS experiment

    International Nuclear Information System (INIS)

    Lacuesta, V

    2013-01-01

    The track and vertex reconstruction algorithms of the ATLAS Inner Detector have demonstrated excellent performance in the early data from the LHC. However, the rapidly increasing number of interactions per bunch crossing introduces new challenges both in computational aspects and physics performance. The combination of both silicon and gas based detectors provides high precision impact parameter and momentum measurement of charged particles, with high efficiency and small fake rate. Vertex reconstruction is used to identify with high efficiency the hard scattering process and to measure the amount of pile-up interactions, both aspects are crucial for many physics analyses. The performance of track and vertex reconstruction efficiency and resolution achieved in the 2011 and 2012 data-taking period are presented.

  17. 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.

  18. 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.

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

    International Nuclear Information System (INIS)

    Damerell, C.J.S.

    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

  20. Leptonic B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  1. Leptonic B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  2. BABAR IFR Replacement R and D

    CERN Document Server

    Berry, M

    2003-01-01

    The Instrumented Flux Return (IFR) of the BaBar detector will soon need to be replaced by a more robust muon detection system. Scintillator bars with embedded Wavelength Shifting (WLS) fibers and Limited Streamer Tubes are two replacement technology options. The scintillator bars are tested for attenuation length; and causes for the large width of the Photo Multiplier Tube (PMT) signal are analyzed by Monte Carlo simulation. Cooling techniques for Avalanche Photo Diodes (APD) are investigated. The fairly high attenuation length coupled with the narrow PMT signal make the scintillator a viable option for a muon detecting system. Continuing work will focus on increasing timing resolution using an APD to read the signal from the WLS fibers, and investigating the lifetime of the APD. The ability to read a signal from the LST on external copper strips is tested and signals are found to be clearly distinguishable from noise. The voltage is compared to count rate to find that the optimal operating voltage for the LS...

  3. First CP violation results from BABAR

    International Nuclear Information System (INIS)

    Hitlin, D.G.

    2001-01-01

    We present a preliminary measurement of time-dependent Cp-violating asymmetries in B 0 → J/ψK 0 S and B 0 → ψ(2S)K 0 S decays recorded by the BABAR. detector at the PEP-2 asymmetric B Factory at SLAC. The data sample consists of 9.0 fb -1 collected at the γ(4S) resonance and 0.8 fb -1 off-resonance. One of the neutral B mesons, produced in pairs at the γ(4S), is fully reconstructed. The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The time difference between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities and the time resolution function are measured with samples of fully-reconstructed semileptonic and hadronic neutral B final states. The value of the asymmetry amplitude, sin 2β, is determined from a maximum likelihood fit to the time distribution of 120 tagged B 0 → J/ψK 0 S and B 0 → ψ(2S)K 0 S candidates: sin 2β=0.12±O.37(stat)±0.09(syst). (author)

  4. Penguin Mediated B Decays at BABAR

    CERN Document Server

    Aubert, B

    2001-01-01

    We report on preliminary results of searches for penguin mediated B decays based on 20.7 fb^{-1} of data collected at the Y(4S) peak with the BABAR detector at PEP-II. The following branching fractions have been measured: BR(B+ --> phi K+) = (7.7^{+1.6}_{-1.4} +- 0.8)*10^{-6}, BR(B0 --> phi K0) = (8.1^{+3.1}_{-2.5} +- 0.8)*10^{-6}, BR(B+ --> phi K*+) = (9.7^{+4.2}_{-3.4} +- 1.7)*10^{-6}, BR(B0 --> phi K*0) = (8.7^{+2.5}_{-2.1} +- 1.1)*10^{-6}, BR(B+--> omega pi+) = (6.6^{+2.1}_{-1.8} +- 0.7)*10^{-6}, BR(B --> eta K^*0) = (19.8^{+6.5}_{-5.6} +-1.7)*10^{-6}, where the first error is statistical and the second systematic. For several other modes we report upper limits on their branching fractions; for example for the following flavor-changing neutral current decays, BR(B--> K l+ l-) K* l+ l-) < 2.5*10^{-6}, at 90% Confidence Level (C.L.).

  5. The BaBar instrumented flux return performance: lessons learned

    CERN Document Server

    Anulli, F; Baldini, R; Band, H R; Bionta, R; Brau, J E; Brigljevic, V; Buzzo, A; Calcaterra, A; Carpinelli, M; Cartaro, C; Cavallo, N; Crosetti, G; De Nardo, Gallieno; De Sangro, R; Eichenbaum, A; Fabozzi, F; Falciai, D; Ferrarotto, F; Ferroni, F; Finocchiaro, G; Forti, F; Frey, R; Gatto, C; Graug; Iakovlev, N I; Iwasaki, M; Johnson, J R; Lange, D J; Lista, L; Lo Vetere, M; Lü, C; Macri, M; Messner, R; Moore, T B; Morganti, S; Neal, H; Neri, N; Palano, A; Paoloni, E; Paolucci, P; Passaggio, S; Pastore, F C; Patteri, P; Peruzzi, I; Piccolo, D; Piccolo, M; Piredda, G; Robutti, E; Roodman, A; Santroni, A; Sciacca, C; Sinev, N B; Soha, A; Strom, D; Tosi, S; Vavra, J; Wisniewski, W J; Wright, D M; Xie, Y; Zallo, A

    2002-01-01

    The BaBar Collaboration has operated an instrumented flux return (IFR) system covering over 2000 m sup 2 with resistive plate chambers (RPCs) for nearly 3 years. The chambers are constructed of bakelite sheets separated by 2 mm. The inner surfaces are coated with linseed oil. This system provides muon and neutral hadron detection for BaBar. Installation and commissioning were completed in 1998, and operation began mid-year 1999. While initial performance of the system reached design, over time, a significant fraction of the RPCs demonstrated significant degradation, marked by increased currents and reduced efficiency. A coordinated effort of investigations have identified many of the elements responsible for the degradation. This article presents our current understanding of the aging process of the BaBar RPCs along with the action plan to combat performance degradation of the IFR system.

  6. The Mark III vertex chamber

    International Nuclear Information System (INIS)

    Adler, J.; Bolton, T.; Bunnell, K.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 μm at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 μm using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin

  7. 500 picosecond TDC for DIRC at BABAR

    International Nuclear Information System (INIS)

    Lebbolo, H.; Bailly, P.; Chauveau, J.

    1997-01-01

    A 16 channel TDC chip has been developed at LPNHE Paris, to equip the Front-End electronics of the Detector of Internally Reflected Cerenkov light (DIRC) of the BABAR experiment at the SLAC B factory (Stanford, USA). Binning is 500 picosecond, conversion time is 32 ns, with a fall range of 32 μs. The chip integrates channel buffering and selective readout of data falling within a programmable window defined by the level one trigger latency and resolution. The selective readout allows to manage random inputs at a maximum average rate of 100 kHz on each channel and makes data available at any time a trigger occurs. The maximum average rate of L1 accept trigger will be 2 kHz. The chip, housed in a 68 pin PLCC package, is designed in 0.7 μm CMOS technology and manufactured by ATMEL ES2. The TDC section and channel FIFOs are full custom designs. The TDC uses 16 independent voltage controlled digital delay lines and a 17th calibration channel which allows to tune the delays on the 59.5 MHZ reference clock. The selective readout algorithm has been synthesized from Verilog description and uses ATMEL ES2 standard cells. Die size is 36 mm2 and power less than 100 mW with all inputs fired at 100 kHZ. Prototypes test results show performances better than the specifications for the chip to be used on the DIRC detector. The ten production prototypes have been delivered mid May 1997

  8. DIRC, the internally reflecting ring imaging Cherenkov detector for BABAR

    International Nuclear Information System (INIS)

    Adam, I.; Aston, D.

    1997-11-01

    The DIRC is a new type of Cherenkov imaging device that will be used for the first time in the BABAR detector at the asymmetric B-factory, PEP-II. It is based on total internal reflection and uses long, rectangular bars made from synthetic fused silica as Cherenkov radiator and light guide. The principles of the DIRC ring imaging Cherenkov technique are explained and results from the prototype program are presented. Its choice for the BABAR detector particle identification system is motivated, followed by a discussion of the quartz radiator properties and the detector design

  9. The DIRC, the particle identification detector of BaBar

    CERN Document Server

    Yéche, C

    1999-01-01

    A novel particle identification detector (PID) has been developed for the BABAR experiment which will operate at the PEP-II B factory at SLAC. The principles of this new concept of PID called the DIRC, based on ring imaging $9 Cherenkov techniques, are briefly described. The results obtained with a large scale prototype and pion, kaon and proton beams at CERN are presented. The performances of this prototype are compared to the Monte-Carlo simulations and $9 the BABAR requirements. (4 refs).

  10. Performance-Optimization Studies for the CLIC Vertex Detector

    CERN Document Server

    AUTHOR|(CDS)2085406; Roloff, Philipp

    The Compact Linear Collider (CLIC) is a mutli-TeV linear e+e- collider currently under development at CERN. In the post-LHC era, CLIC will allow to explore a great number of searches for New Physics such as the precise measurements of the Higgs boson. In this master thesis, we mainly focus on the development and the improvement of the vertex detector. The vertex detector requires excellent spatial resolution, low mass, geometrical coverage down to low polar angles, high rate readout for the sensors and new cooling technologies for heat removal. Considering such requirements, the CLIC vertex detector technology is far more advanced in comparison to the technologies currently used in particle physics. This project consists of two main parts. In the first part, we study the vertex detector and optimize its geometry for the use of airflow cooling techniques and also for flavor tagging. In the second part, we implement a decoder which can respect the timing constraints for the CLICpix chip, a silicon pixel detect...

  11. Connections for Small Vertex Models

    Indian Academy of Sciences (India)

    This paper is a first attempt at calssifying connections on small vertex models i.e., commuting squares of the form displayed in (1.2) below. ... obtain necessary conditions for two such `model connections' in (2, ) to be ... Current Issue : Vol.

  12. A Macdonald refined topological vertex

    Science.gov (United States)

    Foda, Omar; Wu, Jian-Feng

    2017-07-01

    We consider the refined topological vertex of Iqbal et al (2009 J. High Energy Phys. JHEP10(2009)069), as a function of two parameters ≤ft\\lgroup x, y \\right\\rgroup , and deform it by introducing the Macdonald parameters ≤ft\\lgroup q, t \\right\\rgroup , as in the work of Vuletić on plane partitions (Vuletić M 2009 Trans. Am. Math. Soc. 361 2789-804), to obtain ‘a Macdonald refined topological vertex’. In the limit q → t , we recover the refined topological vertex of Iqbal et al and in the limit x → y , we obtain a qt-deformation of the original topological vertex of Aganagic et al (2005 Commun. Math. Phys. 25 425-78). Copies of the vertex can be glued to obtain qt-deformed 5D instanton partition functions that have well-defined 4D limits and, for generic values of ≤ft\\lgroup q, t\\right\\rgroup , contain infinite-towers of poles for every pole present in the limit q → t .

  13. Vertex algebras and mirror symmetry

    International Nuclear Information System (INIS)

    Borisov, L.A.

    2001-01-01

    Mirror Symmetry for Calabi-Yau hypersurfaces in toric varieties is by now well established. However, previous approaches to it did not uncover the underlying reason for mirror varieties to be mirror. We are able to calculate explicitly vertex algebras that correspond to holomorphic parts of A and B models of Calabi-Yau hypersurfaces and complete intersections in toric varieties. We establish the relation between these vertex algebras for mirror Calabi-Yau manifolds. This should eventually allow us to rewrite the whole story of toric mirror symmetry in the language of sheaves of vertex algebras. Our approach is purely algebraic and involves simple techniques from toric geometry and homological algebra, as well as some basic results of the theory of vertex algebras. Ideas of this paper may also be useful in other problems related to maps from curves to algebraic varieties.This paper could also be of interest to physicists, because it contains explicit description of holomorphic parts of A and B models of Calabi-Yau hypersurfaces and complete intersections in terms of free bosons and fermions. (orig.)

  14. Vertex operators and Jordan fields

    International Nuclear Information System (INIS)

    Ferreira, L.A.; Gomes, J.F.; Zimerman, A.H.

    1988-01-01

    The construction of Lie algebras in terms of Jordan algebras generators is discussed. The key to the construction is the triality relation already incorporated into matrix products. A generalisation to Kac-Moody algebras in terms of vertex operators is proposed and may provide a clue for the construction of new representations of Kac-Moody algebras in terms of Jordan fields. (author) [pt

  15. Technologies for Future Vertex and Tracking Detectors at CLIC

    CERN Document Server

    Spannagel, Simon

    2018-01-01

    CLIC is a proposed linear e$^{+}$e$^{-}$ collider with center-of-mass energies of up to 3 TeV. Its main objectives are precise top quark and Higgs boson measurements, as well as searches for Beyond Standard Model physics. To meet the physics goals, the vertex and tracking detectors require not only a spatial resolution of a few micrometers and a very low material budget, but also timing capabilities with a precision of a few nanoseconds to allow suppression of beam-induced backgrounds. Different technologies using hybrid silicon detectors are explored for the vertex detectors, such as dedicated readout ASICs, small-pitch active edge sensors as well as capacitively coupled High-Voltage CMOS sensors. Monolithic sensors are considered as an option for the tracking detector, and a prototype using a CMOS process with a high-resistivity epitaxial layer is being designed. Different designs using a silicon-on-insulator process are under investigation for both vertex and tracking detector. All prototypes are evaluate...

  16. Charged Particle Tracking and Vertex Detection Group summary report

    International Nuclear Information System (INIS)

    Hanson, G.; Meyer, D.

    1984-09-01

    Charged particle tracking is essential in order to investigate the new physics expected at the SSC. The Tracking Group studied radiation damage and rate limitations to tracking devices, vertex detectors, and central tracking. The Group concluded that silicon strips and large wire tracking chambers with small cells can probably survive at the design luminosity of 10 33 cm -2 sec -1 ; however, the presently designed electronics for silicon strip vertex detectors can withstand a luminosity of only 10 31 cm -2 sec -1 . Wire chambers at a radius of less than about 25 cm can withstand a luminosity of less than or equal to 10 32 cm -2 sec -1 only. Actual tracking and pattern recognition in central tracking chambers at a luminosity of 10 33 cm -2 sec -1 will be very difficult because of multiple interactions within the resolving time of the chambers; detailed simulations are needed in order to decide whether tracking is indeed possible at this luminosity. Scintillating glass fibers are an interesting possibility both for vertex detectors and for central trackers, but much research and development is still needed both on the fibers themselves and on the readout

  17. Status and prospects of the LHCb Vertex Locator

    CERN Document Server

    van Beuzekom, Martin

    2007-01-01

    The Vertex Locator of the LHCb experiment is a dedicated subdetector for the reconstruction of primary and secondary vertices in b-hadron decays. The vertex detector features two halves with 21 modules each, mounted on retractable bases. Each module consists of two half-disk silicon micro-strip sensors measuring hits in R and $\\Phi$ coordinates. The strip pitch ranges from 40 to about 100 $\\mu$m. A vacuum boy with a 300 $\\mu$m thick aluminium foil shields the sensors from the wakefields of the proton beams which are passing at a distance of 8 mm from the active area of the sensors. Because of the harsh non-uniform radiation environment we opted for n-on-n strips in diffusion oxygenated float zone silicon. The current status of the vertex detector, which has recently entered the commissioning phase, will be discussed. Given the limited lifetime of the detector due to the radiation environment, developments for a detector replacement with n-on-p type modules have already started. Possible upgrade scenarios fo...

  18. CPLEAR et BABAR, all aspects of CP violation

    International Nuclear Information System (INIS)

    Yeche, Ch.

    2003-06-01

    This report of French 'Habilitation a diriger les recherches' summarizes my scientific activity from 1993 to 2003. During this decade, my research work was related to two particle physics experiments: CPLEAR and BABAR. The first one, CPLEAR, has recorded data from 1988 to 1995 on the low energy anti-proton ring (LEAR) at CERN. This experiment was devoted to the study of T, CPT et CP discrete symmetries. The second experiment, BABAR, has been running since 1999, on the PEP-II B factory at SLAC. This experiment searches for CP violation and tests the Standard Model through the measurements of the angles and the sides of the Unitarity Triangle. My research work is divided in five main topics: Study of CP and CPT violation in K 0 → π + π - decays; Performance optimization of the particle identification detector (DIRC) of the BABAR experiment; B meson tagging in BABAR experiment; Δm d measurement and Search for CP and T violation in mixing with dilepton events; Search for CP violation in B 0 → ρ ± π ± and B 0 → π ± K ± decays. (author)

  19. Study of Charm Baryons with the BaBar Experiment

    International Nuclear Information System (INIS)

    Petersen, Brian Aa.

    2006-01-01

    The authors report on several studies of charm baryon production and decays by the BABAR collaboration. They confirm previous observations of the Ξ' c 0/+ , Ξ c (2980) + and Ξ c (3077) + baryons, measure branching ratios for Cabibbo-suppressed Λ c + decays and use baryon decays to study the properties of the light-quark baryons, (Omega) - and Ξ(1690) 0

  20. The BaBar detector: Upgrades, operation and performance

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; del Amo Sanchez, P.; Gaillard, J. -M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Robbe, P.; Tisserand, V.; Zghiche, A.; Grauges, E.; Garra Tico, J.; Lopez, L.; Martinelli, M.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, G. P.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G. S.; Battaglia, M.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Clark, A. R.; Day, C. T.; Furman, M.; Gill, M. S.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J. A.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Kukartsev, G.; LeClerc, C.; Levi, M. E.; Lynch, G.; Merchant, A. M.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Osipenkov, I. L.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Suzuki, A.; Tackmann, K.; Tanabe, T.; Wenzel, W. A.; Zisman, M.; Barrett, M.; Bright-Thomas, P. G.; Ford, K. E.; Harrison, T. J.; Hart, A. J.; Hawkes, C. M.; Knowles, D. J.; Morgan, S. E.; O' Neale, S. W.; Penny, R. C.; Smith, D.; Soni, N.; Watson, A. T.; Watson, N. K.; Goetzen, K.; Held, T.; Koch, H.; Kunze, M.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Schroeder, T.; Steinke, M.; Fella, A.; Antonioli, E.; Boyd, J. T.; Chevalier, N.; Cottingham, W. N.; Foster, B.; Mackay, C.; Walker, D.; Abe, K.; Asgeirsson, D. J.; Cuhadar-Donszelmann, T.; Fulsom, B. G.; Hearty, C.; Knecht, N. S.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Khan, A.; Kyberd, P.; McKemey, A. K.; Randle-Conde, A.; Saleem, M.; Sherwood, D. J.; Teodorescu, L.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Telnov, V. I.; Todyshev, K. Yu.; Yushkov, A. N.; Best, D. S.; Bondioli, M.; Bruinsma, M.; Chao, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; McMahon, S.; Mommsen, R. K.; Stoker, D. P.; Abachi, S.; Buchanan, C.; Hartfiel, B. L.; Weinstein, A. J. R.; Atmacan, H.; Foulkes, S. D.; Gary, J. W.; Layter, J.; Liu, F.; Long, O.; Shen, B. C.; Vitug, G. M.; Wang, K.; Yasin, Z.; Zhang, L.; Hadavand, H. K.; Hill, E. J.; Paar, H. P.; Rahatlou, S.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Cunha, A.; Dahmes, B.; Hong, T. M.; Kovalskyi, D.; Kuznetsova, N.; Levy, S. L.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beck, T. W.; Beringer, J.; Eisner, A. M.; Flacco, C. J.; Grillo, A. A.; Grothe, M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Nesom, G.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Spencer, E.; Spradlin, P.; Turri, M.; Walkowiak, W.; Wang, L.; Wilder, M.; Williams, D. C.; Wilson, M. G.; Winstrom, L. O.; Chen, E.; Cheng, C. H.; Doll, D. A.; Dorsten, M. P.; Dvoretskii, A.; Echenard, B.; Erwin, R. J.; Fang, F.; Flood, K.; Hitlin, D. G.; Metzler, S.; Narsky, I.; Oyang, J.; Piatenko, T.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Zhu, R. Y.; Andreassen, R.; Devmal, S.; Geld, T. L.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Abe, T.; Antillon, E. A.; Barillari, T.; Becker, J.; Blanc, F.; Bloom, P. C.; Chen, S.; Clifton, Z. C.; Derrington, I. M.; Destree, J.; Dima, M. O.; Ford, W. T.; Gaz, A.; Gilman, J. D.; Hachtel, J.; Hirschauer, J. F.; Johnson, D. R.; Kreisel, A.; Nagel, M.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Ruddick, W. O.; Smith, J. G.; Ulmer, K. A.; van Hoek, W. C.; Wagner, S. R.; West, C. G.; Zhang, J.; Ayad, R.; Blouw, J.; Chen, A.; Eckhart, E. A.; Harton, J. L.; Hu, T.; Toki, W. H.; Wilson, R. J.; Winklmeier, F.; Zeng, Q. L.; Altenburg, D.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Brandt, T.; Brose, J.; Colberg, T.; Dahlinger, G.; Dickopp, M.; Eckstein, P.; Futterschneider, H.; Kaiser, S.; Kobel, M. J.; Krause, R.; Müller-Pfefferkorn, R.; Mader, W. F.; Maly, E.; Nogowski, R.; Otto, S.; Schubert, J.; Schubert, K. R.; Schwierz, R.; Sundermann, J. E.; Volk, A.; Wilden, L.; Bernard, D.; Brochard, F.; Cohen-Tanugi, J.; Dohou, F.; Ferrag, S.; Latour, E.; Mathieu, A.; Renard, C.; Schrenk, S.; T' Jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Clark, P. J.; Lavin, D. R.; Muheim, F.; Playfer, S.; Robertson, A. I.; Swain, J. E.; Watson, J. E.; Xie, Y.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Carassiti, V.; Cecchi, A.; Cibinetto, G.; Cotta Ramusino, A.; Evangelisti, F.; Fioravanti, E.; Franchini, P.; Garzia, I.; Landi, L.; Luppi, E.; Malaguti, R.; Negrini, M.; Padoan, C.; Petrella, A.; Piemontese, L.; Santoro, V.; Sarti, A.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; de Sangro, R.; Santoni, M.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Capra, R.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M. M.; Minutoli, S.; Monge, M. R.; Musico, P.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Pia, M. G.; Robutti, E.; Santroni, A.; Tosi, S.; Bhuyan, B.; Prasad, V.; Bailey, S.; Brandenburg, G.; Chaisanguanthum, K. S.; Lee, C. L.; Morii, M.; Won, E.; Wu, J.; Adametz, A.; Dubitzky, R. S.; Marks, J.; Schenk, S.; Uwer, U.; Klose, V.; Lacker, H. M.; Aspinwall, M. L.; Bhimji, W.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Flack, R. L.; Gaillard, J. R.; Gunawardane, N. J. W.; Morton, G. W.; Nash, J. A.; Nikolich, M. B.; Panduro Vazquez, W.; Sanders, P.; Smith, D.; Taylor, G. P.; Tibbetts, M.; Behera, P. K.; Chai, X.; Charles, M. J.; Grenier, G. J.; Hamilton, R.; Lee, S. -J.; Mallik, U.; Meyer, N. T.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Fischer, P. -A.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Lae, C. K.; Schott, G.; Albert, J. N.; Arnaud, N.; Beigbeder, C.; Breton, D.; Davier, M.; Derkach, D.; Dû, S.; Firmino da Costa, J.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Nief, J. Y.; Petersen, T. C.; Plaszczynski, S.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Tocut, V.; Trincaz-Duvoid, S.; Wang, L. L.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; Simani, M. C.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Coleman, J. P.; Forster, I. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Hutchcroft, D. E.; Kay, M.; Parry, R. J.; Payne, D. J.; Schofield, K. C.; Sloane, R. J.; Touramanis, C.; Azzopardi, D. E.; Bellodi, G.; Bevan, A. J.; Clarke, C. K.; Cormack, C. M.; Di Lodovico, F.; Dixon, P.; George, K. A.; Menges, W.; Potter, R. J. L.; Sacco, R.; Shorthouse, H. W.; Sigamani, M.; Strother, P.; Vidal, P. B.; Brown, C. L.; Cowan, G.; Flaecher, H. U.; George, S.; Green, M. G.; Hopkins, D. A.; Jackson, P. S.; Kurup, A.; Marker, C. E.; McGrath, P.; McMahon, T. R.; Paramesvaran, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Allison, J.; Alwyn, K. E.; Bailey, D. S.; Barlow, N. R.; Barlow, R. J.; Chia, Y. M.; Edgar, C. L.; Forti, A. C.; Fullwood, J.; Hart, P. A.; Hodgkinson, M. C.; Jackson, F.; Jackson, G.; Kelly, M. P.; Kolya, S. D.; Lafferty, G. D.; Lyon, A. J.; Naisbit, M. T.; Savvas, N.; Weatherall, J. H.; West, T. J.; Williams, J. C.; Yi, J. I.; Anderson, J.; Farbin, A.; Hulsbergen, W. D.; Jawahery, A.; Lillard, V.; Roberts, D. A.; Schieck, J. R.; Simi, G.; Tuggle, J. M.; Blaylock, G.; Dallapiccola, C.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Li, X.; Moore, T. B.; Salvati, E.; Saremi, S.; Staengle, H.; Willocq, S. Y.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Koeneke, K.; Lang, M. I.; Sciolla, G.; Spitznagel, M.; Taylor, F.; Yamamoto, R. K.; Yi, M.; Zhao, M.; Zheng, Y.; Klemetti, M.; Lindemann, D.; Mangeol, D. J. J.; Mclachlin, S. E.; Milek, M.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Cerizza, G.; Lazzaro, A.; Lombardo, V.; Neri, N.; Palombo, F.; Pellegrini, R.; Stracka, S.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Godang, R.; Brunet, S.; Cote, D.; Nguyen, X.; Simard, M.; Taras, P.; Viaud, B.; Nicholson, H.; Cavallo, N.; De Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Monorchio, D.; Onorato, G.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Baak, M. A.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Allmendinger, T.; Benelli, G.; Brau, B.; Corwin, L. A.; Gan, K. K.; Honscheid, K.; Hufnagel, D.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Regensburger, J. J.; Smith, D. S.; Ter-Antonyan, R.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Iwasaki, M.; Kolb, J. A.; Lu, M.; Potter, C. T.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Borsato, E.; Castelli, G.; Colecchia, F.; Crescente, A.; Dal Corso, F.; Dorigo, A.; Fanin, C.; Furano, F.; Gagliardi, N.; Galeazzi, F.; Margoni, M.; Marzolla, M.; Michelon, G.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Solagna, P.; Stevanato, E.; Stroili, R.; Tiozzo, G.; Voci, C.; Akar, S.; Bailly, P.; Ben-Haim, E.; Bonneaud, G.; Briand, H.; Chauveau, J.; Hamon, O.; John, M. J. J.; Lebbolo, H.; Leruste, Ph.; Malclès, J.; Marchiori, G.; Martin, L.; Ocariz, J.; Perez, A.; Pivk, M.; Prendki, J.; Roos, L.; Sitt, S.; Stark, J.; Thérin, G.; Vallereau, A.; Biasini, M.; Covarelli, R.; Manoni, E.; Pennazzi, S.; Pioppi, M.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Bucci, F.; Calderini, G.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Morganti, M.; Morsani, F.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Sandrelli, F.; Triggiani, G.; Walsh, J. J.; Haire, M.; Judd, D.; Biesiada, J.; Danielson, N.; Elmer, P.; Fernholz, R. E.; Lau, Y. P.; Lu, C.; Miftakov, V.; Olsen, J.; Lopes Pegna, D.; Sands, W. R.; Smith, A. J. S.; Telnov, A. V.; Tumanov, A.; Varnes, E. W.; Baracchini, E.; Bellini, F.; Bulfon, C.; Buccheri, E.; Cavoto, G.; D' Orazio, A.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Lamanna, E.; Leonardi, E.; Li Gioi, L.; Lunadei, R.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Polci, F.; del Re, D.; Renga, F.; Safai Tehrani, F.; Serra, M.; Voena, C.; Bünger, C.; Christ, S.; Hartmann, T.; Leddig, T.; Schröder, H.; Wagner, G.; Waldi, R.; Adye, T.; Bly, M.; Brew, C.; Condurache, C.; De Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Ricciardi, S.; Roethel, W.; Wilson, F. F.; Xella, S. M.; Aleksan, R.; Bourgeois, P.; Emery, S.; Escalier, M.; Esteve, L.; Gaidot, A.; Ganzhur, S. F.; Giraud, P. -F.; Georgette, Z.; Graziani, G.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; Legendre, M.; London, G. W.; Mayer, B.; Micout, P.; Serfass, B.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Akre, R.; Aston, D.; Azemoon, T.; Bard, D. J.; Bartelt, J.; Bartoldus, R.; Bechtle, P.; Becla, J.; Benitez, J. F.; Berger, N.; Bertsche, K.; Boeheim, C. T.; Bouldin, K.; Boyarski, A. M.; Boyce, R. F.; Browne, M.; Buchmueller, O. L.; Burgess, W.; Cai, Y.; Cartaro, C.; Ceseracciu, A.; Claus, R.; Convery, M. R.; Coupal, D. P.; Craddock, W. W.; Crane, G.; Cristinziani, M.; DeBarger, S.; Decker, F. J.; Dingfelder, J. C.; Donald, M.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Ecklund, S.; Erickson, R.; Fan, S.; Field, R. C.; Fisher, A.; Fox, J.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Gaponenko, I.; Glanzman, T.; Gowdy, S. J.; Graham, M. T.; Grenier, P.; Hadig, T.; Halyo, V.; Haller, G.; Hamilton, J.; Hanushevsky, A.; Hasan, A.; Hast, C.; Hee, C.; Himel, T.; Hryn' ova, T.; Huffer, M. E.; Hung, T.; Innes, W. R.; Iverson, R.; Kaminski, J.; Kelsey, M. H.; Kim, H.; Kim, P.; Kharakh, D.; Kocian, M. L.; Krasnykh, A.; Krebs, J.; Kroeger, W.; Kulikov, A.; Kurita, N.; Langenegger, U.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Libby, J.; Lindquist, B.; Luitz, S.; Lüth, V.; Lynch, H. L.; MacFarlane, D. B.; Marsiske, H.; McCulloch, M.; McDonald, J.; Melen, R.; Menke, S.; Metcalfe, S.; Messner, R.; Moss, L. J.; Mount, R.; Muller, D. R.; Neal, H.; Nelson, D.; Nelson, S.; Nordby, M.; Nosochkov, Y.; Novokhatski, A.; O' Grady, C. P.; O' Neill, F. G.; Ofte, I.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Piemontese, M.; Pierson, S.; Pulliam, T.; Ratcliff, B. N.; Ratkovsky, S.; Reif, R.; Rivetta, C.; Rodriguez, R.; Roodman, A.; Salnikov, A. A.; Schietinger, T.; Schindler, R. H.; Schwarz, H.; Schwiening, J.; Seeman, J.; Smith, D.; Snyder, A.; Soha, A.; Stanek, M.; Stelzer, J.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Tanaka, H. A.; Teytelman, D.; Thompson, J. M.; Tinslay, J. S.; Trunov, A.; Turner, J.; van Bakel, N.; van Winkle, D.; Va' vra, J.; Wagner, A. P.; Weaver, M.; Weinstein, A. J. R.; Weber, T.; West, C. A.; Wienands, U.; Wisniewski, W. J.; Wittgen, M.; Wittmer, W.; Wright, D. H.; Wulsin, H. W.; Yan, Y.; Yarritu, A. K.; Yi, K.; Yocky, G.; Young, C. C.; Ziegler, V.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; Singh, H.; Weidemann, A. W.; White, R. M.; Wilson, J. R.; Yumiceva, F. X.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Edwards, A. J.; Majewski, S. A.; Meyer, T. I.; Miyashita, T. S.; Petersen, B. A.; Roat, C.; Ahmed, M.; Ahmed, S.; Alam, M. S.; Bula, R.; Ernst, J. A.; Jain, V.; Liu, J.; Pan, B.; Saeed, M. A.; Wappler, F. R.; Zain, S. B.; Gorodeisky, R.; Guttman, N.; Peimer, D.; Soffer, A.; De Silva, A.; Lund, P.; Krishnamurthy, M.; Ragghianti, G.; Spanier, S. M.; Wogsland, B. J.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Satpathy, A.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Drummond, B. W.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Ye, S.; Bianchi, F.; Bona, M.; Gallo, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Borean, C.; Bosisio, L.; Cossutti, F.; Della Ricca, G.; Dittongo, S.; Grancagnolo, S.; Lanceri, L.; Poropat, P.; Rashevskaya, I.; Vitale, L.; Vuagnin, G.; Manfredi, P. F.; Re, V.; Speziali, V.; Frank, E. D.; Gladney, L.; Guo, Q. H.; Panetta, J.; Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D. A.; Oyanguren, A.; Agarwal, A.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Brown, C. M.; Choi, H. H. F.; Fortin, D.; Fransham, K. B.; Hamano, K.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Back, J. J.; Gershon, T. J.; Harrison, P. F.; Ilic, J.; Latham, T. E.; Mohanty, G. B.; Puccio, E.; Band, H. R.; Chen, X.; Cheng, B.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hollar, J. J.; Hu, H.; Johnson, J. R.; Kutter, P. E.; Li, H.; Liu, R.; Mellado, B.; Mihalyi, A.; Mohapatra, A. K.; Pan, Y.; Pierini, M.; Prepost, R.; Scott, I. J.; Tan, P.; Vuosalo, C. O.; von Wimmersperg-Toeller, J. H.; Wu, S. L.; Yu, Z.; Greene, M. G.; Kordich, T. M. B.

