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1. Recombination in InGaAs/GaAs quantum wire lasers

Author

Paolo Visconti, Ross Rinaldi, Mauro Lomascolo, M. DeGiorgi, R. Cingolani, Adriana Passaseo, Leander Tapfer, L. DeCaro, Massimo Catalano, M. DeVittorio, Antonietta Taurino, DE VITTORIO, Massimo, Rinaldi, Rosaria, A., Passaseo, M., DE GIORGI, M., Lomascolo, Visconti, Paolo, R., Cingolani, A., Taurino, M., Catalano, L., Decaro, and L., Tapfer

Subjects
Condensed matter physics, Field (physics), Condensed Matter::Other, Chemistry, Exciton, Quantum wire, General Chemistry, Electroluminescence, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Condensed Matter Physics, Laser, Piezoelectricity, law.invention, Condensed Matter::Materials Science, symbols.namesake, Stark effect, law, Materials Chemistry, symbols, Lasing threshold
Abstract

We have studied the recombination mechanism of InGaAs/GaAs V-shaped quantum wire lasers under electrical injection and in high magnetic field, from well below to above lasing threshold. The emission originates from free-carrier recombination independent of temperature and injection density. No excitonic contribution is found, indicating that excitons are weakly bound in these wires due to the internal piezoelectric field causing a strong Stark effect. A quantitative analysis of the piezoelectric field is performed by measuring the screening induced blue-shift of the electroluminescence at different densities and comparing it with the piezoelectric potential calculated from the quantum wire cross-sections observed by transmission electron microscopy. (C) 1999 Elsevier Science Ltd. All rights reserved.

Published
1999

2. Randomised controlled trial of streptokinase, aspirin, and combination of both in treatment of acute ischaemic stroke

Author

F Finzi, G Alunni, G Costantino, E Ghidoni, M Sfrappini, L Roveyaz, M Marra, J Wardlaw, A Ballini, G Lancia, F Zuccari, M Dicostanzo, A Brambilla, E Greco, L Melini, S Terenziani, E Moschini, G Marzara, A Gasparro, G Dalessandro, O Citterio, R Milani, A Pietra, S Comparetti, G Lama, D Sabatini, G Volpi, M Cruciani, L Ralli, A Vinattieri, L Casto, M Rottoli, S Ragaini, S Polonara, M Digiovanni, E Dejuli, G Danieli, P Menegazzo, A Brucato, O Marrazza, A Palumbo, F Costantini, I Laspina, E Righetti, F Deblasi, C Giorgi, G Landini, N Bonasera, L Calvi, A Lorizio, D Vanni, C Delfavero, L Provinciali, R Zucco, U Marini, R Nuzzi, F Cocco, G Crisi, C Defanti, M Porta, M Santangelo, E Pieragnoli, D Belladonna, L Giglia, D Sita, E Cani, V Lolli, S Spolveri, S Ricci, A Perreti, M Rascaroli, P Monaco, G Pisapia, G Candeliere, L Bagnoli, L Bruni, L Curatola, E Decapitani, R Capialbi, P Lattuada, J Bamford, M Poli, G Arena, R Diperri, F Pezzella, A Colombo, F Aloy, S Blanc, M Guidotti, G Baldassarri, A Garagnani, U Loi, C Leviminzi, V Romanazzi, C Sacchet, F Barzizza, V Avenia, M Taglioli, V Pontrelli, M Arnaboldi, G Trianni, F Raudino, A Bettinelli, G Russo, D Belvedere, P Infricciolo, A Paci, E Natali, G Santoro, M Correia, S Pasquali, G Pellegrini, D Mirabile, A Messina, G Alborini, J Bogousslavsky, F Colonna, A Randazzo, F Minotta, F Lincesso, G Degliantoni, T Carboni, A Martelli, A Pirisi, V Miele, P Girardi, C Menozzi, U Scoditti, F Cardopatri, M Santoni, S Gueli, C Scaccabarozzi, A Picchiarelli, M Camerlingo, L Carosella, A Mamoli, F Dacuno, D Tonti, A Troiso, P Piazza, A Castellano, M Veneziani, M Zampolini, S Santini, C Argentino, G Palmieri, G Pinardi, G Bovio, P Sandercock, A Boccali, M Baratti, R Musolino, G Tognoni, A Gatta, E Longhini, L Steidl, G Rosati, M Delgobbo, C Refi, P Panzetti, G Bissi, G Rizzato, M Pratesi, E Bottacchi, L Candelise, G Bollettini, L Fera, P Ottaviano, G Coppola, Vittorio Bertele, M Degiorgi, F Triolo, O Tafani, M Pallone, D Guidetti, N Marcello, C Scarpati, L Desantis, F Rizzitelli, C Conte, M Voloute, G Scialfa, G Lombardo, M Bianchi, G Micili, L Motti, D Bosone, C Fini, C Matacena, F Turiamo, R Luccioli, N Miele, F Rossi, D Gori, C Clarke, T Frattini, M Celani, G Thiella, A Cantini, F Schieroni, O Scarpino, M Masina, P Sorgato, G Capocchi, F Colombo, M Zocchi, I Mazzanti, A Trenta, R Cavestri, R Reginelli, P Bassi, G Grilli, A Fancellu, D Orrico, M Scarpa, M Franceschi, F Passeri, A Ghetti, M Bondi, M Spanu, C Motto, E Negri, M Rezzonico, T Lomuzio, E Pretolani, R Ciola, S Grasselli, G Erli, M Desimoni, D Bertuzzi, H Barnett, A Vemco, G Musco, C Degrandi, A Fennetry, B Censori, A Delfavero, B Biscottini, R Peto, F Federico, C Bonaventi, C Bascelli, G Malferrari, C Alli, D Porazzi, G Sgaroni, A Giannini, G Scarlato, E Boccardi, A Cavallini, R Sterzi, E Aritzu, P Dudine, M Stellio, F Clerici, F Porro, R Grandi, L Munari, M Pacini, S Bartolini, M Zadra, A Balotta, A Sensidoni, B Felice, F Locatelli, W Garuti, R Gobbato, F Solime, L Sallusto, C Warlow, G Pirazzoli, G Ferrarini, M Watt, P Perrone, N Caputo, R Menozzi, M Michelini, R Bellesi, A Lechi, F Marras, I Bartolini, E Pascarelli, I Dascola, G Casu, G Divizia, M Ceravolo, R Ibba, R Insabato, G Venables, I Iori, G Greco, M Deledda, N Bartolini, F Grandi, E Cerioli, S Biagini, G Grampa, P Bannister, F Sasanelli, S Canzi, T Riccardi, A Bartocci, F Basso, A Marceca, C Cappelletti, I Santilli, R Bettini, F Salsa, Maria Carla Roncaglioni, G Bottini, A Ciccone, G Rebucci, A Maggioni, P Marotta, G Iannone, C Longoni, F Milone, V Inchingolo, V Chioma, E Lanza, and R Ferani

Subjects
Aspirin, Randomized controlled trial, law, business.industry, Streptokinase, Anesthesia, Medicine, General Medicine, business, Acute ischemic stroke, law.invention, medicine.drug
Published
1995

3. ELECTRONIC LEVELS AND RECOMBINATION LIFETIMES FORQUANTUM WIRES IN MAGNETIC FIELD

Author

A. Lorenzoni, L. C. Andreani, M. Lomascolo, ANNI, Marco, M. DeGiorgi, A. Passsaseo, R. Cingolani, RINALDI, Rosaria, A., Lorenzoni, L. C., Andreani, M., Lomascolo, Anni, Marco, M., Degiorgi, Rinaldi, Rosaria, A., Passsaseo, and R., Cingolani

Abstract

PHYSICA STATUS SOLIDI. A, APPLICATIONS AND MATERIALS SCIENCE

Published
2000

4. NANOSCALE COMPOSITIONAL FLUCTUATIONS IN MULTIPLE In-GaAs/GaAs QUANTUM WIRES

Author

M. Catalano, A. Taurino, M. Lomascolo, M. DeGiorgi, A. Passaseo, O. Mauritz, G. Goldoni, F. Rossi, E. Molinari, P. Crozier, VASANELLI, Lorenzo, RINALDI, Rosaria, CINGOLANI, Roberto, M., Catalano, A., Taurino, M., Lomascolo, Vasanelli, Lorenzo, M., Degiorgi, A., Passaseo, Rinaldi, Rosaria, Cingolani, Roberto, O., Mauritz, G., Goldoni, F., Rossi, E., Molinari, and P., Crozier

Published
2000

7. Optical processes and electronic states in InGaAs/GaAs V-groove quantum wire lasers

Author

Paolo Visconti, Ross Rinaldi, C. Turco, M. DeVittorio, Adriana Passaseo, R. Cingolani, M. DeGiorgi, R., Cingolani, Rinaldi, Rosaria, Devittorio, M., A., Passaseo, M., Degiorgi, Visconti, Paolo, C., Turco, Cingolani, R., DE VITTORIO, Massimo, Passaseo, A., DE GIORGI, M., Visconti, P., and Turco, C.

Subjects
Physics, Condensed matter physics, Field (physics), Condensed Matter::Other, business.industry, Exciton, Quantum wire, Physics::Optics, Electroluminescence, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Laser, Atomic and Molecular Physics, and Optics, Analytical Chemistry, law.invention, Condensed Matter::Materials Science, symbols.namesake, Stark effect, Quantum dot laser, law, symbols, Optoelectronics, business, Instrumentation, Lasing threshold, Spectroscopy
Abstract

We have fabricated InGaAs/GaAs V-shaped quantum wire lasers operating with threshold in the 100 A cm−2 range at low temperature. The investigation of the electroluminescence and lasing under electrical injection and in high magnetic field elucidates the fundamental physical properties of the device. In contrast to recent claims, the emission is found to originate from free-carrier recombination independent of temperature and injection density. No excitonic lasing is found, indicating that excitons are weakly bound in these wires due to the internal piezoelectric field causing strong Stark effect.

Published
1999

8. Modeling Evolving Coronal Loops with Observations from STEREO, Hinode, and TRACE

Author

Amanda M. DeGiorgi, David M. Kim, Ignacio Ugarte-Urra, and Harry P. Warren

Subjects
Physics, Physical model, Spectrometer, Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), FOS: Physical sciences, Astronomy and Astrophysics, Scale (descriptive set theory), Astrophysics, Coronal loop, Measure (mathematics), Loop (topology), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Energy (signal processing)
Abstract

The high densities, long lifetimes, and narrow emission measure distributions observed in coronal loops with apex temperatures near 1 MK are difficult to reconcile with physical models of the solar atmosphere. It has been proposed that the observed loops are actually composed of sub-resolution ``threads'' that have been heated impulsively and are cooling. We apply this heating scenario to nearly simultaneous observations of an evolving post-flare loop arcade observed with the EUVI/\textit{STEREO}, XRT/\textit{Hinode}, and \textit{TRACE} imagers and the EIS spectrometer on \textit{HINODE}. We find that it is possible to reproduce the extended loop lifetime, high electron density, and the narrow differential emission measure with a multi-thread hydrodynamic model provided that the time scale for the energy release is sufficiently short. The model, however, does not reproduce the evolution of the very high temperature emission observed with XRT. In XRT the emission appears diffuse and it may be that this discrepancy is simply due to the difficulty of isolating individual loops at these temperatures. This discrepancy may also reflect fundamental problems with our understanding of post-reconnection dynamics during the conductive cooling phase of loop evolution., Revised version submitted to ApJ in response to referee's comments

Published
2009

9. A study of the general characteristics of proton-antiproton collisions at √s=0.2 to 0.9 TeV

Author

H. G. Moser, G. Busetto, C. Bacci, A. Bezaguet, D. Linglin, H. Faissner, Christopher Seez, A. Astbury, E. Tscheslog, Daniel J. Smith, James Rohlf, G. Walzel, O. C. Allkofer, Teresa Rodrigo, Jean-Pierre Merlo, R. Bonino, A. Moulin, P. I. P. Kalmus, G. Maurin, J. Garvey, K. Bos, D. Samyn, S. Tether, C. Markou, C. Rubbia, W. van de Guchte, M. Pimiä, J. Dorenbosch, E. Eisenhandler, G. Bauer, P. Erhard, G. Sajot, M. Schröder, Sergio Cittolin, J.P. Vialle, I. F. Fensome, Paraskevas Sphicas, V. O'Dell, D. Schinzel, P. Biddulph, Stefano Veneziano, A. van Dijk, J. Sass, K. Eggert, R. J. Apsimon, X. Wu, I. Zacharov, F. Szoncso, W. von Schlippe, Alessandro Bettini, B. Buschbeck, J. P. Debrion, M. Botlo, A. Schwartz, G. Thompson, R. Leuchs, L. Naumann, Margret Fincke-Keeler, A. Caner, I. Siotis, L. Taylor, G.F. Cox, P. Casoli, W.J. Haynes, Tejinder Virdee, J. P. Revol, P. Cennini, M. Nikitas, A. Geiser, Steve McMahon, J. P. Mendiburu, Francesco Lacava, V. Vuillemin, Carmen Albajar, C. Zaccardelli, D. Joyce, Anton Taurok, H. Dibon, M. G. Albrow, S. Beingessner, W. G. Scott, John A Coughlan, T. Moers, M. Yvert, Veikko Karimäki, Murrough Landon, T. C. Bacon, E. Radermacher, G. Pancheri, Guido Ciapetti, N. Bains, Christian Ghiglino, I. ten Have, Hans Reithler, Jorma Tuominiemi, Anna Teresa Meneguzzo, Th. Müller, Dave Charlton, Claudia J. Stubenrauch, S. Lammel, A. Gonidec, D. Kryn, Aleandro Nisati, T. Redelberger, W. Jank, E. F. Clayton, Pierluigi Zotto, A. Ferrando, M. Jimack, G. Salvini, A. Böhrer, J. P. Porte, M. Preischl, E. Pietarinen, M. A. Marquina, Daniel Denegri, R. Prosi, A. Diciaccio, J. D. Dowell, T. Fuess, Ritva Kinnunen, B. Mours, M. Markytan, Felicitas Pauss, M. Ikeda, Filippo Ceradini, J. Vrana, T. P. Shah, J. Colas, I. Wingerter, J. Kroll, L. Zanello, W. Kienzle, A. Norton, F. Cavanna, G. Piano Mortari, K. Ankoviak, David B. Cline, L. Fortson, M. Degiorgi, H. Bohn, C.-E. Wulz, R. Conte, L. Dobrzynski, G. Jorat, Jonathan M. Gregory, Peter Lipa, M. Lindgren, Alain Givernaud, D. Dau, M. Della Negra, B. Andrieu, F. J. Diez Hedo, S. Geer, P. Nedelec, Akram Khan, P. Colas, Nicolas Ellis, T. C. Meyer, S. Levegrün, Y. Giraud-Héraud, A. Kernan, K. Morgan, E. Petrolo, Richard Keeler, K. Wacker, M. Mohammadi, Manfred Krammer, Konstanty Sumorok, D. J. Holthuizen, S. Centro, M. Demoulin, I. R. Kenyon, Dave Robinson, A. Placci, and B. Aubert

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Proton, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Detector, 7. Clean energy, 01 natural sciences, Charged particle, law.invention, Momentum, Nuclear physics, Transverse plane, law, Antiproton, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Collider, Particle Physics - Experiment
Abstract

The general characteristics of inelastic proton-antiproton collisions at the CERN SPS Collider are studied with the UA1 detector using magnetic and calorimetric analysis. Results are presented on charged particle multiplicities and transverse and longitudinal momenta, and on total transverse energy distributions at centre of mass energies ranging from 0.2 to 0.9 TeV.

