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134 results on '"B. R. French"'

1. Further analysis of a direct soft photon excess in π−p interactions at 280 GeV/c

Author

Irakli Minashvili, V. Lenti, A. Kirk, N.A. Russakovich, P. Sonderegger, A. Jacholkowski, Vito Manzari, W. Beusch, B. R. French, G. Tchlatchidze, J.B. Kinson, I. Vichou, T. J. Brodbeck, O. Villalobos Baillie, David H. Evans, G. Vassiliadis, V.F. Perepelitsa, R. A. Loconsole, M. Spyropoulou-Stassinaki, P. Ganoti, and A. Belogianni

Subjects
Physics, Particle physics, Nuclear and High Energy Physics, Photon, Soft photon, Meson, Bremsstrahlung, Astrophysics::High Energy Astrophysical Phenomena, Elementary particle, Electromagnetic radiation, Soft photons, Nuclear physics, Massless particle, Pion, π−p interactions, Photon excess, High Energy Physics::Experiment, Nuclear Experiment
Abstract

In this Letter we present additional experimental characteristics of anomalous soft photon radiation observed in π−p interactions at 280 GeV/c in the CERN experiment WA91, together with a re-calculated ratio of the observed direct soft photon signal to the expected level of the hadronic inner bremsstrahlung, which is found to be 5.3±1.0. The other presented characteristics, energy dependence and angular distributions of direct soft photons, show the similarity of the observed signal to the expected hadronic bremsstrahlung behaviour.

Published
2002
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2. A partial wave analysis of the centrally produced π0π0 system in pp interactions at 450 GeV/c

Author

T. Hino, Kunio Takamatsu, V.N. Kolosov, Sergey Donskov, Irakli Minashvili, Petr P.M. Shagin, Sergey S.A. Polovnikov, Paolo Martinengo, K. M. Danielsen, G.V. Khaustov, A. Solovjev, Jean Pierre Peigneux, Takemi Nakagawa, A.V. Dolgopolov, M. Venables, B.C. Earl, Yoshiji Yasu, D. Barberis, Susumu Inaba, A. Semenov, V.D. Samoylenko, T. Jacobsen, R. Sené, G. Tchlatchidze, A.M. Blick, V.A. Polyakov, A. A. Kondashov, A. Kirk, Alexandre A.V. Inyakin, M.F. Votruba, W. Klempt, Freddy Binon, A. Sobol, G. T. Jones, S. Maljukov, N. Russakovich, A.V. Singovsky, Andrey Lednev, M. Stassinaki, A. Jacholkowski, Valentine Sugonyaev, K.L. Norman, H. M. Shimizu, J.B. Kinson, T. Ishida, David H. Evans, B. R. French, F.E. Close, W. Beusch, V. Romanovsky, M. Sené, Tsuneaki Tsuru, T. Kinashi, H. Rotscheidt, Jean-Pierre Stroot, O. Villalobos Baillie, V. Rumyantsev, and V. Lenti

Subjects
Physics, Nuclear physics, Momentum, Nuclear and High Energy Physics, Partial wave analysis, Incident beam, Channel (broadcasting), Atomic physics, Central region
Abstract

A partial wave analysis of the centrally produced π 0 π 0 channel has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. Evidence is found for the f 0 (980), f 0 (1300) and f 0 (1500) in the the S -wave. and the f 2 (1270) is observed dominantly in the D 0 − -wave. In addition, there is evidence for a broad enhancement in the D -wave below 1 GeV.

Published
1999
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3. A partial wave analysis of the centrally produced K+K− system in pp interactions at 300 GeV/c

Author

O. Villalobos Baillie, V. Lenti, A. Kirk, B. R. French, M.F. Votruba, M. Stassinaki, J.B. Kinson, and A. Jacholkowski

Subjects
Physics, Nuclear and High Energy Physics, Partial wave analysis, Channel (broadcasting), Atomic physics
Abstract

A partial wave analysis of the centrally produced K + K − channel from the WA76 experiment has been performed and shows evidence for peaks in the S-wave due to the f 0 (1500) and f J (1710) with J =0. The D-wave shows no evidence for a statistically significant contribution in the 1.7 GeV mass region.

Published
1999
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4. Hyperon production in proton-sulphur interaction at 200 GeV/c

Author

S. Abatzis, J. Ftáĉnik, V. Lenti, K. Knudson, P. Ladron de Guevara, J. Urban, N. Carrer, M. Venables, J. N. Carney, Domenico Elia, V. A. Katchanov, Federico Antinori, O. Villalobos Baillie, J. L. Narjoux, R. A. Ricci, A. V. Singovsky, A. C. Bayes, M. Morando, E. Andersen, G.F. Segato, L. Sandor, E. Quercigh, K. Šafařík, M. Sené, T.F. Thorsteinsen, A. Volte, Ph. Leruste, J. P. Davies, J. Bohm, R. Lietava, R. Sené, K.L. Norman, D. Di Bari, F. Pellegrini, Petr Zavada, K. Fanebust, Håvard Helstrup, A. Kirk, A. Jacholkowski, B. De La Cruz, W. Beusch, J.B. Kinson, G. Løvhøiden, B. Ghidini, G. Vassiliadis, J. Kahane, M. Benayoun, F. Navach, A.K. Holme, Alberto Andrighetto, M.F. Votruba, David H. Evans, V. Manzari, R. A. Loconsole, R. Fini, J. C. Lassalle, B. R. French, Ivan Kralik, and P. Sennels

Subjects
Physics, Nuclear and High Energy Physics, Strange quark, High Energy Physics::Phenomenology, Hyperon, General Physics and Astronomy, Elementary particle, Lambda baryon, Xi baryon, Nuclear physics, Baryon, Strange matter, Transverse mass, Nuclear Experiment
Abstract

The WA94 collaboration uses the production of strange and anti-strange particles to investigate the properties of hot hadronic matter created in heavy-ion interactions. Λ,\(\bar \Lambda \), Ξ− and\(\bar \Xi ^ + \) particle yields and transverse mass spectra are presented for pS interactions and are compared with those for SS interactions and for the pW and SW interactions of WA85.

Published
1996
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5. Hyperon production in Pb+Pb collisions at 158 A GeV/c

Author

S. Szafran, Anton Jusko, N. Armenise, Michele Guida, I. Králik, P. Jovanovic, S. Simone, K. Šafařík, Ph. Leruste, H. Helstrup, J. Ftacnik, P. Middelkamp, J. Bán, Paolo Martinengo, E. Nappi, N. Carrer, Leonardo Paolo Rossi, C. Voltolini, Federico Antinori, Håvard Helstrup, Pavel Staroba, Vito Manzari, J.A. Lien, G. Vassiliadis, V. Lenti, K. Fanebust, M. Luptak, G.F. Segato, Eugenio Cantatore, J. Šťastný, K. Knudson, M. Vaníčková, M. A. Mazzoni, S. Di Liberto, L. Lopez, B. Ghidini, A. Singovski, W. Geist, Erik H.M. Heijne, M. Morando, A. Jacholkowski, J.M. Brom, E. Quercigh, R. Blaes, P. Sennels, F. Posa, G. Romano, A. Volte, R. Lietava, R. Sené, B. Pastirčák, A.K. Holme, Alberto Andrighetto, G. Grella, K. Piska, J. L. Narjoux, T.F. Thorsteinsen, E. Andersen, Jean-Charles Fontaine, H. Rotscheidt, F. Navach, M. Dameri, D. Elia, L. Šándor, F. Pellegrini, M. T. Muciaccia, J. P. Davies, O. Villalobos Baillie, R. A. Ricci, David H. Evans, J. C. Lassalle, Petr Zavada, C. Salvo, I. Mácha, Dario Barberis, A. Di Mauro, K.L. Norman, G. Tomasicchio, Giovanni Darbo, V.A. Kachanov, T. Kachelhoffer, E. Chesi, Bianca Osculati, T. Storås, A. Kirk, M. G. Catanesi, B. R. French, M. Sené, B. Sopko, M. Campbell, A. Diaczek, M.E. Michalon-Mentzer, M.F. Votruba, W. Klempt, Franco Meddi, P. Farthouat, J. Bohm, T. Scognetti, J. Urban, H. Beker, J.B. Kinson, M. Venables, Gunnar Løvhøiden, V. Mack, R. A. Fini, A. Michalon, T. Virgili, W. Beusch, D. Huss, M. Benayoun, G. Rosa, and D. Di Bari

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Strange quark, Proton, Hadron, Hyperon, General Physics and Astronomy
Abstract

Preliminary results from WA97 measurements on Λ, Ξ and Ω production in lead-lead and proton-lead collisions are presented, along with a comparison of WA97 proton-lead data with previous WA85 proton-tungsten results. The ratio Ω/Ξ seems to be enhanced in lead initiated reactions compared to proton initiated reactions.