    2013-11-01

    The BaBar detector operated successfully at the PEP-II asymmetric e+e- collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.

  1. 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.

  2. Silicon Tracking Upgrade at CDF

    International Nuclear Information System (INIS)

    Kruse, M.C.

    1998-04-01

    The Collider Detector at Fermilab (CDF) is scheduled to begin recording data from Run II of the Fermilab Tevatron in early 2000. The silicon tracking upgrade constitutes both the upgrade to the CDF silicon vertex detector (SVX II) and the new Intermediate Silicon Layers (ISL) located at radii just beyond the SVX II. Here we review the design and prototyping of all aspects of these detectors including mechanical design, data acquisition, and a trigger based on silicon tracking

  3. 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.

  4. CPLEAR et BABAR, all aspects of CP violation; CPLEAR et BABAR la violation de CP dans tous ses etats

    Energy Technology Data Exchange (ETDEWEB)

    Yeche, Ch

    2003-06-01

    This report of French 'Habilitation a diriger les recherches' summarizes my scientific activity from 1993 to 2003. During this decade, my research work was related to two particle physics experiments: CPLEAR and BABAR. The first one, CPLEAR, has recorded data from 1988 to 1995 on the low energy anti-proton ring (LEAR) at CERN. This experiment was devoted to the study of T, CPT et CP discrete symmetries. The second experiment, BABAR, has been running since 1999, on the PEP-II B factory at SLAC. This experiment searches for CP violation and tests the Standard Model through the measurements of the angles and the sides of the Unitarity Triangle. My research work is divided in five main topics: Study of CP and CPT violation in K{sup 0} {yields} {pi}{sup +} {pi}{sup -} decays; Performance optimization of the particle identification detector (DIRC) of the BABAR experiment; B meson tagging in BABAR experiment; {delta}m{sub d} measurement and Search for CP and T violation in mixing with dilepton events; Search for CP violation in B{sup 0} {yields} {rho}{sup {+-}} {pi}{sup {+-}} and B{sup 0} {yields} {pi}{sup {+-}} K{sup {+-}} decays. (author)

  5. A nonperturbative fermion-boson vertex

    International Nuclear Information System (INIS)

    Bashir, A.; Raya, A.

    2002-01-01

    We calculate the massive fermion propagator at one-loop order in QED3. The Ward-Takahashi identity (WTI) relates the propagator to the vertex. This allows us to split the vertex into its longitudinal and transverse parts. The former is fixed by the WTI. Following the scheme of Ball and Chiu later modified by Kizilersue et. al., we calculate the full vertex at one-loop order. A mere subtraction of the longitudinal part of the vertex gives us the transverse part. The α dependence in the transverse vertex can be eliminated by making use of the perturbative expressions for the wavefunction renormalization function and the mass function of complicated arguments of the incoming and outgoing fermion momenta. This leads us to a vertex which is nonperturbative in nature. We also calculate an effective vertex for which the arguments of the unknown functions have no angular dependence, making it particularly suitable for numerical studies of dynamical symmetry breaking

  6. STAR Vertex Detector Upgrade Development

    International Nuclear Information System (INIS)

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

    2008-01-01

    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

  7. The OPAL vertex drift chamber

    International Nuclear Information System (INIS)

    Carter, J.R.; Elcombe, P.A.; Hill, J.C.; Roach, C.M.; Armitage, J.C.; Carnegie, R.K.; Estabrooks, P.; Hemingway, R.; Karlen, D.; McPherson, A.; Pinfold, J.; Roney, J.M.; Routenburg, P.; Waterhouse, J.; Hargrove, C.K.; Klem, D.; Oakham, F.G.; Carter, A.A.; Jones, R.W.L.; Lasota, M.M.B.; Lloyd, S.L.; Pritchard, T.W.; Wyatt, T.R.

    1990-01-01

    A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar. (orig.)

  8. 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...

  9. Electronics cooling of Phenix multiplicity and vertex detector

    International Nuclear Information System (INIS)

    Chen, Z.; Gregory, W.S.

    1996-08-01

    The Multiplicity and Vertex Detector (MVD) uses silicon strip sensors arranged in two concentric barrels around the beam pipe of the PHENIX detector that will be installed at Brookhaven National Laboratory. Each silicon sensor is connected by a flexible kapton cable to its own front-end electronics printed circuit board that is a multi-chip module or MCM. The MCMs are the main heat source in the system. To maintain the MVD at optimized operational status, the maximum temperature of the multi-chip modules must be below 40 C. Using COSMOS/M HSTAR for the Heat Transfer analysis, a finite element model of a typical MCM plate was created to simulate a 9m/s airflow and 9m/s mixed flow composed of 50% helium and 50% air respectively, with convective heat transfer on both sides of the plate. The results using a mixed flow of helium and air show that the average maximum temperature reached by the MCMs is 37.5 C. The maximum temperature which is represented by the hot spots on the MCM is 39.43 C for the helium and air mixture which meets the design temperature requirement 40 C. To maintain the Multiplicity and Vertex Detector at optimized operational status, the configuration of the plenum chamber, the power dissipated by the silicon chips, the fluid flow velocity and comparison on the MCM design parameters will be discussed

  10. The LHCb vertex locator and level-1 trigger

    CERN Document Server

    Dijkstra, H

    2000-01-01

    LHCb will study CP violation and other rare phenomena in B-decays with a forward detector at the LHC. One of the challenges is to design a fast and efficient trigger. The design of the silicon Vertex Locator (VELO) has been driven by the requirements of one of the most selective triggers of the experiment. The VELO trigger is designed to work at an input rate of 1 MHz. The requirements and implementation of the VELO and the associated trigger are summarised, followed by a description of an upgrade which improves the trigger performance significantly. (3 refs).

  11. Performances of RPCs in the BaBar Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Messner, Robert

    2003-09-26

    The BaBar experiment uses a big system based on RPC detectors to discriminate muons from pions and to identify neutral hadrons. About 2000 m{sup 2} of RPC chambers have been working at SLAC since the end of 1998. We report on the performances of the RPC chambers focusing on new problems discovered in the RPC behavior. These problems started very soon after the installation of the chambers on the detector when the high ambient temperature triggered an increase of dark currents inside the chambers and a reduction of the efficiency. Careful analysis of the BaBar data and dedicated R&D efforts in the laboratory have helped to identify the main source of the trouble in the linseed oil varnish on the bakelite electrodes.

  12. DIRC - a particle identification system for BaBar

    International Nuclear Information System (INIS)

    Hoecker, A.

    1999-10-01

    The DIRC (an acronym for Detection of Internally Reflected Cherenkov light) is a novel type of Cherenkov imaging device that has been developed, built and installed as part of the BaBar detector at the asymmetric B-factory PEP-II at SLAC. The DIRC is based on total internal reflection of Cherenkov photons produced and guided within thin, rectangular quartz bars covering the barrel region of BaBar. The photon detector is an array of photomultiplier tubes covering the photon phase space at the backward end of the bars. In its first few months of operation the DIRC performance has been found to achieve the design requirements. This note presents results from cosmic ray data and an analysis of the first beam collision runs. (author)

  13. Configuration Database for BaBar On-line

    International Nuclear Information System (INIS)

    Salnikov, Andrei

    2003-01-01

    The configuration database is one of the vital systems in the BaBar on-line system. It provides services for the different parts of the data acquisition system and control system, which require run-time parameters. The original design and implementation of the configuration database played a significant role in the successful BaBar operations since the beginning of experiment. Recent additions to the design of the configuration database provide better means for the management of data and add new tools to simplify main configuration tasks. We describe the design of the configuration database, its implementation with the Objectivity/DB object-oriented database, and our experience collected during the years of operation

  14. Vertex trigger implementation using shared memory technology

    CERN Document Server

    Müller, H

    1998-01-01

    The implementation of a 1 st level vertex trigger for LHC-B is particularly difficult due to the high ( 1 MHz ) input data rate. With ca. 350 silicon hits per event, both the R strips and Phi strips of the detectors produce a total of ca 2 Gbyte/s zero-suppressed da ta.1 note succeeds to the ideas to use R-phi coordinates for fast integer linefinding in programmable hardware, as described in LHB note 97-006. For an implementation we propose a FPGA preprocessing stage operating at 1 MHz with the benefit to substantially reduce the amount of data to be transmitted to the CPUs and to liberate a large fraction of CPU time. Interconnected via 4 Gbit/s SCI technol-ogy 2 , a shared memory system can be built which allows to perform data driven eventbuilding with, or without preprocessing. A fully data driven architecture between source modules and destination memories provides a highly reliable memory-to-memory transfer mechanism of very low latency. The eventbuilding is performed via associating events at the sourc...

  15. Performance of the LHCb Vertex Locator

    CERN Document Server

    Aaij, R.; 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 ...

  16. 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.

  17. Data driven processor 'Vertex Trigger' for B experiments

    International Nuclear Information System (INIS)

    Hartouni, E.P.

    1993-01-01

    Data Driven Processors (DDP's) are specialized computation engines configured to solve specific numerical problems, such as vertex reconstruction. The architecture of the DDP which is the subject of this talk was designed and implemented by W. Sippach and B.C. Knapp at Nevis Lab. in the early 1980's. This particular implementation allows multiple parallel streams of data to provide input to a heterogenous collection of simple operators whose interconnection form an algorithm. The local data flow control allows this device to execute algorithms extremely quickly provided that care is taken in the layout of the algorithm. I/O rates of several hundred megabytes/second are routinely achieved thus making DDP's attractive candidates for complex online calculations. The original question was open-quote can a DDP reconstruct tracks in a Silicon Vertex Detector, find events with a separated vertex and do it fast enough to be used as an online trigger?close-quote Restating this inquiry as three questions and describing the answers to the questions will be the subject of this talk. The three specific questions are: (1) Can an algorithm be found which reconstructs tracks in a planar geometry and no magnetic field; (2) Can separated vertices be recognized in some way; (3) Can the algorithm be implemented in the Nevis-UMass and DDP and execute in 10-20 μs?

  18. The BaBar Software Architecture and Infrastructure

    International Nuclear Information System (INIS)

    Cosmo, Gabriele

    2003-01-01

    The BaBar experiment has in place since 1995 a software release system (SRT Software Release Tools) based on CVS (Concurrent Version System) which is in common for all the software developed for the experiment, online or offline, simulation or reconstruction. A software release is a snapshot of all BaBar code (online, offline, utilities, scripts, makefiles, etc.). This set of code is tested to work together, and is indexed by a release number (e.g., 6.8.2) so a user can refer to a particular release and get reproducible results. A release will involve particular versions of packages. A package generally consists of a set of code for a particular task, together with a GNU makefile, scripts and documentation. All BaBar software is maintained in AFS (Andrew File System) directories, so the code is accessible worldwide within the Collaboration. The combination SRT, CVS, AFS, has demonstrated to be a valid, powerful and efficient way of organizing the software infrastructure of a modern HEP experiment with collaborating Institutes distributed worldwide, both in a development and production phase

  19. String bits and the spin vertex

    OpenAIRE

    Jiang, YunfengInstitut de Physique Théorique, DSM, CEA, URA2306 CNRS Saclay, F-91191 Gif-sur-Yvette, France; Kostov, Ivan(Institut de Physique Théorique, DSM, CEA, URA2306 CNRS Saclay, F-91191 Gif-sur-Yvette, France); Petrovskii, Andrei(Institut de Physique Théorique, DSM, CEA, URA2306 CNRS Saclay, F-91191 Gif-sur-Yvette, France); Serban, Didina(Institut de Physique Théorique, DSM, CEA, URA2306 CNRS Saclay, F-91191 Gif-sur-Yvette, France)

    2015-01-01

    We initiate a novel formalism for computing correlation functions of trace operators in the planar N=4 SYM theory. The central object in our formalism is the spin vertex, which is the weak coupling analogy of the string vertex in string field theory. We construct the spin vertex explicitly for all sectors at the leading order using a set of bosonic and fermionic oscillators. We prove that the vertex has trivial monodromy, or put in other words, it is a Yangian invariant. Since the monodromy o...

  20. The OPAL vertex detector prototype

    International Nuclear Information System (INIS)

    Roney, J.M.; Armitage, J.C.; Carnegie, R.K.; Giles, G.L.; Hemingway, R.J.; McPherson, A.C.; Pinfold, J.L.; Waterhouse, J.; Godfrey, L.; Hargrove, C.K.

    1989-01-01

    The prototype test results of a high resolution charged particle tracking detector are reported. The detector is designed to measure vertex topologies of particles produced in the e + e - collisions of the OPAL experiment at LEP. The OPAL vertex detector is a 1 m long, 0.46 m diameter cylindrical drift chamber consisting of an axial and stereo layer each of which is divided into 36 jet cells. A prototype chamber containing four axial and two stereo cells was studied using a pion test beam at CERN. The studies examined the prototype under a variety of operating conditions. An r-Φ resolution of 60 μm was obtained when the chamber was operated with argon (50%)-ethane (50%) at 3.75 bar, and when CO 2 (80%)-isobutane (20%) at 2.5 bar was used a 25 μm resolution was achieved. A z measurement using end-to-end time difference has a resolution of 3.5 cm. The details of these prototype studies are discussed in this paper. (orig.)

  1. 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

  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. The DIRC Particle Identification System for the BaBar Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Adam, I

    2004-06-30

    A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for Detection of Internally Reflected Cherenkov (Light). This paper will discuss the construction, operation and performance of the BABAR DIRC in detail.

  4. Searches for low-mass Higgs and dark bosons at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Oberhof, Benjamin, E-mail: benjamin.oberhof@pi.infn.it [INFN sezione di Pisa and Universitá di Pisa, Polo Fibonacci - Edificio C, Largo B. Pontecorvo 3, 56125 - Pisa (Italy)

    2013-01-15

    We present BaBar latest results for the direct search of a light CP-odd Higgs boson using radiative decays of the ϒ(nS) (n=1,2,3) resonances in different final states. We also present the results for the search of a hidden sector gauge and Higgs bosons using the full BaBar datasample.

  5. Proposal for a CLEO precision vertex detector

    International Nuclear Information System (INIS)

    1991-01-01

    Fermilab experiment E691 and CERN experiment NA32 have demonstrated the enormous power of precision vertexing for studying heavy quark physics. Nearly all collider experiments now have or are installing precision vertex detectors. This is a proposal for a precision vertex detector for CLEO, which will be the pre-eminent heavy quark experiment for at least the next 5 years. The purpose of a precision vertex detector for CLEO is to enhance the capabilities for isolating B, charm, and tau decays and to make it possible to measure the decay time. The precision vertex detector will also significantly improve strange particle identification and help with the tracking. The installation and use of this detector at CLEO is an important step in developing a vertex detector for an asymmetric B factory and therefore in observing CP violation in B decays. The CLEO environment imposes a number of unique conditions and challenges. The machine will be operating near the γ (4S) in energy. This means that B's are produced with a very small velocity and travel a distance about 1/2 that of the expected vertex position resolution. As a consequence B decay time information will not be useful for most physics. On the other hand, the charm products of B decays have a higher velocity. For the long lived D + in particular, vertex information can be used to isolate the charm particle on an event-by-event basis. This helps significantly in reconstructing B's. The vertex resolution for D's from B's is limited by multiple Coulomb scattering of the necessarily rather low momentum tracks. As a consequence it is essential to minimize the material, as measured in radiation lengths, in the beam pip and the vertex detector itself. It is also essential to build the beam pipe and detector with the smallest possible radius

  6. DIRC, a new type of particle identification system For BABAR

    International Nuclear Information System (INIS)

    Schwiening, J.

    1997-12-01

    The DIRC, a new type of Cherenkov imaging device, has been selected as the primary particle identification system for the BABAR detector at the asymmetric B-factory, PEP-II. It is based on total internal reflection and uses long, rectangular bars made from synthetic fused silica as Cherenkov radiators and light guides. In this paper, the principles of the DIRC ring imaging Cherenkov technique are explained and results from the prototype program are presented. The studies of the optical properties and radiation hardness of the quartz radiators are described, followed by a discussion of the detector design

  7. Managing the BaBar object oriented database

    International Nuclear Information System (INIS)

    Hasan, A.; Trunov, A.

    2001-01-01

    The BaBar experiment stores its data in an Object Oriented federated database supplied by Objectivity/DB(tm). This database is currently 350TB in size and is expected to increase considerably as the experiment matures. Management of this database requires careful planning and specialized tools in order to make the data available to physicists in an efficient and timely manner. The authors discuss the operational issues and management tools that were developed during the previous run to deal with this vast quantity of data at SLAC

  8. Comparison of forward collider vertex detectors for B physics at hadron accelerators

    International Nuclear Information System (INIS)

    Harr, R.F.; Karchin, P.E.; Kennedy, C.J.

    1993-01-01

    Two silicon vertex detector designs have been proposed for a forward collider B physics experiment at the SSC: in one the silicon system is put outside the beampipe (like in the forward part of the proposed BCD detector); and in the other the silicon system is put inside the beampipe, close to the circulating beams, with the use of open-quote roman pots close-quote (as in the COBEX proposal). In what follows these will be referred to as the inside and outside designs. The two designs are significantly different in their construction and impact on the rest of the experiment. The authors would like to understand how the designs compare for doing B physics and what are the factors that most greatly influence the results. Two measurements relying on the vertex detector and of particular importance for B physics are the reconstructed vertex position and B mass. They have analyzed the resolution achievable in these 2 quantities for open-quote models close-quote of the two forward collider vertex detector designs. The design parameters - beampipe radius and thickness, silicon position and resolution, etc. - have been varied about their normal values to observe their effect on these resolutions. They find very little difference between the two designs; both give nearly the same decay length error, impact parameter error, and reconstructed B mass error, for a large range of geometrical parameters. The design parameter having the most significant impact on the errors of B decay vertices is found to be the point resolution of the silicon detectors

  9. BaBar computing - From collisions to physics results

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    The BaBar experiment at SLAC studies B-physics at the Upsilon(4S) resonance using the high-luminosity e+e- collider PEP-II at the Stanford Linear Accelerator Center (SLAC). Taking, processing and analyzing the very large data samples is a significant computing challenge. This presentation will describe the entire BaBar computing chain and illustrate the solutions chosen as well as their evolution with the ever higher luminosity being delivered by PEP-II. This will include data acquisition and software triggering in a high availability, low-deadtime online environment, a prompt, automated calibration pass through the data SLAC and then the full reconstruction of the data that takes place at INFN-Padova within 24 hours. Monte Carlo production takes place in a highly automated fashion in 25+ sites. The resulting real and simulated data is distributed and made available at SLAC and other computing centers. For analysis a much more sophisticated skimming pass has been introduced in the past year, ...

  10. Vertex operators for a bosonic string

    International Nuclear Information System (INIS)

    Sasaki, Ryu; Yamanaka, Itaru.

    1985-09-01

    Based on the operator formalism and the Virasoro algebra, we present a simple method of constructing vertex operators describing the emission and absorption of general particles in bosonic string theories. (author)

  11. BaBar - A Community Web Site in an Organizational Setting

    International Nuclear Information System (INIS)

    White, Bebo

    2003-01-01

    The BABAR Web site was established in 1993 at the Stanford Linear Accelerator Center (SLAC) to support the BABAR experiment, to report its results, and to facilitate communication among its scientific and engineering collaborators, currently numbering about 600 individuals from 75 collaborating institutions in 10 countries. The BABAR Web site is, therefore, a community Web site. At the same time it is hosted at SLAC and funded by agencies that demand adherence to policies decided under different priorities. Additionally, the BABAR Web administrators deal with the problems that arise during the course of managing users, content, policies, standards, and changing technologies. Desired solutions to some of these problems may be incompatible with the overall administration of the SLAC Web sites and/or the SLAC policies and concerns. There are thus different perspectives of the same Web site and differing expectations in segments of the SLAC population which act as constraints and challenges in any review or re-engineering activities. Web Engineering, which post-dates the BABAR Web, has aimed to provide a comprehensive understanding of all aspects of Web development. This paper reports on the first part of a recent review of application of Web Engineering methods to the BABAR Web site, which has led to explicit user and information models of the BABAR community and how SLAC and the BABAR community relate and react to each other. The paper identifies the issues of a community Web site in a hierarchical, semi-governmental sector and formulates a strategy for periodic reviews of BABAR and similar sites. A separate paper reports on the findings of a user survey and selected interviews with users, along with their implications and recommendations for future

  12. BaBar - A Community Web Site in an Organizational Setting

    Energy Technology Data Exchange (ETDEWEB)

    White, Bebo

    2003-07-10

    The BABAR Web site was established in 1993 at the Stanford Linear Accelerator Center (SLAC) to support the BABAR experiment, to report its results, and to facilitate communication among its scientific and engineering collaborators, currently numbering about 600 individuals from 75 collaborating institutions in 10 countries. The BABAR Web site is, therefore, a community Web site. At the same time it is hosted at SLAC and funded by agencies that demand adherence to policies decided under different priorities. Additionally, the BABAR Web administrators deal with the problems that arise during the course of managing users, content, policies, standards, and changing technologies. Desired solutions to some of these problems may be incompatible with the overall administration of the SLAC Web sites and/or the SLAC policies and concerns. There are thus different perspectives of the same Web site and differing expectations in segments of the SLAC population which act as constraints and challenges in any review or re-engineering activities. Web Engineering, which post-dates the BABAR Web, has aimed to provide a comprehensive understanding of all aspects of Web development. This paper reports on the first part of a recent review of application of Web Engineering methods to the BABAR Web site, which has led to explicit user and information models of the BABAR community and how SLAC and the BABAR community relate and react to each other. The paper identifies the issues of a community Web site in a hierarchical, semi-governmental sector and formulates a strategy for periodic reviews of BABAR and similar sites. A separate paper reports on the findings of a user survey and selected interviews with users, along with their implications and recommendations for future.

  13. Monte-Carlo Analysis of the Flavour Changing Neutral Current B \\to Gamma at Babar

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D. [Imperial College, London (United Kingdom)

    2001-09-01

    The main theme of this thesis is a Monte-Carlo analysis of the rare Flavour Changing Neutral Current (FCNC) decay b→sγ. The analysis develops techniques that could be applied to real data, to discriminate between signal and background events in order to make a measurement of the branching ratio of this rare decay using the BaBar detector. Also included in this thesis is a description of the BaBar detector and the work I have undertaken in the development of the electronic data acquisition system for the Electromagnetic calorimeter (EMC), a subsystem of the BaBar detector.

  14. First results with prototype ISIS devices for ILC vertex detector

    International Nuclear Information System (INIS)

    Damerell, C.; Zhang, Z.; Gao, R.; John John, Jaya; Li, Y.; Nomerotski, A.; Holland, A.; Seabroke, G.; Havranek, M.; Stefanov, K.; Kar-Roy, A.; Bell, R.; Burt, D.; Pool, P.

    2010-01-01

    The vertex detectors at the International Linear Collider (ILC) (there will be two of them, one for each of two general purpose detectors) will certainly be built with silicon pixel detectors, either monolithic or perhaps vertically integrated. However, beyond this general statement, there is a wide range of options supported by active R and D programmes all over the world. Pixel-based vertex detectors build on the experience at the SLAC large detector (SLD) operating at the SLAC linear collider (SLC), where a 307 Mpixel detector permitted the highest physics performance at LEP or SLC. For ILC, machine conditions demand much faster readout than at SLC, something like 20 time slices during the 1 ms bunch train. The approach of the image sensor with in-situ storage (ISIS) is unique in offering this capability while avoiding the undesirable requirement of 'pulsed power'. First results from a prototype device that approaches the pixel size of 20 μm square, needed for physics, are reported. The dimensional challenge is met by using a 0.18 μm imaging CMOS process, instead of a conventional CCD process.

  15. First results with prototype ISIS devices for ILC vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Damerell, C., E-mail: c.damerell@rl.ac.u [RAL, Oxon OX11 0QX (United Kingdom); Zhang, Z. [RAL, Oxon OX11 0QX (United Kingdom); Gao, R.; John John, Jaya; Li, Y.; Nomerotski, A. [Oxford U (United Kingdom); Holland, A.; Seabroke, G. [Centre for Electronic Imaging, Open U (United Kingdom); Havranek, M. [Czech Technical University in Prague (Czech Republic); Stefanov, K. [Sentec Ltd, Cambridge (United Kingdom); Kar-Roy, A. [Jazz Semiconductors, California (United States); Bell, R.; Burt, D.; Pool, P. [e2V Technologies, Chelmsford (United Kingdom)

    2010-12-11

    The vertex detectors at the International Linear Collider (ILC) (there will be two of them, one for each of two general purpose detectors) will certainly be built with silicon pixel detectors, either monolithic or perhaps vertically integrated. However, beyond this general statement, there is a wide range of options supported by active R and D programmes all over the world. Pixel-based vertex detectors build on the experience at the SLAC large detector (SLD) operating at the SLAC linear collider (SLC), where a 307 Mpixel detector permitted the highest physics performance at LEP or SLC. For ILC, machine conditions demand much faster readout than at SLC, something like 20 time slices during the 1 ms bunch train. The approach of the image sensor with in-situ storage (ISIS) is unique in offering this capability while avoiding the undesirable requirement of 'pulsed power'. First results from a prototype device that approaches the pixel size of 20 {mu}m square, needed for physics, are reported. The dimensional challenge is met by using a 0.18 {mu}m imaging CMOS process, instead of a conventional CCD process.

  16. The Mark II vertex detectors: Status and prospects

    International Nuclear Information System (INIS)

    Jaros, J.A.

    1987-03-01

    The art of detecting the decay vertices from heavy quarks and leptons is comparatively new at electron-positron storage rings. So far, drift chambers positioned just outside the vacuum pipes which surround the interfaction region have provided the first accurate determinations of the tau and bottom lifetimes, and confirmed earlier measurements of charmed particle lifetimes. ''Second generation'' vertex detectors have demonstrated the feasibility of tagging heavy flavors by observing decay vertices, and are being used to search for anomalous decay topologies. These chambers have modest resolution on the scale of the effects they seek to measure, but are now well-understood and reliable tools. A generation of vertex detectors, considerably more ambitious, is under construction for experiments at SLC and LEP. They boast impact parameter resolution improved by a factor of four or more over previous detectors, and sub-millimeter track-pair resolution. The Mark II collaboration hopes to reach these goals with a high pressure precision drift chamber, and eventually surpass them with the addition of a silicon microstrip detector

  17. The Mark II vertex detectors: Status and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Jaros, J.A.

    1987-03-01

    The art of detecting the decay vertices from heavy quarks and leptons is comparatively new at electron-positron storage rings. So far, drift chambers positioned just outside the vacuum pipes which surround the interfaction region have provided the first accurate determinations of the tau and bottom lifetimes, and confirmed earlier measurements of charmed particle lifetimes. ''Second generation'' vertex detectors have demonstrated the feasibility of tagging heavy flavors by observing decay vertices, and are being used to search for anomalous decay topologies. These chambers have modest resolution on the scale of the effects they seek to measure, but are now well-understood and reliable tools. A generation of vertex detectors, considerably more ambitious, is under construction for experiments at SLC and LEP. They boast impact parameter resolution improved by a factor of four or more over previous detectors, and sub-millimeter track-pair resolution. The Mark II collaboration hopes to reach these goals with a high pressure precision drift chamber, and eventually surpass them with the addition of a silicon microstrip detector.

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

    International Nuclear Information System (INIS)

    Collins, P.

    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 ∼7mm from the beam axis at the edge, and the first sensitive strips at a radius of ∼8.2mm are exposed to maximum radiation doses of ∼0.6×10 14 1MeVn eq /cm 2 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 and D for the LHCb VELO Upgrade is outlined.

  19. 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}.

  20. Measurement of the Spin of the Omega- Hyperon at Babar

    International Nuclear Information System (INIS)

    Aubert, B.

    2006-01-01

    A measurement of the spin of the (Omega) - hyperon produced through the exclusive process Ξ c 0 → (Omega) - K + is presented using a total integrated luminosity of 116 fb -1 recorded with the BABAR detector at the e + e - asymmetric-energy B-Factory at SLAC. Under the assumption that the Ξ c 0 has spin 1/2, the angular distribution of the Λ from (Omega) - → ΛK - decay is inconsistent with all half-integer (Omega) - spin values other than 3/2. Lower statistics data for the process (Omega) c 0 → (Omega) - π + from a 230 fb -1 sample are also found to be consistent with (Omega) - spin 3/2. If the Ξ c 0 spin were 3/2, an (Omega) - spin of 5/2 cannot be excluded

  1. Recent Results on T and CP Violation at BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Perez Perez, Alejandro [Istituto Nazionale di Fisica Nucleare (INFN), Pisa (Italy).

    2015-02-06

    CP-violation (CPV) and Time-reversal violation (TRV) are intimately related through the CPT theorem: if one of these discrete symmetries is violated the other one has to be violated in such a way to conserve CPT. Although CPV in the B0B0-bar system has been established by the B-factories, implying indirectly TRV, there is still no direct evidence of TRV. We report on the observation of TRV in the B-meson system performed with a dataset of 468 × 106 BB-bar pairs produced in Υ(4S) decays collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. We also report on other CPV measurements recently performed on the B-meson system

  2. The New BaBar Data Reconstruction Control System

    International Nuclear Information System (INIS)

    Ceseracciu, Antonio

    2003-01-01

    The BaBar experiment is characterized by extremely high luminosity, a complex detector, and a huge data volume, with increasing requirements each year. To fulfill these requirements a new control system has been designed and developed for the offline data reconstruction system. The new control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is actively distributed, enforces the separation between different processing tiers by using different naming domains, and glues them together by dedicated brokers. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes this new control system, currently in use at SLAC and Padova on ∼450 CPUs organized in 12 farms

  3. The BaBar experiment's distributed computing model

    International Nuclear Information System (INIS)

    Boutigny, D.

    2001-01-01

    In order to face the expected increase in statistics between now and 2005, the BaBar experiment at SLAC is evolving its computing model toward a distributed multitier system. It is foreseen that data will be spread among Tier-A centers and deleted from the SLAC center. A uniform computing environment is being deployed in the centers, the network bandwidth is continuously increased and data distribution tools has been designed in order to reach a transfer rate of ∼100 TB of data per year. In parallel, smaller Tier-B and C sites receive subsets of data, presently in Kanga-ROOT format and later in Objectivity format. GRID tools will be used for remote job submission

  4. The BaBar Experiment's Distributed Computing Model

    International Nuclear Information System (INIS)

    Gowdy, Stephen J.

    2002-01-01

    In order to face the expected increase in statistics between now and 2005, the BaBar experiment at SLAC is evolving its computing model toward a distributed multi-tier system. It is foreseen that data will be spread among Tier-A centers and deleted from the SLAC center. A uniform computing environment is being deployed in the centers, the network bandwidth is continuously increased and data distribution tools has been designed in order to reach a transfer rate of ∼100 TB of data per year. In parallel, smaller Tier-B and C sites receive subsets of data, presently in Kanga-ROOT[1] format and later in Objectivity[2] format. GRID tools will be used for remote job submission

  5. Performance simulation of BaBar DIRC bar boxes in TORCH

    Science.gov (United States)

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

    2017-12-01

    TORCH is a large-area precision time-of-flight detector based on the DIRC principle. The DIRC bar boxes of the BaBar experiment at SLAC could possibly be reused to form a part of the TORCH detector time-of-flight wall area, proposed to provide positive particle identification of low momentum kaons in the LHCb experiment at CERN. For a potential integration of BaBar bar boxes into TORCH, new imaging readout optics are required. From the several designs of readout optics that have been considered, two are used in this paper to study the effect of BaBar bar optical imperfections on the detector reconstruction performance. The kaon-pion separation powers obtained from analysing simulated photon hit patterns show the performance reduction for a BaBar bar of non-square geometry compared to a perfectly rectangular cross section.

  6. submitter Performance simulation of BaBar DIRC bar boxes in TORCH

    CERN Document Server

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

    2017-01-01

    TORCH is a large-area precision time-of-flight detector based on the DIRC principle. The DIRC bar boxes of the BaBar experiment at SLAC could possibly be reused to form a part of the TORCH detector time-of-flight wall area, proposed to provide positive particle identification of low momentum kaons in the LHCb experiment at CERN. For a potential integration of BaBar bar boxes into TORCH, new imaging readout optics are required. From the several designs of readout optics that have been considered, two are used in this paper to study the effect of BaBar bar optical imperfections on the detector reconstruction performance. The kaon-pion separation powers obtained from analysing simulated photon hit patterns show the performance reduction for a BaBar bar of non-square geometry compared to a perfectly rectangular cross section.

  7. Exploitation of secondary vertex information at the CDF detector. Final report, 1991--1994

    International Nuclear Information System (INIS)

    Amidei, D.