Published
1990

10. Search for new heavy quarks in proton-antiproton collisions at $$\sqrt s = 0.63 TeV$$

Author

A. Caner, G. Maurin, S. Bartha, Nicolas Ellis, W. van de Guchte, M. Botlo, Peter Lipa, Aleandro Nisati, Christopher Seez, Anna Teresa Meneguzzo, Y. Zolnierowski, Felicitas Pauss, Filippo Ceradini, W. von Schlippe, T. A. Fuess, D. Denegri, V. Vuillemin, A. Ferrando, M. Yvert, T.I. Meyer, J. Dorenbosch, Alain Givernaud, P. Sphicas, L. Taylor, H. Tuchscherer, K. Eggert, D. Samyn, M. Rauschkolb, F. J. Diez Hedo, M. A. Marquina, D. Kryn, D. Brockhausen, Jorma Tuominiemi, G. Busetto, J. Garvey, J. D. Dowell, M. Lindgren, M. Jimack, E. Pietarinen, Carmen Albajar, I. R. Kenyon, Vivian O'Dell, J. Gronberg, C. Bacci, J. P. Vialle, A. Bezaguet, Ludovico Pontecorvo, B. Andrieu, Stefano Veneziano, J. Colas, M. Degiorgi, H. Bohn, G. Sajot, S. A. Robins, S. Tether, J. Salicio, L. Dobrzynski, P. Erhard, Marta Felcini, C. Daum, J. P. Merlo, David Robinson, D. Schinzel, M. Della Negra, John A Coughlan, Maria Isabel Josa, B. Aubert, P. Nedelec, H. Castilla-Valdez, Barbara Alvarez Gonzalez, A. van Dijk, R. Leuchs, L. Zanello, A. Moulin, A. Norton, T. P. Shah, E. Eisenhandler, C.-E. Wulz, E. Tscheslog, J. P. Revol, L. Naumann, A. Gonidec, Andreas Morsch, G. Ciapetti, M. Vargas, R. Conte, E. Rademacher, Claudia J. Stubenrauch, Hal Evans, C. D. Buchanan, Achim Geiser, R. Martinelli, S. Lammel, K. Morgan, F. Cavanna, P. Cennini, Manfred Krammer, Y. Lemoigne, Sergio Cittolin, Konstanty Sumorok, S. Otwinowski, G. Piano Mortari, Hans Reithler, M. P. J. Landon, D. J. Holthuizen, B. Buschbeck, E. F. Clayton, L. Fortson, Emilio Petrolo, Ritva Kinnunen, A. Placci, M. Pimiä, S. Beingessner, James Rohlf, S. Centro, J. Kroll, J. P. Porte, Th. Müller, M. Demoulin, P. I. P. Kalmus, W. Jank, M. Markytan, D. Cline, C. Rubbia, Tejinder Virdee, G. Bauer, Francesco Lacava, D. H. Stork, R. Munoz, F. Szoncso, E. Torrente-Lujan, P. Biddulph, G. Walzel, J. P. Mendiburu, J. Vrana, K. Ankoviak, Alessandro Bettini, G. Thompson, S. Levegrün, D. Linglin, G.F. Cox, P. Casoli, H. Dibon, Veikko Karimäki, K. Bos, G. Pancheri, D. Dau, A. Böhrer, I. F. Fensome, Pierluigi Zotto, H. Faissner, M. Mohammadi, M. Nikitas, D. Drijard, K. Wacker, R. J. Apsimon, T. Rodrigo, Michael Albrow, O. C. Allkofer, Matthias Schröder, Xin Wu, I. Zacharov, R. Bonino, M. Passaseo, R. Prosi, Steve McMahon, Anton Taurok, T. Moers, C. Markou, A. Diciaccio, G. Jorat, and Jonathan M. Gregory

Subjects
Physics, Quark, Particle physics, Large Hadron Collider, Muon, Physics and Astronomy (miscellaneous), Proton, High Energy Physics::Lattice, High Energy Physics::Phenomenology, law.invention, Standard Model, Nuclear physics, law, Antiproton, High Energy Physics::Experiment, Collider, Engineering (miscellaneous), Particle Physics - Experiment, Bar (unit)
Abstract

We report on a search for new heavy quarks decaying semileptonically into muons, using 4.7 pb−1 of data taken during the CERN\(p\bar p\) collider runs in 1988 and 1989. The properties of isolated muons accompanied by jets are consistent with the predictions from the Standard Model but do not show a signal for a new heavy quark. Combining all the UA1 data (5.4 pb−1), lower mass limits are obtained at 60 GeV/c2 (95% CL) for thet-quark and 43 GeV/c2 (95% CL) for a fourth-generation charge-1/3 quark (b′-quark).

Published
1990

11. The ZEUS barrel and rear muon detector

Author

G. Abbiendi a, M. Bonori b, R. Brugnera a, R. . Carlin a, V. Chiaratti a, U. Contino b, G. . D'Agostini b, F. DalCorso a, M. DeGiorgi a, U. Dosselli a, C. Fanin a, F. Gasparini a, R. Giantin a, M. Guida b°t, M. lori b, S. . Limentani a, b, G. Marini b, M. Mattioli b, D. Monaldi b, M. Morandin a, A. Nigro b, M. Posocco a, L. Stanco a, R. Stroili a, C. Voci a. Dtpartimento di Festca dell'Uniuersad di Padoca, INFN, Sezone dt Padoca, Italy n. Dipartcmento di Fisica dell'Universaui di Roma La Sapienza, Sezeone di Roma 1, Italy, MARI, Stefano Maria, G., Abbiendi a, M., Bonori b, R., Brugnera a, Carlin a, R., V., Chiaratti a, U., Contino b, D'Agostini b, G., F., DalCorso a, M., DeGiorgi a, U., Dosselli a, C., Fanin a, F., Gasparini a, R., Giantin a, M., Guida b°t, M., lori b, Limentani a, S., Mari, Stefano Maria, B, G., Marini b, M., Mattioli b, D., Monaldi b, M., Morandin a, A., Nigro b, M., Posocco a, L., Stanco a, R., Stroili a, C. Voci a., Dtpartimento di Festca dell'Uniuersad di Padoca, Infn, Sezone dt, Padoca, Italy n., Dipartcmento di Fisica dell'Universaui di Roma La Sapienza, Sezeone di Roma, 1, and Italy

Subjects
Physics::Fluid Dynamics, Physics::Plasma Physics, Physics::Instrumentation and Detectors, High Energy Physics::Experiment, Quantitative Biology::Cell Behavior
Abstract

Design, construction and performance characteristics of the ZEUS barrel and rear muon detector are presented.

Published
1993

12. Electronic structure consequences of In/Ga composition variations in self-assembledInxGa1−xAs/GaAsalloy quantum dots

Author

Andrew Williamson, John Shumway, Peter A. Crozier, M. DeGiorgi, Massimo Catalano, Alex Zunger, Adriana Passaseo, and R. Cingolani

Subjects
Pseudopotential, Physics, Photoluminescence, Quantum dot, Exciton, Electronic structure, Electron, Atomic physics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Coupling (probability), Spectroscopy
Abstract

Provided that the shape, size, and composition profile of semiconductor-embedded quantum dots are given, theory is able to accurately calculate the excitonic transitions, including the effects of inhomogeneous strain, alloy fluctuations, electron-hole binding, and multiband and intervalley coupling. While experiment can accurately provide the spectroscopic signature of the excitonic transitions, accurate determination of the size, shape, and composition profile of such dots is still difficult. We show how one can arrive at a consistent picture of both the material and the electronic structure by interactive iteration between theory and experiment. Using high-resolution transmission electron microscopy, electron-energy-loss spectroscopy, and photoluminescence (PL) spectroscopy in conjunction with atomistic empirical pseudopotential calculations, we establish a model consistent with both the observed material structure and measured electronic/optical properties of a quantum dot sample. The structural model with best agreement between measured and predicted PL is a truncated cone with height 35 {angstrom}, base diameter 200 {angstrom}, and top diameter 160 {angstrom}, having a nonuniform, peaked composition profile with average 60% In content. Next, we use our best structure to study the effect of varying (i) the amount of In in the dots, and (ii) the spatial distribution of In within the dots. We find thatmore » by either increasing the amount of In within the dot or by concentrating a given amount of In near the center of the dot, both electrons and holes become more strongly bound to the dot. A small change of In content from 50 to 60% causes an exciton redshift of about 70 meV. Changing the composition profile from a uniform In distribution to a centrally peaked distribution can redshift the exciton by an additional 20--40 meV.« less

Published
2001

13. THE ZEUS BARREL AND REAR MUON DETECTOR

Author

Stefano Maria Mari, F. Gasparini, G. Marini, Luca Stanco, D. Monaldi, M. Posocco, Michele Guida, M. Bonori, U. Contino, Roberto Carlin, M. Degiorgi, C. Fanin, S. Limentani, V. Chiaratti, Mario Mattioli, Umberto Dosselli, M. Iori, G. Abbiendi, R. Brugnera, A. Nigro, Mauro Morandin, R. Giantin, C. Voci, G. D'Agostini, R. Stroili, and F. Dalcorso

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, ZEUS (particle detector), Abstract design, Physics::Instrumentation and Detectors, Barrel (horology), Quantitative Biology::Cell Behavior, Physics::Fluid Dynamics, Nuclear physics, Physics::Plasma Physics, High Energy Physics::Experiment, Instrumentation, Muon detector
Abstract

Design, construction and performance characteristics of the ZEUS barrel and rear muon detector are presented.

Published
1993

14. Studies of intermediate vector boson production and decay in UA1 at the CERN proton-antiproton collider

Author

W. G. Scott, Hans Reithler, Tejinder Virdee, R. Frey, Francesco Lacava, J. R. Batley, I. F. Fensome, P. Flynn, K. Morgan, D. Kryn, C. Perault, M. Yvert, A. Placci, D. J. Holthuizen, G.H. Grayer, N. Bains, E. Radermacher, J. P. Porte, S. Centro, C. Bacci, Veikko Karimäki, Ehud Duchovni, H. Faissner, M. Botlo, I. Siotis, D. G. Charlton, W.J. Haynes, Carmen Albajar, M. Mohammadi, L. Naumann, D. Dau, W. Kienzle, J. P. Merlo, C. Cochet, T. P. Shah, H. G. Moser, M. Demoulin, Pierluigi Zotto, Alessandro Bettini, G. Thompson, G.F. Cox, T. Bacon, J. Colas, G. Busetto, Anton Taurok, A. van Dijk, L. Dobrzynski, E. Tscheslog, A. Diciaccio, G.T.J. Arnison, M.-N. Minard, G. Jorat, Jonathan M. Gregory, D. Schinzel, J. Streets, Sergio Cittolin, I. Sheer, Ritva Kinnunen, M. Pimiä, P. M. Watkins, B. Mours, M. Corden, I. Wingerter, J. Kroll, Asoke K. Nandi, F. Szoncso, F. Cavanna, G. Walzel, J. P. Lees, E. Buckley, A. Schwartz, Margret Fincke-Keeler, Shu Li, G. Ciapetti, Philippe Ghez, W. R. Gibson, G. Piano Mortari, Matthias Schröder, J. Dorenbosch, A. Savoy-Navarro, D. Linglin, L. Villasenor, G. Maurin, W. van de Guchte, D. Clarke, W. von Schlippe, H. D. Wahl, Aleandro Nisati, L. Taylor, Alain Givernaud, P. Sphicas, D. Samyn, F. J. Diez Hedo, G. Bauer, J. Vrana, D. Joyce, Bruce Denby, Michael Albrow, M. A. Marquina, J. N. Bellinger, J. P. Debrion, P. Catz, S. Beingessner, S. Levegrün, I. ten Have, A. Bezaguet, Emilio Petrolo, L. Zanello, John A Coughlan, K. Bos, A. Moulin, P. Kyberd, D. Cline, James Rohlf, B. Aubert, P. Nedelec, Akram Khan, P. Colas, Y. Giraud-Héraud, G. Fontaine, T. Redelberger, Xin Wu, Kenneth Long, Peter Lipa, Achim Geiser, Thomas W. Markiewicz, G. Sajot, A. Norton, J. P. Revol, E. Eisenhandler, Christian Ghiglino, J. Garvey, Nicolas Ellis, C. Markou, Daniel J. Smith, Teresa Rodrigo, M. Lindgren, Charling Tao, J. D. Dowell, E. Pietarinen, A. Astbury, Th. Müller, Vivian O'Dell, P. I. P. Kalmus, C. Pigot, T. Meyer, M. Della Negra, S. Geer, A. Honma, Felicitas Pauss, M. Ikeda, M. Markytan, Filippo Ceradini, C. Rubbia, C. Ghesquire, V. Vuillemin, R. J. Homer, M. Jimack, W. Jank, H. Grassmann, R. Bonino, S. Tether, Christopher Seez, K. Eggert, J.P. Vialle, B. Van Eijk, Stephen Haywood, I. Zacharov, A. Wildish, T. Axon, J. Sass, M. Debeer, R. Sobie, Nicolas Zaganidis, I. R. Kenyon, P. Erhard, Jorma Tuominiemi, J. P. Mendiburu, M. Preischl, Daniel Denegri, A. Gonidec, Murrough Landon, Anna Teresa Meneguzzo, Dave Robinson, J. D. Richman, A. Ferrando, G. Pancheri, O. C. Allkofer, H. F. Hoffmann, K. Wacker, R. Edgecock, M. Degiorgi, J. Randsdell, C.-E. Wulz, Elizabeth Locci, J. P. Laugier, Stephen Wimpenny, Claudia J. Stubenrauch, Josef Strauss, G. Salvini, A. Kernan, Terry Richard Wyatt, D. J. Summers, R. Leuchs, Richard Keeler, M. Moricca, Manfred Krammer, Konstanty Sumorok, P. Cennini, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), UA1, and BOMBAR, Claudine

Subjects
Particle physics, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics and Astronomy (miscellaneous), Elementary particle, 7. Clean energy, 01 natural sciences, law.invention, Vector boson, Standard Model, Nuclear physics, law, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Collider, Engineering (miscellaneous), Physics, Muon, Large Hadron Collider, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Weinberg angle, Antiproton, Physics::Accelerator Physics, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract

An extensive study of production and decay properties of charged and neutral Intermediate Vector Bosons (IVB) at the CERN proton-antiproton collider is presented. Intermediate Vector Bosons were detected in the electron, muon, and tau decay modes at centre-of-mass energies of 0.546 and 0.630 TeV. This paper is a summary, based on all the available data from the UA1 experiment from the running periods 1982–1985. Results are presented and compared with expectations of the Standard Eletroweak Model and QCD-improved Drell-Yan annihilation processes. The general conclusion is that there is an excellent agreement between the predictions of the Standard Model and our measurements.