Published
1996
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6. Strangeness production in p+W and S+W Interactions at 200 A GeV/c

Author

David H. Evans, B. R. French, Leonardo Paolo Rossi, T. Storås, R. A. Loconsole, J. C. Lassalle, W. Beusch, Ph. Leruste, M. Benayoun, F. Navach, A. Volte, R. P. Barnes, R. Sené, V. Lenti, J. L. Narjoux, M. Venables, B. Ghidini, K. Knudson, J. N. Carney, V. Manzari, Federico Antinori, R. Fini, A. C. Bayes, E. Quercigh, Håvard Helstrup, B. De La Cruz, G. Vassiliadis, J.A. Lien, A. Jacholkowski, M. Sené, K. Šafařík, S. Abatzis, A. Andrighetto, M.F. Votruba, O. Villalobos-Baillie, J. Kahane, J.B. Kinson, A.K. Holme, D. Evans, D. Di Bari, J. P. Dufey, A. Kirk, D. Elia, and J. P. Davies

Subjects
Nuclear physics, Baryon, Physics, Nuclear and High Energy Physics, High Energy Physics::Phenomenology, Nuclear Theory, Hadron, General Physics and Astronomy, Strangeness production, Transverse mass, Heavy ion, Nuclear Experiment, Spectral line
Abstract

Strange and multistrange baryon and antibaryon production is a useful probe into the dynamics of the hot hadronic matter created in central heavy ion interactions. Relative production yields and transverse mass spectra are presented and compared for pW and SW interactions.

Published
1996
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7. Observation of vertex factorisation breaking in central pp interactions

Author

A.A. Kondashov, Kunio Takamatsu, Hajime Shimizu, S. Maljukov, V.D. Samoylenko, G. Tchlatchidze, David H. Evans, H. Rotscheidt, T. Nakagawa, B.C. Earl, Jean Pierre Peigneux, Yoshiji Yasu, M. Venables, B. R. French, F. Navach, Freddy Binon, V. Manzari, Alexandre A.V. Inyakin, O. Villalobos Baillie, Jean-Pierre Stroot, D. Di Bari, W. Beusch, V. Romanovsky, A. Jacholkowski, J. N. Carney, Sergey Donskov, D. Elia, Masakazu Kobayashi, G. Vassiliadis, G.V. Khaustov, Susumu Inaba, Sergey S.A. Polovnikov, B. Ghidini, Petr P.M. Shagin, A. Solovjev, V.A. Polyakov, R. Sené, Valentine Sugonyaev, A.V. Dolgopolov, D. Barberis, M. Sené, A. V. Shtannikov, Yuri Kulchitsky, A. Kirk, V. A. Lishin, Irakli Minashvili, K.L. Norman, M.F. Votruba, W. Klempt, N.A. Russakovich, J.B. Kinson, Tsuneaki Tsuru, R. A. Loconsole, A. Semenov, V. Lenti, Paolo Martinengo, Yu.D. Prokoshkin, T. Kinashi, R. A. Fini, A.V. Singovsky, and Andrey Lednev

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Factorization, Particle Physics - Experiment, Vertex (geometry)
Abstract

Central \pipi events produced in pp interactions are studied in terms of correlations between the outgoing protons. It is observed there is more $\rho^{0}$(770) and \fmeson production in reactions where the outgoing protons %fastest and slowest particles in the laboratory frame are on opposite sides of the beam. This effect is not attributable to the trigger or the experimental acceptance, and suggests that the vertices do not factorise.

Published
1996
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8. A study of kinematical correlations between charmed particles produced in π-Cu interactions at GeV

Author

J. Batten, N. Hummadi, Leonardo Paolo Rossi, D. Barney, M. Verzocchi, Domizia Orestano, R. Hurst, J.G. McEwen, V. Flaminio, A. Frenkel, M. Adinolfi, P. Nechaeva, A. Forino, Filippo Ceradini, L. Zanello, Dario Barberis, G. Ciapetti, Corrado Angelini, Alessandro Cardini, C. Cianfarani, A. Kirk, Chiara Roda, Yu. Alexandrov, A. Duane, B. R. French, L. Malferrari, Giovanni Darbo, M. I. Adamovich, Stefano Veneziano, Claudio Bruschini, G. Martellotti, Bianca Osculati, H. Rotscheidt, A. Quareni, M. Palutan, Aleandro Nisati, M. Dameri, C. Lazzeroni, M. V. Zavertyaev, D. Websdale, P. Mazzanti, Paolo Martinengo, M. Passaseo, K. Harrison, Ludovico Pontecorvo, Claudia Gemme, and Gianni Penso

Subjects
Physics, Nuclear physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle
Abstract

A sample of 475 events, in which two charmed-particle decays are observed, is analyzed to determine distributions of two-particle kinematic variables. One charmed particle with x F > 0 is fully reconstructed and the other is at least partially recontructed. The distributions of Δo and p T 2 are compared with a next-to-leading order QCD calculation.

Published
1996
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9. Study of charged particle production using Omega RICH in WA94 experiment

Author

B. R. French, W. Beusch, A. Volte, V. Lenti, R. Sené, M. Benayoun, Ivan Kralik, Petr Zavada, R. A. Loconsole, Ph. Leruste, M. Morando, N. Carrer, S. Abatzis, F. Pellegrini, T.F. Thorsteinsen, O. Villalobos Baillie, R. A. Ricci, Federico Antinori, J. L. Narjoux, E. Andersen, V. A. Katchanov, D. Di Bari, A. C. Bayes, J.B. Kinson, B. Ghidini, A. Jacholkowski, M. Sené, Alberto Andrighetto, Vito Manzari, A. Kirk, J. C. Lassalle, R. A. Fini, D. Elia, K. Fanebust, J. Kahane, A. V. Singovsky, David H. Evans, K. Knudson, P. Ladron de Guevara, G.F. Segato, F. Navach, R. P. Barnes, J. N. Carney, E. Quercigh, J. P. Davies, L. Sandor, Roman Lietava, A.K. Holme, J. Bohm, M. Venables, Jozef Urban, K. Šafařík, Håvard Helstrup, B. De La Cruz, G. Vassiliadis, G. Løvhøiden, and M.F. Votruba

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Tracking (particle physics), Omega, Charged particle, Particle identification, Particle detector, Nuclear physics, Particle, High Energy Physics::Experiment, Nuclear Experiment, Nucleon, Charged particle beam, Instrumentation
Abstract

We present preliminary results about charged particle production in SS collisions at 200 GeV/ c per nucleon, obtained by WA94 experiment at CERN-SPS. The particle identification has been provided by the Omega RICH; a silicon telescope and an array of multiwire proportional chambers (MWPC) have been used to track particles to the RICH detector. Details about particle tracking and identification procedure are also reported.

Published
1996
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10. Search for higher twists in meson resonance production in π− N interactions atPT≥2 GeV/c

Author

K. Šafařík, I. J. Bloodworth, A. Jacholkowski, Ph. Leruste, M.F. Votruba, D. Elia, J. Kahane, B. Ghidini, G. Vassiliadis, V. Lenti, F. Navach, M. Benayoun, K. Knudson, A. Kirk, M. Stassinaki, J. N. Carney, E. Quercigh, M. T. Trainor, M. Sené, I. Vichou, A. Malamant, D. Di Bari, R. A. Fini, J. L. Narjoux, B. R. French, J.B. Kinson, R. Zitoun, O. Villalobos Baillie, A. Volte, A. Bellogianni, R. Sené, and Vito Manzari

Subjects
Physics, Particle physics, QCD sum rules, Annihilation, Physics and Astronomy (miscellaneous), Meson, Nuclear Theory, High Energy Physics::Phenomenology, Monte Carlo method, Hadron, Omega, Nuclear physics, Quark–gluon plasma, High Energy Physics::Experiment, Twist, Nuclear Experiment
Abstract

We study the production of meson resonance atpT≥2 GeV/c inπ− Be interactions at two beam energies (150 and 300 GeV/c). The motivation is to look for the higher twist (HT) production mechanism, expected to exist besides standard hadron production through the fragmentation process of scattered quarks and gluons, the so-called leading twist (LT) mechanism. We show that the φ, K*0 (892) andK*0 (892) are found free from HT effects with a good accuracy, as expected from HT estimates and QCD sum rules. The magnitudes of thef2(1270) andρ0 mesons signals are found larger than expected from the standard Lund (LT) Monte Carlo and from information provided bye+e− annihilation experiments. The possible connection of these excesses with HT physics is discussed. We also report the first evidence for the production off0(975) mesons in hadronic experiments at largepT.