    1995-01-01

    In the proposal for this work, submitted in November 1990, the author described the application of silicon micro-vertex tracking to hadron collider physics, and outlined a plan of involvement in the first such application, at the CDF Detector, studying p anti p collisions at √s = 1.8 TeV at the Fermilab Tevatron. The proposal included discussion on the use of silicon tracking in B physics measurements, and also some speculation on the ability of silicon tracking to aid in identification of the top quark. In the five years since this proposal, the author has played a significant role in the installation and commissioning of the first such silicon tracking device at a hadron collider, and the utilization of this device in the discovery of the top quark and the study of B production mechanisms. This paper is a summary of this work

  8. 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.

  9. 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\\.

  10. Secondary vertex detection at the SLC

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The vertex topology of a high energy e + e - interaction contains a wealth of information. These interactions copiously produce the tau lepton and hadrons containing the c and b quarks; all these particles decay within a millimeter or so of the primary interaction point, giving these interactions a rich secondary vertex structure. With suitable detectors, one can hope to reconstruct these vertices and so tag events with tau's, c's and b's; measure lifetimes and mixing angles; and perhaps directly measure the flavor of c and b jets. The spatial resolution and track-pair resolution required of such detectors demand detector development, but several techniques, including solid state microstrip and CCD detectors, pressurized drift chambers, and holographic bubbble chambers look promising. Vertex detection in the colliding beam environment has already yielded a measurement of the tau lifetime. The SLC, with its micron-sized beam and one-centimeter sized beam pipe is uniquely suited for these studies. Compared to conventional storage rings, it offers a well-defined and minute primary interaction point, the possibility of locating a detector within a centimeter of the interaction (an order of magnitude improvement over LEP), negligibly thin beam pipes, and a repetition rate low enough to permit novel detectors and readout schemes. This report discusses the physics accessible with vertex detectors, depicts the physics environment at 100 GeV - particle multiplicities, momenta, angular correlations, and topologies of charm decays, sketches the elements of a vertex detector, and, through some model studies evaluates the spatial resolution and track-pair resolution requirements, and summarizes the detector technologies which seem most promising for vertex detection

  11. Random tree growth by vertex splitting

    International Nuclear Information System (INIS)

    David, F; Dukes, W M B; Jonsson, T; Stefánsson, S Ö

    2009-01-01

    We study a model of growing planar tree graphs where in each time step we separate the tree into two components by splitting a vertex and then connect the two pieces by inserting a new link between the daughter vertices. This model generalizes the preferential attachment model and Ford's α-model for phylogenetic trees. We develop a mean field theory for the vertex degree distribution, prove that the mean field theory is exact in some special cases and check that it agrees with numerical simulations in general. We calculate various correlation functions and show that the intrinsic Hausdorff dimension can vary from 1 to ∞, depending on the parameters of the model

  12. 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.

  13. Primary vertex reconstruction at the ATLAS experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00301388; The ATLAS collaboration; Casper, D.; Hooberman, B.; Gui, B.; Lee, G.; Maurer, J.; Morley, A.; Pagan Griso, S.; Petersen, B.; Prokofiev, K.; Shan, L.; Shope, D.; Wharton, A.; Whitmore, B.; Zhang, M.

    2017-01-01

    These proceedings present the method and performance of primary vertex reconstruction at the ATLAS experiment during Runs 1 and 2 at the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of $\\sqrt{s} = 8$ TeV, and during 2015-2016 at $\\sqrt{s} = 13$ TeV. Some predictions toward future runs are also presented. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed.

  14. 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

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

    International Nuclear Information System (INIS)

    Chen, Xun

    2009-01-01

    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 + e - 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 procedures

  16. The Micro-Vertex-Detector for the P-bar ANDA experiment

    International Nuclear Information System (INIS)

    Zotti, Laura

    2013-01-01

    P-bar ANDA is a fixed target experiment that will be carried out at the future FAIR facility. P-bar ANDA will provide an excellent tool to address fundamental question in the field of hadronic physics, with a physic program that extends from the investigation of QCD (providing insight in the mechanisms of mass generation and confinement) to the test of fundamental symmetries. The Micro-Vertex-Detector located in the innermost part of the central tracking system will be composed by hybrid pixel and double-sided micro-strip silicon detectors. The Micro-Vertex-Detector will play an important role for the P-bar ANDA physics goals. The possibility to reconstruct the secondary vertices and the applicability of a precise D meson tagging is essential for the spectroscopy in the open charm sector and the charmonium mass region. To this aim the Micro-Vertex-Detector features a spatial resolution better than 100μm, a time resolution better than 20ns, a limited material budget, and a high data rate capability in a triggerless environment. An overview of the Micro-Vertex-Detector related to the physics goals will be presented.

  17. Improving vertex position determination by using a kinematic fit

    International Nuclear Information System (INIS)

    Forden, G.E.; Saxon, D.H.

    1985-05-01

    A method is developed for improving decay vertex reconstruction by using kinematic fits. This is applied to generated charm meson decays. An improvement of 16% in the vertex position measurement along the flight path is achieved. (author)

  18. The micro vertex detector for the anti PANDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Esch, Simone [Forschungszentrum Juelich (Germany); Collaboration: PANDA-Collaboration

    2015-07-01

    The anti PANDA detector is one of the main experiments at the upcoming Facility for Antiproton and Ion Research (FAIR), which is under construction in Darmstadt, Germany. The fixed-target experiment will explore anti pp annihilations with intense, phase space-cooled beams with momenta between 1.5 and 15 GeV/c. One aim of the detector is to perform high precision measurements of particles like excited charmonium and D mesons. Essential for background suppression is the tagging of D mesons by measuring their decay point. Therefore, a Micro Vertex Detector (MVD) is planned at anti PANDA as the innermost tracking detector. The MVD aims to reconstruct vertices with a resolution better than 100 μm to cope with the decay length of the D{sup ±} mesons (cτ=315 μm) produced with a mean βγ=2. The detector consists of silicon pixel and double-sided silicon strip detectors, arranged in four barrel layers and six disk layers. An overview of the MVD is given in this talk. Recent developments like laboratory and testbeam results of the current pixel front-end ASIC prototype ToPix 4 are shown. The concept of the newly developed strip front-end ASIC PASTA is presented.

  19. Intertwiner dynamics in the flipped vertex

    Energy Technology Data Exchange (ETDEWEB)

    Alesci, Emanuele; Bianchi, Eugenio; Magliaro, Elena; Perini, Claudio, E-mail: alesci@fis.uniroma3.i, E-mail: e.bianchi@sns.i, E-mail: elena.magliaro@gmail.co, E-mail: claude.perin@libero.i [Centre de Physique Theorique de Luminy, Case 907, F-13288 Marseille (France)

    2009-09-21

    We continue the semiclassical analysis, started in a previous paper, of the intertwiner sector of the flipped vertex spinfoam model. We use independently both a semi-analytical and a purely numerical approach, finding the correct behavior of wavepacket propagation and physical expectation values. In the end, we show preliminary results about correlation functions.

  20. 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.

  1. Twisted Frobenius identies from vertex operator superalgebras

    Czech Academy of Sciences Publication Activity Database

    Zuevsky, Alexander

    2017-01-01

    Roč. 2017, 9 November (2017), č. článku 2340410. ISSN 1687-9120 Institutional support: RVO:67985840 Keywords : vertex operator superalgebras * intertwining operators * Riemann surfaces Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.643, year: 2016 https://www.hindawi.com/journals/amp/2017/2340410/

  2. Algebraic characterization of the Witten vertex

    International Nuclear Information System (INIS)

    Embacher, F.

    1989-01-01

    The Witten vertex of open bosonic string field theory is characterized by a set of algebraic properties written down in the Fock-space operator formalism. The typical 3-string overlap structure as well as the correct ghost midpoint insertion are not required from the outset but arise as consequences. 20 refs. (Author)

  3. 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.

  4. Cluster algebras bases on vertex operator algebras

    Czech Academy of Sciences Publication Activity Database

    Zuevsky, Alexander

    2016-01-01

    Roč. 30, 28-29 (2016), č. článku 1640030. ISSN 0217-9792 Institutional support: RVO:67985840 Keywords : cluster alegbras * vertex operator algebras * Riemann surfaces Subject RIV: BA - General Mathematics Impact factor: 0.736, year: 2016 http://www.worldscientific.com/doi/abs/10.1142/S0217979216400300

  5. 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...

  6. Lifetime tests for MAC vertex chamber

    International Nuclear Information System (INIS)

    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

  7. Perturbative quantum field theory via vertex algebras

    International Nuclear Information System (INIS)

    Hollands, Stefan; Olbermann, Heiner

    2009-01-01

    In this paper, we explain how perturbative quantum field theory can be formulated in terms of (a version of) vertex algebras. Our starting point is the Wilson-Zimmermann operator product expansion (OPE). Following ideas of a previous paper (S. Hollands, e-print arXiv:0802.2198), we consider a consistency (essentially associativity) condition satisfied by the coefficients in this expansion. We observe that the information in the OPE coefficients can be repackaged straightforwardly into 'vertex operators' and that the consistency condition then has essentially the same form as the key condition in the theory of vertex algebras. We develop a general theory of perturbations of the algebras that we encounter, similar in nature to the Hochschild cohomology describing the deformation theory of ordinary algebras. The main part of the paper is devoted to the question how one can calculate the perturbations corresponding to a given interaction Lagrangian (such as λφ 4 ) in practice, using the consistency condition and the corresponding nonlinear field equation. We derive graphical rules, which display the vertex operators (i.e., OPE coefficients) in terms of certain multiple series of hypergeometric type.

  8. Study of the breaking of the CP symmetry in the BABAR experiment; Etude de la violation de la symetrie CP dans l'experience BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Ganjour, S

    2007-09-15

    This report summarizes my scientific activities from 1995 to 2007. During this period of time, my research work was related to the particle physics experiment BABAR. The BABAR experiment has been running since 1999 at the PEP-II e{sup +}e{sup -} asymmetric B-factory located at SLAC. This experiment searches for CP violation in the system of B mesons and tests the Standard Model through the measurements of the angles and the sides of the Unitarity Triangle. My research work is divided in five main topics: study of the BABAR magnet system and measurement of the magnetic field in the central tracking volume; project of the particle identification system based on aerogel counters for the forward region of the detector; conception of the magnetic shield and measurements of the fringe field in the region of photomultipliers of the DIRC (Detector of Internally Reflected Cherenkov light) system, the principal particle identification system of BABAR; development of the partial reconstruction technique of B mesons and study of the B{sup 0} {yields} D{sub s}{sup *} + D{sup *-} decays; measurement of CP violation in the B{sup 0} {yields} D{sup *{+-}}{pi}{sup {+-}} decays and constraint on the Unitary Triangle parameter sin(2{beta} + {gamma}) using these decays. (author)

  9. A Measurement of the CP Parameter sine two beta Using Fully Reconstructed B to ccbar Decays at the BABAR Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Charles, Eric A

    2003-04-22

    This dissertation presents a measurement of the time-dependent CP-violating asymmetries in the neutral B-meson system performed with data collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample used consists of 29.7 fb{sup -1} collected at the {Upsilon}(4S) resonance and 3.9 fb{sup -1} collected off-resonance. We analyze three samples of fully-reconstructed B-meson decays: a sample of decays to CP eigenstates in the modes J/{psi} K{sub s}{sup 0}, {psi}(2S) K{sub s}{sup 0}, {chi}{sub cl} K{sub s}{sup 0}, and J/{psi} K*{sup 0} (822 events); as well as both charged (14304 events) and neutral (10457 events) B decays to flavor-eigenstates including D{sup (*)} and {pi}/{rho}/{alpha}{sub 1}. In all cases, the proper decay time difference between the reconstructed B-meson and the recoiling B-meson is determined by measuring the separation of the two decay vertices. Furthermore, the flavor of the recoiling B-meson is tagged using a neural network algorithm. We use the flavor-eigenstate samples to calibrate both the vertexing and tagging performance. We measure the amplitude of the CP asymmetry, sin2{beta} = 0.61 {+-} 0.14(stat) {+-} 0.06(syst). These results indicate the existence of indirect CP violation in the B-meson system.

  10. On fermionic representation of the framed topological vertex

    International Nuclear Information System (INIS)

    Deng, Fusheng; Zhou, Jian

    2015-01-01

    The Gromov-Witten invariants of ℂ"3 with branes is encoded in the topological vertex which has a very complicated combinatorial expression. A simple formula for the topological vertex was proposed by Aganagic et al. in the fermionic picture. We will propose a similar formula for the framed topological vertex and prove it in the case when there are one or two branes.

  11. The vertex Zagreb indices of some graph operations

    Directory of Open Access Journals (Sweden)

    N. De

    2016-12-01

    Full Text Available Recently, Tavakoli et al. introduced a new version of Zagreb indices, named as vertex Zagreb indices. In this paper explicit expressions of different graphs operations of vertex Zagreb indices are presented and also as an application, explicit formulas for vertex Zagreb indices of some chemical graphs are obtained.

  12. Certain extensions of vertex operator algebras of affine type

    International Nuclear Information System (INIS)

    Li Haisheng

    2001-01-01

    We generalize Feigin and Miwa's construction of extended vertex operator (super)algebras A k (sl(2)) for other types of simple Lie algebras. For all the constructed extended vertex operator (super)algebras, irreducible modules are classified, complete reducibility of every module is proved and fusion rules are determined modulo the fusion rules for vertex operator algebras of affine type. (orig.)

  13. RARE B DECAYS AND DIRECT CP VIOLATION AT BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Laplace, Sandrine

    2003-09-26

    The search for rare B decays and direct CF violation at BABAR is described. The following measurements (based on integrated luminosities ranging from 56.4 to 81.9 fb{sup -1}) are summarized: the inclusive branching fractions and direct CF asymmetries of B{sup +} {yields} h{sup +}h{sup -}H{sup +} (h = {pi}, K), the exclusive branching fractions of B{sup +} {yields} K{sup +}{pi}{sup -}{pi}{sup +} (where significant signals are observed in the B{sup +} {yields} K*{sup 0}(892){pi}{sup +}, B{sup +} {yields} f{sub 0}(98)K{sup +}, B{sup +} {yields} {chi}{sub c0}K{sup +}, B{sup +} {yields} {bar D}{sup 0}{pi}{sup +} and B{sup +} {yields} higher K*{sup 0}{pi}{sup +} channels), the branching fractions of B{sup +} {yields} {rho}{sup 0}{rho}{sup +} and B{sup +} {yields} {rho}{sup 0} K*{sup +}, and finally, the branching fractions, the longitudinal components, and the direct CF asymmetries in B {yields} {phi}K*.

  14. The BaBar Data Reconstruction Control System

    International Nuclear Information System (INIS)

    Ceseracciu, A

    2005-01-01

    The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a Control System has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on ∼450 CPUs organized in 9 farms

  15. Charmed-B decays at BaBar

    International Nuclear Information System (INIS)

    Tisserand, Vincent

    2004-01-01

    We present recent results on charmed-B decays using data collected by the BaBaR experiment at the PEP-II storage ring. This report is subdivided in 3 parts. In a first step, we present preliminary results on the measurement of the branching fractions of seven color-suppressed anti B 0 -meson decays into D (*)0 π 0 , D (*)0 η, D (*)0 ω, and D 0 η ' . Then we discuss the preliminary measurement of the ratio of Cabibbo-suppressed to Cabibbo-favored branching fractions B(B - →D 0 K - )/B(B - →D 0 π - ), where the D 0 is possibly reconstructed in the CP-even π - π + and K - K + modes. For the D 0 decays into CP-eigenstates, a search for a direct CP asymmetry is performed. For the same category of decay processes, we show a precise preliminary measurement of both the branching fraction of B - decaying to D *0 K *- and of the fraction of longitudinal polarization in this decay. Finally, we present a study where the 22 possible B decays to anti D (*) D * K are reconstructed exclusively. The branching fractions of the anti B 0 and of the B + to anti D (*) D (*) K are presented and a search for decays B→anti D (*) D sJ + (→D (*)0 K + ), where the D sJ + represents the orbitally excited D s states, is also discussed. (orig.)

  16. 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.

  17. 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...

  18. Use of a track and vertex processor in a fixed-target charm experiment

    International Nuclear Information System (INIS)

    Schub, M.H.; Carey, T.A.; Hsiung, Y.B.; Kaplan, D.M.; Lee, C.; Miller, G.; Sa, J.; Teng, P.K.

    1996-01-01

    We have constructed and operated a high-speed parallel-pipelined track and vertex processor and used it to trigger data acquisition in a high-rate charm and beauty experiment at Fermilab. The processor uses information from hodoscopes and wire chambers to reconstruct tracks in the bend view of a magnetic spectrometer, and uses these tracks to find the corresponding tracks in a set of silicon-strip detectors. The processor then forms vertices and triggers the experiment if at least one vertex is downstream of the target. Under typical charm running conditions, with an interaction rate of ∼5 MHz, the processor rejects 80-90% of lower-level triggers while maintaining efficiency of ∼70% for two-prong D-meson decays. (orig.)

  19. A 96-channel, 500 ps resolution TDC board for the BaBar experiment at SLAC

    CERN Document Server

    Minutoli, S

    2000-01-01

    A TDC board has been designed and built to complete the readout of the Instrumented Flux Return of the BABAR experiment at the Stanford Linear Accelerator Center. The board has 96 input channels and makes use of 3 general purpose TDC chips designed at CERN, with time resolution up to 500 ps and configurable via a Test Access Port (IEEE standard 1149). Data are stored before readout in a multievent buffer. Communication with BABAR DAQ system is realized through 3 serial lines on the backplane connector. All the logic, including internal registers and the interfaces with the BABAR protocol and the TAP controller, is implemented in two fast FPGAs. The board is designed to work at 59.5 MHz clock frequency. (7 refs).

  20. Final Report: BaBar Detector and Experimental at SLAC, September 30, 1998 - September 29, 1999

    International Nuclear Information System (INIS)

    Judd, Dennis J.

    2000-01-01

    The Prairie View AandM University High Energy Physics Group with its contingent of three undergraduates physics majors, joined the BaBar Collaboration at SLAC in September 1994. BaBar is the experiment and detector running in the PEP-II ring at SLAC as part of the Asymmetric B Factory project there to study CP violation and heavy flavor physics. The focus of our effort before this year was with the Muon/Neutral Hadron Detector/Instrumented Flux Return (IFD) subgroup within the BaBar collaboration, and particularly with the GEANT simulation of the IFR-. With the GEANT3 simulation essentially FR-ozen, and the GEANT4 full simulation of the IFR- done, we have decided to redirect our efforts toward other areas

  1. Limited Streamer Tubes for the BaBar Instrumented Flux Return Upgrade

    International Nuclear Information System (INIS)

    Lu, C.

    2005-01-01

    Starting from the very beginning of their operation the efficiency of the RPC chambers in the BaBar Instrumented Flux Return (IFR) has suffered serious degradation. After intensive investigation, various remediation efforts had been carried out, but without success. As a result the BaBar collaboration decided to replace the dying barrel RPC chambers about two years ago. To study the feasibility of using the Limited Streamer Tube (LST) as the replacement of RPC we carried out an R and D program that has resulted in BaBar's deciding to replace the barrel RPC's with LST's. In this report we summarize the major detector R and D results, and leave other issues of the IFR system upgrade to the future publications

  2. Final Report BaBar Detector and Experimental at SLAC, September 30, 1998 - September 29, 1999

    CERN Document Server

    Judd, D J

    2000-01-01

    The Prairie View AandM University High Energy Physics Group with its contingent of three undergraduates physics majors, joined the BaBar Collaboration at SLAC in September 1994. BaBar is the experiment and detector running in the PEP-II ring at SLAC as part of the Asymmetric B Factory project there to study CP violation and heavy flavor physics. The focus of our effort before this year was with the Muon/Neutral Hadron Detector/Instrumented Flux Return (IFD) subgroup within the BaBar collaboration, and particularly with the GEANT simulation of the IFR-. With the GEANT3 simulation essentially FR-ozen, and the GEANT4 full simulation of the IFR- done, we have decided to redirect our efforts toward other areas.

  3. 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.

  4. Primary vertex reconstruction with the ATLAS detector

    International Nuclear Information System (INIS)

    Meloni, F.

    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.

  5. The three-gluon vertex of QCD

    International Nuclear Information System (INIS)

    Koller, K.; Zerwas, P.M.; Walsh, T.F.

    1978-12-01

    We show how the Q 2 evolution of gluon jets can be used to provide indirect but strong evidence for the 3 gluon vertex of QCD. We propose looking for this evolution in the QantiQ → 3G → hadrons decay of successive 1 3 S 1 quarkonium states. The results apply to other processes if G jets can be isolated. (orig.) [de

  6. Nonperturbative Aspects of Axial Vector Vertex

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; CHEN Xiang-Song; WANG Fan; CHANG Chao-Hsi; ZHAO En-Guang

    2002-01-01

    It is shown how the axial vector current of current quarks is related to that of constituent quarks within the framework of the global color symmetry model.Gluon dressing of the axial vector vertex and the quark self-energy functions are described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger Dyson equation in the rainbow approximation,respectively.

  7. The ZEUS vertex detector: Design and prototype

    International Nuclear Information System (INIS)

    Alvisi, C.; Anzivino, G.; Arzarello, F.; Barbagli, G.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, G.; Bruni, P.; Camerini, U.; Cara Romeo, G.; Castellini, G.; Chiarini, M.; Cifarelli, L.; Cindolo, F.; Ciralli, F.; Contin, A.; Costa, M.; D'Auria, S.; Del Papa, C.; De Pasquale, S.; Fiori, F.; Forte, A.; Frasconi, F.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Lisowski, B.; Maccarrone, G.; Margotti, A.; Massam, T.; Nania, R.; O'Shea, V.; Palmonari, F.; Pelfer, P.; Pilastrini, R.; Qian, S.; Sartorelli, G.; Schioppa, M.; Susinno, G.; Timellini, R.; Zichichi, A.; Bologna Univ.; Cosenza Univ.; Florence Univ.; Istituto Nazionale di Fisica Nucleare, Bologna; Istituto Nazionale di Fisica Nucleare, Florence; Istituto Nazionale di Fisica Nucleare, Frascati; Consiglio Nazionale delle Ricerche, Florence

    1991-01-01

    A gas vertex detector, operated with dimethylether (DME) at atmospheric pressure, is presently being built for the ZEUS experiment at HERA. Its main design features, together with the performances of a prototype measured at various operating voltages, particle rates and geometrical conditions on a CERN Proton Synchrotron test beam, are presented. A spatial resolution down to 35 μm and an average wire efficiency of 96% have been achieved, for a 3 mm gas gap relative to each sense wire. (orig.)

  8. Vertex chamber for the KEDR detector

    International Nuclear Information System (INIS)

    Aulchenko, V.M.; Chilingarov, A.G.; Kolachev, G.M.; Lazarenko, O.B.; Nagaslaev, V.P.; Romanov, L.V.

    1989-01-01

    The project and design of the vertex chamber for the KEDR detector is described. The chamber consists of 6 cylindrical layers of tubes with 10 mm diameter and 800 mm length. The tubes are made of 20 μm thick aluminized mylar. The prototype tests show that it is possible to achieve a resolution of 20-30 μm using the cool gas mixtures. (orig.)

  9. Search for Exclusive Electroweak Penguin Decays at BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsova, Natalia

    2003-04-03

    This dissertation describes the search for the flavor-changing neutral current decays B {yields} K{ell}{sup +}{ell}{sup -} and B {yields} K*(892){ell}{sup +}{ell}{sup -}, performed using a sample of (22.7 {+-} 0.4) x 10{sup 6} {Upsilon}(4S) {yields} B {bar B} decays collected with the BABAR detector at the PEP-II B Factory. The following final states have been reconstructed: B{sup +} {yields} K{sup +}{ell}{sup +}{ell}{sup -}, B{sup 0} {yields} K{sup 0}{ell}{sup +}{ell}{sup -} (K{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}), B{sup +} {yields} K*{sup +}{ell}{sup +}{ell}{sup -} (K*{sup +} {yields} K{sub s}{sup 0}{pi}{sup +}), and B{sup 0} {yields} K*{sup 0}{ell}{sup +}{ell}{sup -} (K*{sup 0} {yields} K{sup +}{pi}{sup -}), where {ell}{sup +}{ell}{sup -}is either an e{sup +}e{sup -} or {mu}{sup +}{mu}{sup -} pair. The established 90% C.L. upper limits are: {Beta}(B {yields} K{ell}{sup +}{ell}{sup -}) < 0.6 x 10{sup -6}; {Beta}(B {yields} K*{ell}{sup +}{ell}{sup -}) < 2.5 x 10{sup -6}. These limits represent a significant improvement over previously published results and are close to Standard Model predictions.

  10. Flipped spinfoam vertex and loop gravity

    Energy Technology Data Exchange (ETDEWEB)

    Engle, Jonathan; Pereira, Roberto [CPT, CNRS Case 907, Universite de la Mediterranee, F-13288 Marseille (France); Rovelli, Carlo [CPT, CNRS Case 907, Universite de la Mediterranee, F-13288 Marseille (France)], E-mail: rovelli@cpt.univ-mrs.fr

    2008-07-21

    We introduce a vertex amplitude for 4d loop quantum gravity. We derive it from a conventional quantization of a Regge discretization of euclidean general relativity. This yields a spinfoam sum that corrects some difficulties of the Barrett-Crane theory. The second class simplicity constraints are imposed weakly, and not strongly as in Barrett-Crane theory. Thanks to a flip in the quantum algebra, the boundary states turn out to match those of SO(3) loop quantum gravity-the two can be identified as eigenstates of the same physical quantities-providing a solution to the problem of connecting the covariant SO(4) spinfoam formalism with the canonical SO(3) spin-network one. The vertex amplitude is SO(3) and SO(4)-covariant. It rectifies the triviality of the intertwiner dependence of the Barrett-Crane vertex, which is responsible for its failure to yield the correct propagator tensorial structure. The construction provides also an independent derivation of the kinematics of loop quantum gravity and of the result that geometry is quantized.

  11. 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.

  12. Markov branching in the vertex splitting model

    International Nuclear Information System (INIS)

    Stefánsson, Sigurdur Örn

    2012-01-01

    We study a special case of the vertex splitting model which is a recent model of randomly growing trees. For any finite maximum vertex degree D, we find a one parameter model, with parameter α element of [0,1] which has a so-called Markov branching property. When D=∞ we find a two parameter model with an additional parameter γ element of [0,1] which also has this feature. In the case D = 3, the model bears resemblance to Ford's α-model of phylogenetic trees and when D=∞ it is similar to its generalization, the αγ-model. For α = 0, the model reduces to the well known model of preferential attachment. In the case α > 0, we prove convergence of the finite volume probability measures, generated by the growth rules, to a measure on infinite trees which is concentrated on the set of trees with a single spine. We show that the annealed Hausdorff dimension with respect to the infinite volume measure is 1/α. When γ = 0 the model reduces to a model of growing caterpillar graphs in which case we prove that the Hausdorff dimension is almost surely 1/α and that the spectral dimension is almost surely 2/(1 + α). We comment briefly on the distribution of vertex degrees and correlations between degrees of neighbouring vertices

  13. Complex growing networks with intrinsic vertex fitness

    International Nuclear Information System (INIS)

    Bedogne, C.; Rodgers, G. J.

    2006-01-01

    One of the major questions in complex network research is to identify the range of mechanisms by which a complex network can self organize into a scale-free state. In this paper we investigate the interplay between a fitness linking mechanism and both random and preferential attachment. In our models, each vertex is assigned a fitness x, drawn from a probability distribution ρ(x). In Model A, at each time step a vertex is added and joined to an existing vertex, selected at random, with probability p and an edge is introduced between vertices with fitnesses x and y, with a rate f(x,y), with probability 1-p. Model B differs from Model A in that, with probability p, edges are added with preferential attachment rather than randomly. The analysis of Model A shows that, for every fixed fitness x, the network's degree distribution decays exponentially. In Model B we recover instead a power-law degree distribution whose exponent depends only on p, and we show how this result can be generalized. The properties of a number of particular networks are examined

  14. Energy Calibration of the BaBar EMC Using the Pi0 Invariant Mass Method

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, David J.; /Manchester U.

    2007-04-06

    The BaBar electromagnetic calorimeter energy calibration method was compared with the local and global peak iteration procedures, of Crystal Barrel and CLEO-II. An investigation was made of the possibility of {Upsilon}(4S) background reduction which could lead to increased statistics over a shorter time interval, for efficient calibration runs. The BaBar software package was used with unreconstructed data to study the energy response of the calorimeter, by utilizing the {pi}{sup 0} mass constraint on pairs of photon clusters.

  15. Operational Aspects of Dealing with the Large BaBar Data Set

    Energy Technology Data Exchange (ETDEWEB)

    Trunov, Artem G

    2003-06-13

    To date, the BaBar experiment has stored over 0.7PB of data in an Objectivity/DB database. Approximately half this data-set comprises simulated data of which more than 70% has been produced at more than 20 collaborating institutes outside of SLAC. The operational aspects of managing such a large data set and providing access to the physicists in a timely manner is a challenging and complex problem. We describe the operational aspects of managing such a large distributed data-set as well as importing and exporting data from geographically spread BaBar collaborators. We also describe problems common to dealing with such large datasets.

  16. Vertex detectors - lectures presented at the Advanced Study Institute on techniques and concepts of high energy physics, St. Croix, June 1986

    International Nuclear Information System (INIS)

    Damerell, C.J.S.

    1986-07-01

    High precision vertex detectors can be used to identify the decay products of parent particles which have lifetimes of the order 10 -13 seconds. The paper summarises the performance achieved by a variety of techniques, and proceeds to a detailed discussion of the current status and potential of silicon detectors for high precision tracking. (author)

  17. 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...

  18. 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...

  19. 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, ...

  20. 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, ...

  1. 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.

  2. Search for Invisible Decays of a Dark Photon Produced in e(+)e(-) Collisions at BABAR

    NARCIS (Netherlands)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Brown, D. N.; Derdzinski, M.; Giuffrida, A.; Kolomensky, Yu. G.; Fritsch, M.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Gary, J. W.; Long, O.; Eisner, A. M.; Lockman, W. S.; Vazquez, W. Panduro; Chao, D. S.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Rohrken, M.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Smith, J. G.; Wagner, S. R.; Bernard, D.; Verderi, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rotondo, M.; Zallo, A.; Passaggio, S.; Patrignani, C.; Lacker, H. M.; Bhuyan, B.; Mallik, U.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Le Diberder, F.; Lutz, A. M.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Banerjee, Sw.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Robertson, S. H.; Dey, B.; Neri, N.; Palombo, F.; Cheaib, R.; Cremaldi, L.; Godang, R.; Summers, D. J.; Taras, P.; De Nardo, G.; Sciacca, C.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Gaz, A.; Margoni, M.; Posocco, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Calderini, G.; Chauveau, J.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Rossi, A.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Rama, M.; Rizzo, G.; Walsh, J. J.; Smith, A. J. S.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Pilloni, A.; Piredda, G.; Buenger, C.; Dittrich, S.; Gruenberg, O.; Hess, M.; Leddig, T.; Voss, C.; Waldi, R.; Adye, T.; Wilson, F. F.; Emery, S.; Vasseur, G.; Aston, D.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Luitz, S.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Ratcliff, B. N.; Roodman, A.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Purohit, M. V.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Schwitters, R. F.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Albert, J.; Beaulieu, A.; Bernlochner, F. U.; Kowalewski, R.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Prepost, R.

    2017-01-01

    We search for single-photon events in 53  fb−1 of e+e− collision data collected with the BABAR detector at the PEP-II B-Factory. We look for events with a single high-energy photon and a large missing momentum and energy, consistent with production of a spin-1 particle A′ through the process

  3. Databases for BaBar Datastream Calibrations and Prompt Reconstruction Processes

    International Nuclear Information System (INIS)

    Bartelt, John E

    1998-01-01

    We describe the design of databases used for performing datastream calibrations in the BABAR experiment, involving data accumulated on multiple processors and possibly over several blocks of events (''ConsBlocks''). The database for tracking the history and status of the ConsBlocks, along with similar databases needed by ''Prompt Reconstruction'' are also described

  4. Electronics for the BaBar experiment at PEP-II: A short review

    International Nuclear Information System (INIS)

    Cavallo, N.

    1999-01-01

    The BaBar detector at the SLAC B-Factory is currently under construction and scheduled for completion at the end of 1998. An innovative data acquisition architecture design has been adopted. Following a brief introduction on the main requirements and concepts, an overview of the architecture, the hardware implementation and status will be presented

  5. BABAR - the detector for the PEP II B Factory at SLAC

    International Nuclear Information System (INIS)

    Lueth, V.

    1994-09-01

    BABAR refers to the detector that is being designed for the PEP II B-Factory at SLAC to perform a comprehensive study of CP violation in B meson decays. The design requirements and the principal detector components are briefly described. A summary of the expected physics performance is presented

  6. Study of the breaking of the CP symmetry in the BABAR experiment

    International Nuclear Information System (INIS)

    Ganjour, S.