Published
1989

15. Bose-Einstein correlations in pp interactions at √s=0.2 to 0.9 TeV

Author

Hans Reithler, H. Bohn, P. Cennini, Christian Ghiglino, E. F. Clayton, W. G. Scott, M. Jimack, Alain Givernaud, C.-E. Wulz, M. Schröder, Sergio Cittolin, I. ten Have, G. Sajot, D. Kryn, I. F. Fensome, F. J. Diez Hedo, Steve McMahon, Anton Taurok, Emilio Petrolo, T. Moers, J. P. Porte, J. Vrana, R. Conte, M. Yvert, T. Bacon, G. Walzel, K. Morgan, H. Faissner, R. Leuchs, L. Zanello, R. Prosi, F. Szoncso, L. Taylor, D. Samyn, A. Astbury, E. Tscheslog, Daniel J. Smith, P. Nedelec, N. Bains, Teresa Rodrigo, Akram Khan, P. Colas, G. Maurin, M. Markytan, W. van de Guchte, M. Pimiä, J. D. Dowell, A. Moulin, K. Ankoviak, David B. Cline, Dave Robinson, L. Dobrzynksi, V. O'Dell, P. I. P. Kalmus, J. P. Mendiburu, A. Placci, A. van Dijk, Paraskevas Sphicas, H. G. Moser, S. Tether, Murrough Landon, Nicolas Ellis, P. Biddulph, Anna Teresa Meneguzzo, Dave Charlton, D. Schinzel, C. Bacci, S. Beingessner, M. Botlo, A. Schwartz, I. Siotis, G. Bauer, A. Bezaguet, A. Ferrando, G. Ciapetti, John A Coughlan, G. Cox, Stefano Veneziano, L. Fortson, B. Buschbeck, J.P. Vialle, M. Nikitas, W.J. Haynes, T. C. Meyer, D. J. Holthuizen, R. K. Keeler, K. Bos, J. Dorenbosch, E. Radermacher, B. Aubert, Alessandro Bettini, Michael Albrow, Ritva Kinnunen, D. Linglin, Carmen Albajar, A. Caner, J. P. Revol, O. C. Allkofer, Th. Müller, G. Thompson, H. Dibon, B. Mours, I. Zacharov, V. Vuillemin, W. Jank, G. Pancheri, P. Casoli, G. Busetto, J. Colas, K. Wacker, I. Wingerter, Peter Lipa, S. Centro, J. P. Debrion, M. Mohammadi, Christopher Seez, B. Andrieu, M. Demoulin, Manfred Krammer, A. Geiser, Konstanty Sumorok, K. Eggert, Jean-Pierre Merlo, Veikko Karimäki, M. Lindgren, A. Norton, T. Redelberger, C. Rubbia, F. Cavanna, D. Dau, M. Della Negra, S. Geer, G. Jorat, P. Erhard, A. Kernan, G. Piano Mortari, I. R. Kenyon, Jonathan M. Gregory, A. Böhrer, Pierluigi Zotto, S. Levegrün, R. Apsimon, Y. Giraud-Héraud, M. Preischl, E. Pietarinen, Daniel Denegri, A. Diciaccio, X. Wu, Jorma Tuominiemi, Claudia J. Stubenrauch, S. Lammel, A. Gonidec, G. Salvini, T. P. Shah, W. Kienzle, C. Markou, J. Sass, R. Bonino, T. Feuss, Margret Fincke-Keeler, Aleandro Nisati, J. Garvey, E. Eisenhandler, Felicitas Pauss, M. Ikeda, Filippo Ceradini, J. Kroll, M. A. Marquina, James Rohlf, W. von Schlippe, Tejinder Virdee, Francesco Lacava, C. Zaccardelli, D. Joyce, L. Naumann, and M. Degiorgi

Subjects
Physics, Nuclear and High Energy Physics, Interaction model, Bose–Einstein correlations, Charged particle, law.invention, Nuclear physics, law, Pseudorapidity, Particle, High Energy Physics::Experiment, Angular dependence, Collider, Constant (mathematics)
Abstract

Bose-Einstein correlations have been measured at the SPS collider at centre-of-mass energies from √ s =0.2 to 0.9 TeV. The size and the incoherence parameter of the particle emitting region have been determined as a function of charged particle density in pseudorapidity Δ n /Δη, centre-of-mass energy and the direction of emission of the charged particles. For fixed values of Δ n /Δη the size of the interaction region and the incoherence parameter remain constant with rising √ s . At fixed √ s , the size of the interaction region increases with rising charged particle density while the incoherence parameter decreases.

Published
1989

16. Two-jet mass distributions at the CERN proton-antiproton collider

Author

P. Nedelec, D. Samyn, D. J. Holthuizen, A. Schwartz, Akram Khan, P. Colas, I. Siotis, W.J. Haynes, Ehud Duchovni, M. Jimack, D. Robinson, Carmen Albajar, Nicolas Ellis, J. P. Revol, S. Centro, Christopher Seez, J. P. Merlo, D. Summers, B. Aubert, A. Wildish, A. Placci, X. Wu, M. Demoulin, L. Dobrzynski, R. K. Keeler, D. Linglin, P. Ghez, Ritva Kinnunen, L. Villasenor, Jorma Tuominiemi, T. P. Shah, C. Ghesquiere, Felicitas Pauss, M. Ikeda, P. Cennini, P. Erhard, J. D. Dowell, G. Sajot, G. Maurin, Filippo Ceradini, S. Li, M. A. Marquina, M. Schröder, Sergio Cittolin, I. R. Kenyon, B. Mours, Jacqueline Batley, W. van de Guchte, M. Pimiä, Josef Strauss, D. Clarke, E. Tscheslog, Emilio Petrolo, A. Diciaccio, J. P. Lees, M.J. Corden, S. J. Haywood, Daniel J. Smith, Nicolas Zaganidis, C. Markou, I. Wingerter, W. Kienzle, R. Leuchs, C. Rubbia, J. Kroll, G. Jorat, G. Bauer, W. G. Scott, Teresa Rodrigo, T. Redelberger, E. Buckley, Jonathan M. Gregory, I. Sheer, M. Preischl, E. Pietarinen, Daniel Denegri, G. Walzel, F. Szoncso, Alain Givernaud, J. Vrana, V. Vuillemin, F. J. Diez Hedo, J. Sass, L. Zanello, O. C. Allkofer, A. Moulin, Tejinder Virdee, H. G. Moser, G. Busetto, K. Sumorok, C. Bacci, H. Grassmann, M. Markytan, J. Colas, Francesco Lacava, C. Perault, P. I. P. Kalmus, M. Yvert, P. Sphicas, H. Faissner, A. Bezaguet, A. van Dijk, J. Rohlf, N. Bains, Hans Reithler, D. Gee, J. P. Mendiburu, D. Kryn, I. F. Fensome, P. Flynn, John A Coughlan, Randall Sobie, S. Beingessner, G. Cox, Margret Fincke-Keeler, K. Morgan, Th. Müller, E. Radermacher, W. Jank, J. Dorenbosch, Murrough Landon, Anna Teresa Meneguzzo, J. P. Porte, L. Naumann, M. Mohammadi, A. Norton, Dave Charlton, A. Taurok, J. Streets, C. Pigot, Claudia J. Stubenrauch, A. Gonidec, Aleandro Nisati, A. Ferrando, G. Salvini, C. Cochet, G. Piano Mortari, G. Ciapetti, Stephen Wimpenny, M.-N. Minard, Michael Albrow, J. Garvey, D. Schinzel, K. Bos, C. Chiglino, J. P. Debrion, M. Degiorgi, A. Kernan, C.-E. Wulz, Elizabeth Locci, David B. Cline, A. Astbury, R. Bonino, S. Tether, J.P. Vialle, K. Wacker, I. Zacharov, Manfred Krammer, T. Axon, A. Geiser, Alessandro Bettini, G. Thompson, Veikko Karimäki, T. C. Meyer, T. C. Bacon, I. ten Have, Pierluigi Zotto, S. Levegrün, Y. Giraud-Héraud, T. Wyatt, Peter Lipa, T. Markiewicz, M. Lindgren, Charling Tao, D. Dau, M. Della Negra, S. Geer, K. Eggert, W. von Schlippe, C. Zaccardelli, D. Joyce, P. Catz, G. Fontaine, and E. Eisenhandler

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Gauge boson, Particle physics, Large Hadron Collider, Proton, Jet (particle physics), law.invention, Nuclear physics, Cross section (physics), law, Antiproton, High Energy Physics::Experiment, Nuclear Experiment, Collider, Particle Physics - Experiment
Abstract

Two-jet mass distributions have been measured as a function of centre-of-mass scattering angle for high-mass jet pairs produced in proton-antiproton collisions at the CERN collider operating at a centre-of-mass energy of 630 GeV. The agreement between QCD expectations and the experimental measurements has been used to place limits on the production cross section of an object X decaying into two jets. In particular we consider the existence of a massive colour octet of vector gauge bosons (axigluons). We exclude axigluons with a width ΛA

Published
1988

17. Measurement of the bottom quark production cross section in proton-antiproton collisions at √s = 0.63 TeV

Author

C. Markou, L. Dobrzynski, T. Redelberger, Hans Reithler, G. Bauer, A. Diciaccio, E. Tscheslog, Daniel J. Smith, Teresa Rodrigo, Alessandro Bettini, G. Jorat, G. Thompson, K. Morgan, G. Sajot, Jonathan M. Gregory, P. I. P. Kalmus, J. Sass, I. Sheer, S. Tether, J. Rohlf, R. Bonino, J. P. Porte, T. C. Meyer, G. Maurin, J. Dorenbosch, T. Bacon, D. Linglin, A. Moulin, K. Eggert, L. Villasenor, P. Ghez, G. Walzel, W. van de Guchte, M. Pimiä, M. Yvert, D. Clarke, D. J. Holthuizen, D. Samyn, Ehud Duchovni, P. Sphicas, H. G. Moser, J. P. Debrion, M. Jimack, M. A. Marquina, V. Vuillemin, N. Bains, G. Busetto, Felicitas Pauss, M. Ikeda, Veikko Karimäki, D. Robinson, S. Centro, Michael Albrow, D. Summers, A. Bezaguet, P. Cennini, Filippo Ceradini, A. Kernan, S. Levegrün, C. Bacci, P. Cavanna, Christopher Seez, M. Degiorgi, John A Coughlan, M. Demoulin, E. Radermacher, V. O'Dell, Tejinder Virdee, X. Wu, Christian Ghiglino, M.-N. Minard, J. Kroll, Francesco Lacava, C. Perault, Pierluigi Zotto, A. van Dijk, Alain Givernaud, Y. Giraud-Héraud, Th. Müller, Claudia J. Stubenrauch, C. Cochet, D. Schinzel, A. Gonidec, J. D. Dowell, S. Beingessner, G. Salvini, W. Jank, G. Ciapetti, C.-E. Wulz, I. ten Have, Peter Lipa, Elizabeth Locci, A. Placci, F. J. Diez Hedo, C. Ghesquiere, P. Erhard, T. Markiewicz, K. Wacker, J. P. Lees, J. P. Revol, R. K. Keeler, Jorma Tuominiemi, T. P. Shah, R. Leuchs, Ritva Kinnunen, M. Lindgren, Charling Tao, Manfred Krammer, L. Naumann, W. Kienzle, David B. Cline, M. Botlo, A. Schwartz, G. Cox, K. Sumorok, B. Van Eijk, D. Dau, A. Astbury, J. Garvey, P. Nedelec, I. Siotis, S. Li, C. Pigot, B. Mours, Stephen Wimpenny, M. Della Negra, W.J. Haynes, S. Geer, I. R. Kenyon, M.J. Corden, S. J. Haywood, J. Colas, Akram Khan, P. Colas, Carmen Albajar, I. Wingerter, C. Rubbia, Margret Fincke-Keeler, M. Preischl, E. Pietarinen, Daniel Denegri, J. P. Merlo, A. Norton, G. Piano Mortari, Aleandro Nisati, J.P. Vialle, Nicolas Ellis, Emilio Petrolo, O. C. Allkofer, M. Markytan, I. Zacharov, B. Aubert, T. Axon, J. Vrana, A. Geiser, L. Zanello, H. Faissner, J. R. Batley, I. F. Fensome, P. Flynn, A. Wildish, Randall Sobie, M. Mohammadi, Nicolas Zaganidis, J. P. Mendiburu, Murrough Landon, Anna Teresa Meneguzzo, Dave Charlton, A. Ferrando, M. Schröder, Sergio Cittolin, F. Szoncso, E. Buckley, K. Bos, W. von Schlippe, C. Zaccardelli, D. Joyce, W. G. Scott, H. Grassmann, D. Kryn, G. Fontaine, A. Taurok, and E. Eisenhandler

Subjects
Physics, Quantum chromodynamics, Quark, Nuclear and High Energy Physics, Particle physics, Muon, Proton, Hadron, Bottom quark, Nuclear physics, Antiproton, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, Particle Physics - Experiment
Abstract

We summarize the results obtained in the UA1 experiment on the production of bottom quarks in proton-antiproton collisions at √ s =0.63 TeV. Independent muon data samples are used to determine the bottom quark production cross section in different transverse momentum ranges from 6 to 30 GeV. A recent theoretical calculation to O(α s 3 ) of the inclusive bottom quark transverse momentum spectrum in hadronic collisions shows reasonable agreement with the data. We extrapolate the integral P T distribution to P T =0 and in rapidity to estimate the total cross section forthe production of bottom quark pairs. Assuming the shape in P T and rapidity given by the O(α s 3 ) calcultaion, we obtain σ( p p→b b +X) = 10.2 ±3.3 μb .