Published
1995
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11. Production of strange and multistrange hyperons and antihyperons in S-W interactions at 200 GeV/c per nucleon

Author

Leonardo Paolo Rossi, A. Kirk, D. Di Bari, Håvard Helstrup, B. De La Cruz, A. C. Bayes, A. Jacholkowski, S. Abatzis, R. A. Fini, O. Villalobos Baillie, G. Vassiliadis, Vito Manzari, J. P. Davies, David H. Evans, J. Kahane, V. Lenti, J. L. Narjoux, B. Ghidini, R. P. Barnes, K. Knudson, E. Quercigh, J. N. Carney, K. Šafařík, A. Volte, F. Navach, R. Sené, Federico Antinori, A. Andrighetto, W. Beusch, J.B. Kinson, M. Benayoun, M. Sené, M.F. Votruba, J. P. Dufey, R. A. Loconsole, D. Elia, B. R. French, Ph. Leruste, A.K. Holme, J. C. Lassalle, and T. Storås

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, High Energy Physics::Phenomenology, Nuclear Theory, Hadron, Hyperon, Spectral line, Nuclear physics, Baryon, Transverse mass, High Energy Physics::Experiment, Heavy ion, Nuclear Experiment, Nucleon
Abstract

Strange and multistrange baryon and antibaryon production is a useful probe into the dynamics of the hot hadronic matter created in central heavy ion interactions. Relative production yields and transverse mass spectra are presented for Λ, Λ, Ξ− and Ξ+ hyperons produced in central sulphur-tungsten interactions at 200 GeV/c per nucleon.

Published
1995
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12. A further study of the centrally produced π+π− and π+π−π+π− channels in pp interactions at 300 and 450 GeV/c

Author

Irakli Minashvili, Federico Antinori, A. Jacholkowski, N.A. Russakovich, Y. Kulchitsky, G. Vassiliadis, C. J. Dodenhoff, B. Ghidini, Paolo Martinengo, R. A. Loconsole, R. A. Fini, K.L. Norman, J. P. Davies, D. Barberis, B. R. French, G. Tchlatchidze, M.F. Votruba, V. Lenti, D. Elia, F. Navach, J.B. Kinson, A. Solovjev, O. Villalobos Baillie, A. Kirk, David H. Evans, A. Semenov, E. Quercigh, M. Sené, R. Sené, A. C. Bayes, Vito Manzari, J. N. Carney, W. Beusch, V. Romanovsky, S. Clewer, S. Maljukov, and D. Di Bari

Subjects
Physics, Crystal, Nuclear and High Energy Physics, Mass spectrum, Atomic physics, Central region, Omega, Particle Physics - Experiment
Abstract

An analysis of the centrally produced π + π − and π + π − π + π − mass spectra from the WA76 and WA91 experiments is presented, which shows that in the π + π − π + π − channel there are two new states, the f 0 (1450) and f 2 (1900). There is another new state in the π + π − channel with M = 1497 ± 30 MeV and Γ = 199 ± 30 MeV, which is compatible with the f 0 (1520) observed by the Crystal Barrel experiment. Another interpretation is discussed, where the 1450 and 1497 GeV structures are explained as being due to an interference effect between the f 0 (1365) and f 0 (1520).

Published
1995
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13. Strange particle production in sulphur-sulphur interactions at 200 GeV/c per nucleon

Author

U. Mueller, Håvard Helstrup, B. De La Cruz, G. Vassiliadis, M. Morando, R. A. Loconsole, A.K. Holme, V. Manzari, K. Šafařík, A. V. Singovsky, M. Passaseo, R. Fini, A. Kirk, A. Jacholkowski, J. P. Dufey, J. C. Lassalle, V. A. Katchanov, G. Waelder, Jürgen Engelfried, Ph. Leruste, V. Lenti, K. Knudson, P. Ladron de Guevara, J. N. Carney, D. Elia, Jozef Urban, D. Di Bari, J. Kahane, K. Martens, I. J. Bloodworth, W. Beusch, J. L. Narjoux, A. Michalon, A. Bravar, M. Benayoun, F. Navach, J. Bohm, R. Sené, C. Voltolini, Alberto Andrighetto, G. Løvhøiden, G.F. Segato, E. Quercigh, G. Undheim, A. Volte, S. Abatzis, L. Šándor, F. Pellegrini, R. Blaes, Petr Zavada, B. Ghidini, J.B. Kinson, M. Sené, S. Clewer, David H. Evans, C.J. Dodenhoff, T.F. Thorsteinsen, O. Villalobos Baillie, R. A. Ricci, R. P. Barnes, A. C. Bayes, M.F. Votruba, H. W. Siebert, B. R. French, Federico Antinori, J. P. Davies, Aldo Penzo, T. Kachelhoffer, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), WA94, Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Heyd, Yvette

Subjects
Physics, Nuclear and High Energy Physics, Strange quark, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Plasma formation, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Nuclear Theory, chemistry.chemical_element, 01 natural sciences, Central region, Omega, Sulfur, Baryon, Nuclear physics, chemistry, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Transverse mass, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Multi-strange baryon and anti-baryon production is expected to be a useful probe in the search for Quark-Gluon Plasma formation. We present the transverse mass distributions of negative particles, K o s, Λs, Λ s, and Ξ − s produced in sulphurtungsten interactions at 200 GeV/c per nucleon and give the corrected ratios Λ Λ, Ξ − Λ and Ξ − /Λ . We note that our ratio Ξ − / Λ appears large in comparison to that from p p interactions.

Published
1995
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14. Results on the production of baryons with |S| = 1, 2, 3 and strange mesons in S-W collisions at 200 GeV/c per nucleon

Author

T. Storås, Domenico Di Bari, A. C. Bayes, Federico Antinori, A. Jacholkowski, R. P. Barnes, J. P. Davies, V. Manzari, Leonardo Paolo Rossi, A. Kirk, E. Quercigh, B. R. French, K. Šafařík, A. Volte, R. Sené, O. Villalobos Baillie, J. Kahane, W. Beusch, A.K. Holme, B. Ghidini, A. Andrighetto, M. Benayoun, F. Navach, Håvard Helstrup, B. De La Cruz, J. L. Narjoux, R. Fini, G. Vassiliadis, J.B. Kinson, V. Lenti, K. Knudson, J. N. Carney, J. C. Lassalle, M. Sené, David H. Evans, D. Di Bari, M.F. Votruba, J. P. Dufey, D. Elia, S. Abatzis, and Ph. Leruste

Subjects
Nuclear physics, Baryon, Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Meson, Production (computer science), Rapidity, Strangeness, Nucleon
Abstract

We report results on the production of strange baryons/antibaryons with 1, 2, and 3 units of strangeness (Λ, Ξ and Ω) and mesons (K s 0 , K + and K − ) in WA85 experiment at the CERN SPS. This experiment was designed to study the production of strange particles in central SW collisions at 200 GeV/c per nucleon, in the central rapidity region with medium to high p t . We have measured the inverse slopes of the m t distributions of such particles and the production ratios Λ /Λ, Ξ + /Ξ − , Ξ − / Λ , Ξ + / Λ , K s 0 / Λ , K s 0 / Λ , (Ω − + Ω + ) (Ξ − + Ξ + ) and K + K − . Preliminary results on the production ratios Ξ − / Λ and Ξ + / Λ in pW collisions at 200 GeV/c are also presented.

Published
1995
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15. Results on charmed meson decay from the WA82 experiment at the CERN omega spectrometer

Author

E. Lamanna, R. Hurst, P. Netchaeva, A. Jacholkowski, B. R. French, D. Barberis, A. Kirk, A. Forino, Bianca Osculati, M. Weymann, Patrick Legros, P. Mazzanti, Fernand Grard, Federico Antinori, V. Casanova, M. Davenport, R. Gessaroli, J. C. Lassalle, Leonardo Paolo Rossi, J. P. Dufey, K. Harrison, G. Tomasini, M. V. Zavertyaev, Yu. Alexandrov, W. Beusch, M. I. Adamovich, A. Quareni, Chiara Roda, N. Radaelli, F. Muller, A. Buys, and M. Dameri

Subjects
Physics, Particle physics, Large Hadron Collider, Meson, Spectrometer, Physics::Instrumentation and Detectors, Branching fraction, High Energy Physics::Phenomenology, Omega, Particle identification, Ring-imaging Cherenkov detector, Nuclear physics, High Energy Physics::Experiment, Impact parameter, Nuclear Experiment
Abstract

The WA82 experiment has collected data with the Ω′ spectrometer at the CERN SPS. Its aim was a high-statistics study of charm hadroproduction, using a silicon microstrip vertex detector and a trigger on impact parameter. WA82 is also studying rare decay modes for charm. Latest results on non-leptonic charmed meson decay branching ratios are presented here, including the study of doubly Cabibbo-suppressed modes for D+. This analysis, using the particle identification provided by a Ring Imaging CHerenkov detector (RICH), gives an indication for a new decay mode, D+→K-K+K+. An upper limit for the D+→K+π-π+ mode branching ratio is also obtained.