    2007-09-01

    This report summarizes my scientific activities from 1995 to 2007. During this period of time, my research work was related to the particle physics experiment BABAR. The BABAR experiment has been running since 1999 at the PEP-II e + e - asymmetric B-factory located at SLAC. This experiment searches for CP violation in the system of B mesons and tests the Standard Model through the measurements of the angles and the sides of the Unitarity Triangle. My research work is divided in five main topics: study of the BABAR magnet system and measurement of the magnetic field in the central tracking volume; project of the particle identification system based on aerogel counters for the forward region of the detector; conception of the magnetic shield and measurements of the fringe field in the region of photomultipliers of the DIRC (Detector of Internally Reflected Cherenkov light) system, the principal particle identification system of BABAR; development of the partial reconstruction technique of B mesons and study of the B 0 → D s * + D *- decays; measurement of CP violation in the B 0 → D *± π ± decays and constraint on the Unitary Triangle parameter sin(2β + γ) using these decays. (author)

  7. CPLEAR and BaBar: CP violation in all its states

    CERN Document Server

    Yeche, Christophe

    2003-01-01

    This report of French 'Habilitation a diriger les recherches' summarizes my scientific activity from 1993 to 2003. During this decade, my research work was related to two particle physics experiments: CPLEAR and BABAR. The first one, CPLEAR, has recorded data from 1988 to 1995 on the low energy anti-proton ring (LEAR) at CERN. This experiment was devoted to the study of T, CPT et CP discrete symmetries. The second experiment, BABAR, has been running since 1999, on the PEP-II B factory at SLAC. This experiment searches for CP violation and tests the Standard Model through the measurements of the angles and the sides of the Unitarity Triangle. My research work is divided in five main topics: Study of CP and CPT violation in K0 → π+ π- decays; Performance optimization of the particle identification detector (DIRC) of the BABAR experiment; B meson tagging in BABAR experiment; Δmd measurement and Search for CP and T violation in mixing with dilepton events; Search for CP violation in B0 → ρ± π± and B0 �...

  8. The BaBar detector for muon identification and neutral hadron detection

    International Nuclear Information System (INIS)

    Paolucci, P.; Evangelista, C.; Palano, A.; Baldini, R.; Calcaterra, A.; De Sangro, R.; Piccolo, M.; Zallo, A.; Peruzzi, I.; Buzzo, A.; Contri, R.; Crosetti, G.; Monge, R.; Passaggio, S.; Patrignani, C.; Pia, M.G.; Santroni, A.; Bionta, R.M.; van Bibber, K.; Wenaus, T.J.; Wright, D.M.; Cavallo, N.; Carlino, G.; Lista, L.; Mele, S.; Parascandolo, P.; Piccolo, D.; Sciacca, C.; Johnson, J.R.

    1996-01-01

    The BaBar experiment is projected to study CP violation in B decays. Muon detection and K L 0 identification are achieved by an instrumented flux return (IFR) system based on resistive plate chamber detectors. In this paper the general layout of the IFR system will be described. (orig.)

  9. The automated stringing system for the BaBar drift chamber

    International Nuclear Information System (INIS)

    Borsato, E.; Caracciolo, R.; Fanin, C.; Galeazzi, F.; Morandin, M.; Santi, S.; Voci, C.; Bronzini, F.; Buccheri, A.; Ferroni, F.; Fratini, K.; Morganti, S.; Patel, P.M.; Pelosi, A.; Piredda, G.; Fernholz, R.; Henderson, R.; Kelsey, M.

    2000-01-01

    After discussing the motivations for the project, the automated equipment used for the BaBar Drift Chamber stringing is described. Details are given mainly concerning the crucial points of setting-up and calibration. The focus is on the high accuracy reached by a large and complex mechanical tool

  10. studies of radiative penguin decays at BaBar (*) + - * -6 * ' * * * -E ...

    Indian Academy of Sciences (India)

    We summarize results on a number of observations of penguin dominated radiative decays of the B meson. Such decays are forbidden at tree level and proceed via electroweak loops. As such they may be sensitive to physics beyond the standard model. The observations have been made at the BaBar experiment at PEP-II, ...

  11. Numerical indications on the semiclassical limit of the flipped vertex

    Energy Technology Data Exchange (ETDEWEB)

    Magliaro, Elena; Perini, Claudio; Rovelli, Carlo [Centre de Physique Theorique de Luminy , Case 907, F-13288 Marseille (France)

    2008-05-07

    We introduce a technique for testing the semiclassical limit of a quantum gravity vertex amplitude. The technique is based on the propagation of a semiclassical wave packet. We apply this technique to the newly introduced 'flipped' vertex in loop quantum gravity, in order to test the intertwiner dependence of the vertex. Under some drastic simplifications, we find very preliminary, but surprisingly good numerical evidence for the correct classical limit.

  12. Loop vertex expansion for higher-order interactions

    Science.gov (United States)

    Rivasseau, Vincent

    2018-05-01

    This note provides an extension of the constructive loop vertex expansion to stable interactions of arbitrarily high order, opening the way to many applications. We treat in detail the example of the (\\bar{φ } φ )^p field theory in zero dimension. We find that the important feature to extend the loop vertex expansion is not to use an intermediate field representation, but rather to force integration of exactly one particular field per vertex of the initial action.

  13. Pion-nucleon vertex function with one nucleon off shell

    International Nuclear Information System (INIS)

    Mizutani, T.; Rochus, P.

    1979-01-01

    The pion-nucleon vertex function with an off-mass-shell nucleon is obtained through sideways dispersion relations with the P 11 and S 11 pion-nucleon phase shifts as only input. Contrary to the recent calculation of Nutt and Shakin, we find that the proper and improper vertex functions behave quite differently, indicating the importance of the nucleon propagator dressing. In particular the proper vertex function is found to have two poles in the unphysical region

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

    International Nuclear Information System (INIS)

    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)

  15. The Mark II Vertex Drift Chamber

    International Nuclear Information System (INIS)

    Alexander, J.P.; Baggs, R.; Fujino, D.

    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 μm spatial resolution and 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 2 mixtures are presented. 10 refs., 12 figs., 1 tab

  16. Loop-quantum-gravity vertex amplitude.

    Science.gov (United States)

    Engle, Jonathan; Pereira, Roberto; Rovelli, Carlo

    2007-10-19

    Spin foam models are hoped to provide the dynamics of loop-quantum gravity. However, the most popular of these, the Barrett-Crane model, does not have the good boundary state space and there are indications that it fails to yield good low-energy n-point functions. We present an alternative dynamics that can be derived as a quantization of a Regge discretization of Euclidean general relativity, where second class constraints are imposed weakly. Its state space matches the SO(3) loop gravity one and it yields an SO(4)-covariant vertex amplitude for Euclidean loop gravity.

  17. Vertex ring-indexed Lie algebras

    International Nuclear Information System (INIS)

    Fairlie, David; Zachos, Cosmas

    2005-01-01

    Infinite-dimensional Lie algebras are introduced, which are only partially graded, and are specified by indices lying on cyclotomic rings. They may be thought of as generalizations of the Onsager algebra, but unlike it, or its sl(n) generalizations, they are not subalgebras of the loop algebras associated with sl(n). In a particular interesting case associated with sl(3), their indices lie on the Eisenstein integer triangular lattice, and these algebras are expected to underlie vertex operator combinations in CFT, brane physics, and graphite monolayers

  18. The BaBar LST Detector High Voltage System: Design And Implementation

    International Nuclear Information System (INIS)

    Benelli, G.; Honscheid, K.; Lewis, E.A.; Regensburger, J.J.; Smith, D.S.; Ohio State U.

    2006-01-01

    In 2004, the first two sextants of the new Limited Streamer Tube (LST) detector were installed in the BABAR experiment to replace the ageing Resistive Plate Chambers (RPCs) as active detectors for the BABAR Instrumented Flux Return (IFR) muon system. Each streamer tube of the new detector consists of 8 cells. The cell walls are coated with graphite paint and a 100 (micro)m wire forms the anode. These wires are coupled in pairs inside the tubes resulting in 4 independent two-cell segments per LST. High voltage (HV) is applied to the 4 segments through a custom connector that also provides the decoupling capacitor to pick up the detector signals from the anode wires. The BABAR LST detector is operated at 5.5 kV. The high voltage system for the LST detector was designed and built at The Ohio State University (OSU HVPS). Each of the 25 supplies built for BaBar provides 80 output channels with individual current monitoring and overcurrent protection. For each group of 20 channels the HV can be adjusted between 0 and 6 kV. A 4-fold fan-out is integrated in the power supplies to provide a total of 320 outputs. The power supplies are controlled through built-in CANbus and Ethernet (TCP/IP) interfaces. In this presentation we will discuss the design and novel features of the OSU HVPS system and its integration into the BABAR EPICS detector control framework. Experience with the supplies operation during the LST extensive quality control program and their performance during the initial data taking period will be discussed

  19. Quantum Vertex Model for Reversible Classical Computing

    Science.gov (United States)

    Chamon, Claudio; Mucciolo, Eduardo; Ruckenstein, Andrei; Yang, Zhicheng

    We present a planar vertex model that encodes the result of a universal reversible classical computation in its ground state. The approach involves Boolean variables (spins) placed on links of a two-dimensional lattice, with vertices representing logic gates. Large short-ranged interactions between at most two spins implement the operation of each gate. The lattice is anisotropic with one direction corresponding to computational time, and with transverse boundaries storing the computation's input and output. The model displays no finite temperature phase transitions, including no glass transitions, independent of circuit. The computational complexity is encoded in the scaling of the relaxation rate into the ground state with the system size. We use thermal annealing and a novel and more efficient heuristic \\x9Dannealing with learning to study various computational problems. To explore faster relaxation routes, we construct an explicit mapping of the vertex model into the Chimera architecture of the D-Wave machine, initiating a novel approach to reversible classical computation based on quantum annealing.

  20. 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.

  1. A hadron-quark vertex function

    International Nuclear Information System (INIS)

    Mitra, A.N.; Bhatnagar, S.

    1992-01-01

    This paper reports that the interrelation between the 4D and 3D forms of the Bethe-Salpeter equation (BSE) with a kernel K(q,q') which depends on the relative four-momenta, q μ = q μ - P · qP μ /P 2 , orthogonal to P μ is exploited to obtain a hadron-quark vertex function of the Lorentz-invariant form Γ(q) = D(q 2 ) circle time φ(q). The denominator function D(q 2 ) is universal and controls the 3D BSE, which provides the mass spectra with the eigenfunctions φ(q). The vertex function, directly related to the 4D wave function Ψ which satisfies a corresponding BSE, defines a natural off-shell extension over the whole of four-momentum space, and provides the basis for the evaluation of transition amplitudes via appropriate quark-loop diagrams. The key role of the quantity q 2 in this formalism is clarified in relation to earlier approaches, in which the applications of this quantity had mostly been limited to the mass shell (q · P = 0). Two applications (f p values for P → ell bar ell and F π for π 0 → γγ) are sketched as illustrations of this formalism, and attention is drawn to the problem of complex amplitudes for bigger quark loops with more hadrons, together with the role of the D(q) function in overcoming this problem

  2. Vertex models, TASEP and Grothendieck polynomials

    International Nuclear Information System (INIS)

    Motegi, Kohei; Sakai, Kazumitsu

    2013-01-01

    We examine the wavefunctions and their scalar products of a one-parameter family of integrable five-vertex models. At a special point of the parameter, the model investigated is related to an irreversible interacting stochastic particle system—the so-called totally asymmetric simple exclusion process (TASEP). By combining the quantum inverse scattering method with a matrix product representation of the wavefunctions, the on-/off-shell wavefunctions of the five-vertex models are represented as a certain determinant form. Up to some normalization factors, we find that the wavefunctions are given by Grothendieck polynomials, which are a one-parameter deformation of Schur polynomials. Introducing a dual version of the Grothendieck polynomials, and utilizing the determinant representation for the scalar products of the wavefunctions, we derive a generalized Cauchy identity satisfied by the Grothendieck polynomials and their duals. Several representation theoretical formulae for the Grothendieck polynomials are also presented. As a byproduct, the relaxation dynamics such as Green functions for the periodic TASEP are found to be described in terms of the Grothendieck polynomials. (paper)

  3. Status of the CBM micro vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Koziel, Michal [Goethe-Universitaet Frankfurt (Germany); Collaboration: CBM-MVD-Collaboration

    2015-07-01

    The fixed-target experiment CBM at FAIR will explore the phase diagram of strongly interacting matter in the regime of highest net baryon densities with numerous probes, among them open charm. For the reconstruction of open charm hadrons with the CBM experiment a Micro Vertex Detector (MVD) with an excellent spatial resolution of the secondary decay vertex is required. Hence, 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 reduce multiple scattering, the MVD operates in vacuum, which poses challenging requirements on both, the power dissipation of the sensors and the integration concept. Here one should mention the selection of high-performance materials providing the mechanical support and cooling for the 0.05 mm thin sensors, establishing the sensor quality assessment procedures as well as defining the sensor integration. In addition, a substantial progress with respect to sensor development will be reported, mainly to the studies on their radiation hardness. Also, the 2nd generation of the sensor control and read-out based on TRBv3 standard has been commissioned. In this contribution we highlight several activities that have been successfully accomplished, which enable us to define the start version of the CBM MVD.

  4. BTeV detached vertex trigger

    International Nuclear Information System (INIS)

    Gottschalk, E.E.

    2001-01-01

    BTeV is a collider experiment that has been approved to run in the Tevatron at Fermilab. The experiment will conduct precision studies of CP violation using a forward-geometry detector. The detector will be optimized for high-rate detection of beauty and charm particles produced in collisions between protons and anti-protons. BTeV will trigger on beauty and charm events by taking advantage of the main difference between these heavy quark events and more typical hadronic events - the presence of detached beauty and charm decay vertices. The first stage of the BTeV trigger will receive data from a pixel vertex detector at a rate of 100 gb s -1 , reconstruct tracks and vertices for every beam crossing, reject 99% of beam crossings that do not produce beauty or charm particles, and trigger on beauty events with high efficiency. An overview of the trigger design and its influence on the design of the pixel vertex detector is presented

  5. Multiplicity-Vertex Detector Electronics Development for Heavy-Ion Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Britton, C.L., Jr.; Bryan, W.L.; Emery, M.S. [and others

    1995-12-31

    This paper presents the electronics work performed to date for the Multiplicity-Vertex Detector (MVD) for the PHENIX collaboration at RHIC. The detector consists of approximately 34,000 channels of both silicon strips and silicon pads. The per-channel signal processing chain consists of a pre-amplifier gain stage, a current mode summed multiplicity discriminator, a 64 deep analog memory (simultaneous read/write), an analog correlator, and a 10-bit microsecs ADC. The system controller or Heap Manager, supplies all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Prototype performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 mu nwell CMOS process used for fabrication.

  6. VETRA - offline analysis and monitoring software platform for the LHCb Vertex Locator

    International Nuclear Information System (INIS)

    Szumlak, Tomasz

    2010-01-01

    The LHCb experiment is dedicated to studying CP violation and rare decay phenomena. In order to achieve these physics goals precise tracking and vertexing around the interaction point is crucial. This is provided by the VELO (VErtex LOcator) silicon detector. After digitization, FPGAs are employed to run several algorithms to suppress noise and reconstruct clusters. This is performed by an FPGA based processing board. An off-line software project, VETRA, has been developed which performs a bit perfect emulation of this complex processing in the FPGAs. This is a novel development as this hardware emulation is not standalone but rather is fully integrated into the LHCb software to allow the reconstruction of full data from the detector. This software platform facilitates the development and understanding of the behaviour of the processing algorithms, the optimization of the parameters of the algorithms that will be loaded into the FPGA and monitoring of the detector performance. This framework has also been adopted by the Silicon Tracker detector of LHCb. This processing framework was successfully used with the first 1500 tracks of data in the VELO obtained from the first LHC beam in September 2008. The software architecture and utilisation of the VETRA project will be discussed in detail.

  7. 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 ...

  8. Performance, Radiation Damage Effects and Upgrade of the LHCb Vertex Locator

    CERN Document Server

    De Capua, S

    2013-01-01

    LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC). Heavy hadrons are identified through their flight distance in the VELO, the retractable silicon-strip vertex detector surrounding the LHCb interaction point at only 7 mm from the beam during normal LHC operation. Both VELO halves comprise 21 silicon micro-strip modules each. A module is made of two n-on-n 300 µm thick half-disc sensors with R- and phi-measuring geometry, mounted on a carbon fibre support paddle. The minimum pitch is approximately 40 µm. The detector is also equipped with the only n-on-p module operating at the LHC. The performance of the VELO in its three years of successful operation during the LHC physics runs will be presented. Highlights will include alignment, cluster finding efficiency, single hit resolution, and impact parameter and vertex resolutions. The VELO module sensors receive a large and non-uniform radiation dose having inner and outer radii of only 7 and 42...

  9. Design of a secondary-vertex trigger system

    International Nuclear Information System (INIS)

    Husby, D.; Chew, P.; Sterner, K.; Selove, W.

    1995-06-01

    For the selection of beauty and charm events with high efficiency at the Tevatron, a secondary-vertex trigger system is under design. It would operate on forward-geometry events. The system would use on-line tracking of all tracks in the vertex detector, to identify events with clearly detached secondary vertices

  10. BRST invariant mixed string vertex for the bosonic string

    International Nuclear Information System (INIS)

    Clarizia, A.; Pezzella, F.

    1987-09-01

    We construct a BRST invariant (N+M)-string vertex including both open and closed string states. When we saturate it with N open string and M closed string physical states it reproduces their corresponding scattering amplitude. As a particular case we obtain BRST invariant vertex for the open-closed string transition. (orig.)

  11. Drift chamber vertex detectors for SLC/LEP

    International Nuclear Information System (INIS)

    Hayes, K.G.

    1987-03-01

    The short but measurable lifetimes of the b and c quarks and the tau lepton have motivated the development of high precision tracking detectors capable of providing information on the decay vertex topology of events containing these particles. This paper reviews the OPAL, L3, and MARK II experiments vertex drift chambers

  12. Algebraic Bethe ansatz for 19-vertex models with reflection conditions

    International Nuclear Information System (INIS)

    Utiel, Wagner

    2003-01-01

    In this work we solve the 19-vertex models with the use of algebraic Bethe ansatz for diagonal reflection matrices (Sklyanin K-matrices). The eigenvectors, eigenvalues and Bethe equations are given in a general form. Quantum spin chains of spin one derived from the 19-vertex models were also discussed

  13. 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...

  14. Drift chamber vertex detectors for SLC/LEP

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, K G

    1988-03-01

    Factors influencing the design of drift chamber vertex detectors for SLC and LEP are discussed including global strategy, chamber gas, cell design, and signal processing. The designs of the vertex chambers for the L3 and OPAL experiments at LEP and the Mark II experiment at the SLC are described.

  15. Fermionic construction of vertex operators for twisted affine algebras

    International Nuclear Information System (INIS)

    Frappat, L.; Sorba, P.; Sciarrino, A.

    1988-03-01

    We construct vertex operator representations of the twisted affine algebras in terms of fermionic (or parafermionic in some cases) elementary fields. The folding method applied to the extended Dynkin diagrams of the affine algebras allows us to determine explicitly these fermionic fields as vertex operators

  16. 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 ...

  17. 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]....

  18. Multipole expansion of vertex functions with two final particles

    International Nuclear Information System (INIS)

    Daumens, Michel

    1977-01-01

    The expansions of the usual vertex functions are generalized to the vertex functions with two final particles. For four vector functions, expressions are similar to those of Chew, Goldberger, Low and Nambu, and of Adler and the consequences of the isobaric model are studied [fr

  19. The Mark III vertex chamber and prototype test results

    International Nuclear Information System (INIS)

    Grab, C.

    1987-07-01

    A vertex chamber has been constructed for use in the Mark III experiment. The chamber is positioned inside the current main drift chamber and will be used to trigger data collection, to aid in vertex reconstruction, and to improve the momentum resolution. This paper discusses the chamber's construction and performance and tests of the prototype

  20. On Pathos Adjacency Cut Vertex Jump Graph of a Tree

    OpenAIRE

    Nagesh.H.M; R.Chandrasekhar

    2014-01-01

    In this paper the concept of pathos adjacency cut vertex jump graph PJC(T) of a tree T is introduced. We also present a characterization of graphs whose pathos adjacency cut vertex jump graphs are planar, outerplanar, minimally non-outerplanar, Eulerian and Hamiltonian.

  1. Vertex Accentuation in Female Pattern Hair Loss in Asians

    Directory of Open Access Journals (Sweden)

    Chavalit Supsrisunjai

    2016-05-01

    Full Text Available Background: The most common cause of hair loss seen in women is female pattern hair loss (FPHL, also known as female androgenetic alopecia. It affects the central part of the scalp, but spares the frontal hairline. Frontal accentuation was also described by Olsen. In Asian women, vertex thinning patterns are frequently developed, but there has been no report about vertex thinning pattern in female pattern hair loss. Objective: To find prevalence of vertex accentuation in female pattern hair loss (FPHL in Asian women. Methods: Scalp hair counting (n/cm2 were measured at 3 different areas; vertex, mid scalp and frontal area respectively by digital dermoscope (Dino digital AM-413T. Visual counting and photography were performed. Outcomes were evaluated by gross appearance of vertex thinning and/or hair density <120 /cm2 in any of 3 areas. Results: 143 patients were evaluated. Mean age was 45.54 years. Of the hair loss type, 36.4% were mid-scalp, 33.6% were vertex accentuation and 30.1% were frontal accentuation, respectively. Age was not significantly different among the 3 types of hair loss (P- value 0.859. Conclusion: Although the most common female pattern hair loss type is diffuse type (Ludwig type, vertex accentuation pattern is the second most common pattern in this study. This study is the first to mention “Vertex accentuation” to be another pattern for FPHL.

  2. CP violation in b → s penguin decays and T, CPT violation at BaBar and BELLE

    International Nuclear Information System (INIS)

    Emery-Schrenk, S.

    2014-01-01

    We report on the first direct observation of time reversal violation at BABAR in the interference between direct decay and decay with B 0 - B-bar 0 mixing, as well as on the most precise search for CPT violation in B 0 - B-bar 0 mixing at BELLE. We then present recent CP violation studies at BABAR in rare b → s penguin decays B → KKK and B → K*l + l - . (author)

  3. Genus Ranges of 4-Regular Rigid Vertex Graphs.

    Science.gov (United States)

    Buck, Dorothy; Dolzhenko, Egor; Jonoska, Nataša; Saito, Masahico; Valencia, Karin

    2015-01-01

    A rigid vertex of a graph is one that has a prescribed cyclic order of its incident edges. We study orientable genus ranges of 4-regular rigid vertex graphs. The (orientable) genus range is a set of genera values over all orientable surfaces into which a graph is embedded cellularly, and the embeddings of rigid vertex graphs are required to preserve the prescribed cyclic order of incident edges at every vertex. The genus ranges of 4-regular rigid vertex graphs are sets of consecutive integers, and we address two questions: which intervals of integers appear as genus ranges of such graphs, and what types of graphs realize a given genus range. For graphs with 2 n vertices ( n > 1), we prove that all intervals [ a, b ] for all a genus ranges. For graphs with 2 n - 1 vertices ( n ≥ 1), we prove that all intervals [ a, b ] for all a genus ranges. We also provide constructions of graphs that realize these ranges.

  4. Twisted vertex algebras, bicharacter construction and boson-fermion correspondences

    International Nuclear Information System (INIS)

    Anguelova, Iana I.

    2013-01-01

    The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras

  5. Resistance Distances in Vertex-Face Graphs

    Science.gov (United States)

    Shangguan, Yingmin; Chen, Haiyan

    2018-01-01

    The computation of two-point resistances in networks is a classical problem in electric circuit theory and graph theory. Let G be a triangulation graph with n vertices embedded on an orientable surface. Define K(G) to be the graph obtained from G by inserting a new vertex vϕ to each face ϕ of G and adding three new edges (u, vϕ), (v, vϕ) and (w, vϕ), where u, v and w are three vertices on the boundary of ϕ. In this paper, using star-triangle transformation and resistance local-sum rules, explicit relations between resistance distances in K(G) and those in G are obtained. These relations enable us to compute resistance distance between any two points of Kk(G) recursively. As explanation examples, some resistances in several networks are computed, including the modified Apollonian network and networks constructed from tetrahedron, octahedron and icosahedron, respectively.

  6. Report of the 'Vertex detector' working group

    International Nuclear Information System (INIS)

    Bellini, G.; Rancoita, P.G.

    1984-01-01

    An analysis, even rough, of the vertex detector performances, based on the pattern recognition and on currently available techniques (see below) makes clear that the high repetition rate option is strongly favoured. In this hypothesis, with a luminosity of approx.= 3 x 10 32 cm -2 s -1 and a time between bunch collision approx.= 25 ns, we expect = 1 as number of events per bunch collision, e.i. 36.8% of events with 0 interaction, 36.8% with 1 and 26.4% with more than 1 event. Two or three events per crossing bunch can be separated and 25 ns of repetition time does not appear to be a major problem. (orig./HSI)

  7. Quarkonium decays: Testing the 3-gluon vertex

    International Nuclear Information System (INIS)

    Koller, K.; Walsh, T.F.; Zerwas, P.M.; Technische Hochschule Aachen

    1980-12-01

    We study the 3-jet decays of S and P-wave quarkonia with C = +. If observed, some of these will offer a way of seeing the 3G vertex of QCD via 1 Ssub(o), 3 Psub(o), 3 P 2 (Qanti Q) → GGG + Gqanti q → 3 jets. (As is well-known, cancellations reduce 3 P 1 (anti Q) → GGG.) We elaborate in detail the S-wave decay as it is expected to show all the characteristic features of orthoquarkonium decays into 4 jets, 3 S 1 (Qanti Q) → GGGG + GGqanti q → 4 jets which we will comment upon. These quarkonium decays offer a very clear signal for QCD as a non-abelian local gauge field theory with color-charged gluons. (orig.)

  8. 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.

  9. Lifetime tests for MAC vertex chamber

    International Nuclear Information System (INIS)

    Nelson, H.

    1986-01-01

    A vertex chamber for MAC was proposed in fall 1983 to increase precision in the measurement of the B hadron and tau lepton lifetimes. The chamber had to be placed within the existing central drift chamber, making access for repairs difficult and costly. Therefore for detector elements thin-walled aluminized mylar drift tubes (straws) were used because of their simplicity and robustness. The diameter of the drift tubes was 6.9 mm. The radial extent of the proposed chamber was from 3 cm to 10 cm, the inner wall of the central drift. It was clear that radiation levels, from synchrotron x-rays and overfocussed electrons, were potentially high. Since the drift distance is short in the straws, it was desirable to operate them at the highest possible gas gain, to achieve the best spatial resolution. There was a likelihood of drawing large currents in the chamber and thus causing radiation damage. Therefore a study of radiation hardness under the conditions of their proposed design was undertaken. In tests, argon-hydrocarbon mixtures consistently became unusable at ∼0.05 C/cm collected charge, due to anode buildup. Argon-CO 2 mixtures, while underquenched, were operational to 0.25 C/cm, at which point loss of cathode material became intolerable. Argon-xenon-CO 2 proved to be quenched as well as argon-hydrocarbons, but was limited by cathode damage. The MAC vertex chamber has operated at a distance of 4.6 cm from the e + e - interaction point at PEP for two years and has shown no aging effects

  10. User Defined Data in the New Analysis Model of the BaBar Experiment

    Energy Technology Data Exchange (ETDEWEB)

    De Nardo, G.

    2005-04-06

    The BaBar experiment has recently revised its Analysis Model. One of the key ingredient of BaBar new Analysis Model is the support of the capability to add to the Event Store user defined data, which can be the output of complex computations performed at an advanced stage of a physics analysis, and are associated to analysis objects. In order to provide flexibility and extensibility with respect to object types, template generic programming has been adopted. In this way the model is non-intrusive with respect to reconstruction and analysis objects it manages, not requiring changes in their interfaces and implementations. Technological details are hidden as much as possible to the user, providing a simple interface. In this paper we present some of the limitations of the old model and how they are addressed by the new Analysis Model.

  11. Aspects of CP violation with the BABAR detector. Constraints on the CKM Matrix

    International Nuclear Information System (INIS)

    Roos, L.

    2004-09-01

    This document presents the work done within the BABAR Collaboration as well as a phenomenological study on the interpretation of the B measurements related to the Unitarity Triangle. The read-out electronics of the Cerenkov detector, the DIRC, and especially the Time-Digital-Converter designed at LPNHE are described. Two major results of the BABAR Collaboration are presented: the measurement of the sin(2β) parameter in the b → ccs modes, which has established the CP violation in the B sector in 2001 and the study of CP asymmetries in the B 0 → π + π - channel. The constraints on the Unitarity Triangle from the K 0 K 0 system, the B semi-leptonic decays, the B oscillation parameters are in excellent agreement with those from sin(2β) and α. (author)

  12. Development of a Data Acquisition System for the BaBar CP Violation Experiment

    International Nuclear Information System (INIS)

    Claus, Richard

    1999-01-01

    Experiences developing data acquisition system for the BaBar CP violation experiment located at the Stanford Linear Accelerator Center are presented. The BaBar detector consists of multiple independent subdetectors joined with a data acquisition system consisting of a large number of embedded PowerPC single board computers residing in VME crates. The data acquisition software is layered on the VxWorks real-time operating system. It is partitionable to allow subsystems (as well as test stands) to operate independently. Data is assimilated into events through a combination of shared memory and a high performance network. This system presents data to a UNIX farm via a high speed non-blocking ethernet switch at a rate of 2 KHz. Topics such as bootstrapping and loading 200 processors, NFS file access for these processors and software development and deployment are discussed

  13. Development of a Data Acquisition System for the BaBar CP Violation Experiment

    CERN Document Server

    Scott, I; Grosso, P; Hamilton, R T; Huffer, M E; O'Grady, C P; Russell, J J

    1999-01-01

    Experiences developing data acquisition system for the BaBar CP violation experiment located at the Stanford Linear Accelerator Center are presented. The BaBar detector consists of multiple independent subdetectors joined with a data acquisition system consisting of a large number of embedded PowerPC single board computers residing in VME crates. The data acquisition software is layered on the VxWorks real-time operating system. It is partitionable to allow subsystems (as well as test stands) to operate independently. Data is assimilated into events through a combination of shared memory and a high performance network. This system presents data to a UNIX farm via a high speed non-blocking ethernet switch at a rate of 2 KHz. Topics such as bootstrapping and loading 200 processors, NFS file access for these processors and software development and deployment are discussed.

  14. Object oriented reconstruction software for the Instrumented Flux Return of BABAR

    CERN Document Server

    Nardo, E D; Lista, L

    2001-01-01

    BABAR experiment is the first High Energy Physics experiment to extensively use object oriented technology and the C++ programming language for online and offline software. Object orientation permits to reach a high level of flexibility and maintainability of the code, which is a key point in a large project with many developers. These goals are reached with the introduction of reusable code elements, with abstraction of code behaviours and polymorphism. Software design, before code implementation, is the key task that determines the achievement of such a goal. We present the experience with the application of object oriented technology and design patterns to the reconstruction software of the Instrumented Flux Return detector of BABAR experiment. The use of abstract interfaces improved the development of reconstruction code and permitted to flexibly apply modification to reconstruction strategies, and eventually to reduce the maintenance load. The experience during the last years of development is presented....

  15. Water resistant rhodium plated reflectors for use in the DIRC BaBar Cherenkov detector

    CERN Document Server

    Benkebil, M; Plaszczynski, S; Schune, M H; Wormser, G

    2000-01-01

    Early simulation studies showed that reflectors mounted on the photomultipliers would be useful for the DIRC BaBar Cherenkov detector, showing a gain between 20% and 30% in the number of Cherenkov photons. The proof of principle for these reflectors has been obtained during the beam test of a large-scale prototype of the DIRC detector. An extensive R and D has been conducted in order to test different metallization procedures. Indeed, the challenge was to find a metallization technique which can resist the pure de-ionized water (>15 M OMEGA) up to 10 yr. The chosen technology was rhodium plated reflectors. During the first BaBar cosmic run, the measured performance confirmed the results of the simulation, the prototype-II and the R and D.

  16. A Measurement of the Exclusive Branching Fraction for B → π K at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Aspinwall, Marie Louise [Imperial College, London (United Kingdom)

    2002-02-01

    This thesis presents an exclusive measurement of the branching fraction B for the rare charmless hadronic B decays to πK final states. A sample of 22.57±0.36 million BB pairs was collected with the BaBar detector at the Stanford Linear Accelerator Center's PEP-II B Factory, during the Run 1 data taking period (1999-2000).

  17. The RPC-based IFR system at BaBar experiment: preliminary results

    International Nuclear Information System (INIS)

    Piccolo, Davide; Palano, A.; Bagnasco, S.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Santroni, A.; Anulli, F.; Baldini, R.; Calcaterra, A.; De Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I.; Piccolo, M.; Yu, Z.; Zallo, A.; Cavallo, N.; De Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Sciacca, C.; Bionta, R.; Wright, D.; Band, H.; Johnson, J.