Published
1988

18. Events with large missing transverse energy at the CERN collider: III. Mass limits on supersymmetric particles

Author

Stephen Wimpenny, T. Bacon, G. Maurin, M. Pimiä, D. Clarke, Anna Teresa Meneguzzo, Dave Charlton, W. G. Scott, K. Sumorok, J. P. Lees, Michael Levi, J. D. Dowell, John A Coughlan, A. Ferrando, G. Walzel, R. Leuchs, Christian Ghiglino, Margret Fincke-Keeler, M. Degiorgi, D. Samyn, Ehud Duchovni, M. Jimack, D. J. Holthuizen, G.H. Grayer, D. Robinson, S. Centro, M. Demoulin, Aleandro Nisati, Alessandro Bettini, G. Thompson, M.-N. Minard, J. N. Bellinger, D. Summers, J. Vrana, C. Ghesquiere, D. Schinzel, G. Cox, C.-E. Wulz, H. Faissner, T. P. Shah, N. Zaganidis, Kenneth Long, G. Busetto, Elizabeth Locci, J. P. Laugier, J. R. Batley, I. F. Fensome, P. Flynn, Randall Sobie, W. Kienzle, A. Kernan, W. von Schlippe, L. Zanello, M. Mohammadi, B. Aubert, R. Frey, Alain Givernaud, F. J. Diez Hedo, A. Taurok, C. Zaccardelli, H. G. Moser, Bruce Denby, A. Bezaguet, P. Catz, J. Dorenbosch, A. Savoy-Navarro, P. Nedelec, Akram Khan, P. Colas, A. Wildish, Michael Albrow, Christopher Seez, S. Tether, Hans Reithler, Felicitas Pauss, M. Ikeda, Filippo Ceradini, J. P. Debrion, D. Gee, G. Fontaine, Nicolas Ellis, W. Ruhm, J. P. Mendiburu, T. Redelberger, A. Schwartz, M. Preischl, E. Pietarinen, Daniel Denegri, J. Kroll, L. Naumann, K. Morgan, E. Eisenhandler, I. Siotis, W.J. Haynes, T. Markiewicz, Veikko Karimäki, P. Erhard, G. Sajot, K. Eggert, C. Pigot, T. Meyer, A. Diciaccio, A. Placci, Carmen Albajar, S. Beingessner, J. Garvey, Charling Tao, G. Bauer, E. Tscheslog, David B. Cline, E. Petrolo, Daniel J. Smith, D. Dau, M. Della Negra, Pierluigi Zotto, S. Geer, J. P. Merlo, A. Honma, Teresa Rodrigo, J. P. Porte, I. ten Have, P. I. P. Kalmus, X. Wu, Ritva Kinnunen, S. Levegrün, E. Buckley, A. Astbury, S. Li, B. Mours, M.J. Corden, S. J. Haywood, M. Debeer, R. Edgecock, R. Bonino, Jorma Tuominiemi, Richard Keeler, M. Schröder, Sergio Cittolin, I. Wingerter, Y. Giraud-Héraud, T. Wyatt, J.P. Vialle, J. Rohlf, I. R. Kenyon, K. Wacker, O. C. Allkofer, I. Zacharov, Manfred Krammer, T. Axon, Jeffrey Richman, A. Geiser, P. Ghez, E. Radermacher, Josef Strauss, D. Linglin, L. Villasenor, Asoke K. Nandi, F. Szoncso, C. Markou, J. Sass, J. Streets, Paolo Rossi, M. A. Marquina, Claudia J. Stubenrauch, A. Gonidec, G. Salvini, M. Yvert, P. Sphicas, Tejinder Virdee, Francesco Lacava, N. Bains, C. Perault, V. Vuillemin, K. Bos, C. Cochet, G. Ciapetti, H. von der Schmitt, C. Rubbia, M. Moricca, J. P. Revol, Th. Müller, W. Jank, L. Dobrzynski, G. Jorat, I. Sheer, H. Grassmann, D. Kryn, P. Cennini, C. Bacci, M. Markytan, B. Van Eijk, Peter Watkins, J. Colas, A. Norton, and G. Piano Mortari

Subjects
Physics, Nuclear and High Energy Physics, Stop squark, Gluino, Particle physics, Large Hadron Collider, High Energy Physics::Phenomenology, Lightest Supersymmetric Particle, law.invention, Nuclear physics, Massless particle, law, High Energy Physics::Experiment, Limit (mathematics), Nuclear Experiment, Collider, Photino
Abstract

A sample of events with large missing transverse energy from 715 nb −1 of data from the UA1 experiment at the CERN proton-antiproton collider is used to search for evidence of supersymmetric particle production. Assuming that the photino is the lightest supersymmetric particle and that it is massless, we find a limit on the squark mass of m q >45 GeV /c 2 at 90% CL, independently of the gluino mass. Similarly, we find a limit on the gluino mass of m g >53 GeV /c 2 (at 90% CL) independently of the squark mass, provided that the gluino is not long-lived (i.e. provided that the squark is not too heavy, m q ⪅1 TeV /c 2 ). For equal squark and gluino masses we find a limit m q =m g >75 GeV /c 2 at 90% CL. The effect of a non-zero photino mass on these limits is studied.

Published
1987

19. Performance of a uranium/tetramethylpentane electromagnetic calorimeter

Author

S. Ochsenbein, P. Cennini, K. Sumorok, W.F. Schmidt, C. Markou, A. Bezaguet, G. Maurin, R. Conte, J. Sass, Christopher Seez, Anna Teresa Meneguzzo, R. J. Apsimon, J. D. Dowell, M. Pripstein, Michael Albrow, A. Diciaccio, T. Mueller, D. Robinson, S. Centro, A. Looten, M. Degiorgi, R. Bonino, Stefano Veneziano, E. Radermacher, C. Cochet, Philippe Ghez, B. Aubert, L. Zanello, J. Streets, A. Gonidec, W. Seidl, L. Naumann, L. Dumps, F. Diez-Hedo, D. Schinzel, C. Rubbia, Alain Givernaud, Filippo Ceradini, C. Pigot, J. P. Debrion, C. Bacci, W. Kienzle, R. Munoz, J. Colas, A. Placci, E. Petrolo, E. Warmuth, T. Markiewicz, Tejinder Virdee, Francesco Lacava, Laboratoire d'Annecy de Physique des Particules (LAPP), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Free electron model, Physics, Nuclear and High Energy Physics, Calorimeter (particle physics), Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Detector, chemistry.chemical_element, Electron, Uranium, 7. Clean energy, 01 natural sciences, chemistry, Ionization, 0103 physical sciences, Electrode, High Energy Physics::Experiment, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Detectors and Experimental Techniques, Atomic physics, 010306 general physics, Instrumentation, Noise (radio)
Abstract

A calorimeter, consisting of uranium plates and thin liquid ionization chambers filled with tetramethylpentane (TMP) at room temperature, has been tested using electrons between 10 and 70 GeV. The essential characteristics of the liquid are discussed, including measurements of the free electron lifetime. Results on uniformity, linearity and energy resolution are described and some information on the response to hadrons has been obtained. A single TMP box containing four electrodes and a TMP position detector for electromagnetic showers have also been tested.

Published
1988

20. Direct photon production at the CERN proton-antiproton collider

Author

C. Albajar, M.G. Albrow, O.C. Allkofer, A. Astbury, B. Aubert, T. Axon, C. Bacci, T. Bacon, N. Bains, J.R. Batley, G. Bauer, S. Beingessner, A. Bettini, A. Bezaguet, R. Bonino, K. Bos, E. Buckley, G. Busetto, P. Catz, P. Cennini, S. Centro, F. Ceradini, D.G. Charlton, G. Ciapetti, S. Cittolin, D. Clarke, D. Cline, C. Cochet, J. Colas, P. Colas, M. Corden, J.A. Coughlan, G. Cox, D. Dau, J.P. Debrion, M. Degiorgi, M.Della Negra, M. Demoulin, D. Denegri, A. Diciaccio, F.J. Diez Hedo, L. Dobrzynski, J. Dorenbosch, J.D. Dowell, E. Duchovni, K. Eggert, E. Eisenhandler, N. Ellis, P. Erhard, H. Faissner, I.F. Fensome, A. Ferrando, M. Fincke-Keeler, P. Flynn, G. Fontaine, J. Garvey, D. Gee, S. Geer, A. Geiser, C. Ghesquiere, P. Ghez, C. Ghiglino, Y. Giraud-Heraud, A. Givernaud, A. Gonidec, H. Grassmann, J.M. Gregory, W. Haynes, S.J. Haywood, D.J. Holthuizen, M. Ikeda, W. Jank, M. Jimack, G. Jorat, D. Joyce, P.I.P. Kalmus, V. Karimaki, R. Keeler, I. Kenyon, A. Kernan, A. Khan, W. Kienzle, R. Kinnunen, M. Krammer, J. Kroll, D. Kryn, F. Lacava, M. Landon, J.P. Lees, R. Leuchs, S. Levegrün, S. Li, M. Lindgren, D. Linglin, P. Lipa, E. Locci, T. Markiewicz, C. Markou, M. Markytan, M.A. Marquina, G. Maurin, J.-P. Mendiburu, A. Meneguzzo, J.P. Merlo, T. Meyer, M.-N. Minard, M. Mohammadi, K. Morgan, H.-G. Moser, A. Nisati, B. Mours, Th. Muller, L. Naumann, P. Nedelec, A. Norton, F. Pauss, C. Perault, E. Petrolo, G. Piano Mortari, E. Pietarinen, C. Pigot, M. Pimiä, A. Placci, J.-P. Porte, M. Preischl, A. Radermacher, T. Redelberger, H. Reithler, J.-P. Revol, D. Robinson, T. Rodrigo, J. Rohlf, C. Rubbia, G. Sajot, G. Salvini, J. Sass, D. Samyn, D. Schinzel, M. Schröder, A. Schwartz, W. Scott, C. Seez, T.P. Shah, I. Sheer, I. Siotis, D. Smith, R. Sobie, P. Sphicas, J. Strauss, J. Streets, C. Stubenrauch, D. Summers, K. Sumorok, F. Szoncso, C. Tao, A. Taurok, I. Ten Have, S. Tether, G. Thompson, E. Tscheslog, J. Tuominiemi, W. Van De Guchte, A. Van Eijk, B. Van Eijk, J.P. Vialle, L. Villasenor, T.S. Virdee, W. Von Schlippe, J. Vrana, V. Vuillemin, K. Wacker, G. Walzel, A. Wildish, I. Wingerter, S.J. Wimpenny, X. Wu, C.-E. Wulz, T. Wyatt, M. Yvert, C. Zaccardelli, I. Zacharov, N. Zaganidis, L. Zanello, and P. Zotto

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Photon, Large Hadron Collider, Proton, Scattering process, UA1 experiment, law.invention, Nuclear physics, law, Antiproton, High Energy Physics::Experiment, Nuclear Experiment, Collider, Particle Physics - Experiment
Abstract

Isolated photons, produced directly by a scattering process, have been observed in the UA1 experiment at the CERN p p collider at centre-of-mass energies √=546 GeV and √=630 GeV . Single and double photon differential cross sections have been determined and found to be consistent with the expectations of QCD.

Published
1988

21. Search for oscillations at the CERN proton-antiproton collider

Author

J. Colas, D. Linglin, L. Villasenor, T. Bacon, H. Faissner, J. Vrana, Veikko Karimäki, W. Ruhm, G.T.J. Arnison, J. R. Batley, I. F. Fensome, P. Flynn, Randall Sobie, M. Yvert, P. Sphicas, L. Zanello, A. Norton, N. Bains, Stephen Wimpenny, Pierluigi Zotto, A. Astbury, G. Bauer, J. Dorenbosch, A. Savoy-Navarro, M.-N. Minard, D. Schinzel, M. Mohammadi, E. Pietarinen, Daniel Denegri, G. Piano Mortari, C. Ghesquiere, Ritva Kinnunen, G. Sajot, W.R. Gibson, W. G. Scott, S. Li, B. Mours, D. Pitman, C. Cochet, G. Maurin, J. P. Debrion, H. G. Moser, A. Placci, M.J. Corden, S. J. Haywood, I. Wingerter, Paul Kyberd, Hans Reithler, G. Ciapetti, D. Gee, M. Pimiä, D. Clarke, J. D. Dowell, John A Coughlan, E. Radermacher, R. Edgecock, L. Dobrzynski, Tejinder Virdee, R. Frey, Francesco Lacava, M. Ikeda, J.P. Vialle, A. Schwartz, A. Bezaguet, L. Naumann, C. Perault, Paolo Rossi, M. Debeer, O. C. Allkofer, Felicitas Pauss, A. Diciaccio, M. Markytan, K. Morgan, I. Siotis, C. Pigot, E. Tscheslog, Daniel J. Smith, E. Petrolo, M. Moricca, J. P. Revol, M. Degiorgi, I. Zacharov, D. Pascoli, Filippo Ceradini, John Wilson, T. Meyer, S. Tether, C. Markou, P. I. P. Kalmus, G. Jorat, I. Sheer, W.J. Haynes, T. Axon, Jeffrey Richman, A. Geiser, Christopher Seez, J. Kroll, Alessandro Bettini, Paolo Giacomelli, I. R. Kenyon, G. Thompson, D. Samyn, T. Redelberger, J. Streets, Ehud Duchovni, Michael Albrow, Richard Keeler, G. Fontaine, J. P. Porte, C.-E. Wulz, A. Taurok, Elizabeth Locci, S. Levegrün, M. Jimack, S. Beingessner, Claudia J. Stubenrauch, J. Sass, J. P. Mendiburu, A. Gonidec, J. P. Laugier, G. Salvini, B. Van Eijk, Peter Watkins, G. Busetto, K. Sumorok, Carmen Albajar, L. Gately, E. Eisenhandler, D. Summers, K. Wacker, P. Petta, R. J. Homer, P. Erhard, Th. Müller, David B. Cline, W. Jank, Margret Fincke-Keeler, V. Vuillemin, C. Rubbia, Y. Giraud-Héraud, H. F. Hoffmann, B. Aubert, D. J. Holthuizen, G.H. Grayer, I. ten Have, J. P. Merlo, Manfred Krammer, Anna Teresa Meneguzzo, Dave Charlton, T. Wyatt, T. P. Shah, X. Wu, J. P. Lees, H. D. Wahl, G. Cox, F. Ghio, W. Kienzle, Kenneth Long, D. Robinson, S. Centro, A. Wildish, J. N. Bellinger, T. Markiewicz, N. Zaganidis, Jorma Tuominiemi, M. Demoulin, H. von der Schmitt, Charling Tao, J. Garvey, D. Dau, M. Della Negra, R. Leuchs, J. Rohlf, S. Geer, A. Honma, P. Ghez, P. Cennini, C. Bacci, Josef Strauss, K. Eggert, R. Frühwirth, G. Bunce, P. Nedelec, Akram Khan, P. Colas, Nicolas Ellis, H. Grassmann, D. Kryn, Alain Givernaud, A. Kernan, K. Bos, E. Buckley, Sergio Cittolin, Asoke K. Nandi, F. Szoncso, W. von Schlippe, C. Zaccardelli, Bruce Denby, and P. Catz

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Muon, Large Hadron Collider, Proton, Electric charge, law.invention, Nuclear physics, law, Antiproton, Charm (quantum number), Collider, Mixing (physics)
Abstract

We report on a search for B0↔B¯0 oscillations (mixing) using events with two identified muons from data collected at the CERN p¯p collider. In the absence of B0↔B¯0 oscillations, dimuons coming directly from decays of beauty-antibeauty paris must have opposite signs. Like-sign dimuons are expected from events where one muon arises from beauty decay and the other from the charm decay of the associated beauty-charm cascade. Taking these processes into account, together with the contribution from charm production, the predicted ratio of like-sign to unlike-sign muon pairs is 0.26±0.03. Experimentally we measure 0.42±0.07±0.03. A natural explanation for the excess of like-sign events is the existence of a significant amount of B0↔B¯0 transitions. The fraction of beauty particles that produce first-generation decay muons with the opposite electric charge from that expected without mixing is deduced to be: χ = 0.121±0.047. Combined with the null result from searches for B0↔B¯0 oscillations at e+e− colliders, our results are consistent with transitions inthe B0s system, as favoured theoretically.