Published
1994
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16. Study of the vector-vector final states centrally produced in pp interactions at 300 GeV/c

Author

M. Girone, Ph. Leruste, A. Malamant, N. G. Redaelli, I. J. Bloodworth, O. Villalobos Baillie, V. Lenti, M. Benayoun, K. Knudson, Giuseppe Zito, M. Stassinaki, J.B. Kinson, J. N. Carney, A. Jacholkowski, R. Sené, C. Evangelista, B. Ghidini, J. Kahane, F. Navach, T. A. Armstrong, B. R. French, M.F. Votruba, G. Vassiliadis, A. Palano, A. Kirk, M. Sené, Leonardo Paolo Rossi, and J. L. Narjoux

Subjects
Physics, Nuclear physics, Particle physics, Large Hadron Collider, Spectrometer
Abstract

We have performed a search for vector-vector final states centrally produced in the reaction pp→pf(VV)ps at 300 GeV/c using the CERN Ω spectrometer. Evidence is found for ωπ0, ωω, π0π0 and π+π- associated production. No evidence is found for ωϕ production.

Published
1994
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17. First results from experiment WA91 at the CERN omega spectrometer

Author

Irakli Minashvili, G. Vassiliadis, D. Barberis, N.A. Russakovich, A. Solovjev, I. Vichou, A. Jacholkowski, V. Lenti, A. C. Bayes, G. Tchlatchidze, Vito Manzari, W. Beusch, V. Romanovsky, A. Semenov, Maria Girone, M. Sené, B. Ghidini, J.B. Kinson, F. Navach, R. Sené, S. Maljukov, J. N. Carney, A. Loconsole, D. Di Bari, M.F. Votruba, A. Kirk, O. Villalobos Baillie, R. P. Barnes, C. J. Dodenhoff, J. P. Davies, S. Clewer, D. Evans, E. Quercigh, R. A. Fini, Federico Antinori, and B. R. French

Subjects
Physics, Nuclear physics, Particle physics, Large Hadron Collider, Meson, Spectrometer, Omega, Central region, Particle Physics - Experiment, Bar (unit)
Abstract

Experiment WA91 searches for non-\(q\bar q\) mesons produced in the central region in the reaction pp→pf(X0)ps at 450 GeV/c using the CERN Omega Spectrometer. WA91 is a continuation of the WA76 experiment which has studied this reaction using beams of 85 and 300 GeV/c. Preliminary results from experiment WA91 are presented. In particular the X(1450) and X(1900) observed for the first time in the π+π-π+π- channel of the WA76 experiment at 300 GeV/c are confirmed by the WA91 data.

Published
1994
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18. Shape distortions of meson resonances produced in hadron interactions atP T≧2 GeV/c

Author

V. Lenti, R. Zitoun, M.F. Votruba, E. Quercigh, A. Bellogianni, M. Stassinaki, B. R. French, A. Malamant, B. Ghidini, M. T. Trainor, M. Sené, A. Kirk, I. J. Bloodworth, F. Navach, D. Elia, Ph. Leruste, G. Vassiliadis, J. Kahane, R. A. Fini, K. Knudson, J. N. Carney, J. L. Narjoux, Vito Manzari, M. Benayoun, I. Vichou, A. Jacholkowski, D. DiBari, J.B. Kinson, A. Volte, R. Sené, K. Šařík, O. Villalobos Baillie, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Lantz, Simone

Subjects
Physics, Particle physics, Large Hadron Collider, Physics and Astronomy (miscellaneous), Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Hadron, 01 natural sciences, Omega, Spectral line, [PHYS.HPHE] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Nuclear physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Quark–gluon plasma, Damping factor, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment, 010306 general physics, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

We study the shape of the invariant mass spectra of several resonances produced atPT≧2.0 GeV/c and observed through two-particle final states, namely thef2(1270),K*(892),\(\bar K*(892)\),K*(1430), and\(\bar K*(1430)\) mesons. The data sample comes from π− Be interactions atPlab=150 GeV/c and 300 GeV/c which have been collected using the OMEGA spectrometer at CERN. We find that although these meson resonances have their masses and widths consistent with the corresponding world average values, their shapes are all subject to the same kind of distortion: their low-mass tail is enhanced while their high-mass tail is sharply cut. This observation indicates that meson resonances produced in the fragmentation of quarks and gluons are distorted by the same damping factor in a way which preserves their masses and lifetimes.

Published
1994
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19. Study of Φ and f2(1270) meson polarization atp T ≥2 GeV/c in π- interactions at CERN SPS

Author

Z. Krumstein, J. L. Narjoux, J. Kahane, M. T. Trainor, M. Sené, V. Lenti, E. Quercigh, G. Vassiliadis, A. Volte, M. Stassinaki, A. Kirk, D. Di Bari, R. Sené, Z. Zitoun, A. Malamant, B. Ghidini, R. A. Fini, A. Jacholkowski, K. Knudson, J. N. Carney, F. Navach, M. Benayoun, Vito Manzari, K. Satarik, Yu.P. Merekov, A. Belogianni, O. Villalobos Baillie, Ph. Leruste, I. Vichou, J.B. Kinson, B. R. French, D. Elia, M.F. Votruba, and I. J. Bloodworth

Subjects
Physics, Particle physics, Large Hadron Collider, Physics and Astronomy (miscellaneous), Meson, 010308 nuclear & particles physics, Parton, Polarization (waves), 01 natural sciences, Charged particle, Nuclear physics, Fragmentation (mass spectrometry), 0103 physical sciences, Transverse momentum, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Engineering (miscellaneous)
Abstract

We present the analysis of data samples taken by the WA77 experiment for π- interactions at 300 and 150 GeV/c. The trigger selects a pair of oppositely charged particles withp T ≥2 GeV/c balancing the transverse momentum of a third high-p T track. The primary aim of this experiment was the search for higher-twist production, mainly that of vector mesons. Since there are definite predictions for the polarization of mesons produced in fragmentation and through the higher-twist mechanism, we study the polarization properties of clearly identified mesons, namely the Φ and f2(1270) mesons. The results are compatible with no polarization. This can be interpreted as a production dominantly due to parton fragmentation.

Published
1994
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20. Ω− signal in WA85

Author

J. P. Dufey, O. Villalobos Baillie, K. Knudson, J. N. Carney, D. Elia, Maria Girone, Leonardo Paolo Rossi, M.F. Votruba, B. De La Cruz, A. Jacholkowski, V. Lenti, S. Abatzis, A. Volte, Haavard Helstrup, J. Kahane, A. Kirk, W. Beusch, A. C. Bayes, R. Sené, A.K. Holme, B. Ghidini, M. Benayoun, Vito Manzari, R. P. Barnes, Ph Leruste, F. Navach, A. Bravar, K. Šafařík, Alberto Andrighetto, M. Sene, Federico Antinori, J. C. Lassalle, J.B. Kinson, A. Penzo, D. Di Bari, D. Evans, B. R. French, E. Quercigh, J. L. Narjoux, R. A. Fini, J. P. Davies, and G. Vassiliadis

Subjects
Physics, Nuclear and High Energy Physics, Particle decay, Branching fraction, Hadron, Analytical chemistry, Mass spectrum, Rapidity, Lambda baryon, Omega baryon, Xi baryon
Abstract

We have extracted from the full WA85 1990 data set a sample of 14ω − + ω − candidates. We describe the selection criteria, and give a measurement of the ω − /ω − ratio at central rapidity and PT > 1.6 GeV/c.