    2002-01-01

    The IFR system is a RPC-based detector used to identify muons and neutral hadrons in the BaBar experiment at PEP II machine in SLAC. The RPC system can be used to reconstruct the trajectory of muons, pions and neutral hadrons interacting in the iron of the IFR. The different range and hit pattern allow to discriminate different particles crossing the IFR. An overview of the system design and the preliminary results on the IFR performances are reported

  18. Distributing File-Based Data to Remote Sites Within the BABAR Collaboration

    International Nuclear Information System (INIS)

    Gowdy, Stephen J.

    2002-01-01

    BABAR [1] uses two formats for its data: Objectivity database and root [2] files. This poster concerns the distribution of the latter--for Objectivity data see [3]. The BABAR analysis data is stored in root files--one per physics run and analysis selection channel--maintained in a large directory tree. Currently BABAR has more than 4.5 TBytes in 200,000 root files. This data is (mostly) produced at SLAC, but is required for analysis at universities and research centers throughout the us and Europe. Two basic problems confront us when we seek to import bulk data from slac to an institute's local storage via the network. We must determine which files must be imported (depending on the local site requirements and which files have already been imported), and we must make the optimum use of the network when transferring the data. Basic ftp-like tools (ftp, scp, etc) do not attempt to solve the first problem. More sophisticated tools like rsync [4], the widely-used mirror/synchronization program, compare local and remote file systems, checking for changes (based on file date, size and, if desired, an elaborate checksum) in order to only copy new or modified files. However rsync allows for only limited file selection. Also when, as in BABAR, an extremely large directory structure must be scanned, rsync can take several hours just to determine which files need to be copied. Although rsync (and scp) provides on-the-fly compression, it does not allow us to optimize the network transfer by using multiple streams, adjusting the tcp window size, or separating encrypted authentication from unencrypted data channels

  19. Distributing file-based data to remote sites within the BABAR collaboration

    International Nuclear Information System (INIS)

    Adye, T.; Dorigo, A.; Forti, A.; Leonardi, E.

    2001-01-01

    BABAR uses two formats for its data: Objectivity database and ROOT files. This poster concerns the distribution of the latter--for Objectivity data see. The BABAR analysis data is stored in ROOT files--one per physics run and analysis selection channel-maintained in a large directory tree. Currently BABAR has more than 4.5 TBytes in 200,00- ROOT files. This data is (mostly) produced at SLAC, but is required for analysis at universities and research centres throughout the US and Europe. Two basic problems confront us when we seek to import bulk data from SLAC to an institute's local storage via the network. We must determine which files must be imported (depending on the local site requirements and which files have already been imported), and the authors must make the optimum use of the network when transferring the data. Basic ftp-like tools (ftp, scp, etc) do not attempt to solve the first problem. More sophisticated tools like rsync, the widely-used mirror/synchronisation program, compare local and remote file systems, checking for changes (based on file date, size and, if desired, an elaborate checksum) in order to only copy new or modified files. However rsync allows for only limited file selection. Also when, as in BABAR, an extremely large directory structure must be scanned, rsync can take several hours just to determine which files need to be copied. Although rsync (and scp) provides on-the-fly compression, it does not allow us to optimise the network transfer by using multiple streams, adjusting the TCP window size, or separating encrypted authentication from unencrypted data channels

  20. The RPC-based IFR system at BaBar experiment preliminary results

    CERN Document Server

    Piccolo, D; Bagnasco, S; Baldini, R; Band, H R; Bionta, R; Buzzo, A; Calcaterra, A; Cavallo, N; Contri, R; Crosetti, G; De Nardo, Gallieno; De Sangro, R; Fabozzi, F; Falciai, D; Finocchiaro, G; Gatto, C; Johnson, J; Lista, L; Lo Vetere, M; Macri, M; Monge, R; Palano, A; Paolucci, P; Passaggio, S; Patrignani, C; Patteri, P; Peruzzi, I; Piccolo, M; Robutti, E; Santroni, A; Sciacca, C; Wright, D; Yu, Z; Zallo, A

    2002-01-01

    The IFR system is a RPC-based detector used to identify muons and neutral hadrons in the BaBar experiment at PEP II machine in SLAC. The RPC system can be used to reconstruct the trajectory of muons, pions and neutral hadrons interacting in the iron of the IFR. The different range and hit pattern allow to discriminate different particles crossing the IFR. An overview of the system design and the preliminary results on the IFR performances are reported.

  1. Gas system Upgrade for the BaBar IFR Detector at SLAC

    International Nuclear Information System (INIS)

    Foulkes, S

    2004-01-01

    A new gas distribution and monitoring system was installed as part of an upgrade of the forward endcap muon detection system (IFR) of the BaBar detector at SLAC. Over 300 gas circuits are controlled and monitored. The return gas flow is monitored by digital bubblers which use photo-gate electronics to count the bubbling rate. The rates are monitored in real time and recorded in a history database allowing studies of flow rate versus chamber performance

  2. Applying object-oriented software engineering at the BaBar collaboration

    International Nuclear Information System (INIS)

    Jacobsen, B.

    1997-01-01

    The BaBar experiment at SLAC will start taking data in 1999. We are attempting to build its reconstruction software using good software engineering practices, including the use of object-oriented technology. We summarize our experience to date with analysis and design activities, training, CASE and documentation tools, C++ programming practice and similar topics. The emphasis is on the practical issues of simultaneously introducing new techniques to a large collaboration while under a deadline for system delivery. (orig.)

  3. Locking mechanisms in degree-4 vertex origami structures

    Science.gov (United States)

    Fang, Hongbin; Li, Suyi; Xu, Jian; Wang, K. W.

    2016-04-01

    Origami has emerged as a potential tool for the design of mechanical metamaterials and metastructures whose novel properties originate from their crease patterns. Most of the attention in origami engineering has focused on the wellknown Miura-Ori, a folded tessellation that is flat-foldable for folded sheet and stacked blocks. This study advances the state of the art and expands the research field to investigate generic degree-4 vertex (4-vertex) origami, with a focus on facet-binding. In order to understand how facet-binding attributes to the mechanical properties of 4-vertex origami structures, geometries of the 4-vertex origami cells are analyzed and analytically expressed. Through repeating and stacking 4-vertex cells, origami sheets and stacked origami blocks can be constructed. Geometry analyses discover four mechanisms that will lead to the self-locking of 4-vertex origami cells, sheets, and stacked blocks: in-cell facet-binding, inlayer facet-binding, inter-layer facet binding, and in-layer and inter-layer facet-bindings. These mechanisms and the predicted self-locking phenomena are verified through 3D simulations and prototype experiments. Finally, this paper briefly introduces the unusual mechanical properties caused by the locking of 4-vertex origami structures. The research reported in this paper could foster a new breed of self-locking structures with various engineering applications.

  4. 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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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 m 2 . 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 cm 2 . 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/cm 2 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

  6. Choosing CPUs in an Open Market: System Performance Testing for the BaBar Online Farm

    International Nuclear Information System (INIS)

    Pavel, Tomas J

    1998-01-01

    BABAR is a high-rate experiment to study CP violation in asymmetric e + e - collisions. The BABAR Online Farm is a pool of workstations responsible for the last layer of event selection, as well as for full reconstruction of selected events and for monitoring functions. A large number of machine architectures were evaluated for use in this Online Farm. We present an overview of the results of this evaluation, which include tests of low-level OS primitives, tests of memory architecture, and tests of application-specific CPU performance. Factors of general interest to others making hardware decisions are highlighted. Performance of current BABAR reconstruction (written in C++) is found to scale fairly well with SPECint95, but with some noticeable deviations. Even for machines with similar SPEC CPU ratings, large variations in memory system performance exist. No single operating system has an overall edge in the performance of its primitives. In particular, freeware operating systems perform no worse overall than the commercial offerings

  7. The IFR Online Detector Control system at the BaBar Experiment

    International Nuclear Information System (INIS)

    Paolucci, Pierluigi

    1999-01-01

    The Instrumented Flux Return (IFR)[1] is one of the five subdetectors of the BaBar[2] experiment on the PEP II accelerator at SLAC. The IFR consists of 774 Resistive Plate Chamber (RPC) detectors, covering an area of about 2,000 m 2 and equipped with 3,000 Front-end Electronic Cards (FEC) reading about 50,000 channels (readout strips). The first aim of a B-factory experiment is to run continuously without any interruption and then the Detector Control system plays a very important role in order to reduce the dead-time due to the hardware problems. The I.N.F.N. group of Naples has designed and built the IFR Online Detector Control System (IODC)[3] in order to control and monitor the operation of this large number of detectors and of all the IFR subsystems: High Voltage, Low Voltage, Gas system, Trigger and DAQ crates. The IODC consists of 8 custom DAQ stations, placed around the detector and one central DAQ station based on VME technology and placed in electronic house. The IODC use VxWorks and EPICS to implement slow control data flow of about 2500 hardware channels and to develop part of the readout module consisting in about 3500 records. EPICS is interfaced with the BaBar Run Control through the Component Proxy and with the BaBar database (Objectivity) through the Archiver and KeyLookup processes

  8. An application framework and data model prototype for the BaBar experiment

    CERN Document Server

    Quarrie, D

    2003-01-01

    The BaBar experiment is a high energy physics experiment to do physics with e sup + e sup - colliding beams in the 10 GeV center-of-mass energy at the PEP-II accelerator at the Stanford Linear Accelerator Center. The principal objectives are to study CP violation and rare processes in decays of B mesons. The experiment is under construction, with first data anticipated in 1999. The BaBar experiment is expected to accumulate of order 10 sup 9 events per calendar year, with over 10 sup 8 interesting hadronic events. The data must be stored efficiently, but must be easily accessible in order for multiple and frequent physics analyses to be carried out. The analysis framework must be flexible enough to accommodate a variety of analysis modules and multiple input/output streams. The BaBar collaboration has developed a prototype for the analysis framework and data access, written in C++ using an object-oriented design philosophy. The data access is based on the Farfalla package. The base class is a ''node''. Variou...

  9. Study of charmonium decays of B mesons in the Babar experiment; Etude des desintegrations charmonium des mesons B dans l'experience BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, Philippe

    2006-04-15

    This document is organized into 4 parts. The first part is dedicated to the Babar experiment that is installed on the e{sup +}e{sup -} collider at Stanford linear accelerator center. The formalism of the standard model and the CP violation in the B meson system are first introduced, then the Babar experiment is described and its main results are recalled: sin(2{beta}) 0.722 {+-} 0.040 {+-} 0.023; {alpha} = (103 + 11 - 9) degrees; {gamma} = (52 + 23 - 18) degrees. The author highlights 2 issues in which he was involved: the detector background noise induced by the machine and the beam injection system. The second part deals with DIRC (detector of internally reflected Cherenkov light) that is used for particle identification. The phenomenology of hadron decay of B mesons is described in the third part, the hypothesis of the factorization approximation is challenged. The last part is dedicated to experimental results concerning the measurement of branching ratios, the search for suppressed modes and the determination of decay amplitudes.

  10. 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.

  11. Tracking and vertexing for B physics at hadron accelerators

    International Nuclear Information System (INIS)

    Johnson, R.; Purohit, M.; Weidemann, A.W.

    1993-01-01

    In this note, the authors report on some of the activities of the Tracking and Vertexing Working Group of this Workshop. Track and vertex finding is essential to exploit the high production rate of B-mesons at hadron accelerators, both for triggering and analysis. Here, they review the tracking and vertex-finding systems of some of the major existing and proposed collider and fixed-target experiments at existing and future hadron accelerators, with a view towards their usefulness for B-physics. The capabilities of both general-purpose detectors and those of dedicated B-physics experiments are considered

  12. Silicon pixel R&D 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 vertex and tracking detector system. In particular the detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence 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 highly granular all- silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints.

  13. Quarkonium Spectroscopy And Search for New States at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Cibinetto, G.

    2011-11-04

    The BaBar experiment at the PEP-II B-factory gives excellent opportunities for the quarkonium spectroscopy. Investigation of the properties of new states like the X(3872), Y(3940) and Y(4260) are performed aiming to understand their nature. Recent BaBar results will be presented in this paper. At the B-factories charmonium and charmonium-like states are copiously produced via several mechanisms: in B decay (color suppressed b {yields} c transition), double charmonium production (e{sup +}e{sup -} {yields} c{bar c} + c{bar c}), two photons production ({gamma}*{gamma}* {yields} c{bar c}, where the c{bar c} state has positive C-parity) and in initial state radiation (ISR) when the e{sup {+-}} in its initial state emits a photon lowering the effective center of mass energy of the e{sup +}e{sup -} interaction (e{sup +}e{sup -} {yields} {gamma}{sub ISR} + c{bar c}, where the charmonium state has the quantum numbers J{sup PC} = 1{sup -2}). Many new states have been recently discovered at the B-factories, BaBar and Belle, above the D{bar D} threshold in the charmonium energy region. While some of them appear to be consistent with conventional c{sub c} states others do not fit with any expectation. Several interpretations for these states have been proposed: for some of them the mass values suggest that they could be conventional charmonia, but also other interpretations like D{sup 0}{bar D}*{sup 0} molecule or diquark-antidiquark states among many other models have been advanced. Reviews can be found in Refs. [1][2]. In all cases the picture is not completely clear. This situation could be remedied by a coherent search of the decay pattern to D{bar D}, search for production in two-photon fusion and ISR, and of course improving the statistical precision upon the current measurements. The BaBar experiment at the PEP-II asymmetric collider, designed to perform precision measurement of CP violation in the B meson system, has an extensive quarkonium spectroscopy program. Recent

  14. Vertex Normals and Face Curvatures of Triangle Meshes

    KAUST Repository

    Sun, Xiang; Jiang, Caigui; Wallner, Johannes; Pottmann, Helmut

    2016-01-01

    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

  15. 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.

  16. Vertex function of an electron in a constant electromagnetic field

    International Nuclear Information System (INIS)

    Morozov, D.A.; Narozhnyj, N.B.; Ritus, V.I.

    1981-01-01

    The third order with respect to radiation field vertex function for an electron located in a constant crossed field of arbitrary intensity is determined. It is shown that radiative interaction smears out the Airy function which describes the intensity of the interaction between electrons and photons in an external field as a function of the nonconserving momentum component. The qualitative relation Vsup((3)) approximately αchisup(2/3)Vsup((1)) between the third and first order vertex functions is found for large values of the dynamic parameter chi=((eFp)sup(2))sup(1/2)msup(-2). It is also shown that radiative interaction does not alter the order of magnitude of the squared mass of the system transferred at the vertex. The vertex function satisfies the Ward identity modified by the external field [ru

  17. The NA50 segmented target and vertex recognition system

    International Nuclear Information System (INIS)

    Bellaiche, F.; Cheynis, B.; Contardo, D.; Drapier, O.; Grossiord, J.Y.; Guichard, A.; Haroutunian, R.; Jacquin, M.; Ohlsson-Malek, F.; Pizzi, J.R.

    1997-01-01

    The NA50 segmented target and vertex recognition system is described. The segmented target consists of 7 sub-targets of 1-2 mm thickness. The vertex recognition system used to determine the sub-target where an interaction has occured is based upon quartz elements which produce Cerenkov light when traversed by charged particles from the interaction. The geometrical arrangement of the quartz elements has been optimized for vertex recognition in 208 Pb-Pb collisions at 158 GeV/nucleon. A simple algorithm provides a vertex recognition efficiency of better than 85% for dimuon trigger events collected with a 1 mm sub-target set-up. A method for recognizing interactions of projectile fragments (nuclei and/or groups of nucleons) is presented. The segmented target allows a large target thickness which together with a high beam intensity (∼10 7 ions/s) enables high statistics measurements. (orig.)

  18. Vertex functions at finite momentum: Application to antiferromagnetic quantum criticality

    Science.gov (United States)

    Wölfle, Peter; Abrahams, Elihu

    2016-02-01

    We analyze the three-point vertex function that describes the coupling of fermionic particle-hole pairs in a metal to spin or charge fluctuations at nonzero momentum. We consider Ward identities, which connect two-particle vertex functions to the self-energy, in the framework of a Hubbard model. These are derived using conservation laws following from local symmetries. The generators considered are the spin density and particle density. It is shown that at certain antiferromagnetic critical points, where the quasiparticle effective mass is diverging, the vertex function describing the coupling of particle-hole pairs to the spin density Fourier component at the antiferromagnetic wave vector is also divergent. Then we give an explicit calculation of the irreducible vertex function for the case of three-dimensional antiferromagnetic fluctuations, and show that it is proportional to the diverging quasiparticle effective mass.

  19. Uncovering the triple omeron vertex from Wilson line formalism

    International Nuclear Information System (INIS)

    Chirilli, G. A.; Szymanowski, L.; Wallon, S.

    2011-01-01

    We compute the triple omeron vertex from the Wilson line formalism, including both planar and nonplanar contributions, and get perfect agreement with the result obtained in the Extended Generalized Logarithmic Approximation based on Reggeon calculus.

  20. Vertex Reconstruction in the ATLAS Experiment at the LHC

    CERN Document Server

    Bouhova-Thacker, E; The ATLAS collaboration; Kostyukhin, V; Liebig, W; Limper, M; Piacquadio, G; Lichard, P; Weiser, C; Wildauer, A

    2009-01-01

    In the harsh environment of the Large Hadron Collider at CERN (design luminosity of $10^{34}$ cm$^{-2}$ s$^{-1}$) efficient reconstruction of vertices is crucial for many physics analyses. Described in this paper are the strategies for vertex reconstruction used in the ATLAS experiment and their implementation in the software framework Athena. The algorithms for the reconstruction of primary and secondary vertices as well as for finding of photon conversions and vertex reconstruction in jets are described. A special emphasis is made on the vertex fitting with application of additional constraints. The implementation of mentioned algorithms follows a very modular design based on object-oriented C++ and use of abstract interfaces. The user-friendly concept allows event reconstruction and physics analyses to compare and optimize their choice among different vertex reconstruction strategies. The performance of implemented algorithms has been studied on a variety of Monte Carlo samples and results are presented.

  1. Discussion on the electronic problems of straw vertex detector

    International Nuclear Information System (INIS)

    Xi Deming

    1992-01-01

    The measurement of the characteristic time of the output waveform of straw vertex detector, the design of its high resolution and high counting rate readout system and the problems of the charge and time calibrations are discussed

  2. A new method for computing the quark-gluon vertex

    International Nuclear Information System (INIS)

    Aguilar, A C

    2015-01-01

    In this talk we present a new method for determining the nonperturbative quark-gluon vertex, which constitutes a crucial ingredient for a variety of theoretical and phenomenological studies. This new method relies heavily on the exact all-order relation connecting the conventional quark-gluon vertex with the corresponding vertex of the background field method, which is Abelian-like. The longitudinal part of this latter quantity is fixed using the standard gauge technique, whereas the transverse is estimated with the help of the so-called transverse Ward identities. This method allows the approximate determination of the nonperturbative behavior of all twelve form factors comprising the quark-gluon vertex, for arbitrary values of the momenta. Numerical results are presented for the form factors in three special kinematical configurations (soft gluon and quark symmetric limit, zero quark momentum), and compared with the corresponding lattice data. (paper)

  3. Fluctuations in two-dimensional six-vertex systems

    International Nuclear Information System (INIS)

    Youngblood, R.W.; Axe, J.D.; McCoy, B.M.

    1979-01-01

    The character of polarization correlations in six-vertex systems is discussed. With the aid of a connection between the 1-d Heisenberg--Ising chain and the six-vertex problem, existing results for the chain correlations are used to obtain information about long-wavelength polarization correlations in six-vertex models. These results are compared with a neutron scattering study of 2-d polarization correlations in the layered compound copper formate tetrahydrate. Because the six-vertex model is equivalent to a particular roughening model, these results also explicitly predict the critical behavior of that roughening model just above its roughening temperature. The results correspond to the predictions of Kosterlitz and Thouless for the phase transition in the 2-d Coulomb gas. 5 figures

  4. Ghost story. II. The midpoint ghost vertex

    International Nuclear Information System (INIS)

    Bonora, L; Maccaferri, C; Scherer Santos, R.J.; Tolla, D D

    2009-01-01

    We construct the ghost number 9 three strings vertex for OSFT in the natural normal ordering. We find two versions, one with a ghost insertion at z = i and a twist-conjugate one with insertion at z = -i. For this reason we call them midpoint vertices. We show that the relevant Neumann matrices commute among themselves and with the matrix G representing the operator K 1 . We analyze the spectrum of the latter and find that beside a continuous spectrum there is a (so far ignored) discrete one. We are able to write spectral formulas for all the Neumann matrices involved and clarify the important role of the integration contour over the continuous spectrum. We then pass to examine the (ghost) wedge states. We compute the discrete and continuous eigenvalues of the corresponding Neumann matrices and show that they satisfy the appropriate recursion relations. Using these results we show that the formulas for our vertices correctly define the star product in that, starting from the data of two ghost number 0 wedge states, they allow us to reconstruct a ghost number 3 state which is the expected wedge state with the ghost insertion at the midpoint, according to the star recursion relation.

  5. Dynamical Vertex Approximation for the Hubbard Model

    Science.gov (United States)

    Toschi, Alessandro

    A full understanding of correlated electron systems in the physically relevant situations of three and two dimensions represents a challenge for the contemporary condensed matter theory. However, in the last years considerable progress has been achieved by means of increasingly more powerful quantum many-body algorithms, applied to the basic model for correlated electrons, the Hubbard Hamiltonian. Here, I will review the physics emerging from studies performed with the dynamical vertex approximation, which includes diagrammatic corrections to the local description of the dynamical mean field theory (DMFT). In particular, I will first discuss the phase diagram in three dimensions with a special focus on the commensurate and incommensurate magnetic phases, their (quantum) critical properties, and the impact of fluctuations on electronic lifetimes and spectral functions. In two dimensions, the effects of non-local fluctuations beyond DMFT grow enormously, determining the appearance of a low-temperature insulating behavior for all values of the interaction in the unfrustrated model: Here the prototypical features of the Mott-Hubbard metal-insulator transition, as well as the existence of magnetically ordered phases, are completely overwhelmed by antiferromagnetic fluctuations of exponentially large extension, in accordance with the Mermin-Wagner theorem. Eventually, by a fluctuation diagnostics analysis of cluster DMFT self-energies, the same magnetic fluctuations are identified as responsible for the pseudogap regime in the holed-doped frustrated case, with important implications for the theoretical modeling of the cuprate physics.

  6. Functional imaging of sleep vertex sharp transients.

    Science.gov (United States)

    Stern, John M; Caporro, Matteo; Haneef, Zulfi; Yeh, Hsiang J; Buttinelli, Carla; Lenartowicz, Agatha; Mumford, Jeanette A; Parvizi, Josef; Poldrack, Russell A

    2011-07-01

    The vertex sharp transient (VST) is an electroencephalographic (EEG) discharge that is an early marker of non-REM sleep. It has been recognized since the beginning of sleep physiology research, but its source and function remain mostly unexplained. We investigated VST generation using functional MRI (fMRI). Simultaneous EEG and fMRI were recorded from seven individuals in drowsiness and light sleep. VST occurrences on EEG were modeled with fMRI using an impulse function convolved with a hemodynamic response function to identify cerebral regions correlating to the VSTs. A resulting statistical image was thresholded at Z>2.3. Two hundred VSTs were identified. Significantly increased signal was present bilaterally in medial central, lateral precentral, posterior superior temporal, and medial occipital cortex. No regions of decreased signal were present. The regions are consistent with electrophysiologic evidence from animal models and functional imaging of human sleep, but the results are specific to VSTs. The regions principally encompass the primary sensorimotor cortical regions for vision, hearing, and touch. The results depict a network comprising the presumed VST generator and its associated regions. The associated regions functional similarity for primary sensation suggests a role for VSTs in sensory experience during sleep. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  7. 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.

  8. 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.

  9. The quintic interaction vertex in light-cone gravity

    International Nuclear Information System (INIS)

    Ananth, Sudarshan

    2008-01-01

    We consider pure gravity in light-cone gauge and derive the complete quintic interaction vertex. Up to quartic order, the Kawai-Lewellen-Tye (KLT) relations can be made manifest at the level of the Einstein-Hilbert Lagrangian. The quintic interaction vertex represents an essential first step in further extending the off-shell validity of the KLT relations to higher order vertices

  10. Stochastic higher spin six vertex model and Macdonald measures

    Science.gov (United States)

    Borodin, Alexei

    2018-02-01

    We prove an identity that relates the q-Laplace transform of the height function of a (higher spin inhomogeneous) stochastic six vertex model in a quadrant on one side and a multiplicative functional of a Macdonald measure on the other. The identity is used to prove the GUE Tracy-Widom asymptotics for two instances of the stochastic six vertex model via asymptotic analysis of the corresponding Schur measures.

  11. 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.

  12. Construction of vertex operators using operator formalism techniques

    International Nuclear Information System (INIS)

    Gato, B.; Massachusetts Inst. of Tech., Cambridge

    1989-01-01

    We derive vertex operators in oscillator form as an application of the conserved charges method developed by Vafa for the operator formalism in higher genus Riemann surfaces. This construction proves to be clear, direct and valid for the bosonic and fermionic strings as wells as for twisted strings on orbifolds. We discuss the method and construct vertex operators for the bosonic string moving on Z N orbifolds and for the fermionic string in the NSR formulation. (orig.)

  13. The vertex detector for the Lepton/Photon Collaboration

    International Nuclear Information System (INIS)

    Sullivan, J.P.; Boissevain, J.G.; Fox, D.; van Hecke, H.; Jacak, B.V.; Kapustinsky, J.S.; Leitch, M.J.; McGaughey, P.L.; Moss, J.M.; Sondheim, W.E.

    1991-01-01

    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 concentric layers of single-sided Si strips. The expected performance as a multiplicity detector and in measuring the pseudo-rapidity η 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

  14. 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.

  15. Smarandachely Adjacent-Vertex-Distinguishing Proper Edge Chromatic Number of Cm∨Kn

    OpenAIRE

    Shunqin Liu

    2016-01-01

    According to different conditions, researchers have defined a great deal of coloring problems and the corresponding chromatic numbers. Such as, adjacent-vertex-distinguishing total chromatic number, adjacent-vertex-distinguishing proper edge chromatic number, smarandachely-adjacent-vertex-distinguishing proper edge chromatic number, smarandachely-adjacent-vertex-distinguishing proper total chromatic number. And we focus on the smarandachely adjacent-vertex-distinguishing proper edge chromatic...

  16. 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.

  17. The DELPHI Silicon Tracker in the global pattern recognition

    CERN Document Server

    Elsing, M

    2000-01-01

    ALEPH and DELPHI were the first experiments operating a silicon vertex detector at LEP. During the past 10 years of data taking the DELPHI Silicon Tracker was upgraded three times to follow the different tracking requirements for LEP 1 and LEP 2 as well as to improve the tracking performance. Several steps in the development of the pattern recognition software were done in order to understand and fully exploit the silicon tracker information. This article gives an overview of the final algorithms and concepts of the track reconstruction using the Silicon Tracker in DELPHI.

  18. The DELPHI Silicon Tracker in the global pattern recognition

    International Nuclear Information System (INIS)

    Elsing, M.

    2000-01-01

    ALEPH and DELPHI were the first experiments operating a silicon vertex detector at LEP. During the past 10 years of data taking the DELPHI Silicon Tracker was upgraded three times to follow the different tracking requirements for LEP 1 and LEP 2 as well as to improve the tracking performance. Several steps in the development of the pattern recognition software were done in order to understand and fully exploit the silicon tracker information. This article gives an overview of the final algorithms and concepts of the track reconstruction using the Silicon Tracker in DELPHI

  19. 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...

  20. Development of Data Processing Algorithms for the Upgraded LHCb Vertex Locator

    CERN Document Server

    AUTHOR|(CDS)2101352

    The LHCb detector will see a major upgrade during LHC Long Shutdown II, which is planned for 2019/20. The silicon Vertex Locator subdetector will be upgraded for operation under the new run conditions. The detector will be read out using a data acquisition board based on an FPGA. The work presented in this thesis is concerned with the development of the data processing algorithms to be used in this data acquisition board. In particular, work in three different areas of the FPGA is covered: the data processing block, the low level interface, and the post router block. The algorithms produced have been simulated and tested, and shown to provide the required performance. Errors in the initial implementation of the Gigabit Wireline Transmitter serialized data in the low level interface were discovered and corrected. The data scrambling algorithm and the post router block have been incorporated in the front end readout chip.

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

    CERN Document Server

    AUTHOR|(SzGeCERN)734627

    2017-01-01

    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.

  2. The Belle II DEPFET pixel vertex detector. Development of a full-scale module prototype

    International Nuclear Information System (INIS)

    Lemarenko, Mikhail

    2013-11-01

    The Belle II experiment, which will start after 2015 at the SuperKEKB accelerator in Japan, will focus on the precision measurement of the CP-violation mechanism and on the search for physics beyond the Standard Model. A new detection system with an excellent spatial resolution and capable of coping with considerably increased background is required. To address this challenge, a pixel detector based on DEPFET technology has been proposed. A new all silicon integrated circuit, called Data Handling Processor (DHP), is implemented in 65 nm CMOS technology. It is designed to steer the detector and preprocess the generated data. The scope of this thesis covers DHP tests and optimization as well the development of its test environment, which is the first Full-Scale Module Prototype of the DEPFET Pixel Vertex detector.

  3. 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 ...

  4. Expected performance of tracking and vertexing with the HL-LHC ATLAS detector

    CERN Document Server

    Calace, Noemi; The ATLAS collaboration

    2018-01-01

    The High Luminosity LHC (HL-LHC) aims to increase the LHC data-set by an order of magnitude in order to increase its potential for discoveries. Starting from the middle of 2026, the HL-LHC is expected to reach the peak instantaneous luminosity of $7.5 \\cdot 10^{34} cm^{-2}s^{-1}$ which corresponds to about 200 inelastic proton-proton collisions per beam crossing. To cope with the large radiation doses and high pileup, the current ATLAS Inner Detector will be replaced with a new all-silicon Inner Tracker. In this talk the expected performance of tracking and vertexing with the HL-LHC tracker is presented. Comparison is made to the performance with the Run2 detector. Ongoing developments of the track reconstruction for the HL-LHC are also discussed.

  5. Improving the Security and Performance of the BaBar Detector Controls System

    International Nuclear Information System (INIS)

    Kotturi, Karen D.

    2003-01-01

    It starts out innocently enough--users want to monitor Online data and so run their own copies of the detector control GUIs in their offices and at home. But over time, the number of processes making requests for values to display on GUIs, webpages and stripcharts can grow, and affect the performance of an Input/Output Controller (IOC) such that it is unable to respond to requests from requests critical to data-taking. At worst, an IOC can hang, its CPU having been allocated 100% to responding to network requests. For the BaBar Online Detector Control System, we were able to eliminate this problem and make great gains in security by moving all of the IOCs to a non-routed, virtual LAN and by enlisting a workstation with two network interface cards to act as the interface between the virtual LAN and the public BaBar network. On the interface machine, we run the Experimental Physics Industrial Control System (EPICS) Channel Access (CA) gateway software (originating from Advanced Photon Source). This software accepts as inputs, all the channels which are loaded into the EPICS databases on all the IOCs. It polls them to update its copy of the values. It answers requests from applications by sending them the currently cached value. We adopted the requirement that data-taking would be independent of the gateway, so that, in the event of a gateway failure, data-taking would be uninterrupted. In this way, we avoided introducing any new risk elements to data-taking. Security rules already in use by the IOC were propagated to the gateway's own security rules and the security of the IOCs themselves was improved by removing them from the public BaBar network

  6. Mechanisms Affecting Performance of the BaBar Resistive Plate Chambers and Searches for Remediation

    International Nuclear Information System (INIS)

    Lu, Changguo

    2003-01-01

    The BaBar experiment at PEPII relies on the Instrumentation of the Flux Return (IFR) for both muon identification and KL detection. The active detector is composed of Resistive Plate Chambers (RPC's) operated in streamer mode. Since the start of operation the RPC's have suffered persistent efficiency deterioration and dark current increase problems. The ''autopsy'' of bad BaBar RPC's revealed that in many cases uncured Linseed oil droplets had formed on the inner surface of the Bakelite plates, leading to current paths from oil ''stalagmites'' bridging the 2 mm gap. In this paper a possible model of this ''stalagmite'' formation and its effect on the dark current and efficiency of RPC chambers is presented. Laboratory test results strongly support this model. Based upon this model we are searching for solutions to eliminate the unfavorable effect of the oil stalagmites. The lab tests show that the stalagmite resistivity increases dramatically if exposed to the air, an observation that points to a possible way to remedy the damage and increase the efficiency. We have seen that flowing an oxygen gas mixture into the chamber helps to polymerize the uncured linseed oil. Consequently the resistivity of the bridged oil stalagmites increases, as does that of the oil coating on the frame edges and spacers, significantly reducing the RPC dark currents and low-efficiency regions. We have tested this idea on two chambers removed from BaBar because of their low efficiency and high dark current. These test results are reported in the paper, and two other remediation methods also mentioned. We continue to study this problem, and try to find new treatments with permanent improvement

  7. The silicon strip detector at the Mark 2

    International Nuclear Information System (INIS)

    Jacobsen, R.; Golubev, V.; Lueth, V.; Barnett, B.; Dauncey, P.; Matthews, J.; Adolphsen, C.; Burchat, P.; Gratta, G.; King, M.; Labarga, L.; Litke, A.; Turala, M.; Zaccardelli, C.