Published
1987

22. Events with large missing transverse energy at the cern collider: I.W→τν decay and test of τμe universality at Q2=mw2

Author

Jacqueline Batley, Nicolas Zaganidis, W. R. Gibson, J. P. Mendiburu, A. Schwartz, J. Colas, J. Sass, Dave Charlton, I. Siotis, A. Kernan, G. Sajot, E. Petrolo, W.J. Haynes, G.T.J. Arnison, J. P. Lees, Alessandro Bettini, G. Thompson, K. Sumorok, Carmen Albajar, Anton Taurok, M.-N. Minard, R. Leuchs, G.F. Cox, D. J. Holthuizen, G.H. Grayer, W. Kienzle, J. P. Merlo, K. Bos, D. Pitman, R. K. Keeler, D. Schinzel, G. Bunce, T.P. Shah, Veikko Karimäki, D. Robinson, S. Centro, A. Meneguzzo, M. Demoulin, H. G. Moser, G. Busetto, A. Geisser, Ritva Kinnunen, C. Bacci, Sergio Cittolin, J. Streets, Josef Strauss, A. Bezaguet, Claudia J. Stubenrauch, Pierluigi Zotto, P. M. Watkins, G. Salvini, Stephen Wimpenny, Philippe Ghez, S. Li, Asoke K. Nandi, F. Szoncso, Ehud Duchovni, B. Mours, M. Jimack, G. Piano Mortari, M.J. Corden, S. J. Haywood, J. Vrana, I. Wingerter, R. Frühwirth, Kenneth Long, D. Summers, P. Cennini, C. Ghesquiere, G. Maurin, D. Linglin, Tejinder Virdee, W. G. Scott, L. Villasenor, R. Frey, Francesco Lacava, C. Perault, Christopher Seez, B. Van Eijk, D. Clarke, L. Zanello, H. Grassmann, D. Pascoli, L. Dobrzynski, D. Kryn, C. Markou, J. D. Dowell, S. Levegrün, S. Beingessner, John A Coughlan, G. Jorat, P. Erhard, Paul Kyberd, I. Sheer, M. Markytan, J. Dorenbosch, A. Savoy-Navarro, Y. Giraud-Héraud, T. Wyatt, J. P. Debrion, Paolo Rossi, Michael Levi, H. Faissner, P. Petta, P. Nedelec, Th. Müller, W. Jank, Akram Khan, P. Colas, I. F. Fensome, P. Flynn, E. Tscheslog, Daniel J. Smith, Nicolas Ellis, M. Mohammadi, P. I. P. Kalmus, T. Markiewicz, Alain Givernaud, D. Samyn, Charling Tao, D. Dau, M. Della Negra, S. Geer, M. G. Albrow, A. Honma, H. D. Wahl, L. Naumann, J. N. Bellinger, D. Cline, Felicitas Pauss, Filippo Ceradini, J. Kroll, Paolo Giacomelli, C. Pigot, M. Pincke-Keeler, R. J. Homer, O. C. Allkofer, R. Edgecock, J. Garvey, J. Rohlf, T. Redelberger, E. Buckley, R. J. Sobie, K. Wacker, M. Debeer, H. F. Hoffmann, H. von der Schmitt, I. R. Kenyon, J. A. Wilson, Manfred Krammer, M. Pimiä, Hans Reithler, D. Gee, K. Morgan, M. Degiorgi, W. Ruhm, A. Placci, A. Gonidec, K. Eggert, W. von Schlippe, E. Radermacher, A. Astbury, T.I. Meyer, J. P. Porte, C. Zaccardelli, Bruce Denby, P. Catz, V. Vuillemin, S. Tether, C.-E. Wulz, Elizabeth Locci, M. Ikeda, J.P. Vialle, F. Ghio, C. Rubbia, J. P. Laugier, B. Aubert, G. Bauer, G. Fontaine, A. Norton, L. Gately, E. Eisenhandler, T. C. Bacon, I. ten Have, M. Yvert, P. Sphicas, A. Wildish, N. Bains, X. Wu, I. Zacharov, C. Cochet, Jorma Tuominiemi, G. Ciapetti, T. Axon, Jeffrey Richman, M. Moricca, J. P. Revol, E. Pietarinen, Daniel Denegri, and A. Diciaccio

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Transverse plane, Particle physics, Large Hadron Collider, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Nuclear Experiment, UA1 experiment, Universality (dynamical systems)
Abstract

We report results based on a sample of events with large missing transverse energy corresponding to 715 nb−n of data from the UA1 experiment at the CERN proton-antiproton collider. High transverse-momentum tau-leptons from W decays are observed for the first time through their semi-hadronic decay modes and associated missing transverse energy. The measured relative rates of W→eν, W→μν, and W→τν provide the first direct tests of the electron-muon-tau universality of the weak charged couplings at Q2=mw2. We determine g τ g e =1.01±0.09±0.05 and g μ g e =1.05±0.07±0.08 .

Published
1987

23. Events with large missing transverse energy at the cern collider: II. search for the decays of W± into heavy leptons and of Z0 into non-interacting particles

Author

G. Busetto, C. Bacci, A. Taurok, A. Bezaguet, P. Nedelec, John Wilson, Jacqueline Batley, Paolo Rossi, L. Dobrzynski, B. Aubert, Akram Khan, P. Colas, R. Frühwirth, M. Degiorgi, S. Tether, Felicitas Pauss, Nicolas Ellis, Filippo Ceradini, K. Eggert, E. Petrolo, G. Sajot, E. Tscheslog, H. F. Hoffmann, Daniel J. Smith, V. Vuillemin, W. von Schlippe, Veikko Karimäki, O. C. Allkofer, J. P. Mendiburu, P. Petta, J. Rohlf, A. Wildish, Sergio Cittolin, W.R. Gibson, P. Kyberd, P. I. P. Kalmus, S. Levegrün, C.-E. Wulz, Elizabeth Locci, Th. Müller, D. Linglin, P. Ghez, J. Kroll, Paolo Giacomelli, W. Jank, C. Zaccardelli, Alain Givernaud, J. P. Laugier, D. Pitman, A. Astbury, Bruce Denby, P. Catz, L. Villasenor, G.T.J. Arnison, J. Dorenbosch, A. Savoy-Navarro, Pierluigi Zotto, Asoke K. Nandi, E. Radermacher, F. Szoncso, G. Maurin, T. Redelberger, E. Buckley, Y. Giraud-Héraud, Richard Keeler, T. Wyatt, Anna Teresa Meneguzzo, Dave Charlton, Michael Levi, W. Ruhm, Josef Strauss, Tejinder Virdee, J. P. Lees, R. J. Homer, K. Wacker, R. Frey, Francesco Lacava, David B. Cline, M. Pimiä, Alessandro Bettini, G. Thompson, R. Leuchs, C. Rubbia, C. Perault, J. Streets, Manfred Krammer, H. Faissner, D. Clarke, Ritva Kinnunen, G. Bauer, Claudia J. Stubenrauch, G. Bunce, Margret Fincke-Keeler, E. Pietarinen, Daniel Denegri, A. Gonidec, T. C. Meyer, J. P. Debrion, N. Zaganidis, A. Schwartz, I. Siotis, G. Salvini, S. Li, A. Placci, B. Mours, W.J. Haynes, K. Sumorok, Hans Reithler, D. Gee, H. D. Wahl, M. Debeer, M.J. Corden, S. J. Haywood, G. Cox, D. Pascoli, Carmen Albajar, I. Wingerter, M. Moricca, J. P. Revol, T. P. Shah, A. Kernan, F. Ghio, T. Markiewicz, J. P. Merlo, J. N. Bellinger, M.-N. Minard, R. Edgecock, D. Samyn, L. Naumann, Kenneth Long, Ehud Duchovni, J. Vrana, W. Kienzle, K. Bos, I. R. Kenyon, D. Schinzel, K. Morgan, M. Yvert, Charling Tao, Stephen Wimpenny, I. F. Fensome, P. Flynn, A. Diciaccio, John A Coughlan, P. Sphicas, M. Markytan, N. Bains, D. Dau, C. Pigot, L. Zanello, M. Jimack, M. Della Negra, J. Garvey, S. Geer, A. Honma, Christopher Seez, J. Colas, S. Beingessner, D. J. Holthuizen, G.H. Grayer, C. Cochet, G. Ciapetti, M. Ikeda, D. Summers, Randall Sobie, A. Norton, J.P. Vialle, X. Wu, Jorma Tuominiemi, G. Piano Mortari, J. P. Porte, D. Robinson, C. Ghesquiere, G. Fontaine, P. Erhard, S. Centro, B. Van Eijk, Peter Watkins, M. Demoulin, E. Eisenhandler, I. Zacharov, H. von der Schmitt, J. D. Dowell, T. Axon, Jeffrey Richman, A. Geiser, L. Gately, T. C. Bacon, I. ten Have, M. Mohammadi, Michael Albrow, W. G. Scott, G. Jorat, I. Sheer, C. Markou, P. Cennini, J. Sass, H. Grassmann, D. Kryn, and H. G. Moser

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, High Energy Physics::Phenomenology, UA1 experiment, law.invention, Standard Model, Nuclear physics, Transverse plane, law, High Energy Physics::Experiment, Neutrino, Nuclear Experiment, Collider, Event (particle physics), Lepton
Abstract

We report on further analysis of events with large missing transverse energy from 715 nb −1 of data from the UA1 experiment at the CERN proton-antiproton collider. Measured W and Z 0 rates and heavy flavour cross sections are used to predict rates of missing transverse energy event from all known standard model process. Limits are derived on two possible new sources, namely: (1) semi-hadronic decays of a fourth sequential charged heavy lepton coupling to the W boson, (2) Z 0 decays into additional pairs of non-interacting particles. After taking into additional pairs of non-interacting particles. After taking into account all known sources of missing transverse energy events, we find a mass limit on a fourth-generation charged lepton of m L >41 GeV / c 2 (90% CL) and a limit on the number of additional neutrino species of n ⩽7 (90% CL).

Published
1987

24. Search For New Heavy Quarks At the Cern Proton-antiproton Collider

Author

D. J. Holthuizen, G.H. Grayer, J. Dorenbosch, A. Savoy-Navarro, G. Cox, Murrough Landon, Anna Teresa Meneguzzo, D. Robinson, Dave Charlton, J. Garvey, S. Centro, Kenneth Long, G. Sajot, K. Eggert, P. Cennini, M. Demoulin, A. Ferrando, W. G. Scott, Hans Reithler, D. Gee, J. P. Debrion, W. von Schlippe, Michael Albrow, J. P. Revol, G. Maurin, M. Pimiä, D. Clarke, T. Bacon, Christopher Seez, M. Preischl, E. Pietarinen, Daniel Denegri, K. Morgan, P. Erhard, E. Buckley, Alain Givernaud, L. Naumann, C. Zaccardelli, H. Grassmann, Bruce Denby, C. Pigot, P. Sphicas, Alessandro Bettini, G. Thompson, P. Catz, G. Walzel, D. Kryn, Felicitas Pauss, M. Ikeda, Filippo Ceradini, H. G. Moser, F. J. Diez Hedo, J. Kroll, Emilio Petrolo, T. Markiewicz, M. Schröder, Sergio Cittolin, P. Rossi, G. Busetto, R. Kunnunen, J. D. Dowell, J. P. Porte, Nicolas Zaganidis, C. Bacci, A. Bezaguet, David B. Cline, K. Sumorok, J. Vrana, A. Kernan, T. Redelberger, John A Coughlan, D. Linglin, Margret Fincke-Keeler, E. Tscheslog, A. Taurok, M. Yvert, L. Villasenor, G. Fontaine, M. A. Marquina, M. Markytan, H. Faissner, J. R. Batley, I. F. Fensome, P. Flynn, Randall Sobie, L. Zanello, Aleandro Nisati, E. Eisenhandler, A. van Dijk, T. P. Shah, Veikko Karimäki, P. Nedelec, I. Zacharov, D. Dau, J. Colas, Teresa Rodrigo, P. I. P. Kalmus, J. P. Mendiburu, Akram Khan, P. Colas, J. N. Bellinger, M. Degiorgi, G. Bauer, E. Radermacher, W. Kienzle, Pierluigi Zotto, P. Ghez, N. Bains, H. von der Schmitt, Charling Tao, T. Axon, A. Norton, S. Beingessner, Asoke K. Nandi, F. Szoncso, M. Mohammadi, W. Ruhm, Stephen Wimpenny, M. Della Negra, Nicolas Ellis, Jeffrey Richman, A. Geiser, R. Leuchs, S. Geer, C.-E. Wulz, G. Piano Mortari, A. Honma, Elizabeth Locci, Jorma Tuominiemi, C. Ghesquiere, M.-N. Minard, J. P. Laugier, A. Astbury, L. Dobrzynski, K. Wacker, D. Schinzel, J. P. Lees, M. Moricca, C. Cochet, David Smith, Manfred Krammer, A. Diciaccio, C. Ghighno, G. Ciapetti, G. Jorat, R. Edgecock, J. Ransdell, I. Sheer, Tejinder Virdee, Francesco Lacava, O. C. Allkofer, Josef Strauss, S. Levegrün, C. Perault, R. K. Keeler, R. Bonino, Y. Giraud-Héraud, T. Wyatt, A. Placci, J. Streets, S. Tether, K. Bos, J. Rohlf, Claudia J. Stubenrauch, A. Gonidec, V. Vuillemin, G. Salvini, Th. Müller, C. Rubbia, M. Debeer, D. Samyn, Ehud Duchovni, M. Jimack, T. C. Meyer, A. Schwartz, W. Jank, P. M. Watkins, I. Siotis, I. R. Kenyon, J.P. Vialle, D. Summers, W.J. Haynes, Carmen Albajar, S. Li, J. P. Merlo, B. Mours, B. Aubert, M.J. Corden, S. J. Haywood, A. Wildish, I. ten Have, I. Wingerter, Xin Wu, C. Markou, and J. Sass

Subjects
Quark, Physics, Quantum chromodynamics, Particle physics, Top quark, Muon, Physics and Astronomy (miscellaneous), Proton, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Strong interaction, 01 natural sciences, 7. Clean energy, Nuclear physics, Antiproton, 0103 physical sciences, High Energy Physics::Experiment, Production (computer science), 010306 general physics, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

We report on a search for new heavy quarks using data collected by the UA1 experiment during 1983, 1984 and 1985 at the CERN proton-antiproton collider, corresponding to an integrated luminosity of approximately 700 nb−1. Studying events with a muon or an isolated electron, accompanied by one or more jets, we find good agreement between our data and Monte Carlo predictions for the production of charm and beauty, without the need for a new quark. A top quark model, involving the decayW→t $$\bar b$$ and directt $$\bar t$$ production via the strong interaction, is used to determine our detection efficiency for top. This allows us to place an upper limit on the cross section for producing top quarks as a function of the top quark mass. Our analysis is not sensitive to theW→t $$\bar b$$ process alone. By comparing our limit with a calculation of thet $$\bar t$$ cross section, added to theW→t $$\bar b$$ cross section derived from our own measurements ofW →lv, we are able to place a lower limit on the mass of the top quark. From the lowest order (α 2 ) calculation, using the choice of structure functions andQ 2 scale that give the lowest cross section, we find: $$m_{top} > 44GeV/c^2 \left( {95\% c.l.} \right).$$ Including an estimate of the next higher order (α 2 ) and calculating the cross section with the EUROJET QCD Monte Carlo program using a less extreme choice for the structure functions andQ 2 scale gives: $$m_{top} > 56GeV/c^2 \left( {95\% c.l.} \right).$$ A search has also been made for a fourth generation, charge 1/3 quark (b'). Assuming that theb' mass is smaller than that of the top quark and that it can-not be produced inW decays, the mass limits, using the above procedures, are respectivelym b' >32 GeV/c2 andm b' >44 GeV/c2, both at 95% confidence level.