Published
1994
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21. Strange particle production in sulphur-sulphur interactions at 200 per nucleon

Author

C.J. Dodenhoff, J. C. Lassalle, S. Abatzis, V. Lenti, K. Martens, A. C. Bayes, Vito Manzari, G.F. Segato, F. Pellegrini, K. Šafařík, E. Quercigh, B. R. French, R. P. Barnes, A. Kirk, J.B. Kinson, A. V. Singovsky, M.F. Votruba, A. Volte, A.K. Holme, M. Passaseo, C. Voltolini, R. Sené, Aldo Penzo, R. A. Fini, Alberto Andrighetto, A. Michalon, O. Villalobos Baillie, R. A. Ricci, H. W. Siebert, G. Undheim, T.F. Thorsteinsen, L. Sandor, A. Jacholkowski, U. Mueller, Federico Antinori, Haavard Helstrup, R. Blaes, Petr Zavada, B. De La Cruz, S. Clewer, J. P. Dufey, D. Di Bari, D. Elia, I. J. Bloodworth, R. A. Loconsole, V. A. Katchanov, A. Bravar, J-L. Narjoux, David H. Evans, M. Morando, J. Kahane, G. Waelder, G. Vassiliadis, Gunnar Løvhøiden, Jürgen Engelfried, M. Sené, K. Knudson, P. Ladron de Guevara, J. N. Carney, J. Urban, J. Bohm, W. Beusch, M. Benayoun, B. Ghidini, F. Navach, Ph Leruste, J. P. Davies, and T. Kachelhoffer

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Strange quark, chemistry, chemistry.chemical_element, Nucleon, Sulfur
Published
1994
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22. New results from WA85 on multistrange hyperon production in 200 A S-W interactions

Author

Maria Girone, V. Lenti, Federico Antinori, D. Evans, J. P. Dufey, D. Elia, R. P. Barnes, D. Di Bari, W. Beusch, G. Vassiliadis, M. Benayoun, J. P. Davies, A. Volte, B. Ghidini, S. Abatzis, Haavard Helstrup, A.K. Holme, R. A. Fini, A. Bravar, B. de la Cruzy, Alberto Andrighetto, R. Sené, F. Navach, J. Kahane, M. Sene, A. C. Bayes, A. Kirk, E. Quercigh, J. C. Lassalle, Vito Manzari, A. Jacholkowski, B. R. French, M.F. Votruba, Leonardo Paolo Rossi, Karel Safarik, J.B. Kinson, A. Penzo, J. L. Narjoux, O. Villalobos Baillie, K. Knudson, Ph Leruste, and J. N. Carney

Subjects
Physics, Nuclear and High Energy Physics, Particle decay, Particle physics, Meson, Hadron, Hyperon, Lambda baryon, Omega baryon, Xi baryon, Boson
Published
1994
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23. Study of the centrally produced ωρ0 and ωω systems inpp interactions at 300 GeV/c

Author

Leonardo Paolo Rossi, C. Evangelista, B. Ghidini, J. Kahane, J. L. Narjoux, V. Lenti, G. Vassiliadis, M. Sené, F. Navach, A. Palano, M. Stassinaki, K. Knudson, J. N. Carney, O. Villalobos Baillie, J.B. Kinson, T. A. Armstrong, M. Benayoun, A. Kirk, A. Jacholkowski, R. Sené, A. Malamant, Giuseppe Zito, B. R. French, N. G. Redaelli, Maria Girone, M.F. Votruba, I. J. Bloodworth, and Ph. Leruste

Subjects
Nuclear physics, Physics, Particle acceleration, Large Hadron Collider, Physics and Astronomy (miscellaneous), Proton, Spectrometer, Elementary particle, Field theory (psychology), Quantum field theory, Engineering (miscellaneous)
Abstract

We have performed a search for vector-vector final states centrally produced in proton proton interactions at 300 GeV/c using the CERN Ω spectrometer. Evidence is found for ωρ0 production in the reactionpp→p f (2π+2π−2π0)p s and for ωω production in the reactionpp→p f (2π+2π−2π0)p s . However no evidence is found for ωo production in the reactionpp→p f (K + K −π+π−π0)p s .

Published
1993
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24. Transverse momentum distributions for meson resonances at central rapidity andP T≧2 GeV/c

Author

A. Kirk, G. Vassiliadis, J. Kahane, V. Lenti, E. Quercigh, M.F. Votruba, K. Knudson, I. J. Bloodworth, J. N. Carney, B. R. French, K. Šafařík, C. Evangelista, B. Ghidini, F. Navach, I. Vichou, Ph. Leruste, A. Malamant, R. A. Fini, A. Belogianni, W. Beusch, J. L. Narjoux, A. Jacholkowski, M. Benayoun, M. T. Trainor, M. Sené, D. Di Bari, R. Zitoun, R. Sené, J.B. Kinson, Vito Manzari, O. Villalobos Baillie, and M. Stassinaki-Spyropoulou

Subjects
Physics, Nuclear reaction, Particle physics, Physics and Astronomy (miscellaneous), Meson, Hadron, Quarkonium, Nuclear physics, Particle decay, Pair production, Pion, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

The transverse momentum distributions for\(\rho ^0 (770),f_2 (1270),K*^0 (892),\bar K*^0 (892)\) and ϕ (1020) have been studied in thept region between 2 and 4 GeV/c and central rapidity. The data analysed come from the WA77 experiment at CERN with a 300 GeV/c π− beam incident on a Be target. These distributions are well described by the functionpt−n withn∼8. A sample of simulated events from the Lund Monte Carlo in the same experimental conditions reproduces well the data.

Published
1993
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25. Study of theπ + π − γ system centrally produced in the reactionpp→p f (π + π − γ)p s at 300 GeV/c

Author

A. Kirk, O. Villalobos Baillie, G. Vassiliadis, K. Knudson, D. Evans, J. N. Carney, Maria Girone, B. R. French, R. Sené, E. Quercigh, T. A. Armstrong, A. Palano, M. Sené, C. J. Dodenhoff, D. DiBari, J.B. Kinson, I. J. Bloodworth, V. Lenti, R. P. Barnes, W. Beusch, M. Benayoun, A. Jacholkowski, M.F. Votruba, C. Evangelista, B. Ghidini, F. Navach, and Vito Manzari

Subjects
Physics, Physics and Astronomy (miscellaneous), Branching fraction, Mass spectrum, Atomic physics, Engineering (miscellaneous)
Abstract

The reactionpp→pf(π+π−γ)ps, where theπ+π−γ system is centrally produced, has been studied at 300 GeV/c. Theπ+π−γ mass spectrum shows evidence for aρ0γ decay mode of theη′ (958) andf1 (1285). The branching ratio (f1(1285)→ηπ+π+)/(f1(1285)→ρ0γ) is found to be 5.0±0.7. No evidence is found for aρ0(770)γ decay mode of theE/f1 (1420) for which an upper limit BR (E/f1(1420)→ρ0γ)

Published
1992
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26. Results on charm physics from WA82

Author

N. G. Redaelli, A. Brunengo, G. Tomasini, V. Casanova, M. Davenport, A. Jacholkowski, R. Gessaroli, W. Beusch, S. Gerasimov, R. Hurst, Patrick Legros, Leonardo Paolo Rossi, P. Nechaeva, P. Mazzanti, Fernand Grard, A. Kirk, Bianca Osculati, D. Barberis, F. Muller, J. C. Lassalle, M. Demeri, J. P. Dufey, Yu. Alexandrov, Federico Antinori, B. R. French, P. Viaggi, M. I. Adamovich, A. Quareni, A. Forino, S. P. Kharlamov, A. Buys, and M. V. Zavertyaev

Subjects
Mass number, Scattering cross-section, Physics, Semileptonic decay, Nuclear and High Energy Physics, Particle physics, Meson, Proton, Nuclear Theory, High Energy Physics::Phenomenology, Measure (physics), Atomic and Molecular Physics, and Optics, Nuclear physics, Physics::Accelerator Physics, High Energy Physics::Experiment, Charm (quantum number), Nuclear Experiment, Beam (structure)
Abstract

Experiment WA82 studies the hadroproduction of charmed mesons with a 340 GeV/c pion beam and a 370 GeV/c proton beam. The high and clean statistics of collected charms has been used to measure the differential cross section and its dependence on target nucleon number. The analysis of semileptonic decay D→K ∗ eν is presented.

Published
1992
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27. Measurement of relative branching fractions of D° Cabibbo-suppressed decays

Author

B. R. French, Federico Antinori, M. V. Zavertyaev, W. Beusch, S. Gerasimov, P. Nechaeva, F. Viaggi, R. Gessaroli, M. Davenport, A. Forino, F. Muller, A. Jacholkowski, M. I. Adamovich, M. Dameri, A. Kirk, J. C. Lassalle, Leonardo Paolo Rossi, A. Quareni, D. Barberis, Fernand Grard, P. Mazzanti, J. P. Dufey, Patrick Legros, R. Hurst, N. Redaelli, Yu. Alexandrov, Chiara Meroni, Bianca Osculati, G. Tomasini, A. Buys, and D. Torretta

Subjects
Physics, Nuclear and High Energy Physics, Quantum electrodynamics, Analytical chemistry, Branching (polymer chemistry), Omega
Abstract

The decay modes D0→K−π+, K−K+, π−π+, K−π−π+π+ and π−π−π+π+ have been studied by the hadroproduction experiment WA82. The following ratios of branching fractions have been measured: B(D0→K−K+)B(D0→π−π+)=2.23±0.81±0.46, B(D0→K−K+)B(D0→K−π+)=0.107±0.029±0.015, B(D0→π−π+)B(D0→K−π+)=0.048±0.013±0.008, B(D0→π−π−π+π+)B(D0→K−π−π−π+π+)=0.115±0.023±0.016.