    1990-04-01

    We have installed a Silicon Strip Vertex Detector in the Mark II detector at the Stanford Linear Collider. We report on the performance of the detector during a recent test run, including backgrounds, stability and charged particle tracking. 10 refs., 9 figs

  8. 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

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

    International Nuclear Information System (INIS)

    Trimpl, M.

    2005-12-01

    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.)

  10. 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.)

  11. Search for B+ --> mu+ nu_mu With Inclusive Reconstruction at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, Antimo; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, Bjarne; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Cahn, Robert N.; Jacobsen, R.G.; /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Banca di Roma /Frascati /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2008-08-01

    We search for the purely leptonic decay B{sup {+-}} {yields} {mu}{sup {+-}}{nu}{sub {mu}} in the full BABAR dataset, having an integrated luminosity of approximately 426 fb{sup -1}. We adopt a fully inclusive approach, where the signal candidate is identified by the highest momentum lepton in the event and the companion B is inclusively reconstructed without trying to identify its decay products. We set a preliminary upper limit on the branching fraction of {Beta}(B{sup {+-}} {yields} {mu}{sup {+-}}{nu}{sub {mu}}) < 1.3 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.

  12. Study of B --> S Gamma at BaBar Using the Sum of Exclusive Modes

    Energy Technology Data Exchange (ETDEWEB)

    Pulliam, T

    2003-12-17

    The electromagnetic penguin process b {yields} s{gamma} is very interesting to theorists because it can be used to constrain contributions from new physics that could enter at the one loop level. The high statistics of B{bar B} events collected at the BABAR experiment make a measurement of this rare decay possible. The branching fraction of a sum of exclusive b {yields} s{gamma} decay modes is measured as a function of the strange hadronic mass. This is a large step toward the measurement of the b {yields} s{gamma} rate.

  13. 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.

  14. Calculation of track and vertex errors for detector design studies

    International Nuclear Information System (INIS)

    Harr, R.

    1995-01-01

    The Kalman Filter technique has come into wide use for charged track reconstruction in high-energy physics experiments. It is also well suited for detector design studies, allowing for the efficient estimation of optimal track covariance matrices without the need of a hit level Monte Carlo simulation. Although much has been published about the Kalman filter equations, there is a lack of previous literature explaining how to implement the equations. In this paper, the operators necessary to implement the Kalman filter equations for two common detector configurations are worked out: a central detector in a uniform solenoidal magnetic field, and a fixed-target detector with no magnetic field in the region of the interactions. With the track covariance matrices in hand, vertex and invariant mass errors are readily calculable. These quantities are particularly interesting for evaluating experiments designed to study weakly decaying particles which give rise to displaced vertices. The optimal vertex errors are obtained via a constrained vertex fit. Solutions are presented to the constrained vertex problem with and without kinematic constraints. Invariant mass errors are obtained via propagation of errors; the use of vertex constrained track parameters is discussed. Many of the derivations are new or previously unpublished

  15. A covariant representation of the Ball–Chiu vertex

    International Nuclear Information System (INIS)

    Ahmadiniaz, Naser; Schubert, Christian

    2013-01-01

    In nonabelian gauge theory the three-gluon vertex function contains important structural information, in particular on infrared divergences, and is also an essential ingredient in the Schwinger–Dyson equations. Much effort has gone into analyzing its general structure, and at the one-loop level also a number of explicit computations have been done, using various approaches. Here we use the string-inspired 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 all cases. The vertex is computed fully off-shell and in dimensionally continued form, so that it can be used as a building block for higher-loop calculations. We find that the Bern–Kosower loop replacement rules, originally derived for the on-shell case, hold off-shell as well. We explain the relation of the structure of this representation to the low-energy effective action, and establish the precise connection with the standard Ball–Chiu decomposition of the vertex. This allows us also to predict that the vanishing of the completely antisymmetric coefficient function S of this decomposition is not a one-loop accident, but persists at higher-loop orders. The sum rule found by Binger and Brodsky, which leads to the vanishing of the one-loop vertex in N=4 SYM theory, in the present approach relates to worldline supersymmetry

  16. A covariant representation of the Ball–Chiu vertex

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadiniaz, Naser, E-mail: naser@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Apdo. Postal 2-82, C.P. 58040, Morelia, Michoacán (Mexico); Dipartimento di Fisica, Università di Bologna and INFN, Sezione di Bologna, Via Irnerio 46, I-40126 Bologna (Italy); Schubert, Christian, E-mail: schubert@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Apdo. Postal 2-82, C.P. 58040, Morelia, Michoacán (Mexico); Dipartimento di Fisica, Università di Bologna and INFN, Sezione di Bologna, Via Irnerio 46, I-40126 Bologna (Italy); Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Mühlenberg 1, D-14476 Potsdam (Germany)

    2013-04-21

    In nonabelian gauge theory the three-gluon vertex function contains important structural information, in particular on infrared divergences, and is also an essential ingredient in the Schwinger–Dyson equations. Much effort has gone into analyzing its general structure, and at the one-loop level also a number of explicit computations have been done, using various approaches. Here we use the string-inspired 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 all cases. The vertex is computed fully off-shell and in dimensionally continued form, so that it can be used as a building block for higher-loop calculations. We find that the Bern–Kosower loop replacement rules, originally derived for the on-shell case, hold off-shell as well. We explain the relation of the structure of this representation to the low-energy effective action, and establish the precise connection with the standard Ball–Chiu decomposition of the vertex. This allows us also to predict that the vanishing of the completely antisymmetric coefficient function S of this decomposition is not a one-loop accident, but persists at higher-loop orders. The sum rule found by Binger and Brodsky, which leads to the vanishing of the one-loop vertex in N=4 SYM theory, in the present approach relates to worldline supersymmetry.

  17. A measurement of B0 meson properties using partially reconstructed B0 to D*- pi+ and B0 tp D*- lepton+ nu-lepton decays with the BABAR detector

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Barbara

    2000-10-13

    The two B{sup 0} decay processes B{sup 0} {yields} D*{sup -} {pi}{sup +} and B{sup 0} {yields} D*{sup -} {ell}{sup +} {nu}{sub {ell}} have been studied by means of a partial reconstruction technique using a data sample collected with the BABAR detector at the PEP-II storage ring. To increase statistics, only the soft {pi}{sup -} from the decay D*{sup -} {yields} {pi}{sup -} D{sup 0} was used in association with either an oppositely-charged high-momentum pion or lepton. Events were then identified by exploiting the constraints from the simple kinematics of {Upsilon}(4S) decays. A clear signature is obtained in each case. The position of the B{sup 0} decay point was obtained from the reconstructed {pi}{sup +} ({ell}{sup +}){pi}{sup -} vertex. The position of the other {bar B}{sup 0} in the event was also determined. Taking advantage of the boost given to the {Upsilon}(4S) system by the asymmetric beam energies of PEP-II, the lifetime of the B{sup 0} meson has been measured from the separation distance between the two vertices along the beam direction.

  18. Silicon Detectors-Tools for Discovery in Particle Physics

    International Nuclear Information System (INIS)

    Krammer, Manfred

    2009-01-01

    Since the first application of Silicon strip detectors in high energy physics in the early 1980ies these detectors have enabled the experiments to perform new challenging measurements. With these devices it became possible to determine the decay lengths of heavy quarks, for example in the fixed target experiment NA11 at CERN. In this experiment Silicon tracking detectors were used for the identification of particles containing a c-quark. Later on, the experiments at the Large Electron Positron collider at CERN used already larger and sophisticated assemblies of Silicon detectors to identify and study particles containing the b-quark. A very important contribution to the discovery of the last of the six quarks, the top quark, has been made by even larger Silicon vertex detectors inside the experiments CDF and D0 at Fermilab. Nowadays a mature detector technology, the use of Silicon detectors is no longer restricted to the vertex regions of collider experiments. The two multipurpose experiments ATLAS and CMS at the Large Hadron Collider at CERN contain large tracking detectors made of Silicon. The largest is the CMS Inner Tracker consisting of 200 m 2 of Silicon sensor area. These detectors will be very important for a possible discovery of the Higgs boson or of Super Symmetric particles. This paper explains the first applications of Silicon sensors in particle physics and describes the continuous development of this technology up to the construction of the state of the art Silicon detector of CMS.

  19. Silicone metalization

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

    2008-12-09

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  20. Performance characteristics and radiation damage results from the Fermilab E706 silicon microstrip detector system

    Energy Technology Data Exchange (ETDEWEB)

    Engels, E Jr; Mani, S; Orris, D; Shepard, P F; Weerasundara, P D; Choudhary, B C; Joshi, U; Kapoor, V; Shivpuri, R; Baker, W

    1989-07-01

    A charged particle spectrometer containing a 7120-channel silicon microstrip detector system, one component of Fermilab experiment E706 to study direct photon production in hadron-hadron collisions, was utilized in a run in which 6 million events were recorded. We describe the silicon system, provide early results of track and vertex reconstruction, and present data on the radiation damage to the silicon wafers resulting from the narrow high intensity beam. (orig.).

  1. Plethystic vertex operators and boson-fermion correspondences

    International Nuclear Information System (INIS)

    Fauser, Bertfried; Jarvis, Peter D; King, Ronald C

    2016-01-01

    We study the algebraic properties of plethystic vertex operators, introduced in (2010 J. Phys. A: Math. Theor. 43 405202), underlying the structure of symmetric functions associated with certain generalized universal character rings of subgroups of the general linear group, defined to stabilize tensors of Young symmetry type characterized by a partition of arbitrary shape π . Here we establish an extension of the well-known boson-fermion correspondence involving Schur functions and their associated (Bernstein) vertex operators: for each π , the modes generated by the plethystic vertex operators and their suitably constructed duals, satisfy the anticommutation relations of a complex Clifford algebra. The combinatorial manipulations underlying the results involve exchange identities exploiting the Hopf-algebraic structure of certain symmetric function series and their plethysms. (paper)

  2. Measurement of Rb Using a Vertex Mass Tag

    International Nuclear Information System (INIS)

    Steiner, R.; Benvenuti, A.C.; Coller, J.A.; Hedges, S.J.; Johnson, A.S.; Shank, J.T.; Whitaker, J.S.; Allen, N.J.; Cotton, R.; Dervan, P.J.; Hasan, A.; McKemey, A.K.; Watts, S.J.; Caldwell, D.O.; Lu, A.; Yellin, S.J.; Cavalli-Sforza, M.; Coyne, D.G.; Fernandez, J.P.; Liu, X.; Reinertsen, P.L.; Schalk, T.; Schumm, B.A.; DOliveira, A.; Johnson, R.A.; Meadows, B.T.; Nussbaum, M.; Dima, M.; Harton, J.L.; Smy, M.B.; Staengle, H.; Wilson, R.J.; Baranko, G.; Fahey, S.; Fan, C.; Krishna, N.M.; Lauber, J.A.; Nauenberg, U.; Wagner, D.L.; Bazarko, A.O.; Bolton, T.; Rowson, P.C.; Shaevitz, M.H.; Camanzi, B.; Mazzucato, E.; Piemontese, L.; Calcaterra, A.; De Sangro, R.; Peruzzi, I.; Piccolo, M.; Eisenstein, B.I.; Gladding, G.; Karliner, I.; Shapiro, G.; Steiner, H.; Bardon, O.; Burrows, P.N.; Busza, W.; Cowan, R.F.; Dong, D.N.; Fero, M.J.; Gonzalez, S.; Kendall, H.W.; Lath, A.; Lia, V.; Osborne, L.S.; Quigley, J.; Taylor, F.E.; Torrence, E.; Verdier, R.; Williams, D.C.

    1998-01-01

    We report a new measurement of R b =Γ Z 0 →bbar b /Γ Z 0 →hadrons using a double tag technique, where the b hemisphere selection is based on the reconstructed mass of the B hadron decay vertex. The measurement was performed using a sample of 130x10 3 hadronic Z 0 events, collected with the SLD detector at SLC. The method utilizes the 3D vertexing abilities of the CCD pixel vertex detector and the small stable SLC beams to obtain a high b -tagging efficiency and purity. We obtain R b =0.2142±0.0034(stat) ±0.0015(syst)±0.0002( R c ) . copyright 1998 The American Physical Society

  3. Plethystic vertex operators and boson-fermion correspondences

    Science.gov (United States)

    Fauser, Bertfried; Jarvis, Peter D.; King, Ronald C.

    2016-10-01

    We study the algebraic properties of plethystic vertex operators, introduced in (2010 J. Phys. A: Math. Theor. 43 405202), underlying the structure of symmetric functions associated with certain generalized universal character rings of subgroups of the general linear group, defined to stabilize tensors of Young symmetry type characterized by a partition of arbitrary shape π. Here we establish an extension of the well-known boson-fermion correspondence involving Schur functions and their associated (Bernstein) vertex operators: for each π, the modes generated by the plethystic vertex operators and their suitably constructed duals, satisfy the anticommutation relations of a complex Clifford algebra. The combinatorial manipulations underlying the results involve exchange identities exploiting the Hopf-algebraic structure of certain symmetric function series and their plethysms.

  4. Measurement of Charmless B to Vector-Vector decays at BaBar

    International Nuclear Information System (INIS)

    Olaiya, Emmanuel

    2011-01-01

    The authors present results of B → vector-vector (VV) and B → vector-axial vector (VA) decays B 0 → φX(X = φ,ρ + or ρ 0 ), B + → φK (*)+ , B 0 → K*K*, B 0 → ρ + b 1 - and B + → K* 0 α 1 + . The largest dataset used for these results is based on 465 x 10 6 Υ(4S) → B(bar B) decays, collected with the BABAR detector at the PEP-II B meson factory located at the Stanford Linear Accelerator Center (SLAC). Using larger datasets, the BABAR experiment has provided more precise B → VV measurements, further supporting the smaller than expected longitudinal polarization fraction of B → φK*. Additional B meson to vector-vector and vector-axial vector decays have also been studied with a view to shedding light on the polarization anomaly. Taking into account the available errors, we find no disagreement between theory and experiment for these additional decays.

  5. BaBar MC production on the Canadian grid using a web services approach

    International Nuclear Information System (INIS)

    Agarwal, A; Armstrong, P; Desmarais, R; Gable, I; Popov, S; Ramage, S; Schaffer, S; Sobie, C; Sobie, R; Sulivan, T; Vanderster, D; Mateescu, G; Podaima, W; Charbonneau, A; Impey, R; Viswanathan, M; Quesnel, D

    2008-01-01

    The present paper highlights the approach used to design and implement a web services based BaBar Monte Carlo (MC) production grid using Globus Toolkit version 4. The grid integrates the resources of two clusters at the University of Victoria, using the ClassAd mechanism provided by the Condor-G metascheduler. Each cluster uses the Portable Batch System (PBS) as its local resource management system (LRMS). Resource brokering is provided by the Condor matchmaking process, whereby the job and resource attributes are expressed as ClassAds. The important features of the grid are automatic registering of resource ClassAds to the central registry, ClassAds extraction from the registry to the metascheduler for matchmaking, and the incorporation of input/output file staging. Web-based monitoring is employed to track the status of grid resources and the jobs for an efficient operation of the grid. The performance of this new grid for BaBar jobs, and the existing Canadian computational grid (GridX1) based on Globus Toolkit version 2 is found to be consistent

  6. BaBar MC production on the Canadian grid using a web services approach

    Science.gov (United States)

    Agarwal, A.; Armstrong, P.; Desmarais, R.; Gable, I.; Popov, S.; Ramage, S.; Schaffer, S.; Sobie, C.; Sobie, R.; Sulivan, T.; Vanderster, D.; Mateescu, G.; Podaima, W.; Charbonneau, A.; Impey, R.; Viswanathan, M.; Quesnel, D.

    2008-07-01

    The present paper highlights the approach used to design and implement a web services based BaBar Monte Carlo (MC) production grid using Globus Toolkit version 4. The grid integrates the resources of two clusters at the University of Victoria, using the ClassAd mechanism provided by the Condor-G metascheduler. Each cluster uses the Portable Batch System (PBS) as its local resource management system (LRMS). Resource brokering is provided by the Condor matchmaking process, whereby the job and resource attributes are expressed as ClassAds. The important features of the grid are automatic registering of resource ClassAds to the central registry, ClassAds extraction from the registry to the metascheduler for matchmaking, and the incorporation of input/output file staging. Web-based monitoring is employed to track the status of grid resources and the jobs for an efficient operation of the grid. The performance of this new grid for BaBar jobs, and the existing Canadian computational grid (GridX1) based on Globus Toolkit version 2 is found to be consistent.

  7. Study of charmonium decays of B mesons in the Babar experiment

    International Nuclear Information System (INIS)

    Grenier, Philippe

    2006-04-01

    This document is organized into 4 parts. The first part is dedicated to the Babar experiment that is installed on the e + e - collider at Stanford linear accelerator center. The formalism of the standard model and the CP violation in the B meson system are first introduced, then the Babar experiment is described and its main results are recalled: sin(2β) 0.722 ± 0.040 ± 0.023; α = (103 + 11 - 9) degrees; γ = (52 + 23 - 18) degrees. The author highlights 2 issues in which he was involved: the detector background noise induced by the machine and the beam injection system. The second part deals with DIRC (detector of internally reflected Cherenkov light) that is used for particle identification. The phenomenology of hadron decay of B mesons is described in the third part, the hypothesis of the factorization approximation is challenged. The last part is dedicated to experimental results concerning the measurement of branching ratios, the search for suppressed modes and the determination of decay amplitudes

  8. A binary link tracker for the BaBar level 1 trigger system

    International Nuclear Information System (INIS)

    Berenyi, A.; Chen, H.K.; Dao, K.

    1999-01-01

    The BaBar detector at PEP-II will operate in a high-luminosity e + e - collider environment near the Υ(4S) resonance with the primary goal of studying CP violation in the B meson system. In this environment, typical physics events of interest involve multiple charged particles. These events are identified by counting these tracks in a fast first level (Level 1) trigger system, by reconstructing the tracks in real time. For this purpose, a Binary Link Tracker Module (BLTM) was designed and fabricated for the BaBar Level 1 Drift Chamber trigger system. The BLTM is responsible for linking track segments, constructed by the Track Segment Finder Modules (TSFM), into complete tracks. A single BLTM module processes a 360 MBytes/s stream of segment hit data, corresponding to information from the entire Drift Chamber, and implements a fast and robust algorithm that tolerates high hit occupancies as well as local inefficiencies of the Drift Chamber. The algorithms and the necessary control logic of the BLTM were implemented in Field Programmable Gate Arrays (FPGAs), using the VHDL hardware description language. The finished 9U x 400 mm Euro-format board contains roughly 75,000 gates of programmable logic or about 10,000 lines of VHDL code synthesized into five FPGAs

  9. Studying b --> s gamma at BABAR Using a Fully Inclusive Method

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, R

    2004-02-23

    The b {yields} s{gamma} decay represents a possible electromagnetic ''loop'' penguin decay of the B meson. This FCNC process is of high theoretical interest because various scenarios of new physics are expected to have contributions at the same (one loop) level as the Standard Model. The large sample of B{bar B} meson decays collected by the BaBar experiment makes a precision measurement of this rare decay possible. In conjunction with Standard Model predictions at the 10% level, it brings new physics effects into the realm of detection--or seriously constrains models that could predict them. A fully inclusive technique is presented to study the b {yields} s{gamma} transition as a function of photon energy, using 88.5 {+-} 1.0 x 10{sup 6} B{bar B} meson decays collected by the BaBar experiment in the years 2000 to 2002. The expected statistical and systematic uncertainties have been fully determined which enables first comparisons with theoretical predictions and other experimental results. It also lays the basis for the determination of the inclusive branching fraction {Beta}(B {yields} X{sub s}{gamma}) and the measurement of the photon energy spectrum.

  10. High speed digital TDC for D0 vertex reconstruction

    International Nuclear Information System (INIS)

    Gao Guosheng; Partridge, R.

    1992-01-01

    A high speed digital TDC has been built as part of the Level 0 trigger for the D0 experiment at Fermilab. The digital TDC is used to make a fast determination of the primary vertex position by timing the arrival time of beam jets detected in the Level 0 counters. The vertex position is then used by the Level 1 trigger to determine the proper sinθ weighting factors for calculation transverse energies. Commercial GaAs integrated circuits are used in the digital TDC to obtain a time resolution of σ t == 226 ps

  11. Simulations with the PANDA micro-vertex-detector

    International Nuclear Information System (INIS)

    Kliemt, Ralf

    2013-01-01

    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.

  12. Vertex-Detector R&D for CLIC

    OpenAIRE

    Dannheim, Dominik

    2013-01-01

    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 curr...

  13. RAVE-a Detector-independent vertex reconstruction toolkit

    International Nuclear Information System (INIS)

    Waltenberger, Wolfgang; Mitaroff, Winfried; Moser, Fabian

    2007-01-01

    A detector-independent toolkit for vertex reconstruction (RAVE) is being developed, along with a standalone framework (VERTIGO) for testing, analyzing and debugging. The core algorithms represent state of the art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available

  14. The RAVE/VERTIGO vertex reconstruction toolkit and framework

    Science.gov (United States)

    Waltenberger, W.; Mitaroff, W.; Moser, F.; Pflugfelder, B.; Riedel, H. V.

    2008-07-01

    A detector-independent toolkit for vertex reconstruction (RAVE1) is being developed, along with a standalone framework (VERTIGO2) for testing, analyzing and debugging. The core algorithms represent state-of-the-art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.

  15. RAVE-a Detector-independent vertex reconstruction toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Waltenberger, Wolfgang [Institute of High Energy Physics, Austrian Academy of Sciences A-1050 Vienna (Austria)], E-mail: walten@hephy.oeaw.ac.at; Mitaroff, Winfried; Moser, Fabian [Institute of High Energy Physics, Austrian Academy of Sciences A-1050 Vienna (Austria)

    2007-10-21

    A detector-independent toolkit for vertex reconstruction (RAVE) is being developed, along with a standalone framework (VERTIGO) for testing, analyzing and debugging. The core algorithms represent state of the art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.

  16. The RAVE/VERTIGO vertex reconstruction toolkit and framework

    Energy Technology Data Exchange (ETDEWEB)

    Waltenberger, W; Mitaroff, W; Moser, F; Pflugfelder, B; Riedel, H V [Austrian Academy of Sciences, Institute of High Energy Physics, A-1050 Vienna (Austria)], E-mail: walten@hephy.oeaw.ac.at

    2008-07-15

    A detector-independent toolkit for vertex reconstruction (RAVE{sup 1}) is being developed, along with a standalone framework (VERTIGO{sup 2}) for testing, analyzing and debugging. The core algorithms represent state-of-the-art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.

  17. Z H η vertex in the simplest little Higgs model

    Science.gov (United States)

    He, Shi-Ping; Mao, Ying-nan; Zhang, Chen; Zhu, Shou-hua

    2018-04-01

    The issue of deriving Z H η vertex in the simplest little Higgs (SLH) model is revisited. Special attention is paid to the treatment of noncanonically-normalized scalar kinetic matrix and vector-scalar two-point transitions. We elucidate a general procedure to diagonalize a general vector-scalar system in gauge theories and apply it to the case of SLH. The resultant Z H η vertex is found to be different from those which have already existed in the literature for a long time. We also present an understanding of this issue from an effective field theory viewpoint.

  18. 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.

  19. Electromagnetic form factors and vertex constants for 6Li

    International Nuclear Information System (INIS)

    Blokhintsev, L.D.; Shvarts, I.A.

    1977-01-01

    It has been assumed that the main contribution to the rapidly changing part of the charge form factor of 6 Li provides the amplitude of the triangle diagram containing virtual lines of deuteron and α particle. The vertex constant G 2 for the 6 Li→α+d decay is expressed through the nuclear charge radii for 6 Li, d, and α. Taking into account coulomb interaction in the vertex of the 6 Li→α+d reaction increases G 2 by about a factor of two. The account of virtuality of a deuteron cluster also leads to an increase in G 2

  20. Development of carbon fiber staves for the strip part of the PANDA micro vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Quagli, Tommaso; Brinkmann, Kai-Thomas [II. Physikalisches Institut, Justus-Liebig Universitaet Giessen (Germany); Fracassi, Vincenzo; Grunwald, Dirk; Rosenthal, Eberhard [ZEA-1, Forschungszentrum Juelich GmbH, Juelich (Germany); Collaboration: PANDA-Collaboration

    2015-07-01

    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. Because of the compact layout of the system, its integration poses significant challenges. The detectors in the strip barrels will be supported by a composite structure of carbon fiber and carbon foam; a water-based cooling system embedded in the mechanical supports will be used to remove the excess heat from the readout electronics. In this contribution the design of the barrel stave and the ongoing development of some hardware components related to its integration will be presented.

  1. SVX/silicon detector studies

    International Nuclear Information System (INIS)

    Bagby, L.; Johnson, M.; Lipton, R.; Gu, W.

    1995-11-01

    AC coupled silicon detectors, being used for the DO upgrade, may have substantial voltage across the coupling capacitor. Failed capacitors can present ∼50 V to the input of the SVX, Silicon Vertex, device. We measured the effects that failed detector coupling capacitors have on the SVXD (rad soft 3μm), SVXH (rad hard 1.2μm), and SVXIIb (rad soft 1.2μm) amplifier / readout devices. The test results show that neighboring channels saturate when an excessive voltage is applied directly to a SVX channel. We believe that the effects are due to current diffusion within the SVX substrate rather than surface currents on the detectors. This paper discusses the magnitude of the saturation and a possible solution to the problem

  2. On the local vertex antimagic total coloring of some families tree

    Science.gov (United States)

    Febriani Putri, Desi; Dafik; Hesti Agustin, Ika; Alfarisi, Ridho

    2018-04-01

    Let G(V, E) be a graph of vertex set V and edge set E. Local vertex antimagic total coloring developed from local edge and local vertex antimagic coloring of graph. Local vertex antimagic total coloring is defined f:V(G)\\cup E(G)\\to \\{1,2,3,\\ldots,|V(G)|+|E(G)|\\} if for any two adjacent vertices v 1 and v 2, w({v}1)\

  3. Conservation laws, vertex corrections, and screening in Raman spectroscopy

    Science.gov (United States)

    Maiti, Saurabh; Chubukov, Andrey V.; Hirschfeld, P. J.

    2017-07-01

    We present a microscopic theory for the Raman response of a clean multiband superconductor, with emphasis on the effects of vertex corrections and long-range Coulomb interaction. The measured Raman intensity, R (Ω ) , is proportional to the imaginary part of the fully renormalized particle-hole correlator with Raman form factors γ (k ⃗) . In a BCS superconductor, a bare Raman bubble is nonzero for any γ (k ⃗) and diverges at Ω =2 Δmax , where Δmax is the largest gap along the Fermi surface. However, for γ (k ⃗) = constant, the full R (Ω ) is expected to vanish due to particle number conservation. It was sometimes stated that this vanishing is due to the singular screening by long-range Coulomb interaction. In our general approach, we show diagrammatically that this vanishing actually holds due to vertex corrections from the same short-range interaction that gives rise to superconductivity. We further argue that long-range Coulomb interaction does not affect the Raman signal for any γ (k ⃗) . We argue that vertex corrections eliminate the divergence at 2 Δmax . We also argue that vertex corrections give rise to sharp peaks in R (Ω ) at Ω <2 Δmin (the minimum gap along the Fermi surface), when Ω coincides with the frequency of one of the collective modes in a superconductor, e.g., Leggett and Bardasis-Schrieffer modes in the particle-particle channel, and an excitonic mode in the particle-hole channel.

  4. Fast simulation and topological vertex finding in JAVA

    International Nuclear Information System (INIS)

    Walkowiak, Wolfgang

    2001-01-01

    An overview of the fast Monte Carlo simulation for NLC detector studies as currently provided in the Java Analysis Studio environment is presented. Special emphasis is given to the simulation of tracks. In addition, the SLD collaboration's topological vertex finding algorithm (ZVTOP) has been implemented in the Java Analysis Studio framework

  5. 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...

  6. Self-locking degree-4 vertex origami structures.

    Science.gov (United States)

    Fang, Hongbin; Li, Suyi; Wang, K W

    2016-11-01

    A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.

  7. The role of geometry in 4-vertex origami mechanics

    Science.gov (United States)

    Waitukaitis, Scott; Dieleman, Peter; van Hecke, Martin

    Origami offers an interesting design platform metamaterials because it strongly couples mechanics with geometry. Even so, most research carried out so far has been limited to one or two particular patterns. I will discuss the full geometrical space of the most common origami building block, the 4-vertex, and show how exotic geometries can have dramatic effects on the mechanics.

  8. Multipole expansion of vertex functions in an arbitrary frame

    International Nuclear Information System (INIS)

    Daumens, Michel

    1977-01-01

    Vertex functions are expanded on the bases of tensor spherical harmonics and tensor multipoles. The coefficients of the expansions are rotational invariant form factors. The relations with those defined in particular frames by Durand, De Celles and Marr, and by De Rafael are exhibited. Finally multipolar form factors are built which are irreducible under pure Lorentz transformations [fr

  9. Tripartite connection condition for a quantum graph vertex

    Czech Academy of Sciences Publication Activity Database

    Cheon, T.; Exner, Pavel; Turek, Ondřej

    2010-01-01

    Roč. 375, č. 2 (2010), s. 113-118 ISSN 0375-9601 R&D Projects: GA MŠk LC06002 Institutional research plan: CEZ:AV0Z10480505 Keywords : Schrodinger operator * Singular vertex * Boundary conditions Subject RIV: BA - General Mathematics Impact factor: 1.963, year: 2010

  10. Tests of track segment and vertex finding with neural networks

    International Nuclear Information System (INIS)

    Denby, B.; Lessner, E.; Lindsey, C.S.

    1990-04-01

    Feed forward neural networks have been trained, using back-propagation, to find the slopes of simulated track segments in a straw chamber and to find the vertex of tracks from both simulated and real events in a more conventional drift chamber geometry. Network architectures, training, and performance are presented. 12 refs., 7 figs

  11. Network Unfolding Map by Vertex-Edge Dynamics Modeling.

    Science.gov (United States)

    Verri, Filipe Alves Neto; Urio, Paulo Roberto; Zhao, Liang

    2018-02-01

    The emergence of collective dynamics in neural networks is a mechanism of the animal and human brain for information processing. In this paper, we develop a computational technique using distributed processing elements in a complex network, which are called particles, to solve semisupervised learning problems. Three actions govern the particles' dynamics: generation, walking, and absorption. Labeled vertices generate new particles that compete against rival particles for edge domination. Active particles randomly walk in the network until they are absorbed by either a rival vertex or an edge currently dominated by rival particles. The result from the model evolution consists of sets of edges arranged by the label dominance. Each set tends to form a connected subnetwork to represent a data class. Although the intrinsic dynamics of the model is a stochastic one, we prove that there exists a deterministic version with largely reduced computational complexity; specifically, with linear growth. Furthermore, the edge domination process corresponds to an unfolding map in such way that edges "stretch" and "shrink" according to the vertex-edge dynamics. Consequently, the unfolding effect summarizes the relevant relationships between vertices and the uncovered data classes. The proposed model captures important details of connectivity patterns over the vertex-edge dynamics evolution, in contrast to the previous approaches, which focused on only vertex or only edge dynamics. Computer simulations reveal that the new model can identify nonlinear features in both real and artificial data, including boundaries between distinct classes and overlapping structures of data.

  12. Recent developments in high precision vertex chambers at SLAC

    International Nuclear Information System (INIS)

    Rust, D.R.

    1984-04-01

    Three detectors MARK II, MAC, AND HRS are using or planning small drift chambers placed as close as possible to the interaction print at PEP. There is also a program of development for a gaseous vertex detector for MARK II at SLC. All these programs are reviewed. 13 references

  13. Proton Form Factors And Related Processes in BaBar by ISR

    Energy Technology Data Exchange (ETDEWEB)

    Ferroli, R.B.; /Enrico Fermi Ctr., Rome /INFN, Rome

    2007-02-12

    BaBar has measured with unprecedented accuracy e{sup +}e{sup -} {yields} p{bar p} from the threshold up to Q{sub p{bar p}}{sup 2} {approx} 20 GeV{sup 2}/c{sup 4}, finding out an unexpected cross section, with plateaux and drops. In particular it is well established a sharp drop near threshold, where evidence for structures in multihadronic channels has also been found. Other unexpected and spectacular features of the Nucleon form factors are reminded, the behavior of space-like G{sub E}{sup p}/G{sub M}{sup p} and the neutron time-like form factors.

  14. A Study of Production and Decay of Omegac0 Baryons in BABAR

    International Nuclear Information System (INIS)

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B.