Published
1988

25. Intermediate vector boson cross sections at the CERN super proton synchrotron collider and the number of neutrino types

Author

Anna Teresa Meneguzzo, Dave Charlton, A. Ferrando, G. Cox, P. Nedelec, Akram Khan, P. Colas, W. G. Scott, P. Ghez, Kenneth Long, K. Bos, J. Colas, Christian Ghiglino, G. Sajot, Josef Strauss, S. Beingessner, H. Grassmann, D. Kryn, M. Debeer, H. Faissner, Hans Reithler, D. Gee, I. ten Have, Tejinder Virdee, E. Buckley, J. R. Batley, I. F. Fensome, P. Flynn, C. Markou, Alain Givernaud, M. Schröder, Sergio Cittolin, A. Norton, K. Morgan, T. Bacon, R. Frey, Francesco Lacava, C. Perault, J. P. Mendiburu, A. Schwartz, Randall Sobie, S. Tether, I. Sacharov, G. Piano Mortari, L. Dobrzynski, F. J. Diez Hedo, Asoke K. Nandi, K. Sumorok, G. Walzel, A. Taurok, I. Siotis, W.J. Haynes, A. Astbury, X. Wu, W. Ruhm, C. Ghesquiere, J. P. Porte, Ritva Kinnunen, S. Li, A. Placci, M. Mohammadi, F. Szoncso, J. Sass, D. J. Holthuizen, G.H. Grayer, B. Aubert, B. Mours, M.J. Corden, S. J. Haywood, Christopher Seez, R. Bonino, Carmen Albajar, D. Samyn, V. Vuillemin, G. Jorat, D. Robinson, S. Centro, G. Fontaine, J. P. Merlo, I. Sheer, I. Wingerter, M.-N. Minard, D. Schinzel, Ehud Duchovni, M. Demoulin, M. Jimack, E. Tscheslog, Daniel J. Smith, Jorma Tuominiemi, G. Maurin, M. Pimiä, E. Eisenhandler, D. Clarke, E. Petrolo, J.P. Vialle, M. Markytan, Teresa Rodrigo, T. C. Meyer, J. Vrana, A. Wildish, H. von der Schmitt, J. D. Dowell, P. Erhard, D. Summers, P. I. P. Kalmus, Felicitas Pauss, M. Ikeda, John A Coughlan, E. Radermacher, O. C. Allkofer, Filippo Ceradini, L. Zanello, G. Bauer, P. Cennini, C. Bacci, B. Van Eijk, Paolo Rossi, Peter Watkins, J. Dorenbosch, A. Savoy-Navarro, T. Axon, Michael Albrow, Veikko Karimäki, Jeffrey Richman, A. Geiser, J. Kroll, W. von Schlippe, T. Markiewicz, C. Zaccardelli, Bruce Denby, Pierluigi Zotto, Charling Tao, J. P. Debrion, P. Catz, Th. Müller, M. Preischl, E. Pietarinen, Daniel Denegri, W. Jank, D. Dau, M. Moricca, J. P. Revol, M. Della Negra, Alessandro Bettini, G. Thompson, S. Geer, A. Honma, A. Diciaccio, D. Linglin, L. Villasenor, M. Yvert, P. Sphicas, I. Kenyon, N. Bains, J. Garvey, M. A. Marquina, S. Levegrün, Y. Giraud-Héraud, T. Wyatt, Margret Fincke-Keeler, C. Cochet, Aleandro Nisati, G. Ciapetti, J. N. Bellinger, N. Ells, J. P. Lees, R. Leuchs, L. Naumann, H. G. Moser, G. Busetto, C. Pigot, A. Bezaguet, C. Rubbia, K. Eggert, J. Rohlf, Richard Keeler, M. Degiorgi, K. Wacker, T. Redelberger, Manfred Krammer, N. Zaganidis, A. Kernan, C.-E. Wulz, Elizabeth Locci, J. P. Laugier, David B. Cline, J. Streets, Claudia J. Stubenrauch, R. Edgecock, A. Gonidec, G. Salvini, T. P. Shah, W. Kienzle, and Stephen Wimpenny

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Top quark, Particle physics, Muon, Large Hadron Collider, Electron, Neutrino, Super Proton Synchrotron, UA1 experiment, Particle Physics - Experiment, Vector boson
Abstract

We present updated results from the UA1 experiment on cross sections times leptonic branching ratios for intermediate vector bosons produced in proton-antiproton collisions at a centre-of-mass energy of 0.630 TeV. We find that σ·B( W → l βn)=0.63±0.04±0.10 nb and σ·B( Z 0 → l + l − =0.071±0.011 nb where l denotes an average of electron and muon channels. An average over all data (electron and muon channels at 0.546 and 0.630 TeV) gives a ratio of R≡σ·( W → l ν)/σ·B( Z 0 → l + l − ) = 9.1 +1.7 −1.2 . Using current theoretical predictions for this quantity, limits are extracted on the number of light neutrino types. Combining UA1 and UA2 data and imposing the bound N ν ⩾3 we find that N ν ⩽5.9 at 90% CL. Constraints on the mass of the top quark are also discussed.

Published
1987

26. Production of W's with large transverse momentum at the CERN proton-antiproton collider

Author

A. Astbury, L. Dobrzynski, H. von der Schmitt, David B. Cline, G. Jorat, D. J. Holthuizen, G.H. Grayer, I. Sheer, E. Tscheslog, Daniel J. Smith, T. Markiewicz, Richard Keeler, D. Robinson, Charling Tao, S. Centro, J.P. Vialle, M. Degiorgi, Christian Ghiglino, D. Dau, M. Della Negra, W. Ruhm, K. Wacker, Christopher Seez, Jacqueline Batley, S. Geer, A. Honma, Alessandro Bettini, G. Thompson, M. Yvert, M. Demoulin, C. Markou, P. Sphicas, N. Bains, Hans Reithler, Manfred Krammer, A. Savoy-Navarro, L. Gately, Elizabeth Locci, D. Gee, J. Dorenbosch, J. Colas, K. Morgan, J. P. Laugier, S. Levegrün, E. Pietarinen, Daniel Denegri, A. Placci, J. P. Mendiburu, C. Ghesquiere, P. Erhard, T. C. Bacon, M. Debeer, G. Sajot, I. ten Have, W.R. Gibson, J. P. Debrion, J. P. Porte, J. Sass, C. Cochet, R. Edgecock, A. Diciaccio, Y. Giraud-Héraud, T. Wyatt, P. Nedelec, G. Ciapetti, Felicitas Pauss, Akram Khan, K. Bos, P. Colas, M. Ikeda, I. R. Kenyon, Michael Albrow, P.I.P. Kalmus, Anna Teresa Meneguzzo, Dave Charlton, V. Vuillemin, Filippo Ceradini, A. Norton, K. Sumorok, K. Eggert, W. G. Scott, D. Linglin, E. Petrolo, S. Beingessner, L. Villasenor, C. Rubbia, J. Kroll, Nicolas Ellis, G. Piano Mortari, G. Bauer, T. C. Meyer, G. Maurin, G.T.J. Arnison, M. Pimiä, D. Clarke, N. Zaganidis, X. Wu, G. Cox, M.-N. Minard, A. Kernan, P. Cennini, B. Aubert, Kenneth Long, Alain Givernaud, D. Schinzel, M. Moricca, Jorma Tuominiemi, J. D. Dowell, H. Faissner, J. P. Revol, John A Coughlan, Ritva Kinnunen, S. Li, I. F. Fensome, P. Flynn, B. Mours, Randall Sobie, M. Markytan, A. Wildish, M.J. Corden, S. J. Haywood, R. J. Homer, I. Wingerter, M. Mohammadi, Margret Fincke-Keeler, I. Zacharov, Sergio Cittolin, B. Van Eijk, Peter Watkins, Asoke K. Nandi, F. Szoncso, T. Axon, Jeffrey Richman, H. D. Wahl, T. P. Shah, J. N. Bellinger, L. Naumann, A. Geiser, C. Pigot, P. Kyberd, W. Kienzle, J. Garvey, Tejinder Virdee, R. Frey, Francesco Lacava, C. Perault, D. Pascoli, D. Samyn, Ehud Duchovni, M. Jimack, J. Vrana, J. Streets, Claudia J. Stubenrauch, A. Gonidec, G. Salvini, Stephen Wimpenny, L. Zanello, Paolo Rossi, P. Petta, Th. Müller, W. Jank, Veikko Karimäki, Pierluigi Zotto, H. Grassmann, D. Kryn, A. Schwartz, I. Siotis, W.J. Haynes, A. Taurok, Carmen Albajar, S. Tether, J. P. Merlo, H. G. Moser, G. Busetto, C. Bacci, A. Bezaguet, John Wilson, Claudia-Elisabeth Wulz, P. Ghez, H. F. Hoffmann, J. P. Lees, E. Radermacher, Josef Strauss, R. Leuchs, O. C. Allkofer, G. Pancheri, J. Rohlf, G. Fontaine, D. Summers, T. Redelberger, E. Buckley, E. Eisenhandler, W. von Schlippe, C. Zaccardelli, Bruce Denby, and P. Catz

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Proton, Hadron, UA1 experiment, law.invention, Nuclear physics, Transverse plane, Antiproton, law, High Energy Physics::Experiment, Nuclear Experiment, Collider, Particle Physics - Experiment
Abstract

We have measured the W transverse momentum distribution (pTW) using a sample of 323 W → eν and W → μν events produced in proton-antiproton collisions at the CERN collider. In the present letter we extend the study of the distribution up to pTW ∼- m W and compare to leading and higher order QCD. This comparison is a precise test of QCD with hadron colliders and the inclusive spectrum gives good agreement over a large range of pTW. However we observed two events at very large pTW (∼- 100 GeV/c) in which the W candidate recoils against an energetic di-jet system. Both events have a very large missing transverse energy and a jet-jet mass compatible with the W mass. In a separate analysis, a topologically similar event has been observed in which a high-mass di-jet system is balanced by a large missing transverse energy which could be interpreted as Z0 → ν ν decay. We cannot easily explain these three events in terms of explicit second-order QCD calculations. However we cannot exclude at this stage the possibility that they are the result of non-gaussian fluctuations in the response of UA1 calorimetry or a statistical fluctuation in the data.

Published
1987

27. Measurement of the inclusive jet cross section at the CERN p collider

Author

G. Arnison, M.G. Albrow, O.C. Allkofer, A. Astbury, B. Aubert, C. Bacci, J.R. Batley, G. Bauer, A. Bettini, A. Bézaguet, R.K. Bock, K. Bos, E. Buckley, J. Bunn, G. Busetto, P. Catz, P. Cennini, S. Centro, F. Ceradini, G. Ciapetti, S. Cittolin, D. Clarke, D. Cline, C. Cochet, J. Colas, P. Colas, M. Corden, G. Cox, D. Dallman, D. Dau, M. Debeer, J.P. Debrion, M. Degiorgi, M. Della Negra, M. Demoulin, B. Denby, D. Denegri, A. Diciaccio, L. Dobrzynski, J. Dorenbosch, J.D. Dowell, E. Duchovni, R. Edgecock, K. Eggert, E. Eisenhandler, N. Ellis, P. Erhard, H. Faissner, M. Fince Keeler, P. Flynn, G. Fontaine, R. Frey, R. Frühwirth, J. Garvey, D. Gee, S. Geer, C. Ghesquière, P. Ghez, F. Ghio, P. Giacomelli, W.R. Gibson, Y. Giraud-Héraud, A. Givernaud, A. Gonidec, M. Goodman, H. Grassmann, G. Grayer, W. Guryn, T. Hansl-Kozanecka, W. Haynes, S.J. Haywood, H. Hoffmann, D.J. Holthuizen, R.J. Homer, A. Honma, W. Jank, M. Jimack, G. Jorat, P.I.P. Kalmus, V. Karimäri, R. Keeler, I. Kenyon, A. Kernan, W. Kienzle, R. Kinnunen, W. Kozanecki, J. Kroll, D. Kryn, P. Kyberd, F. Lacava, J.P. Laugier, J.P. Lees, R. Leuchs, S. Levegrun, A. Lévêque, M. Levi, D. Linglin, E. Locci, K. Long, T. Markiewicz, M. Markytan, T. Martin, F. Maurin, T. McMahon, J.-P. Mendiburu, A. Meneguzzo, O. Meyer, T. Meyer, M.-N. Minard, M. Mohammadi, K. Morgan, M. Moricca, H. Moser, B. Mours, Th. Muller, A. Nandi, L. Naumann, A. Norton, L. Paoluzi, D. Pascoli, F. Pauss, C. Perault, G. Piano Mortari, E. Pietarinen, C. Pigot, M. Pimiä, D. Pitman, A. Placci, J.-P. Porte, E. Radermacher, J. Ransdell, T. Redelberger, H. Reithler, J.P. Revol, J. Richman, M. Rijssenbeek, J. Rohlf, P. Rossi, C. Roberts, W. Ruhm, C. Rubbia, G. Sajot, G. Salvini, J. Sass, B. Sadoulet, D. Samyn, A. Savoy-Navarro, D. Schinzel, A. Schwartz, W. Scott, T.P. Shah, I. Sheer, I. Siotis, D. Smith, R. Sobie, P. Sphicas, J. Strauss, J. Streets, C. Stubenrauch, D. Summers, K. Sumorok, F. Szonczo, C. Tao, I. Ten Have, G. Thompson, E. Tscheslog, J. Tuominiemi, B. Van Eijk, P. Verecchia, J.P. Vialle, T.S. Virdee, H. Von Der Schmitt, W. Von Schlippe, J. Vrana, V. Vuillemin, H.D. Wahl, P. Watkins, R. Wilke, J. Wilson, I. Wingerter, S.J. Wimpenny, C.-E. Wulz, T. Wyatt, M. Yvert, I. Zacharov, N. Zaganidis, L. Zanello, and P. Zotto

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, 010308 nuclear & particles physics, Jet (particle physics), 7. Clean energy, 01 natural sciences, UA1 experiment, law.invention, Nuclear physics, Cross section (physics), law, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Collider, Scaling
Abstract

The inclusive jet cross section has been measured in the UA1 experiment at the CERN p p Collider at centre-of-mass energies √s = 546 GeV and √s = 630 eV. The cross sections are found to be consistent with QCD predictions, The observed change in the cross section with the centre-of-mass energy √s is accounted for in terms of xT scaling.