Published
1992
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28. production in sulphur-tungsten interactions at 200 GeV/c per nucleon

Author

S. Abatzis, M.F. Votruba, K. Šafařík, A. Bravar, V. Lenti, K. Knudson, J. N. Carney, J. Kahane, I. J. Bloodworth, Federico Antinori, M. Tamazouzt, M. T. Trainor, V. Manzari, R. Fini, J.B. Kinson, A. Penzo, R. P. Barnes, M. Sené, A. Palano, J. C. Lassalle, A. Jacholkowski, A. Volte, B. De La Cruz, G. Vassiliadis, R. Sené, A. Kirk, J. P. Dufey, R. A. Loconsole, L. Lima Frances, O. Villalobos Baillie, Ph. Leruste, B. R. French, M. Girone, Leonardo Paolo Rossi, A.K. Holme, J. L. Narjoux, Haavard Helstrup, B. Ghidini, David H. Evans, W. Beusch, M. Benayoun, F. Navach, E. Quercigh, A. Malamant, and D. Di Bari

Subjects
Physics, Nuclear and High Energy Physics, Plasma formation, Nuclear Theory, chemistry.chemical_element, Tungsten, Omega, Sulfur, Baryon, Nuclear physics, chemistry, Quark–gluon plasma, Transverse mass, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Nucleon
Abstract

Multi-strange baryon and antibaryon production is expected to be a useful probe in the search for quark-gluon plasma formation. We present the transverse mass distributions of negative particles, Λ' s , Λ ' s and Ξ − ' s produced in sulphur-tungsten interactions at 200 GeV/c per nucleon and give the corrected rations Λ /Λ, Ξ − /Λ and Ξ − / Λ . Our ratio Ξ − / Λ appears to be larger than that from pp interactions.

Published
1991
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29. A microstrip vertex detector for studying charm hadroproduction

Author

J. C. Lassalle, Leonardo Paolo Rossi, A. Jacholkowski, J. P. Dufey, B. R. French, F. Viaggi, D. Barberis, Chiara Meroni, Paolo Martinengo, E. Torassa, Pierre Jarron, Patrick Legros, Federico Antinori, R. Hurst, Erik H.M. Heijne, S. Gerasimov, M. Davenport, R. Gessaroli, Bianca Osculati, F. Bourgeois, P. Mazzanti, Fernand Grard, A. Buys, A. Kirk, A. Forino, L. Malferrari, M. I. Adamovich, G. Tomasini, A. Quareni, Yu. Alexandrov, M. V. Zavertyaev, F. Muller, W. Beusch, M. Dameri, and N. Redaelli

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Hadron, Microstrip, Magnetic field, Vertex (geometry), law.invention, Nuclear physics, Telescope, Transverse plane, law, High Energy Physics::Experiment, Impact parameter, Nuclear Experiment, Instrumentation
Abstract

The WA82 experiment has collected data at the Ω facility at CERN for the study of charmed particles produced in hadronic interactions. In order to select charmed particles in the much larger background of ordinary hadronic interactions precise reconstruction of tracks in high-multiplicity events is necessary. The required accuracy, 10 μm in the transverse plane, has been obtained with a telescope made of 23 silicon microstrip detectors, with pitch ranging from 10 to 50 μm. This telescope has been operated in a 1.3 T magnetic field and has been specially designed to select on-line events with secondary vertices. The trigger, based on the measurement of the impact parameter of a track relative to the primary vertex, enriched the charm sample by a factor 15.

Published
1991
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30. Study of the centrally producer ?? andK $$\bar K$$ systems at 85 and 300 GeV/c

Author

W. Beusch, M. Benayoun, R. Childs, A. Malamant, A. Jacholkowski, Ph. Leruste, K. Knudson, J.B. Kinson, B. R. French, J. N. Carney, M.F. Votruba, J. Kahane, C. Evangelista, B. Ghidini, V. Lenti, N. G. Redaelli, A. Palano, Maria Girone, A. Kirk, Leonardo Paolo Rossi, E. Quercigh, M. Stassinaki, F. Navach, T. A. Armstrong, R. Sené, I. J. Bloodworth, J. L. Narjoux, O. Villalobos Baillie, G. Vassiliadis, M. T. Trainor, and M. Sené

Subjects
Particle acceleration, Physics, Nuclear physics, Formalism (philosophy of mathematics), Large Hadron Collider, Physics and Astronomy (miscellaneous), Spectrometer, Mass spectrum, Elementary particle, Quantum field theory, Atomic physics, Engineering (miscellaneous)
Abstract

We have studied the ππ andK\(\bar K\) systems centrally produced in proton proton collisions at 300 GeV/c and π+/p proton collisions at 85 GeV/c using the CERN Ω spectrometer. Clear evidence forS*/fo(975) production is observed. An analysis performed on the π+ π− mass spectrum in the 1.0 GeV region, using a coupled channel formalism, shows that it is possible to describe theS*/fo(975) effect with one single resonance once interference of theS*/fo(975) with theS-wave background is introduced. The resultingS*/fo(975) parameters aremo=979±4MeV,gπ=0.28±0.04,gK=0.56±0.18 corresponding to a pole position on sheet II at (1001±2)−i(36±4) MeV. Evidence is also found for a structure having a mass of 1472±12 MeV and a width of 195±33 MeV.

Published
1991
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31. Study of the ηπ+π− system centrally producedin the reactionpp→p f (ηπ+π−)p s at 300 GeV/c

Author

W. Beusch, M. Benayoun, I. J. Bloodworth, K. Knudson, M.F. Votruba, J. N. Carney, A. Palano, A. Jacholkowski, David H. Evans, V. Lenti, A. Kirk, D. DiBari, G. Vassiliadis, Maria Girone, O. Villalobos Baillie, T. A. Armstrong, C. J. Dodenhoff, J.B. Kinson, Vito Manzari, E. Quercigh, C. Evangelista, B. Ghidini, B. R. French, M. Sené, F. Navach, R. Sené, and R. P. Barnes

Subjects
Momentum, Pseudoscalar, Nuclear physics, Particle acceleration, Physics, Physics and Astronomy (miscellaneous), Spectrometer, Meson, Mass spectrum, Elementary particle, Engineering (miscellaneous), Omega
Abstract

The reactionpp→pf(ηπ+π−)ps where the ηπ+π− system is centrally produced has been studied at 300 GeV/c incident momentum at the CERN Ω spectrometer. The ηπ± mass spectrum shows a strong δ/a0(980) signal having a mass of 984±4 and Γ=95±14 MeV. The ηπ+π− mass spectrum shows η′ andf1(1285) signals over little background. A spin-parity analysis of the ηπ+π− system shows evidence for aJPC=1++ peak at thef1(1285) mass but no evidence for the pseudoscalar states η(1270) andl/η(1440). No evidence is found for the ηππ decay of theE/f1(1420) meson for which we set an upper limit BR(E/f1(1420)→ηππ)

Published
1991
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32. Λ and anti-Λ production in 32S + W and p + W interactions at 200 A GeV/c

Author

R. Zitoun, V. Lenti, K. Knudson, J. N. Carney, M. T. Trainer, B. R. French, David H. Evans, I. J. Bloodworth, K. Manzari, A. Malamant, B. Ghidini, A. Jacholkowski, E. Quercigh, S. Abatzis, R. A. Loconsole, A. Bravar, W. Beusch, R. P. Barnes, Ph. Leruste, A. Volte, M. Benayoun, F. Navach, R. Sené, J. Kahane, A. Kirk, R. Fini, J. C. Lassalle, O. Villalobos Baillie, M. Tamazouzt, L. Lima Frances, J.B. Kinson, A. Penzo, J. P. Dufey, A. Palano, M. Stassinaki, M. Sené, M.F. Votruba, Leonardo Paolo Rossi, J. L. Narjoux, and G. Vassiliadis

Subjects
Nuclear reaction, Nuclear physics, Physics, Nuclear and High Energy Physics, Particle decay, Meson, Hadron, Hyperon, Nucleon, Lambda baryon, Boson
Published
1991
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33. Preliminary results on direct soft photon production in π−p interactions at 280 GeV/c

Author

M. Grabowski, G.W. Wilson, A. Weigend, P. Sonderegger, K. Knudson, U. Kerres, J.A.G. Morris, Irene Vichou, A. Belogianni, B. R. French, G. Vassiliadis, E. Quercigh, A. Subramanian, W. Beusch, Yves Goldschmidt-Clermont, M. Spyropoulou-Stassinaki, Sw. Banerjee, T.J. Brodbeck, Dario Barberis, and S. Abatzis

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Soft photon
Published
1991
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34. Multi-strange baryon and antibaryon production in sulphur-tungsten and proton-tungsten interactions at 200 GeV/c per nucleon