    2005-01-01

    Production and decay of (Omega) c 0 baryons is studied with ∼ 230 fb -1 of data recorded with the BABAR detector at the PEP-II e + e - asymmetric-energy storage ring at SLAC. The (Omega) c 0 is reconstructed through its decays into (Omega) - π + , (Omega) - π + π - π + , Ξ - K - π + π + final states. The invariant mass spectra are presented and the signal yields are extracted. Ratios of branching fractions are measured relative to the (Omega) c 0 → (Omega) - π + mode Β((Omega) c 0 → Ξ - K - π + π + )/Β((Omega) c 0 → (Omega) - π + ) = 0.31 ± 0.15(stat.) ± 0.04(syst.), Β((Omega) c 0 → (Omega) - π + π - π + )/Β((Omega) c 0 → (Omega) - π + ) c 0 baryons is extracted from decays into (Omega) - π + , establishing the first observation of (Omega) c 0 production from B decays

  15. A Barrel IFR Instrumented With Limited Streamer Tubes for BABAR Experiment

    International Nuclear Information System (INIS)

    Andreotti, M.; Ferrara U.; INFN, Ferrara

    2006-01-01

    The new barrel Instrumented Flux Return (IFR) of BABAR detector will be reported here. Limited Streamer Tubes (LSTs) have been chosen to replace the existing RPCs as active elements of the barrel IFR. The layout of the new detector will be discussed: in particular, a cell bigger than the standard one has been used to improve efficiency and reliability. The extruded profile is coated with a resistive layer of graphite having a typical surface resistivity between 0.2 and 0.4 MOhm/square. The tubes are assembled in modules and installed in 12 active layers of each sextant of the IFR detector. R and D studies to choose the final design and Quality Control procedure adopted during the tube production will be briefly discussed. Finally the performances of installed LSTs into 2/3 of IFR after 8 months of operations will be reported

  16. Search for a dark photon in e(+)e(-) collisions at BABAR.

    Science.gov (United States)

    Lees, J P; Poireau, V; Tisserand, V; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, D N; Feng, M; Kerth, L T; Kolomensky, Yu G; Lee, M J; Lynch, G; Koch, H; Schroeder, T; Hearty, C; Mattison, T S; McKenna, J A; So, R Y; Khan, A; Blinov, V E; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Lankford, A J; Mandelkern, M; Dey, B; Gary, J W; Long, O; Campagnari, C; Franco Sevilla, M; Hong, T M; Kovalskyi, D; Richman, J D; West, C A; Eisner, A M; Lockman, W S; Panduro Vazquez, W; Schumm, B A; Seiden, A; Chao, D S; Cheng, C H; Echenard, B; Flood, K T; Hitlin, D G; Miyashita, T S; Ongmongkolkul, P; Porter, F C; Andreassen, R; Huard, Z; Meadows, B T; Pushpawela, B G; Sokoloff, M D; Sun, L; Bloom, P C; Ford, W T; Gaz, A; Smith, J G; Wagner, S R; Ayad, R; Toki, W H; Spaan, B; Bernard, D; Verderi, M; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Piemontese, L; Santoro, V; Calcaterra, A; de Sangro, R; Finocchiaro, G; Martellotti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Bhuyan, B; Prasad, V; Adametz, A; Uwer, U; Lacker, H M; Dauncey, P D; Mallik, U; Chen, C; Cochran, J; Prell, S; Ahmed, H; Gritsan, A V; Arnaud, N; Davier, M; Derkach, D; Grosdidier, G; Le Diberder, F; Lutz, A M; Malaescu, B; Roudeau, P; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Coleman, J P; Fry, J R; Gabathuler, E; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Di Lodovico, F; Sacco, R; Cowan, G; Bougher, J; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Griessinger, K; Hafner, A; Schubert, K R; Barlow, R J; Lafferty, G D; Cenci, R; Hamilton, B; Jawahery, A; Roberts, D A; Cowan, R; Sciolla, G; Cheaib, R; Patel, P M; Robertson, S H; Neri, N; Palombo, F; Cremaldi, L; Godang, R; Sonnek, P; Summers, D J; Simard, M; Taras, P; De Nardo, G; Onorato, G; Sciacca, C; Martinelli, M; Raven, G; Jessop, C P; LoSecco, J M; Honscheid, K; Kass, R; Feltresi, E; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simi, G; Simonetto, F; Stroili, R; Akar, S; Ben-Haim, E; Bomben, M; Bonneaud, G R; Briand, H; Calderini, G; Chauveau, J; Leruste, Ph; Marchiori, G; Ocariz, J; Biasini, M; Manoni, E; Pacetti, S; Rossi, A; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Casarosa, G; Cervelli, A; Chrzaszcz, M; Forti, F; Giorgi, M A; Lusiani, A; Oberhof, B; Paoloni, E; Perez, A; Rizzo, G; Walsh, J J; Lopes Pegna, D; Olsen, J; Smith, A J S; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Pilloni, A; Piredda, G; Bünger, C; Dittrich, S; Grünberg, O; Hartmann, T; Hess, M; Leddig, T; Voß, C; Waldi, R; Adye, T; Olaiya, E O; Wilson, F F; Emery, S; Vasseur, G; Anulli, F; Aston, D; Bard, D J; Cartaro, C; Convery, M R; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Ebert, M; Field, R C; Fulsom, B G; Graham, M T; Hast, C; Innes, W R; Kim, P; Leith, D W G S; Lewis, P; Lindemann, D; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Muller, D R; Neal, H; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Snyder, A; Su, D; Sullivan, M K; Va'vra, J; Wisniewski, W J; Wulsin, H W; Purohit, M V; White, R M; Wilson, J R; Randle-Conde, A; Sekula, S J; Bellis, M; Burchat, P R; Puccio, E M T; Alam, M S; Ernst, J A; Gorodeisky, R; Guttman, N; Peimer, D R; Soffer, A; Spanier, S M; Ritchie, J L; Ruland, A M; Schwitters, R F; Wray, B C; Izen, J M; Lou, X C; Bianchi, F; De Mori, F; Filippi, A; Gamba, D; Lanceri, L; Vitale, L; Martinez-Vidal, F; Oyanguren, A; Villanueva-Perez, P; Albert, J; Banerjee, Sw; Beaulieu, A; Bernlochner, F U; Choi, H H F; King, G J; Kowalewski, R; Lewczuk, M J; Lueck, T; Nugent, I M; Roney, J M; Sobie, R J; Tasneem, N; Gershon, T J; Harrison, P F; Latham, T E; Band, H R; Dasu, S; Pan, Y; Prepost, R; Wu, S L

    2014-11-14

    Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} using 514  fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10^{-4}-10^{-3} for dark photon masses in the range 0.02-10.2  GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.

  17. A Monte Carlo Study of the Momentum Dependence on the Results of Tracking Unknown Particle Species in the BaBar Detector

    Energy Technology Data Exchange (ETDEWEB)

    Sewerynek, Stephen; /British Columbia U.

    2007-04-06

    The BABAR experiment is composed of an international collaboration that will test the Standard Model prediction of CP violation. To accomplish this a new detector was constructed at the asymmetric B Factory, located at the Stanford Linear Accelerator Center. The tests will shed some light on the origins of CP violation, which is an important aspect in explaining the matter/antimatter asymmetry in the universe. In particular, the BABAR experiment will measure CP violation in the neutral B meson system. In order to succeed, the BABAR experiment requires excellent track fitting and particle species identification. Prior to the current study, track fitting was done using only one particle species--the pion. But given the momentum dependence on the accuracy of the results from this choice of particle species, a better algorithm needed to be developed. Monte Carlo simulations were carried out and a new algorithm utilizing all five particle species present in the BABAR detector was created.

  18. Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar

    International Nuclear Information System (INIS)

    Gandini, Paolo

    2012-01-01

    We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f L in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f L ∼ 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B → ρρ and B + → (Omega)ρ + decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f L ∼ 0.5 in B → φK* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.

  19. Design and Application of the Reconstruction Software for the BaBar Calorimeter

    International Nuclear Information System (INIS)

    Strother, Philip David; Imperial Coll., London

    2006-01-01

    The BaBar high energy physics experiment will be in operation at the PEP-II asymmetric e + e - collider in Spring 1999. The primary purpose of the experiment is the investigation of CP violation in the neutral B meson system. The electromagnetic calorimeter forms a central part of the experiment and new techniques are employed in data acquisition and reconstruction software to maximize the capability of this device. The use of a matched digital filter in the feature extraction in the front end electronics is presented. The performance of the filter in the presence of the expected high levels of soft photon background from the machine is evaluated. The high luminosity of the PEP-II machine and the demands on the precision of the calorimeter require reliable software that allows for increased physics capability. BaBar has selected C++ as its primary programming language and object oriented analysis and design as its coding paradigm. The application of this technology to the reconstruction software for the calorimeter is presented. The design of the systems for clustering, cluster division, track matching, particle identification and global calibration is discussed with emphasis on the provisions in the design for increased physics capability as levels of understanding of the detector increase. The CP violating channel B 0 → J/Ψ K s 0 has been studied in the two lepton, two π 0 final state. The contribution of this channel to the evaluation of the angle sin 2β of the unitarity triangle is compared to that from the charged pion final state. An error of 0.34 on this quantity is expected after 1 year of running at design luminosity

  20. Design and Application of the Reconstruction Software for the BaBar Calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Strother, Philip David; /Imperial Coll., London

    2006-07-07

    The BaBar high energy physics experiment will be in operation at the PEP-II asymmetric e{sup +}e{sup -} collider in Spring 1999. The primary purpose of the experiment is the investigation of CP violation in the neutral B meson system. The electromagnetic calorimeter forms a central part of the experiment and new techniques are employed in data acquisition and reconstruction software to maximize the capability of this device. The use of a matched digital filter in the feature extraction in the front end electronics is presented. The performance of the filter in the presence of the expected high levels of soft photon background from the machine is evaluated. The high luminosity of the PEP-II machine and the demands on the precision of the calorimeter require reliable software that allows for increased physics capability. BaBar has selected C++ as its primary programming language and object oriented analysis and design as its coding paradigm. The application of this technology to the reconstruction software for the calorimeter is presented. The design of the systems for clustering, cluster division, track matching, particle identification and global calibration is discussed with emphasis on the provisions in the design for increased physics capability as levels of understanding of the detector increase. The CP violating channel B{sup 0} {yields} J/{Psi}K{sub S}{sup 0} has been studied in the two lepton, two {pi}{sup 0} final state. The contribution of this channel to the evaluation of the angle sin 2{beta} of the unitarity triangle is compared to that from the charged pion final state. An error of 0.34 on this quantity is expected after 1 year of running at design luminosity.

  1. Radiative Penguin Decays at the BaBar Experiment B to K*gamma, B to rho gamma, B to omega gamma and B to Xs gamma

    International Nuclear Information System (INIS)

    Grauges, E.

    2004-01-01

    A review of the results obtained from the analysis of the B meson decays that involve Radiative Penguin processes, recorded at the BaBar experiment at the Stanford Linear Accelerator Center PEP-II B-Factory, is presented. The physics interest of these processes and their SM prediction are discussed briefly. The most relevant selection techniques used in the analysis are described before quoting the latest results made public by the BaBar collaboration as of July 2003

  2. Operator Product Formulas in the Algebraic Approach of the Refined Topological Vertex

    International Nuclear Information System (INIS)

    Cai Li-Qiang; Wang Li-Fang; Wu Ke; Yang Jie

    2013-01-01

    The refined topological vertex of Iqbal—Kozçaz—Vafa has been investigated from the viewpoint of the quantum algebra of type W 1+∞ by Awata, Feigin, and Shiraishi. They introduced the trivalent intertwining operator Φ which is normal ordered along with some prefactors. We manage to establish formulas from the infinite operator product of the vertex operators and the generalized ones to restore this prefactor, and obtain an explicit formula for the vertex realization of the topological vertex as well as the refined topological vertex

  3. 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.

  4. Worldline calculation of the three-gluon vertex

    International Nuclear Information System (INIS)

    Ahmadiniaz, N.; Schubert, C.

    2012-01-01

    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.

  5. 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.

  6. Six-vertex model and Schramm-Loewner evolution

    Science.gov (United States)

    Kenyon, Richard; Miller, Jason; Sheffield, Scott; Wilson, David B.

    2017-05-01

    Square ice is a statistical mechanics model for two-dimensional ice, widely believed to have a conformally invariant scaling limit. We associate a Peano (space-filling) curve to a square ice configuration, and more generally to a so-called six-vertex model configuration, and argue that its scaling limit is a space-filling version of the random fractal curve SL E κ, Schramm-Loewner evolution with parameter κ , where 4 <κ ≤12 +8 √{2 } . For square ice, κ =12 . At the "free-fermion point" of the six-vertex model, κ =8 +4 √{3 } . These unusual values lie outside the classical interval 2 ≤κ ≤8 .

  7. Development of pixel detectors for SSC vertex tracking

    International Nuclear Information System (INIS)

    Kramer, G.; Shapiro, S.L.; Arens, J.F.; Jernigan, J.G.; Skubic, P.

    1991-04-01

    A description of hybrid PIN diode arrays and a readout architecture for their use as a vertex detector in the SSC environment is presented. Test results obtained with arrays having 256 x 256 pixels, each 30 μm square, are also presented. The development of a custom readout for the SSC will be discussed, which supports a mechanism for time stamping hit pixels, storing their xy coordinates, and storing the analog information within the pixel. The peripheral logic located on the array, permits the selection of those pixels containing interesting data and their coordinates to be selectively read out. This same logic also resolves ambiguous pixel ghost locations and controls the pixel neighbor read out necessary to achieve high spatial resolution. The thermal design of the vertex tracker and the proposed signal processing architecture will also be discussed. 5 refs., 13 figs., 3 tabs

  8. 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.

  9. Analysis of bilinear relation of a six-vertex model

    International Nuclear Information System (INIS)

    Korepin, V.E.

    1982-01-01

    A problem of calculating all matrices of T(μ) monodromy satisfying certain commutation relations for the six-vertex model matrix is considered. The paper presents full description of all accurate L-operators (all monodromy-matrices per one lattice step). It is noted that the a/d function has the simpliest form for L operators, and the corresponding A, B, C, D operators act transitively in rather narrow subspace of the constructed space

  10. Edge union of networks on the same vertex set

    International Nuclear Information System (INIS)

    Loe, Chuan Wen; Jensen, Henrik Jeldtoft

    2013-01-01

    Random network generators such as Erdős–Rényi, Watts–Strogatz and Barabási–Albert models are used as models to study real-world networks. Let G 1 (V, E 1 ) and G 2 (V, E 2 ) be two such networks on the same vertex set V. This paper studies the degree distribution and clustering coefficient of the resultant networks, G(V, E 1 ∪E 2 ). (paper)

  11. Edge union of networks on the same vertex set

    Science.gov (United States)

    Loe, Chuan Wen; Jeldtoft Jensen, Henrik

    2013-06-01

    Random network generators such as Erdős-Rényi, Watts-Strogatz and Barabási-Albert models are used as models to study real-world networks. Let G1(V, E1) and G2(V, E2) be two such networks on the same vertex set V. This paper studies the degree distribution and clustering coefficient of the resultant networks, G(V, E1∪E2).

  12. Track fitting in the opal vertex detector with stereo wires

    Energy Technology Data Exchange (ETDEWEB)

    Shally, R; Hemingway, R J; McPherson, A C

    1987-10-01

    The geometry of the vertex chamber for the OPAL detector at LEP is reviewed and expressions for the coordinates of the hits are given in terms of the measured drift distance and z-coordinate. The tracks are fitted by a procedure based on the Lagrange multipliers method. The increase in the accuracy of the fit due to the use of the stereo wires is discussed.

  13. 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.

  14. General Vertex-Distinguishing Total Coloring of Graphs

    Directory of Open Access Journals (Sweden)

    Chanjuan Liu

    2014-01-01

    Full Text Available The general vertex-distinguishing total chromatic number of a graph G is the minimum integer k, for which the vertices and edges of G are colored using k colors such that any two vertices have distinct sets of colors of them and their incident edges. In this paper, we figure out the exact value of this chromatic number of some special graphs and propose a conjecture on the upper bound of this chromatic number.

  15. Edge-injective and edge-surjective vertex labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Regen, F.

    2010-01-01

    For a graph G = (V, E) we consider vertex-k-labellings f : V → {1,2, ,k} for which the induced edge weighting w : E → {2, 3,., 2k} with w(uv) = f(u) + f(v) is injective or surjective or both. We study the relation between these labellings and the number theoretic notions of an additive basis and ...

  16. Fatigue crack shape prediction based on vertex singularity

    Czech Academy of Sciences Publication Activity Database

    Hutař, Pavel; Náhlík, Luboš

    2008-01-01

    Roč. 2, č. 1 (2008), s. 45-52 ISSN 1802-680X R&D Projects: GA ČR GA101/08/1623; GA ČR GP106/06/P239 Institutional research plan: CEZ:AV0Z20410507 Keywords : 3D vertex singularity * crack shape * fatigue crack propagation Subject RIV: JL - Materials Fatigue, Friction Mechanics

  17. Vertex maps on graphs -- Perron-Frobenius Theory

    OpenAIRE

    Bernhardt, Chris

    2015-01-01

    The goal of this paper is to describe the connections between Perron-Frobenius theory and vertex maps on graphs. In particular, it is shown how Perron-Frobenius theory gives results about the sets of integers that can arise as periods of periodic orbits, about the concepts of transitivity and topological mixing, and about horseshoes and topological entropy. This is a preprint. The final version will appear in the Journal of Difference Equations and Applications.

  18. Readout ASIC for ILC-FPCCD vertex detector

    International Nuclear Information System (INIS)

    Takubo, Yosuke; Miyamoto, Akiya; Ikeda, Hirokazu; Yamamoto, Hitoshi; Itagaki, Kennosuke; Nagamine, Tadashi; Sugimoto, Yasuhiro

    2010-01-01

    The concept of FPCCD (Fine Pixel CCD) whose pixel size is 5x5μm 2 has been proposed as vertex detector at ILC. Since FPCCD has 128 x20,000 pixels in one readout channel, its readout poses a considerable challenge. We have developed a prototype of readout ASIC to readout the large number of pixels during the inter-train gap of the ILC beam. In this paper, we report the design and performance of the readout ASIC.

  19. Track fitting in the opal vertex detector with stereo wires

    International Nuclear Information System (INIS)

    Shally, R.; Hemingway, R.J.; McPherson, A.C.

    1987-01-01

    The geometry of the vertex chamber for the OPAL detector at LEP is reviewed and expressions for the coordinates of the hits are given in terms of the measured drift distance and z-coordinate. The tracks are fitted by a procedure based on the Lagrange multipliers method. The increase in the accuracy of the fit due to the use of the stereo wires is discussed. (orig.)

  20. The Mark III vertex chamber: Studies using DME

    International Nuclear Information System (INIS)

    Pitman, D.

    1987-04-01

    Studies have been performed using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. A 35 μm spatial resolution using dimethyl ether (DME) at 1 bar and 30 μm using argon ethane (50/50 mixture) at 4 bar was obtained. Preliminary studies show the DME to adversely affect such materials as aluminized Mylar and Delrin

  1. 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.

  2. Colour-independent partition functions in coloured vertex models

    International Nuclear Information System (INIS)

    Foda, O.; Wheeler, M.

    2013-01-01

    We study lattice configurations related to S n , the scalar product of an off-shell state and an on-shell state in rational A 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 n models, and to all n. This n-independence explains, in vertex-model terms, results from recent studies of S 2 (Caetano and Vieira, 2012, [1], Wheeler, (arXiv:1204.2089), [2]). Namely, 1.S 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 1 vertex-model partition function

  3. Track and vertex reconstruction: From classical to adaptive methods

    International Nuclear Information System (INIS)

    Strandlie, Are; Fruehwirth, Rudolf

    2010-01-01

    This paper reviews classical and adaptive methods of track and vertex reconstruction in particle physics experiments. Adaptive methods have been developed to meet the experimental challenges at high-energy colliders, in particular, the CERN Large Hadron Collider. They can be characterized by the obliteration of the traditional boundaries between pattern recognition and statistical estimation, by the competition between different hypotheses about what constitutes a track or a vertex, and by a high level of flexibility and robustness achieved with a minimum of assumptions about the data. The theoretical background of some of the adaptive methods is described, and it is shown that there is a close connection between the two main branches of adaptive methods: neural networks and deformable templates, on the one hand, and robust stochastic filters with annealing, on the other hand. As both classical and adaptive methods of track and vertex reconstruction presuppose precise knowledge of the positions of the sensitive detector elements, the paper includes an overview of detector alignment methods and a survey of the alignment strategies employed by past and current experiments.

  4. Measurement of Collins asymmetries in inclusive production of charged pion pairs in e(+)e(-) annihilation at BABAR

    NARCIS (Netherlands)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Dey, B.; Gary, J. W.; Long, O.; Vitug, G. M.; Campagnari, C.; Sevilla, M. Franco; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Schwierz, R.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Morii, M.; Adametz, A.; Uwer, U.; Lacker, H. M.; Dauncey, P. D.; Mallik, U.; Cochran, J.; Meyer, W. T.; Prell, S.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Bougher, J.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Behn, E.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Dujmic, D.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Sonnek, P.; Summers, D. J.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Pegna, D. Lopes; Olsen, J.; Smith, A. J. S.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Gioi, L. Li; Piredda, G.; Buenger, C.; Grueberg, O.; Leddig, T.; Voss, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; de Monchenault, G. Hamel; Vasseur, G.; Yeche, Ch.; Anulli, F.; Aston, D.; Bard, D. J.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindemann, D.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Zambito, S.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Ahmed, H.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Choi, H. H. F.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.

    2014-01-01

    We present measurements of Collins asymmetries in the inclusive process e+e−→ππX, where π stands for charged pions, at a center-of-mass energy of 10.6 GeV. We use a data sample of 468  fb−1 collected by the BABAR experiment at the PEP-II B factory at SLAC, and consider pairs of charged pions

  5. Study of the reaction e(+)e(-) -> psi(2S)pi(+)pi(-) via initial-state radiation at BABAR

    NARCIS (Netherlands)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Tico, J. Garra; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Rakitin, A. Y.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Uwer, U.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Behera, P. K.; Mallik, U.; Cochran, J.; Meyer, W. T.; Prell, S.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Behn, E.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Cheaib, R.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; de Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Pegna, D. Lopes; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Gioi, L. Li; Mazzoni, M. A.; Piredda, G.; Buenger, C.; Gruenberg, O.; Leddig, T.; Schroeder, H.; Vo, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; de Monchenault, G. Hamel; Vasseur, G.; Ysche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Sevilla, M. Franco; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Lund, P.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Zambito, S.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Ahmed, H.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Choi, H. H. F.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Puccio, E. M. T.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.

    2014-01-01

    We study the process e+e−→ψ(2S)π+π− with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(nS) (n=2,3,4) resonances and correspond to an integrated luminosity of 520  fb−1. We

  6. Bottomonium spectroscopy and radiative transitions involving the chi(bJ)(1P, 2P) states at BABAR

    NARCIS (Netherlands)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Mandelkern, M.; Dey, B.; Gary, J. W.; Long, O.; Campagnari, C.; Sevilla, M. Franco; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Vazquez, W. Panduro; Schumm, B. A.; Seiden, A.; Chao, D. S.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Roehrken, M.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Adametz, A.; Uwer, U.; Lacker, M.; Dauncey, P. D.; Mallik, U.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Bougher, J.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Sonnek, P.; Summers, D. J.; Simard, M.; Taras, P.; De Nardo, G.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Feltresi, E.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Pegna, D. Lopes; Olsen, J.; Smith, A. J. S.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Gioi, L. Li; Pilloni, A.; Piredda, G.; Buenger, C.; Dittrich, S.; Gruenber, O.; Hess, M.; Leddig, T.; Voss, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Vasseur, G.; Anulli, F.; Aston, D.; Bard, D. J.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Lewis, P.; Lindemann, D.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Wulsin, H. W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Albert, J.; Banerjee, Sw.; Beaulieu, A.; Bernlochner, F. U.; Choi, H. H. F.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.

    2014-01-01

    We use (121±1) million Υ(3S) and (98±1) million Υ(2S) mesons recorded by the BABAR detector at the PEP-II e+e− collider at SLAC to perform a study of radiative transitions involving the χbJ(1P,2P) states in exclusive decays with μ+μ−γγ final states. We reconstruct twelve channels in four cascades

  7. The CMS all silicon Tracker simulation

    CERN Document Server

    Biasini, Maurizio

    2009-01-01

    The Compact Muon Solenoid (CMS) tracker detector is the world's largest silicon detector with about 201 m$^2$ of silicon strips detectors and 1 m$^2$ of silicon pixel detectors. It contains 66 millions pixels and 10 million individual sensing strips. The quality of the physics analysis is highly correlated with the precision of the Tracker detector simulation which is written on top of the GEANT4 and the CMS object-oriented framework. The hit position resolution in the Tracker detector depends on the ability to correctly model the CMS tracker geometry, the signal digitization and Lorentz drift, the calibration and inefficiency. In order to ensure high performance in track and vertex reconstruction, an accurate knowledge of the material budget is therefore necessary since the passive materials, involved in the readout, cooling or power systems, will create unwanted effects during the particle detection, such as multiple scattering, electron bremsstrahlung and photon conversion. In this paper, we present the CM...

  8. Silicon pixel-detector R&D for CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)718101

    2016-01-01

    The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to 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 a few μm, ultra-low mass (∼ 0.2% X${}_0$ per layer for the vertex region and ∼ 1 % X${}_0$ per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ∼ 10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with small pitch (25 μm) and analog readout are explored. For the outer trac...

  9. Silicon pixel R&D for the CLIC detector

    CERN Document Server

    AUTHOR|(SzGeCERN)674552

    2017-01-01

    The physics aims at the future CLIC high-energy linear $e^{+}e^{−}$ collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The main challenges are: a point resolution of a few microns, ultra-low mass (~0.2% X$_{0}$ per layer for the vertex region and ~1% X$_{0}$ per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ~10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with small pitch (25 μm) and analogue readout are explored. For the outer tra...

  10. Silicon detectors

    International Nuclear Information System (INIS)

    Klanner, R.

    1984-08-01

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  11. Microscopic models for hadronic form factors and vertex functions

    International Nuclear Information System (INIS)

    Santhanam, I.; Bhatnagar, S.; Mitra, A.N.

    1990-01-01

    We review the status of nucleon (N) and few-nucleon form factors (f.f.'s) from the view-point of a gradual unfolding of successively inner degrees of freedom (d.o.f.) with increase in q 2 . To this end we focus attention on the problem of a microscopic formulation of hadronic vertex functions (v.f.) from the point of view of their key role in understanding the physics of a large variety of few-hadron reactions on the one hand, and their practical usefulness in articulating the internal dynamics of hadron and few-hadron systems on the other hand. The criterion of an integrated view from low-energy spectroscopy to high-q 2 amplitudes is employed to emphasize the desirability of formulations in terms of relativistic dynamical equations based on Lorentz and gauge invariance in preference to phenomenological models, which often require additional assumptions beyond their original premises to extend their applicability domains. In this respect, the practical possibilities of the Bethe-Salpeter equation (BSE) in articulating the necessary dynamical ingredients are emphasized on a two-tier basis, the basis constants (3) being pre-determined from the mass spectral data (1 st stage) in preparation for the construction of the hadron-quark vertex functions (2 nd stage). An explicit construction is outlined for meson-quark and baryon-quark vertex functions as well as of meson-nucleon vertex functions in a stepwise fashion. The role of the latter as basic parameter-free ingredients is discussed for possible use in the more serious treatment in the current literature of quark-meson level (α) and meson-isobar (β) d.o.f. in 2-N and 3-N form factor studies. Since most of these studies are characterized by the use of RGM techniques at the six-quark level, a comparative discussion is also given of several contemporary RGM based models. Finally, the concrete prospects for employing such hardon-quark vertex functions for evaluating pp-bar annihilation amplitudes are briefly indicated

  12. Development of vertexing and lifetime triggers and a study of B(s) mixing using hadronic decays at D0

    International Nuclear Information System (INIS)

    Barnes, Christopher P.

    2005-01-01

    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 super conducting 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 B s 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 B s → D s π. This important mode provides the best proper time resolution for B s mixing and is reconstructed for the first time at D0. Projections on the sensitivity to B s oscillations are then presented

  13. Study of Rare B Meson Decays Related to the CKM Angle Beta at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Keith; /Amherst Coll.

    2007-06-06

    This study reports measurements of the branching fractions of B meson decays to {eta}{prime}K{sup +}, {eta}{prime}K{sup 0}, {omega}{pi}{sup +}, {omega}K{sup +}, and {omega}K{sup 0}. Charge asymmetries are measured for the charged modes and the time-dependent CP-violation parameters S and C are measured for the neutral modes. The results are based on a data sample of 347 fb{sup -1} containing 383 million B{bar B} pairs recorded by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring located at the Stanford Linear Accelerator Center. Statistically significant signals are observed for all channels with the following results: B(B{sup +} {yields} {eta}{prime}K{sup +}) = (70.0{+-}1.5{+-}2.8)x10{sup -6}, B(B{sup 0} {yields} {eta}{prime}K{sup 0}) = (66.6{+-}2.6{+-}2.8)x10{sup -6}, B(B{sup +} {yields} {omega}{pi}{sup +}) = (6.7{+-}0.5{+-}0.4)x10{sup -6}, B(B{sup +} {yields} {omega}K{sup +}) = (6.3{+-}0.5{+-}0.3)x10-6, and B(B{sup 0} {yields} ?K0) = (5.6{+-}0.8{+-}0.3)x10-6, where the first uncertainty is statistical and the second is systematic. We measure A{sub ch}({eta}{prime}K{sup +}) = +0.010{+-}0.022{+-}0.006, A{sub ch}({omega}{pi}{sup +}) = -0.02{+-}0.08{+-}0.01, A{sub ch}({omega}K{sup +}) = -0.01{+-}0.07{+-}0.01, S{sub {eta}{prime}K{sup 0}{sub S}} = 0.56{+-}0.12{+-}0.02, C{sub {eta}{prime}K{sup 0}{sub S}} = -0.24 {+-} 0.08 {+-} 0.03, S{sub {omega}{prime}K{sup 0}{sub S}} = 0.62+0.25 -0.29 {+-} 0.02, and C{sub {omega}{prime}K{sup 0}{sub S}} = -0.39+0.25 -0.24 {+-} 0.03. The result in S{sub {eta}{prime}K{sup 0}{sub S}} contributes to the published measurement from BABAR, which differs from zero by 5.5 standard deviations and is the first observation of mixing-induced CP-violation in a charmless B decay.

  14. 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

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

    International Nuclear Information System (INIS)

    Schrader, Christoph

    2011-01-01

    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 μm), low material budget (∝50 μm 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 HADES data

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

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Shun, E-mail: s-ono@champ.hep.sci.osaka-u.ac.jp [Osaka University, 1-1 Machikaneyama, Toyonaka (Japan); Togawa, Manabu; Tsuji, Ryoji; Mori, Teppei [Osaka University, 1-1 Machikaneyama, Toyonaka (Japan); Yamada, Miho; Arai, Yasuo; Tsuboyama, Toru; Hanagaki, Kazunori [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Org. (KEK), 1-1 Oho, Tsukuba (Japan)

    2017-02-11

    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 μm{sup 2} 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.

  17. A doublet of 3" cylindrical silicon drift detectors in the CERES/NA45 experiment

    CERN Document Server

    Faschingbauer, U; Baur, R; Ceretto, F; Drees, A; Fraenkel, Zeev; Fuchs, C; Gatti, E; Glässel, P; Hemberger, M; Pérez de los Heros, C; Hess, F; Holl, P; Irmscher, D; Jacob, C; Kemmer, J; Minaev, Yu I; Panebratsev, Yu A; Pfeiffer, A; Ravinovich, I; Razin, S V; Rehak, P; Sampietro, M; Schükraft, Jürgen; Shimansky, S S; Socol, E; Specht, H J; Tel-Zur, G; Tserruya, Itzhak; Ullrich, T S; Voigt, C A; Wurm, J P; Yurevich, V I

    1995-01-01

    We report on the performance of a doublet of 3" cylindrical silicon drift detectors installed as an upgrade of the CERES/NA45 electron pair spectrometer for the Pb-beam at the CERN SPS. The silicon detectors provide external particle tracking and background rejection of conversions and close Dalitz pairs. Results on vertex reconstruction and rejection from Pb test-run in 1994 are presented.

  18. Production and performance of the silicon sensor and custom readout electronics for the PHENIX FVTX tracker

    International Nuclear Information System (INIS)

    Kapustinsky, Jon S.

    2010-01-01

    The Forward Silicon Vertex Tracker (FVTX) upgrade for the PHENIX detector at RHIC will extend the vertex capability of the central PHENIX Silicon Vertex Tracker (VTX). The FVTX is designed with adequate spatial resolution to separate decay muons coming from the relatively long-lived heavy quark mesons (Charm and Beauty), from prompt particles and the longer-lived pion and kaon decays that originate at the primary collision vertex. These heavy quarks can be used to probe the high-density medium that is formed in Au+Au collisions at RHIC. The FVTX is designed as two endcaps. Each endcap comprises four silicon disks covering opening angles from 10 o to 35 o to match the existing muon arm acceptance. Each disk consists of p-on-n, silicon wedges, with ac-coupled mini-strips on 75 μm radial pitch and projective length in the phi direction that increases with radius. A custom front-end chip, the FPHX, has been designed for the FVTX. The chip combines fast trigger capability with data push architecture in a low-power design.