Published
1986

28. High transverse momentum J/ψ production at the CERN proton-antiproton collider

Author

Felicitas Pauss, M. Ikeda, Filippo Ceradini, J. Kroll, G. Maurin, T. P. Shah, V. Vuillemin, David B. Cline, M. Pimiä, D. Clarke, J. Colas, G. Walzel, A. Norton, G. Piano Mortari, B. Van Eijk, W. Kienzle, W. Ruhm, Emilio Petrolo, P. Nedelec, A. Schwartz, I. Siotis, J. D. Dowell, M. Markytan, E. Tscheslog, Daniel J. Smith, O. C. Allkofer, Tejinder Virdee, W.J. Haynes, I. Zacharov, Hans Reithler, D. Gee, K. Morgan, S. Tether, R. K. Keeler, Jacqueline Batley, Nicolas Zaganidis, Francesco Lacava, Akram Khan, P. Colas, Carmen Albajar, M. Yvert, P. Sphicas, N. Bains, J. Rohlf, T. C. Meyer, C. Markou, A. Placci, C. Perault, K. Eggert, John A Coughlan, E. Radermacher, J. P. Porte, G. Cox, J. P. Merlo, Teresa Rodrigo, P. I. P. Kalmus, T. Axon, Jeffrey Richman, A. Geiser, Kenneth Long, Nicolas Ellis, T. Markiewicz, M.-N. Minard, J. P. Lees, Ritva Kinnunen, P. M. Watkins, Veikko Karimäki, G. Fontaine, B. Aubert, D. Schinzel, X. Wu, K. Sumorok, S. Li, G. Sajot, J. Sass, Charling Tao, R. Leuchs, C. Cochet, D. Samyn, B. Mours, A. Astbury, D. Dau, J. Dorenbosch, A. Savoy-Navarro, M. Della Negra, Ehud Duchovni, J. P. Mendiburu, P. Ghez, Aleandro Nisati, Pierluigi Zotto, M.J. Corden, S. J. Haywood, S. Geer, A. Honma, Jorma Tuominiemi, M. Jimack, E. Eisenhandler, A. Wildish, D. Linglin, G. Ciapetti, J. N. Bellinger, I. Wingerter, Alain Givernaud, D. J. Holthuizen, G.H. Grayer, L. Villasenor, T. Redelberger, E. Buckley, Murrough Landon, W. von Schlippe, H. G. Moser, M. A. Marquina, K. Bos, Anna Teresa Meneguzzo, Dave Charlton, Josef Strauss, D. Robinson, H. von der Schmitt, R. Bonino, F. J. Diez Hedo, G. Busetto, M. Debeer, S. Levegrün, D. Summers, C. Bacci, M. Moricca, J. P. Revol, Alessandro Bettini, J. P. Debrion, Michael Albrow, A. Bezaguet, A. Ferrando, J. Garvey, C. Zaccardelli, Christopher Seez, S. Centro, Bruce Denby, M. Preischl, E. Pietarinen, Daniel Denegri, G. Thompson, J.P. Vialle, P. Catz, Y. Giraud-Héraud, T. Wyatt, L. Naumann, A. van Dijk, M. Demoulin, Christian Ghiglino, I. R. Kenyon, J. A. Wilson, M. Fincke-Keller, C. Pigot, S. Beingessner, L. Dobrzynski, A. Diciaccio, H. Faissner, T. C. Bacon, G. Jorat, P. Erhard, I. F. Fensome, P. Flynn, Randall Sobie, I. Sheer, I. ten Have, C. Rubbia, M. Schröder, Sergio Cittolin, M. Mohammadi, Asoke K. Nandi, G. Bauer, F. Szoncso, P. Cennini, A. Taurok, W. G. Scott, H. Grassmann, D. Kryn, M. Degiorgi, C.-E. Wulz, Elizabeth Locci, J. P. Laugier, R. Edgecock, J. Vrana, L. Zanello, Paolo Rossi, Th. Müller, W. Jank, J. Streets, Claudia J. Stubenrauch, A. Gonidec, G. Salvini, Stephen Wimpenny, K. Wacker, Manfred Krammer, C. Ghesouiere, and A. Kernan

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Proton, Branching fraction, Hadron, law.invention, Nuclear physics, law, Antiproton, Bound state, High Energy Physics::Experiment, Collider, Event (particle physics), Particle Physics - Experiment
Abstract

We have studied high transverse momentum J/ψ production in pp interactions at s=630 GeV. The measured cross section times branching fraction for J/ψ→μ+μ− production with pT⩾5 GeV/c and |y

Published
1988

29. BEAUTY PRODUCTION AT THE CERN PROTON-ANTIPROTON COLLIDER

Author

W.R. Gibson, Tejinder Virdee, R. Frey, Francesco Lacava, C. Perault, F. Ghio, T. Markiewicz, Margret Fincke-Keeler, L. Dobrzynski, D. Pitman, W. Ruhm, J. P. Revol, A. Placci, V. Vuillemin, D. Pascoli, Charling Tao, L. Naumann, H. D. Wahl, G. Jorat, R. Edgecock, D. Dau, M. Della Negra, S. Geer, C. Pigot, A. Honma, I. Sheer, E. Buckley, N. Zaganidis, G. Bauer, M. Markytan, K. Sumorok, J. N. Bellinger, B. Aubert, A. Wildish, M. Debeer, J. Colas, I. R. Kenyon, Paolo Rossi, Sergio Cittolin, P. Ghez, A. Kernan, T. P. Shah, D. J. Holthuizen, G.H. Grayer, H. Faissner, P. Kyberd, J. R. Batley, I. F. Fensome, P. Flynn, P.I.P. Kalmus, Anna Teresa Meneguzzo, Dave Charlton, E. Radermacher, Alain Givernaud, P. Cennini, Josef Strauss, Alessandro Bettini, G. Thompson, T. Bacon, G. Cox, D. Robinson, D. Samyn, S. Beingessner, H. von der Schmitt, J. P. Lees, Randall Sobie, Ehud Duchovni, A. Norton, J. Dorenbosch, T. C. Meyer, Asoke K. Nandi, W. Kienzle, P. Petta, C. Bacci, S. Centro, A. Savoy-Navarro, F. Szoncso, H. Grassmann, Th. Müller, M. Jimack, David B. Cline, G.T.J. Arnison, C. Markou, W. Jank, Kenneth Long, M. Mohammadi, G. Piano Mortari, M. Demoulin, D. Kryn, E. Pietarinen, Daniel Denegri, R. Leuchs, D. Linglin, L. Gately, Hans Reithler, A. Schwartz, Christopher Seez, I. Siotis, L. Villasenor, M. Degiorgi, J. Garvey, Ritva Kinnunen, D. Gee, Michael Albrow, S. Levegrün, J. P. Debrion, K. Morgan, C. Ghesquiere, W.J. Haynes, Veikko Karimäki, Carmen Albajar, Richard Keeler, S. Li, I. ten Have, B. Mours, G. Bunce, A. Diciaccio, J. Streets, B. Van Eijk, Y. Giraud-Héraud, M.-N. Minard, A. Taurok, Claudia J. Stubenrauch, A. Gonidec, David Smith, J. P. Merlo, Pierluigi Zotto, D. Schinzel, M.J. Corden, S. J. Haywood, I. Wingerter, J. Sass, T. Wyatt, Peter Watkins, G. Salvini, H. G. Moser, G. Busetto, J. P. Mendiburu, J. Rohlf, J. Vrana, K. Bos, K. Wacker, P. Erhard, Stephen Wimpenny, P. Nedelec, Felicitas Pauss, M. Ikeda, Filippo Ceradini, J. P. Porte, L. Zanello, A. Astbury, Manfred Krammer, A. Bezaguet, C.-E. Wulz, Elizabeth Locci, J. Kroll, Paolo Giacomelli, G. Maurin, E. Tscheslog, Akram Khan, P. Colas, R. Frühwirth, X. Wu, J. P. Laugier, S. Tether, M. Pimiä, D. Clarke, John Wilson, W. G. Scott, R. J. Homer, J.P. Vialle, K. Eggert, E. Petrolo, Jorma Tuominiemi, J. D. Dowell, G. Fontaine, John A Coughlan, Nicolas Ellis, O. C. Allkofer, I. Zacharov, D. Summers, T. Redelberger, T. Axon, Jeffrey Richman, A. Geiser, E. Eisenhandler, H. F. Hoffmann, W. von Schlippe, C. Zaccardelli, Bruce Denby, P. Catz, M. Moricca, M. Yvert, P. Sphicas, N. Bains, C. Cochet, G. Ciapetti, C. Rubbia, and G. Sajot

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Muon, media_common.quotation_subject, UA1 experiment, Nuclear physics, Angular distribution, Antiproton, Beauty, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment, media_common
Abstract

We report evidence for beauty particle production through the observation of dimuon events from proton-antiproton collisions at energies of √s=546 GeV and √s=630 GeV at the CERN collider. Our data indicate that semi-leptonic decays of beauty particles are the dominant source of pairs of high-pT muons. The beauty flavour creation (gg or q¯q→b¯b) cross-section needed to explain the dimuon rate is σ{p¯p→b¯b+X, pbT5 GeV/c, |η

Published
1987

30. Angular distributions for high-mass jet pairs and a limit on the energy scale of compositeness for quarks from the CERN pp̄ collider

Author

J. Vrana, T. C. Bacon, Felicitas Pauss, M. Ikeda, I. ten Have, L. Zanello, Filippo Ceradini, G.T.J. Arnison, J. Kroll, Paolo Giacomelli, M. Yvert, P. Sphicas, R. K. Keeler, J. Garvey, M. Goodman, R. K. Bock, R. J. Homer, Ritva Kinnunen, P. M. Watkins, E. Buckley, B. Mours, H. D. Wahl, D. J. Holthuizen, G.H. Grayer, Hans Reithler, J. N. Bellinger, D. Gee, C. Cochet, M.J. Corden, S. J. Haywood, I. Wingerter, P. Erhard, G. Ciapetti, G. Sajot, R. Wilke, Paolo Rossi, G. Bauer, D. Robinson, G. Maurin, A. Astbury, R. Frühwirth, A. Schwartz, S. Centro, D. Linglin, D. Pitman, O. Meyer, D. Clarke, G. Fontaine, L. Villasenor, I. Siotis, Sergio Cittolin, F. Ghio, C. Rubbia, A. Norton, M. Demoulin, P. Cennini, K. Morgan, J. D. Dowell, W. G. Scott, E. Eisenhandler, Michael Rijssenbeek, A. Kernan, Michael Albrow, John A Coughlan, Anton Taurok, H. Grassmann, M. Moricca, W. von Schlippe, D. Kryn, J. P. Revol, A. Placci, W.J. Haynes, T.I. Meyer, M.-N. Minard, Th. Müller, W. Jank, C. Zaccardelli, C. Ghesquiere, W. Kienzle, Bruce Denby, Kenneth Long, D. Schinzel, Philippe Ghez, P. Catz, K. Sumorok, L. Naumann, J. P. Porte, M. Debeer, C. Pigot, Stephen Wimpenny, S. Tether, B. Sadoulet, Asoke K. Nandi, T. Martin, F. Szoncso, Nicolas Zaganidis, P. Verecchia, Veikko Karimäki, Tejinder Virdee, T. J. McMahon, H. G. Moser, G. Busetto, Carmen Albajar, R. Frey, Francesco Lacava, C. Perault, H. Faissner, J.P. Vialle, H. von der Schmitt, T. P. Shah, A. Lévêque, J. R. Batley, P. Flynn, P. Colas, D. Pascoli, Pierluigi Zotto, A. Bezaguet, Ehud Duchovni, L. Dobrzynski, M. Jimack, K. Bos, W. R. Gibson, S. Levegrün, D. Summers, J. Streets, Claudia J. Stubenrauch, J. P. Mendiburu, W. Guryn, G. Salvini, V. Vuillemin, G. Jorat, I. Sheer, W. Kozanecki, M. Fincke Keeler, Anna Teresa Meneguzzo, E. Petrolo, I. Zacharov, Alessandro Bettini, G. Thompson, G.F. Cox, Nicolas Ellis, T. Hansl-Kozanecka, Y. Giraud-Héraud, T. Wyatt, C. Bacci, T. Axon, Jeffrey Richman, E. Radermacher, T. Markiewicz, Charling Tao, D. Dau, M. Della Negra, S. Geer, A. Honma, Alain Givernaud, D. Samyn, I. R. Kenyon, J. A. Wilson, Josef Strauss, J. Sass, Michael Levi, J. P. Lees, W. Ruhm, R. Leuchs, A. Gonidec, E. Pietarinen, Daniel Denegri, A. Diciaccio, B. Aubert, O. C. Allkofer, A. Wildish, Jorma Tuominiemi, J. Rohlf, R. J. Sobie, Manfred Krammer, H. F. Hoffmann, M. Pimiä, K. Eggert, T. Redelberger, E. Tscheslog, Daniel J. Smith, P. I. P. Kalmus, R. Edgecock, J. Ransdell, J. Dorenbosch, A. Savoy-Navarro, J. P. Debrion, M. Degiorgi, C.-E. Wulz, Elizabeth Locci, J. P. Laugier, David B. Cline, J. Colas, G. Piano Mortari, Paul Kyberd, M. Markytan, M. Mohammad, and B. Van Eijk

Subjects
Quark, Physics, Nuclear and High Energy Physics, Jet (fluid), Range (particle radiation), Particle physics, Large Hadron Collider, Scale (ratio), Astrophysics::High Energy Astrophysical Phenomena, Quark model, law.invention, Nuclear physics, Distribution (mathematics), law, High Energy Physics::Experiment, Collider, Particle Physics - Experiment
Abstract

Angular distributions of high-mass jet pairs (180 ( s =630 GeV ) . We show that angular distributions are independent of the subprocess centre-of-mass (CM) energy over this range, and use the data to put constraints on the definition of the Q2 scale. The distribution for the very high mass jet pairs (240 415 GeV at 95% confidence level.