Author

E. Quercigh, S. Abatzis, M. Sene, R. P. Barnes, B. Ghidini, F. Navach, J. P. Dufey, R. A. Fini, A. Palano, I. J. Bloodworth, O. Villalobos Baillie, A. Malamant, R. Falcone, M. T. Trainor, A. Volte, A. Bravar, J. Kahane, A. Kirk, Vito Manzari, G. Vassiliadis, R. Sené, W. Beusch, M.F. Votruba, B. R. French, M. Tamazouzt, R. A. Loconsole, Ph Leruste, J.B. Kinson, A. Penzo, M. Benayoun, K. Knudson, J. N. Carney, Leonardo Paolo Rossi, J. L. Narjoux, V. Lenti, M. Stassinaki, A. Jacholkowski, J. C. Lassalle, L. Lima Frances, and D. Evans

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, High Energy Physics::Phenomenology, Nuclear Theory, Hadron, Hyperon, Lambda baryon, Xi baryon, Nuclear physics, Baryon, Strange matter, Nuclear Experiment, Nucleon
Abstract

Production of multi-strange baryons and antibaryons is expected to be a useful indicator in the search for Quark-Gluon Plasma formation. Production of Ξ− and Ξ − has been observed for the first time in ultra-relativistic heavy ion interactions by the WA85 Experiment. We describe the procedure used to select these cascade candidates and show that Ξ− and Ξ − decays can be identified. Preliminary ratios of Ξ/Ξ production in sulphur-tungsten and proton-tungsten interactions are also presented.

Published
1991
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35. A study of the centrally producedK *0 $$K^{*0} \bar K^{*0} $$ final state in the reactionpp→p f (K + K -π+π-)p s at 300 GeV/c

Author

V. Lenti, O. Villalobos Baillie, G. Vassiliadis, I. J. Bloodworth, M. Stassinaki, B. R. French, R. Childs, B. Ghidini, M. T. Trainor, F. Navach, M.F. Votruba, J.B. Kinson, E. Quercigh, J. Kahane, A. Jacholkowski, T. A. Armstrong, R. Sené, A. Palano, W. Beusch, M. Benayoun, K. Knudson, Leonardo Paolo Rossi, J. N. Carney, J. L. Narjoux, M. Sené, Ph. Leruste, A. Kirk, R. Zitoun, N. G. Redaelli, Giuseppe Zito, and A. Malamant

Subjects
Particle acceleration, Physics, Physics and Astronomy (miscellaneous), Production (computer science), Field theory (psychology), Elementary particle, State (functional analysis), Quantum field theory, Atomic physics, Engineering (miscellaneous), Bar (unit)
Abstract

The reactionpp→pf(K+K-π+π-)ps, where theK+K− π+π- system is centrally produced, has been studied at 300 GeV/c. TheK*0\(K^{*0} \bar K^{*0} \) final state has been observed and the cross sections for its central production are found to be the same at 300 and 85 GeV/c. TheK*0\(K^{*0} \bar K^{*0} \) final state appears to be produced as a non-resonant threshold enhancement.

Published
1990
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36. A search for non-q mesons in the central region

Author

A. Malamant, I. J. Bloodworth, A. Palano, C. Evangelista, B. Ghidini, T. A. Armstrong, V. Lenti, G. Vassiliadis, F. Navach, E. Quercigh, Leonardo Paolo Rossi, A. Kirk, W. Beusch, B. R. French, R. Childs, K. Knudson, J. N. Carney, M.F. Votruba, M. Stassinaki, A. Jacholkowski, J. L. Narjoux, Ph. Leruste, M. T. Trainor, N. G. Redaelli, Maria Girone, M. Sené, J. Kahane, J.B. Kinson, O. Villalobos Baillie, R. Sené, and M. Benayoun

Subjects
Physics, Nuclear physics, Momentum, Nuclear and High Energy Physics, Particle physics, Meson, State (functional analysis), Central region, Atomic and Molecular Physics, and Optics
Abstract

The aim of this experiment is to search for non-qq mesons in the reaction pp→pf(XO)ps at 300 GeV/c incident momentum, where the XO system is a centrally produced meson. The θ/f2(1720), E/f1(1420) and a new state in the 2π+2π− channel are presented as candidate non-qq mesons.

Published
1990
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37. Strangeness production in sulphur-tungsten interactions at 200 GeV/c per nucleon

Author

J. L. Narjoux, Michele Arturo Caponero, G. Vassiliadis, R. Zitoun, A. Volte, R. Fini, M.F. Votruba, A. Malamant, J. C. Lassalle, R. Sené, B. R. French, A. Kirk, D. Evans, J.B. Kinson, A. Penzo, W. Beusch, M. Benayoun, F. Navach, V. Lenti, K. Knudson, R. Falcone, M. Sené, J. Kahane, M. Stassinaki, B. Ghidini, I. J. Bloodworth, A. Bravar, E. Quercigh, J. N. Carney, A. Jacholkowski, M. T. Trainor, J. P. Dufey, A. Palano, R. A. Loconsole, Ph. Leruste, S. Abatzis, O. Villalobos Baillie, and Leonardo Paolo Rossi

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, Hadron, Strangeness production, Strangeness, Lambda baryon, Atomic and Molecular Physics, and Optics, Charged particle, Nuclear physics, Baryon, High Energy Physics::Experiment, Nuclear Experiment, Nucleon, Particle Physics - Experiment
Abstract

Preliminary results from the WA85 Experiment at the CERN Omega Spectrometer are presented. A 200 A GeV/c beam of 22S ions was used with a tungsten target. The apparatus is used to detect V°s and charged tracks in the range PT > 0.9 GeV/c and 2.3 Λ, Λ and cascade particles is discussed. A study of the multiplicity dependence of Λ, Λ and hadron production is presented.

Published
1990
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38. Λ and production in sulphur-tungsten interactions at 200 GeV/c per nucleon

Author

W. Beusch, M. Benayoun, F. Navach, M. Stassinaki, A. Volte, R. Sené, E. Quercigh, R. Zitoun, J. Kahane, Leonardo Paolo Rossi, David H. Evans, Michele Arturo Caponero, B. Ghidini, A. Bravar, A. Malamant, R. Fini, A. Jacholkowski, J. L. Narjoux, M. T. Trainor, R. A. Loconsole, B. R. French, A. Kirk, Ph. Leruste, M.F. Votruba, J. C. Lassalle, I. J. Bloodworth, J. P. Dufey, M. Tamazouzt, A. Palano, M. Sené, S. Abatzis, V. Lenti, K. Knudson, J. N. Carney, J.B. Kinson, A. Penzo, L. Lima Frances, G. Vassiliadis, O. Villalobos Baillie, and R. P. Barnes

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Meson, Hadron, Lambda baryon, Charged particle, Nuclear physics, Antimatter, High Energy Physics::Experiment, Rapidity, Atomic physics, Nuclear Experiment, Nucleon
Abstract

Results from the WA85 Experiment at the CERN Ω Spectrometer are presented. A 200 A GeV/ c beam of 32 S ions was used with a tungsten target. The apparatus is used to detect V 0, s and charged tracks in the range p T > 0.9 GeV/ c and 2.3 Y lab Λ and negative hadrons all show a linear increase with rapidity density in the range 70–140 as expected from models based on a superposition of independent NN collisions.

Published
1990
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39. A study of the centrally produced ?+???0 system formed in the reactionpp?p f (?+???0)p s at 300 GeV/c

Author

R. Childs, M.F. Votruba, E. Quercigh, O. Villalobos Baillie, N. G. Redaelli, Maria Girone, W. Beusch, Leonardo Paolo Rossi, M. Benayoun, J. Kahane, I. J. Bloodworth, V. Lenti, A. Kirk, A. Jacholkowski, Ph. Leruste, J.B. Kinson, M. T. Trainor, J. L. Narjoux, A. Palano, M. Stassinaki, B. R. French, C. Evangelista, B. Ghidini, R. Sené, G. Vassiliadis, K. Knudson, J. N. Carney, M. Sené, A. Malamant, F. Navach, and T. A. Armstrong

Subjects
Nuclear physics, Physics, Particle acceleration, Physics and Astronomy (miscellaneous), S-wave, Mass spectrum, Dalitz plot, Field theory (psychology), Elementary particle, Atomic physics, Quantum field theory, Engineering (miscellaneous)
Abstract

The reactionpp→p f (π+π−π0)p s , where the π+π−π0 system is centrally produced, has been studied at 300 GeV/c. The π+π−π0 mass spectrum shows evidence for the η, ω anda 2 (1320) as well as an enhancement in thea 1 (1260) region. A Dalitz plot analysis of the π+π−π0 system has been performed. Thea 1 (1260) parameters coming from the fit of the 1+ S wave arem=1208±15 MeV and Γ=430±50 MeV. No evidence is found for theh 1(1170) orh 1(1380).