  19. Production and performance of the silicon sensor and readout electronics for the PHENIX FVTX tracker

    International Nuclear Information System (INIS)

    Kapustinsky, Jon Steven

    2009-01-01

    The Forward Silicon Vertex Tracker (FVTX) upgrade for the PHENIX detector at RHIC will extend the vertex capability of the central PHENIX Silicon Vertex Tracker (VTX). The FVTX is designed with adequate spatial resolution to separate decay muons coming from the relatively long-lived heavy quark mesons (Charm and Beauty), from prompt particles and the longer-lived pion and kaon decays that originate at the primary collision vertex. These heavy quarks can be used to probe the high density medium that is formed in Au+Au collisions at RHIC. The FVTX is designed as two endcaps. Each endcap is comprised of four silicon disks covering opening angles from 10 to 35 degrees to match the existing muon arm acceptance. Each disk consists of p-on-n, silicon wedges, with ac-coupled mini-strips on 75 (micro)m radial pitch and proj ective length in the phi direction that increases with radius. A custom front-end chip, the FPHX, has been designed for the FVTX. The chip combines fast trigger capability with data push architecture in a low power design.

  20. Production and performance of the silicon sensor and custom readout electronics for the PHENIX FVTX tracker

    Energy Technology Data Exchange (ETDEWEB)

    Kapustinsky, Jon S., E-mail: jonk@lanl.go [Los Alamos National Laboratory, Mailstop H846, PO Box 1663, Los Alamos, 87545 New Mexico (United States)

    2010-05-21

    The Forward Silicon Vertex Tracker (FVTX) upgrade for the PHENIX detector at RHIC will extend the vertex capability of the central PHENIX Silicon Vertex Tracker (VTX). The FVTX is designed with adequate spatial resolution to separate decay muons coming from the relatively long-lived heavy quark mesons (Charm and Beauty), from prompt particles and the longer-lived pion and kaon decays that originate at the primary collision vertex. These heavy quarks can be used to probe the high-density medium that is formed in Au+Au collisions at RHIC. The FVTX is designed as two endcaps. Each endcap comprises four silicon disks covering opening angles from 10{sup o} to 35{sup o} to match the existing muon arm acceptance. Each disk consists of p-on-n, silicon wedges, with ac-coupled mini-strips on 75 {mu}m radial pitch and projective length in the phi direction that increases with radius. A custom front-end chip, the FPHX, has been designed for the FVTX. The chip combines fast trigger capability with data push architecture in a low-power design.

  1. First-order corrections to random-phase approximation GW calculations in silicon and diamond

    NARCIS (Netherlands)

    Ummels, R.T.M.; Bobbert, P.A.; van Haeringen, W.

    1998-01-01

    We report on ab initio calculations of the first-order corrections in the screened interaction W to the random-phase approximation polarizability and to the GW self-energy, using a noninteracting Green's function, for silicon and diamond. It is found that the first-order vertex and self-consistency

  2. Challenges for secondary vertex reconstruction in CBM at SIS100 and SIS300 at FAIR

    International Nuclear Information System (INIS)

    Lymanets, A.; Kotynia, A.; Heuser, J.

    2010-01-01

    Full text: The CBM experiment at FAIR will explore the QCD phase diagram in the region of highest baryon densities. In contrast to other experimental programs in the same energy domain, CBM will be able to explore rare probes such as charm and dileptons due to its capability of running at interaction rates as high as 10 MHz. In order to cope with the related experimental challenges detailed simulations studies as well as extensive R and D activities on the detector and readout systems are ongoing. In this contribution, the challenges of open charm measurement in pA collisions, e.g. already at SIS100, and in AA collisions at SIS300 will be investigated. In order to extract open charm decays from the large background of produced charged particles, secondary vertex reconstruction with a precision of less than 0.1 mm is required. The involved tracking and reconstruction procedures have to be fast in order to allow their implementation already on the trigger level. Prerequisite for this are ultra-low mass, fast and radiation tolerant silicon detectors. These two aspects of a finally successful measurement, hardware development and reconstruction routines, are being developed in close contact to each other and their status is demonstrated in this talk. (author)

  3. 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...

  4. 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...

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rescigno, R., E-mail: regina.rescigno@iphc.cnrs.fr [Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, 67037 Strasbourg Cedex 2 (France); Finck, Ch.; Juliani, D. [Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, 67037 Strasbourg Cedex 2 (France); Spiriti, E. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Frascati (Italy); Istituto Nazionale di Fisica Nucleare - Sezione di Roma 3 (Italy); Baudot, J. [Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, 67037 Strasbourg Cedex 2 (France); Abou-Haidar, Z. [CNA, Sevilla (Spain); Agodi, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (Italy); Alvarez, M.A.G. [CNA, Sevilla (Spain); Aumann, T. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Battistoni, G. [Istituto Nazionale di Fisica Nucleare - Sezione di Milano (Italy); Bocci, A. [CNA, Sevilla (Spain); Böhlen, T.T. [European Organization for Nuclear Research CERN, Geneva (Switzerland); Medical Radiation Physics, Karolinska Institutet and Stockholm University, Stockholm (Sweden); Boudard, A. [CEA-Saclay, IRFU/SPhN, Gif sur Yvette Cedex (France); Brunetti, A.; Carpinelli, M. [Istituto Nazionale di Fisica Nucleare - Sezione di Cagliari (Italy); Università di Sassari (Italy); Cirrone, G.A.P. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (Italy); Cortes-Giraldo, M.A. [Departamento de Fisica Atomica, Molecular y Nuclear, University of Sevilla, 41080-Sevilla (Spain); Cuttone, G.; De Napoli, M. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (Italy); Durante, M. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); and others

    2014-12-11

    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 methods are implemented. The algorithm performances and the accuracy on reconstructed observables are evaluated on the basis of simulated and experimental data.

  7. Track and vertex reconstruction on GPUs for the Mu3e experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bruch, Dorothea vom; Kozlinskiy, Alexandr [Physikalisches Institut, Universitaet Heidelberg (Germany); Berger, Niklaus [Institut fuer Kernphysik, Universitaet Mainz (Germany); Collaboration: Mu3e-Collaboration

    2015-07-01

    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 pixel 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 implementation of the fits on the GPU, which processes 10{sup 10} combinations of hits from three layers per second.

  8. Recent results on search for new physics at BaBar

    Directory of Open Access Journals (Sweden)

    Oberhof Benjamin

    2017-01-01

    Full Text Available We present some recent measurements for the search of New Physics using 514 fb−1 of e+e− collisions collected with the BaBar detector at the PEP-II e+e− collider at SLAC. First we present a search for the decay ϒ (1S → γA0, A0 → cc̄, where A0 is a candidate for the CP-odd Higgs boson of the next-to-minimal supersymmetric standard model. No significant signal is observed and we set 90% confidence-level upper limits on B(ϒ(1S → γA0 × B(A0 → cc̄. We report the search for a light non-Standard Model gauge boson Z′ coupling only to the second and third lepton families. Our results significantly improve current limits and further constrain the remaining region of the allowed parameter space. Finally, we present a search for a long-lived particle L that is produced in e+e− annihilations and decays into two oppositely charged tracks. We do not observe a significant signal and we and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency as a function of the L mass. In addition, upper limits are provided on the branching fraction B(B → XsL, where Xs is an hadronic system with strangeness -1.

  9. Radiative Bottomonium Spectroscopy at the Y(2, 3S) Resonances at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Peter M. [Stanford Univ., CA (United States)

    2013-08-01

    The compact bound state consisting of a bottom and anti-bottom quark pair interacting via the strong nuclear force is called “bottomonium.” A wealth of long-lived bottomonium states can be both experimentally produced and theoretically described, providing a unique tool to probe calculation techniques with experiment. Bottomonia with total angular momentum J = 1 and orbital angular momentum L = 0 at a variety of radial excitations n – called Υ(nS) – can be produced at electron-positron colliders. The BABAR experiment, located at the interaction point of such a collider (the PEP-II storage ring), has observed 122 million Υ(3S) and 100 million Υ(2S) decays. Some of these involve a transition to the bottomonium state χbJ (nP) (L = 1 and J = (0, 1, 2)), emitting a photon, with subsequent transition to a lower Υ(nS), also emitting a photon. The final Υ(nS) can be identified through a decay to two muons. The dependence of the branching fractions and photon energies in this process on the spin state of the intermediate χbJ (nP) is a key test of phenomenological models. To this end, this dissertation contains a nearly comprehensive study of these transitions with an emphasis on experimentally optimal discrimination between various models. This focus spurs innovative techniques that complement a large array of physics results, both presented in detail herein.

  10. Hadronic and rare B decays with the BaBar and Belle experiments

    Energy Technology Data Exchange (ETDEWEB)

    Prudent, Xavier [Technische Univ. Dresden, Dresden (Germany)

    2012-05-07

    We review recent experimental results on Bd and Bs mesons decays by the BaBar and Belle experiments. These include measurements of the color-suppressed decays B¯0 → D(*)0h0,h0 = π0,η,η',ω, observation of the baryonic decay B¯0 → Λc+Λ¯K, measurements of the charmless decays B → ηh,h = π,K, B → Kπ, and observation of CP eigenstates in the Bs decays: Bs0 → J/ψf0(980), Bs0 → J/ψf0(1370) and Bs0 → J/ψη. As a result, the theoretical implications of these results will be considered.ided

  11. Study of the Rare Decay B0 to pi0 pi0 at BaBar

    CERN Document Server

    Bowerman, D A

    2003-01-01

    The BABAR experiment operating at the PEP-II e sup + e sup - collider is designed to study CP violation effects in the B-meson system. From May 1999 to June 2002 approximately 81 fb sup - sup 1 of data have been collected at the UPSILON(4S) resonance, containing (87.9 +- 1.4) Million BB pairs. From this data sample the branching fraction for the decay B sup 0 -> pi sup 0 pi sup 0 has been extracted using a multi-dimensional maximum likelihood technique. With an efficiency of 20.4%, we find 36 sub - sub 1 sub 4 sub - sub 1 sup + sup 1 sup 5 sup + sup 1 B sup 0 -> pi sup 0 pi sup 0 events and measure the branching fraction to be BETA(B sup 0 -> pi sup 0 pi sup 0) = (2.0 sub - sub 0 sub . sub 8 sub - sub 0 sub . sub 2 sup + sup 0 sup . sup 9 sup + sup 0 sup . sup 3) x 10 sup - sup 6 where the first error is statistical and the second systematic. The statistical significance is 3.1 sigma and we report an upper limit of BETA(B sup 0 -> pi sup 0 pi sup 0) < 3.6 x 10 sup - sup 6 (90%CL). The results of the fit ar...

  12. Investigation of B-->D{sup (*)}anti-D{sup (*)}K Decays with the BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jean-Pierre

    2001-07-30

    Using about 23M B{bar B} events collected in 1999-2000 with the BABAR detector, they report the observation of several hundred B {yields} D{sup (*)} {bar D}(*) K decays with two completely reconstructed D mesons. The preliminary branching fractions of the low background decay modes B{sup 0} {yields} D*{sup -} D{sup (*)}{sup 0} K{sup +} are determined to be {Beta}(B{sup 0} {yields} D*{sup -} D{sup 0}K{sup +}) = (2.8 {+-} 0.7 {+-} 0.05) x 10{sup -3} and {Beta}(B{sup 0} {yields} D*{sup -} D*{sup 0} K{sup +}) = (6.8 {+-} 1.7 {+-} 1.7) x 10{sup -3}. Observation of a significant number of candidates in the color-suppressed decay mode B{sup +} {yields} D*{sup +} D*{sup -} K{sup +} is reported with a preliminary branching fraction {Beta}(B{sup +} {yields} D*{sup +} D*{sup -} K{sup +}) = (3.4 {+-} 1.6 {+-} 0.9) x 10{sup -3}.

  13. Study of the doubly-charmed decays of B mesons with the experiment BABAR in SLAC

    International Nuclear Information System (INIS)

    Robbe, P.

    2002-04-01

    The BABAR experiment at SLAC (Stanford linear acceleration center) has been studying since 1999 B meson decays from e + e - collisions at the γ(4S) resonance. The first goal of the collaboration was to measure the sin (2β) CP-violation parameter within the standard model. This measurement requires to know with precision the absolute length scale of the detector. A method to test this scale was developed using nuclear interactions in the beam-pipe material. The longitudinal length scale was then determined at the 1 % level precision. The systematic error associated with length measurement in the detector concerning B meson lifetime and B meson oscillation frequency is then negligible with respect to the other errors. The K meson content of B decays is a key ingredient of the sin (2β) measurement and is used to tag the flavour of the other B in events containing a B decaying to a CP eigenstate. The K charge is correlated to the B flavour. Wrong sign kaons, which can dilute B tagging, can come from wrong sign D decays (B→ DX). Doubly charmed decays (B→ D (*) D-bar (*) K are one possibility to produce wrong sign D decays. The twenty-two decay modes are reconstructed exclusively. The total branching fraction is measured with enough precision to establish that B→ D (*) D-bar (*) K decays are not the only source of wrong sign D mesons in B decays. (author)

  14. Study of B --> D*{sup +}D*{sup -} Decays with the BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2004-02-10

    Decays of the type B {yields} D(*){bar D}(*) can be used to provide a measurement of the parameter sin2{beta} of the Unitarity Triangle that is complementary to that derived from the mode B{sup 0} {yields} J/{psi}K{sub S}{sup 0}. Here we report a measurement of the branching fraction and a study of the CP parity content for the decay B{sup 0} {yields} D*{sup +}D*{sup -} with the BABAR detector. With data corresponding to an integrated luminosity of 20.7 fb{sup -1} collected at the {Upsilon}(4S) resonance during 1999-2000, we determine the branching fraction to be {Beta}(B{sup 0} {yields} D*{sup +}D*{sup -}) = (8.0 {+-} 1.6(stat ) {+-} 1.2(syst.)) x 10{sup -4}. The measured fraction of the component with odd CP parity is 0.22 {+-} 0.18(stat) {+-} 0.03(syst). Observation of a significant number of candidates in the decay modes B{sup 0} {yields} D*{sup +}D{sup -} and B{sup +} {yields} D*{sup +}D*{sup 0} is reported. All results presented in this note are preliminary.

  15. Study of the Rare Decay B0 to pi0 pi0 at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Bowerman, Daniel

    2003-08-20

    The BABAR experiment operating at the PEP-II e{sup +}e{sup -} collider is designed to study CP violation effects in the B-meson system. From May 1999 to June 2002 approximately 81 fb{sup -1} of data have been collected at the {Upsilon}(4S) resonance, containing (87.9 {+-} 1.4) Million BB pairs. From this data sample the branching fraction for the decay B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0} has been extracted using a multi-dimensional maximum likelihood technique. With an efficiency of 20.4%, we find 36{sub -14-1}{sup +15+1} B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0} events and measure the branching fraction to be {Beta}(B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}) = (2.0{sub -0.8-0.2}{sup +0.9+0.3}) x 10{sup -6} where the first error is statistical and the second systematic. The statistical significance is 3.1{sigma} and we report an upper limit of {Beta}(B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}) < 3.6 x 10{sup -6} (90%CL). The results of the fit are confirmed using a simple cut based analysis technique.

  16. Silicon position sensitive detectors for the Helios (NA 34) experiment

    Energy Technology Data Exchange (ETDEWEB)

    Engels, E Jr; Mani, S; Manns, T; Plants, D; Shepard, P F; Thompson, J A; Tosh, R; Chand, T; Shivpuri, R; Baker, W

    1987-01-15

    The design construction and testing of X-Y tracking modules for a silicon microstrip vertex detector for use in Fermilab experiment E706 is discussed. A successful adaptation of various technologies, essential for instrumenting this class of detectors at a university laboratory is described. Emphasis is placed on considerable cost reduction, design flexibiity and more rapid turnover with a view toward large detectors for the future.

  17. Gauge covariant fermion-photon vertex in quenched, massless three dimensional quantum electrodynamics

    International Nuclear Information System (INIS)

    Tjiang, P.C.; Burden, C.J.

    1998-01-01

    Full text: We consider the problem of designing an Ansatz for the transverse part of the fermion-photon vertex in QED 3 . Our work is based on that of Ball and Chiu, who consider restrictions placed on the vertex by the U(1) Ward identity, and on subsequent modifications which attempt to satisfy the Landau-Khalatnikov transformation rules. A class of vertex Ansaetze including that proposed by Dong et al is tested using the gauge invariance of the vacuum polarisation scalar

  18. Three-coloring graphs with no induced seven-vertex path II : using a triangle

    OpenAIRE

    Chudnovsky, Maria; Maceli, Peter; Zhong, Mingxian

    2015-01-01

    In this paper, we give a polynomial time algorithm which determines if a given graph containing a triangle and no induced seven-vertex path is 3-colorable, and gives an explicit coloring if one exists. In previous work, we gave a polynomial time algorithm for three-coloring triangle-free graphs with no induced seven-vertex path. Combined, our work shows that three-coloring a graph with no induced seven-vertex path can be done in polynomial time.

  19. Intrinsic-normal-ordered vertex operators from the multiloop N-tachyon amplitude

    International Nuclear Information System (INIS)

    Aldazabal, G.; Nunez, C.; Bonini, M.; Iengo, R.

    1987-09-01

    We construct vertex operators for arbitrary mass level states of the closed bosonic string. Starting from a generalization of the Koba-Nielsen amplitude which is suitable for an arbitrary genus Riemann surface, we read the vertex operators from the residues of the poles for the intermediate states. Since the original expression is metric independent and normal ordered without the need of inventing any regularization scheme, our vertex operators also possess these properties. We discuss their general features. (author). 17 refs

  20. 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

  1. Effects of Vertex Activity and Self-organized Criticality Behavior on a Weighted Evolving Network

    International Nuclear Information System (INIS)

    Zhang Guiqing; Yang Qiuying; Chen Tianlun

    2008-01-01

    Effects of vertex activity have been analyzed on a weighted evolving network. The network is characterized by the probability distribution of vertex strength, each edge weight and evolution of the strength of vertices with different vertex activities. The model exhibits self-organized criticality behavior. The probability distribution of avalanche size for different network sizes is also shown. In addition, there is a power law relation between the size and the duration of an avalanche and the average of avalanche size has been studied for different vertex activities

  2. Operadic formulation of topological vertex algebras and gerstenhaber or Batalin-Vilkovisky algebras

    International Nuclear Information System (INIS)

    Huang Yizhi

    1994-01-01

    We give the operadic formulation of (weak, strong) topological vertex algebras, which are variants of topological vertex operator algebras studied recently by Lian and Zuckerman. As an application, we obtain a conceptual and geometric construction of the Batalin-Vilkovisky algebraic structure (or the Gerstenhaber algebra structure) on the cohomology of a topological vertex algebra (or of a weak topological vertex algebra) by combining this operadic formulation with a theorem of Getzler (or of Cohen) which formulates Batalin-Vilkovisky algebras (or Gerstenhaber algebras) in terms of the homology of the framed little disk operad (or of the little disk operad). (orig.)

  3. A NEW HYBRID GENETIC ALGORITHM FOR VERTEX COVER PROBLEM

    OpenAIRE

    UĞURLU, Onur

    2015-01-01

    The minimum vertex cover  problem belongs to the  class  of  NP-compl ete  graph  theoretical problems. This paper presents a hybrid genetic algorithm to solve minimum ver tex cover problem. In this paper, it has been shown that when local optimization technique is added t o genetic algorithm to form hybrid genetic algorithm, it gives more quality solution than simple genet ic algorithm. Also, anew mutation operator has been developed especially for minimum verte...

  4. Vertex operator construction of superconformal ghosts and string field theory

    International Nuclear Information System (INIS)

    Ezawa, Z.F.; Nakamura, S.; Tezuka, A.

    1987-01-01

    Superconformal ghosts in string theories are characterized by the SU(1,1) Kac-Moody algebra with central charge -1/2. These ghost fields are constructed as the vertex operators realizing spinor representations of the Kac-Moody algebra. Representations of the canonical commutation relations of the superconformal ghosts are analyzed extensively. All irreducible representations are found to possess only the trivial inner product but for one exceptional case. Consequently, in superstring field theory it is necessary to consider reducible representations in general. Hilbert spaces with a non-trivial inner product are explicitly obtained upon which second quantization of superstring may be carried out. (orig.)

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Performance of the VTL PEPR vertex guidance system

    International Nuclear Information System (INIS)

    Dunn, L.A.; Harris, R.; Kenyon, R.G.; Lubatti, H.J.; Moriyasu, K.

    1975-01-01

    A PEPR vertex guidance system requiring no operator intervention has been operating at the University of Washington's Visual Techniques Laboratory since 1972. The measurement of 140 000 events consisting of 3, 4, 5, and 6-prong interactions of a 15 GeV/c π - beam with deuterium was recently completed. The system employs global transformations that reduce circular tracks to a point in a two-dimensional angle-curvature space. Noise reduction techniques are used to improve position and angle accuracy and thereby the system resolution and efficiency. Monitoring criteria were developed to ensure continuous peak performance over long production periods. (Auth.)

  10. Structure of the vertex function in finite quantum electrodynamics

    International Nuclear Information System (INIS)

    Mannheim, P.D.

    1975-01-01

    We study the structure of the renormalized electromagnetic current vertes, GAMMA-tilde/sub μ/(p,p+q,q), in finite quantum electrodynamics. Using conformal invariance we find that GAMMA-tilde/sub μ/(p,p,0) takes the simple form of Z 1 γ/sub μ/ when the external fermions are far off the mass shell. We interpret this result as an old theorem on the structure of the vertex function due to Gell--Mann and Zachariasen. We give the general structure of the vertex for arbitrary momentum transfer parametrically, and discuss how the Bethe--Salpeter equation and the Federbush--Johnson theorem are satisfied. We contrast the meaning of pointlike in a finite field theory with the meaning understood in the parton model. We discuss to what extent the condition Z 1 = 0, which may hold in conformal theories other than finite quantum electrodynamics, may be interpreted as a bootstrap condition. We show that the vanishing of Z 1 prevents their being bound states in the Migdal--Polyakov bootstrap

  11. 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.

  12. Nonperturbative aspects of the quark-photon vertex

    International Nuclear Information System (INIS)

    Frank, M.R.

    1994-01-01

    The electromagnetic interaction with quarks is investigated through a relativistic, electromagnetic gauge-invariant treatment. Gluon dressing of the quark-photon vertex and the quark self-energy functions is described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger-Dyson equation in the rainbow approximation respectively. Results for the calculation of the quark-photon vertex are presented in both the time-like and space-like regions of photon momentum squared, however emphasis is placed on the space-like region relevant to electron scattering. The treatment presented here simultaneously addresses the role of dynamically generated q bar q vector bound states and the approach to asymptotic behavior. The resulting description is therefore applicable over the entire range of momentum transfers available in electron scattering experiments. Input parameters are limited to the model gluon two-point function which is chosen to reflect confinement and asymptotic freedom and are largely constrained by the obtained bound-state spectrum

  13. Commissioning of the control and data acquisition electronics for the CDF Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Tkaczyk, S.M.; Turner, K.J.; Nelson, C.A.; Shaw, T.M.; Wesson, T.R.; Bailey, M.W.; Kruse, M.C.; Castro, A.

    1991-11-01

    The SVX data acquisition system includes three components: a Fastbus Sequencer, an SVX Rabbit Crate Controller and a Digitizer. These modules are integrated into the CDF DAQ system and operate the readout chips. The results of the extensive functional tests of the SVX modules are reported. We discuss the stability of the Sequencers, systematic differences between them and methods of synchronization with the Tevatron beam crossings. The Digitizer ADC calibration procedure run on the microsequencer is described. The microsequencer code used for data taking and SVX chip calibration modes is described. Measurements of the SVX data scan time are discussed

  14. Development of a Data Acquisition Program for the Purpose of Monitoring Processing Statistics Throughout the BaBar Online Computing Infrastructure's Farm Machines

    Energy Technology Data Exchange (ETDEWEB)

    Stonaha, P.

    2004-09-03

    A current shortcoming of the BaBar monitoring system is the lack of systematic gathering, archiving, and access to the running statistics of the BaBar Online Computing Infrastructure's farm machines. Using C, a program has been written to gather the raw data of each machine's running statistics and compute various rates and percentages that can be used for system monitoring. These rates and percentages then can be stored in an EPICS database for graphing, archiving, and future access. Graphical outputs show the reception of the data into the EPICS database. The C program can read if the data are 32- or 64-bit and correct for overflows. This program is not exclusive to BaBar and can be easily modified for any system.

  15. Measurement of branching fraction ratios and CP asymmetries in B → DCP0K decays with the BABAR detector

    International Nuclear Information System (INIS)

    Marchiori, Giovanni

    2010-01-01

    The primary goals of the BABAR experiment are the detection of CP violation (CPV) in the B meson system, the precise measurement of some of the elements of the CKM matrix and the measurement of the rates of rare B meson decays. At present, BABAR has achieved major successes: (1) the discovery, in neutral B decays, of direct and mixing-induced CP violation; (2) accurate measurements of the magnitudes of the CKM matrix elements |V cb | and |V ub |; (3) a precise measurement of the CKM parameter β (triple b ond) arg(- V cd V* cb /V td V* tb ); (4) a first measurement of the CKM parameters α (triple b ond) arg(- V td V* tb /V ud V* ub ), γ (triple b ond) arg(- V ud V* ub /V cd V* cb ); and (5) the observation of several rare B decays and the discovery of new particles (in the charmed and charmonium mesons spectroscopy). However, the physics program of BABAR is not yet complete. Two of the key elements of this program that still need to be achieved are: (1) the observation of direct CP violation in charged B decays, which would constitute the first evidence of direct CPV in a charged meson decay; and (2) the precise measurement of α and γ, which are necessary ingredients for a stringent test of the Standard Model predictions in the quark electroweak sector. A possibility for the discovery of direct CP violation in charged B decays would be the observation of a non-vanishing rate asymmetry in the Cabibbo-suppressed decay B - → D 0 K - , with the D 0 decaying to either a CP-even or a CP-odd eigenstate. This class of decays can also provide theoretically-clean information on γ.

  16. The measurements of angle γ of the unitarity triangle with the BaBar detector

    International Nuclear Information System (INIS)

    Derkach, D.

    2010-06-01

    In this thesis, we present studies of the B mesons system performed using the full dataset collected by the BABAR experiment at the PEP-II collider at SLAC. The first analysis presented here is the search of the rare V ub mediated decays B + → D + K *0 . The experimental analysis is performed looking at several D + decay modes. No signals have been found and upper limits have been set to be: Br(B + → D + K 0 ) -6 at 90% prob.; Br(B + → D + K *0 ) -6 at 90% prob. In the second part we present the CP violation studies in the B-meson system, and in particular the measurements of the γ angle of the unitarity triangle. The γ angle is the relative weak phase between the V ub and V cb elements of the CKM matrix. We present and describe the analysis using the charged B meson decays: B + → D 0 K + . These decays are studied through the ADS method, where the neutral D mesons are reconstructed into Kππ 0 final states. Combining this analysis with a similar one that used Kπ as a D 0 final state, we have obtained the following values: ratio r(DK) 0.083+0.028-0.043; γ angle = (86+51-45) degrees. If the results of this thesis are used in the full system of the B → DK and B → DK * decay amplitudes, other interesting results can be obtained. The error on the ratio r(DK * ) for the charged B decays is improved by a factor 3 resulting in r(DK * ) = (0.08 ± 0.03). The ration between the V ub mediated annihilation (A) and the color suppressed (C) amplitudes is obtained to be A/C 0 ) for neutral B decays is found to be (0.27 ± 0.09)

  17. Hyperon AND Hyperon Resonance Properties From Charm Baryon Decays At BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, Veronique; /Iowa U.

    2007-07-03

    This report describes studies of hyperons and hyperon resonances produced in charm baryon decays at BABAR. Using two-body decays of the {Xi}{sub c}{sup 0} and {Omega}{sub c}{sup 0}, it is shown, for the first time, that the spin of the {omega}{sup -} is 3/2. The {Omega}{sup -} analysis procedures are extended to three-body final states and properties of the {Xi}(1690){sup 0} are extracted from a detailed isobar model analysis of the {Lambda}{sub c}{sup +} {yields} {Lambda}{bar K}{sup 0}K{sup +} Dalitz plot. The mass and width values of the {Xi}(1690){sup 0} are measured with much greater precision than attained previously. The hypothesis that the spin of the {Xi}(1690) resonance is 1/2 yields an excellent description of the data, while spin values 3/2 and 5/2 are disfavored. The {Lambda}a{sub 0}(980){sup +} decay mode of the {Lambda}{sub c}{sup +} is observed for the first time. Similar techniques are then used to study {Xi}(1530){sup 0} production in {Lambda}{sub c}{sup +} decay. The spin of the {Xi}(1530) is established for the first time to be 3/2. The existence of an S-wave amplitude in the {Xi}{sup -}{pi}{sup +} system is shown, and its interference with the {Xi}(1530){sup 0} amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the {Xi}(1530). The {Xi}{sup -}{pi}{sup +} mass distribution in the vicinity of the {Xi}(1690){sup 0} exhibits interesting structure which may be interpreted as indicating that the {Xi}(1690) has negative parity.

  18. Search for Rare Multi-Pion Decays of the Tau Lepton Using the BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ter-Antonyan, Ruben [The Ohio State Univ., Columbus, OH (United States)

    2007-09-18

    A search for the decay of the τ lepton to rare multi-pion final states is performed using the BABAR detector at the PEP-II asymmetric-energy e+e- collider. The analysis uses 232 fb-1 of data at center-of-mass energies on or near the Y(4S) resonance. In the search for the τ- → 3π-+0vτ decay, we observe 10 events with an expected background of 6.5$+2.0\\atop{-1.4}$ events. In the absence of a signal, we calculate the decay branching ratio upper limit β(τ- → 3π-2π+2π0vτ) < 3.4 x 10-6 at the 90% confidence level. This is more than a factor of 30 improvement over the previously established limit. In addition, we search for the exclusive decay mode τ- → 2ωπ-vτ with the further decay of ω →π-π+π0. We observe 1 event, expecting 0.4$+1.0\\atop{-0.4}$ background events, and calculate the upper limit βτ-→ 2ωπ-vτ < 5.4 x 10-7 at the 90% confidence level. This is the first upper limit for this mode.

  19. A Measurement of the B ---> Eta/C K Branching Fraction Using the BaBar Detector

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Frank; /Manchester U.

    2006-04-26

    The branching fraction is measured for the decay channels B{sup 0} {yields} {eta}{sub c}K{sub S}{sup 0} and B{sup +} {yields} {eta}{sub c}K{sup +} where {eta}{sub c} {yields} K{bar K}{pi}, using the BABAR detector. The {eta}{sub c} {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -} and {eta}{sub c} {yields} K{sup +}K{sup -}{pi}{sup 0} decay channels are used, including non-resonant decays and possibly those through intermediate resonances.

  20. Time-dependent Dalitz-Plot Analysis of the Charmless Decay B^0 -> K^0S Pi Pi- at BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Ilic, J

    2009-10-17

    A time-dependent amplitude analysis of B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} decays is performed in order to extract the CP violation parameters of f{sub 0}(980)K{sub S}{sup 0} and {rho}{sup 0}(770)K{sub S}{sup 0} and direct CP asymmetries of K*{sup +}(892){pi}{sup -}. The results are obtained from the final BABAR data sample of (465 {+-} 5)10{sup 6} B{bar B} decays, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The time dependent CP asymmetry for f{sub 0}(980)K{sub S}{sup 0} and {rho}{sup 0}(770)K{sub S}{sup 0} are measured to be S(f{sub 0}(980)K{sub S}{sup 0}) = -0.97 {+-} 0.09 {+-} 0.01 {+-} 0.01, and S({rho}{sup 0}(770)K{sub S}{sup 0}) = 0.67 {+-} 0.20 {+-} 0.06 {+-} 0.04, respectively. In decays to K*{sup +}(892){pi}{sup -} the direct CP asymmetry is found to be A{sub CP}(K*{sup {+-}}(892){pi}{sup {-+}}) = -0.18 {+-} 0.10 {+-} 0.04 {+-} 0.00. The relative phases between B{sup 0} {yields} K*{sup +}(892){pi}{sup -} and {bar B}{sup 0} {yields} K*{sup -}(892){pi}{sup +}, relevant for the extraction of the unitarity triangle angle {gamma}, is measured to be {Delta}{phi}(K*(892){pi}) = (34.9 {+-} 23.1 {+-} 7.5 {+-} 4.7){sup o}, where uncertainties are statistical, systematic and model-dependent, respectively. Fit fractions, direct CP asymmetries and the relative phases of different other resonant modes have also been measured. A new method for extracting longitudinal shower development information from longitudinally unsegmented calorimeters is also presented. This method has been implemented as a part of the BABAR final particle identification algorithm. A significant improvement in low momenta muon identification at BABAR is obtained.