Published
1986

31. Low mass dimuon production at the CERN proton-antiproton collider

Author

C. Albajar, M.G. Albrow, O.C. Allkofer, A. Astbury, B. Aubert, T. Axon, C. Bacci, T. Bacon, N. Bains, J.R. Batley, G. Bauer, S. Beingessner, A. Bettini, A. Bezaguet, R. Bonino, K. Bos, E. Buckley, G. Busetto, P. Catz, P. Cennini, S. Centro, F. Ceradini, D.G. Charlton, G. Ciapetti, S. Cittolin, D. Clarke, D. Cline, C. Cochet, J. Colas, P. Colas, M. Corden, J.A. Coughlan, G. Cox, D. Dau, J.P. Debrion, M. Degiorgi, M. Della Negra, M. Demoulin, D. Denegri, A. Diciaccio, F.J. Diez Hedo, L. Dobrzynski, J. Dorenbosch, J.D. Dowell, E. Duchovni, K. Eggert, E. Eisenhandler, N. Ellis, P. Erhard, H. Faissner, I.F. Fensome, A. Ferrando, M. Fincke-Keeler, P. Flynn, G. Fontaine, J. Garvey, D. Gee, S. Geer, A. Geiser, C. Ghesquiere, P. Ghez, C. Ghiglino, Y. Giraud-Heraud, A. Givernaud, A. Gonidec, H. Grassmann, J.M. Gregory, W. Haynes, S.J. Haywood, D.J. Holthuizen, M. Ikeda, W. Jank, M. Jimack, G. Jorat, D. Joyce, P.I.P. Kalmus, V. Karimäki, R. Keeler, I. Kenyon, A. Kernan, A. Khan, W. Kienzle, R. Kinnunen, M. Krammer, J. Kroll, D. Kryn, F. Lacava, S. Lammel, M. Landon, J.P. Lees, R. Leuchs, S. Levegrün, S. Li, M. Lindgren, D. Linglin, P. Lipa, E. Locci, T. Markiewicz, C. Markou, M. Markytan, M.A. Marquina, G. Maurin, J.-P. Mendiburu, A. Meneguzzo, J.P. Merlo, T. Meyer, M.-N. Minard, M. Mohammadi, K. Morgan, H.-G. Moser, A. Moulin, B. Mours, Th. Muller, L. Naumann, P. Nedelec, A. Nisati, A. Norton, F. Pauss, C. Perault, E. Petrolo, G. Piano Mortari, E. Pietarinen, C. Pigot, M. Pimiä, A. Placci, J.-P. Porte, M. Preischl, E. Radermacher, T. Redelberger, H. Reitheler, J.-P. Revol, D. Robinson, T. Rodrigo, J. Rohlf, C. Rubbia, G. Sajot, G. Salvini, J. Sass, D. Samyn, D. Schinzel, M. Schröder, A. Schwartz, W. Scott, C. Seez, T.P. Shah, I. Sheer, I. Siotis, D. Smith, R. Sobie, P. Sphicas, J. Strauss, J. Streets, C. Stubenrauch, D. Summers, K. Sumorok, F. Szoncso, C. Tao, A. Taurok, I. Ten Have, S. Tether, G. Thompson, E. Tscheslog, J. Tuominiemi, W. Van De Guchte, A. Van Eijk, J.P. Vialle, L. Villasenor, T.S. Virdee, W. Von Schlippe, J. Vrana, V. Vuillemin, K. Wacker, G. Walzel, A. Wildish, I. Wingerter, S.J. Wimpenny, X. Wulz, C.-E. Wulz, T. Wyatt, M. Yvert, C. Zaccardelli, I. Zacharov, N. Zaganidis, L. Zanello, and P. Zotto

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Photon, Large Hadron Collider, Proton, Meson, Branching fraction, Nuclear Theory, High Energy Physics::Phenomenology, law.invention, Nuclear physics, Antiproton, law, High Energy Physics::Experiment, Nuclear Experiment, Collider, Particle Physics - Experiment
Abstract

We present a study of low mass dimuon events [m(μμ) < 6 GeV/c2] from the UA1 experiment at the CERN pp collider. Contributions from semileptonic decays of heavy flavour particles, Drell-Yan type processes, J/ψ decays and leptonic decays of light mesons are extracted, and cross sections for high pT beauty and Drell-Yan production are derived. A limit for the branching fraction for the exotic decay B0→μ+μ− is also obtained. The cross section for section for low mass, high pT Drell-Yan prod uction is compared to the measured direct photon cross section using QED and QCD derived relationship. This relationship is used to infer a measurement of the single photon cross section at lower values of transverse momentum, where photons cannot be unambigously identified.

Published
1988

32. Study of heavy flavour production in events with a muon accompanied by jet(s) at the CERN proton-antiproton collider

Author

Alessandro Bettini, T. Bacon, D. Samyn, T. Redelberger, R. K. Keeler, G. Thompson, G. Cox, G. Walzel, Ehud Duchovni, W. Ruhm, Emilio Petrolo, O. C. Allkofer, A. Schwartz, Ritva Kinnunen, M. Jimack, J. Rohlf, Kenneth Long, I. Siotis, Hans Reithler, D. Gee, David B. Cline, G. Busetto, A. Taurok, Nicolas Zaganidis, W.J. Haynes, M. Yvert, P. Sphicas, S. Li, B. Mours, M.J. Corden, S. J. Haywood, N. Bains, A. Placci, K. Eggert, J. P. Lees, P. Nedelec, Akram Khan, P. Colas, K. Morgan, E. Tscheslog, I. Wingerter, S. Tether, C. Markou, D. J. Holthuizen, G. Sajot, G.H. Grayer, I. ten Have, Margret Fincke-Keeler, C. Bacci, M. Markytan, Carmen Albajar, D. Summers, D. Linglin, L. Villasenor, Daniel J. Smith, Teresa Rodrigo, J. P. Merlo, J. P. Mendiburu, M.-N. Minard, P. I. P. Kalmus, J. P. Porte, C. Cochet, P. Cennini, Aleandro Nisati, A. Kernan, B. Aubert, M. A. Marquina, D. Schinzel, D. Robinson, G. Ciapetti, J. P. de Brion, P. Watkims, J. Sass, Nicolas Ellis, J. N. Bellinger, J. Dorenbosch, Murrough Landon, X. Wu, H. G. Moser, W. G. Scott, J. P. Revol, S. Centro, H. Faissner, A. Savoy-Navarro, Tejinder Virdee, A. Wildish, R. Leuchs, S. Levegrün, B. Van Eijk, A. van Dijk, Christopher Seez, Anna Teresa Meneguzzo, M. Debeer, J. R. Batley, I. F. Fensome, P. Flynn, Francesco Lacava, C. Perault, Dave Charlton, S. Beingessner, Felicitas Pauss, M. Ikeda, H. Grassmann, D. Kryn, M. Demoulin, Filippo Ceradini, K. Wacker, P. Ghez, V. Vuillemin, A. Bezaguet, M. Moricca, Manfred Krammer, J. Colas, Veikko Karimäki, J. Kroll, P. Rossi, Randall Sobie, I. R. Kenyon, Christian Ghiglino, C. Rubbia, A. Ferrando, Josef Strauss, Alain Givernaud, I. Zacharov, D. Dau, P. Erhard, Jorma Tuominiemi, G. Bauer, A. Norton, R. Edgecock, J. Ransdell, M. Mohammadi, Y. Giraud-Héraud, F. J. Diez Hedo, Pierluigi Zotto, G. Piano Mortari, M. Degiorgi, T. Wyatt, J. Garvey, L. Dobrzynski, J. Vrana, H. von der Schmitt, Michael Albrow, L. Naumann, A. Diciaccio, C. Pigot, G. Jorat, M. Preischl, E. Pietarinen, Daniel Denegri, K. Sumorok, L. Zanello, I. Sheer, C. Ghesquiere, C.-E. Wulz, Elizabeth Locci, T. C. Meyer, G. Maurin, T. Axon, M. Pimiä, Jeffrey Richman, D. Clarke, J. P. Laugier, E. Buckley, J. D. Dowell, A. Geiser, T. Markiewicz, M. Schröder, Sergio Cittolin, John A Coughlan, Th. Müller, E. Radermacher, W. Jank, Charling Tao, A. Astbury, M. Della Negra, Asoke K. Nandi, S. Geer, F. Szoncso, A. Honma, R. Bonino, J.P. Vialle, W. von Schlippe, C. Zaccardelli, Bruce Denby, P. Catz, K. Bos, G. Fontaine, E. Eisenhandler, Stephen Wimpenny, J. Streets, Claudia J. Stubenrauch, A. Gonidec, G. Salvini, T. P. Shah, and W. Kienzle

Subjects
Quantum chromodynamics, Physics, Quark, Particle physics, Muon, Large Hadron Collider, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Jet (particle physics), 01 natural sciences, law.invention, Nuclear physics, law, Antiproton, 0103 physical sciences, High Energy Physics::Experiment, Charm (quantum number), Nuclear Experiment, 010306 general physics, Collider, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

We present a study of heavy flavour (charm and beauty) production using data collected with the UA1 detector at the CERN Proton-Antiproton collider at a centre-of-mass energy of 630 GeV for an integrated luminosity of 556 nb−1. This follows our earlier study ofb $$\bar b$$ andc $$\bar c$$ production in dimuon events and the evidence for mixing betweenB 0 and $$\bar B^0 $$ states. Properties of an inclusive sample of events containing a muon withp T >6 GeV/c are compared with QCD predictions for heavy flavour production, using the ISAJET Monte Carlo program. The predicted largep T muon yield from heavy flavour production and decay agrees with the data to within 30%. For events with a muon ofp T >10 GeV/c and at least one jet withE T >10 GeV, we measure the ratio charm/(charm+beauty) to be (24±8±9)%. We also show that the correlations observed between the two heavy quark jets expected by flavour conservation are consistent with the mixture of lowest and higher order QCD processes. We study in detail the topological and kinematic properties of a subsample of events containing a highp T muon and one or more jets. The good agreement of the theoretical predictions with our data in a region dominated by the production of charm and beauty shows that one of the main background sources to a new heavy quark signature is well understood.

Published
1988

33. Near-field low-temperature photoluminescence spectroscopy of single V-shaped quantum wires

Author

Adriana Passaseo, M. DeGiorgi, R. Cingolani, M. Hauert, Ch. Lienau, Ross Rinaldi, G. Coli, and Valentina Emiliani

Subjects
Length scale, Materials science, Condensed matter physics, Exciton, Quantum wire, Monolayer, Quantum point contact, Quantum-optical spectroscopy, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Spectroscopy, Nitrogen-vacancy center, Molecular physics
Abstract

We report on a near-field spectroscopic study of single V-shaped ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}$ quantum wires. With subwavelength resolution, the emission from single ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ wires and connecting planar quantum wells---separated by 250 nm---are individually resolved. The contributions of both monolayer height fluctuations on a 100 nm length scale and of short range compositional disorder to the localization of excitons in V-shaped quantum wires are separately identified and their implications for far-field PL spectra discussed. An upper limit for the migration length of the photogenerated excitons within the GaAs barrier layers of 250 nm is determined.

34. Led-based Public Lighting System Reliability for a Reduced Impact on Environment and Energy Consumption

Author

LAY EKUAKILLE, A, Vendramin, G, Bellone, M, Carracchia, A, Corso, D, DE GIORGI, M, Deodati, A, Laforgia, D, Pelillo, V, Petrachi, E, Sarcinella, A, Trotta, Amerigo, IEEE SSD-07, LAY EKUAKILLE, Aime, G., Vendramin, M., Bellone, A., Carracchia, D., Corso, M., Degiorgi, A., Deodati, Laforgia, Domenico, V., Pelillo, E., Petrachi, A., Sarcinella, and A., Trotta

Subjects
LEDs
Abstract

Light Emitting Diodes (LEDs) contain solid_state technology made in Silicon Valley using similar technologies that are used in the latest microprocessors. These solid_state devices have no moving parts, no fragile glass environments, no mercury, no toxic gasses, and no filament. There is nothing to break, rupture, shatter, leak, or contaminate. They are playing a significant role in energy saving policy; since private and public lighting are indicators of development in many countries. Developing policy must be envisaged in order to reduce impact on environment and energy consumption without sacrificing an important part of economic growth. This research outlines results of a campaign which has been conducting in the Town of Leporano, in the district of Taranto (Apulia Region, Italy) in cooperation with the local government. Different led system have been located on public posts.

Published
2007

35. Spectroscopy of semiconductors at nanoscale

Author

Cingolani, R, DeVittorio, M, DeGiorgi, M, Lomascolo, M, Rinaldi, R, Johal, T, Passaseo, Cingolani, Roberto, DE VITTORIO, Massimo, M., Degiorgi, M., Lomascolo, Rinaldi, Rosaria, T., Johal, and A., Passaseo

Published
2001

36. Longitudinal stark effect in parabolic quantum dots

Author

T. Drufva, Harri Lipsanen, Markku Sopanen, Paolo Visconti, Roberto Cingolani, Ross Rinaldi, Jukka Tulkki, Angelo Melcarne, Milena DeGiorgi, M. DeVittorio, Rinaldi, Rosaria, DE GIORGI, M., DE VITTORIO, Massimo, Melcarne, A., Visconti, Paolo, Cingolani, R, Lipsanen, H., Sopanen, M., Drufva, T., Tulkki, J., M., Degiorgi, Devittorio, M., R. Cingolani H., Lipsanen, M., Sopanen, T., Drufva, and J., Tulkki

Subjects
Physics, Condensed matter physics, Field (physics), Quantum-confined Stark effect, Quantum point contact, General Engineering, General Physics and Astronomy, Smart Electronic Board for PV Streetlight, symbols.namesake, Stark effect, Quantum dot laser, Quantum dot, Electric field, Electro-absorption modulator, symbols
Abstract

We present an experimental and theoretical investigation of the longitudinal quantum confined Stark effect in strain-induced parabolic InGaAs quantum dots. The electric field is applied in the plane perpendicular to the growth axis (quantum well plane), through a sub-micron gap opened in a metallic contact, which contains just a few dots. The changes in the microphotoluminescence (µ-PL) spectra were measured versus the bias, at low temperature. Due to the device geometry, the electric field profile in the gate is not constant resulting in an asymmetric Stark effect as a function of the applied field polarity. Calculations of the field profile in the conatct gap and of the distorsion of the parabolic-like potential as a function of the applied field have been made in order to correlate the observed changes in the electro-optical properties of the dots with the carrier spill over and wavefunction modifications under electric field.

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