Published
1990
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40. Results on a 10 micron pitch detector with individual strip readout

Author

W. Beusch, Bianca Osculati, A. Forino, Pierre Jarron, F. Muller, D. Barberis, A. Jacholkowski, B. R. French, C. Meroni, Federico Antinori, Patrick Legros, Erik H.M. Heijne, J. P. Dufey, A. Olcese, M. Dameri, D. Torretta, D. Marioli, L. Rossi, and N. Redaelli

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Analogue electronics, Spectrometer, Physics::Instrumentation and Detectors, Preamplifier, business.industry, Detector, Integrated circuit, Multiplexer, Particle detector, law.invention, Semiconductor detector, law, Optoelectronics, High Energy Physics::Experiment, business, Instrumentation
Abstract

A 10 μm pitch silicon microstrip detector with individual strip readout via hybrid electronics has been produced and operated. Connections to digital and analog electronics is realized through an insensitive fan-out structure on the detector itself. The detector has been used in the WA82 experiment at the CERN Ω′ spectrometer.

Published
1990
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41. A highly integrated trigger and readout system for a silicon mu strip detector installed at the Omega spectrometer at CERN

Author

G. Darbo, B. R. French, Christian Enz, G. Schuler, P. Farthouat, Francois Krummenacher, L. Rossi, L. Malferrari, M. Weymann, A. Beer, Paolo Martinengo, A. Corre, C. Salvo, and V. Ryzhov

Subjects
Physics, Large Hadron Collider, Spectrometer, Silicon, Physics::Instrumentation and Detectors, business.industry, Detector, Electrical engineering, chemistry.chemical_element, Integrated circuit, Omega, law.invention, chemistry, law, Nuclear electronics, Electronics, business
Abstract

The readout electronics of a silicon microstrip vertex detector aimed at finding secondary vertices for beauty identification is described. High density and high speed have been achieved, allowing the detector to take part in the trigger. Despite the large number of channels and thanks to the use of application-specific integrated circuits (ASICs), the amount of electronics needed for the readout is rather small, increasing the level of confidence and simplifying the maintenance and the cabling of the system. The use of computer-aided engineering tools allowed a very fast design (1.5 year), which was reliable and well documented. >

Published
2002
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42. Measurement of the Ds→μνμ branching fraction and of the Ds decay constant

Author

K. Harrison, L. Malferrari, C. Lazzeroni, P. Netchaeva, Filippo Ceradini, H. Rotscheidt, Leonardo Paolo Rossi, Yu. Alexandrov, Corrado Angelini, P. Mazzanti, M. V. Zavertyaev, Giovanni Darbo, Dario Barberis, C. Gemme, A. Duane, D. Websdale, Bianca Osculati, G. Martellotti, M. Dameri, Domizia Orestano, B. R. French, V. Flaminio, Gianni Penso, R. Hurst, Alexandrov, Y, Angelini, C, Barberis, D, Ceradini, Filippo, Dameri, M, Darbo, G, Duane, A, Flaminio, V, French, Br, Gemme, C, Harrison, K, Hurst, R, Lazzeroni, C, Malferrari, L, Martellotti, G, Mazzanti, P, Netchaeva, P, Orestano, Domizia, Osculati, B, Penso, G, Rossi, L, Rotscheidt, H, Websdale, D, and Zavertyaev, M.

Subjects
Physics, Nuclear and High Energy Physics, chemistry, Branching fraction, chemistry.chemical_element, Value (computer science), Atomic physics, Tungsten, Exponential decay, Omega, Copper
Abstract

Using interactions of 350 GeV/c pi(-) in copper and tungsten targets, the branching fraction for the leptonic decay B(D-s --> mu v(mu)) is measured to he (0.83 +/- 0.23(stat.)+/- 0.06 +/- 0.18(B(Ds --> phi pi)))%. The resulting value for the D-s decay constant is f(D,) = 323 +/- 44 +/- 12 +/- 34. (C) 2000 Elsevier Science B.V. All rights reserved.

Published
2000

43. A study of the $\eta\eta$ channel produced in central pp interactions at 450 GeV/c

Author

David H. Evans, V. Romanovsky, B. R. French, S. Inaba, Freddy Binon, B.C. Earl, F.E. Close, A. Semenov, T. Jacobsen, A. Sobol, T. Tsuru, D. Barberis, T. Hino, Jean-Pierre Stroot, Petr P.M. Shagin, A. Jacholkowski, Irakli Minashvili, A.A. Lednev, Yoshiji Yasu, K. M. Danielsen, A. Kirk, O. Villalobos Baillie, G.V. Khaustov, A. A. Kondashov, Jean Pierre Peigneux, H. M. Shimizu, J.B. Kinson, K. Takamatsu, M.F. Votruba, V. Lenti, Sergey Donskov, M. Stassinaki, N. Russakovich, A.V. Singovsky, 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), WA102, and BOMBAR, Claudine

Subjects
Physics, Nuclear and High Energy Physics, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], 010308 nuclear & particles physics, Glueball, Partial wave analysis, SEARCH ENGINE RANKING, FOS: Physical sciences, RELEVANCE RANKING, 01 natural sciences, Central region, Omega, Projection (linear algebra), High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, LINK POPULARITY, 010306 general physics, Nuclear Experiment, Particle Physics - Experiment, Spin-½
Abstract

The reaction pp -> pf (eta eta) ps has been studied at 450 GeV/c. For the first time a partial wave analysis of the centrally produced eta eta system has been performed. Signals for the f0(1500), f0(1710) and f2(2150) are observed and the decay branching fractions of these states are determined., 14 pages, Latex, 5 Figures

Published
2000

44. D*(+/-) production in 350 GeV/c pi(-)-N interactions

Author

M. Verzocchi, A. Frenkel, D. Websdale, M. V. Zavertyaev, Corrado Angelini, P. Netchaeva, Dario Barberis, R. Hurst, Filippo Ceradini, L. Malferrari, B. R. French, V. Flaminio, G. Martellotti, Alessandro Cardini, Leonardo Paolo Rossi, M. Dameri, C. Gemme, Gianni Penso, C. Lazzeroni, K. Harrison, Yu. Alexandrov, P. Mazzanti, Giovanni Darbo, M. Adinolfi, Bianca Osculati, and A. Duane

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, chi(f) and p-tau(2) distributions, Meson, charmed-meson hadroproduction, Hadron, Elementary particle, vector mesons compared with pseudoscalar mesons, Pseudoscalar, Nuclear physics, Transverse momentum, d*(+/-) masons, Nucleon, Boson, cross-section measurements
Abstract

We report measurements of D ∗± production in interactions between 350 GeV/c π− particles and nuclei. Reconstruction of the decay D ∗+ → D 0 π + and charge conugate, with D0 identified via its decays to K−π+ and K−π−π+π+, has allowed isolation of a sample of 611 ± 28 D ∗± mesons, produced at positive xF. Assuming a linear A-dependence, the cross-section per nucleon in the region xF > 0 is measured to be 1.41 ± 0.10 ± 0.11 μ b for D ∗+ and 1.84 ± 0.12 ± 0.15 μ b for D ∗− . We present measurements of differential cross-sections with respect to xF and Pt2, and compare data for D ∗± (vector-meson) production with data for production of charmed pseudoscalar mesons.

Published
1999

45. Measurement of the beauty production cross-section in 350 GeV/c $\pi^-$ -Cu interactions

Author

V. Flaminio, P. Martinengo, D. Barney, Domizia Orestano, A. De Santo, R. Santonico, P. Nechaeva, C. Salvo, N. Hummadi, Yu. Alexandrov, V. Casanova, K. Harrison, R. Gessaroli, Federico Antinori, G. Schuler, S. Maljukov, Dario Barberis, Leonardo Paolo Rossi, A. Frenkel, M. Adinolfi, J.G. McEwen, C. Bacci, P. Mazzanti, A. Kirk, J. P. Dufey, Alessandro Cardini, Corrado Angelini, D. Websdale, G. Ciapetti, J. Batten, A. Forino, G. Martellotti, A. Semenov, Giovanni Darbo, A. Solovjev, M. Weymann, A. Di Ciaccio, V. Ryzhov, B. R. French, C. Lazzeroni, Bianca Osculati, C. Gemme, P. Farthouat, M. Dameri, P. Musico, Ludovico Pontecorvo, R. Hurst, J. C. Lassalle, M. Torelli, M. Palutan, N. Russakovich, Claudio Bruschini, M. Verzocchi, Stefano Veneziano, Roberto Cardarelli, L. Malferrari, L. Zanello, Gianni Penso, Emilio Petrolo, A. Duane, H. Rotscheidt, Filippo Ceradini, C. Cianfarani, Chiara Roda, Irakli Minashvili, M. V. Zavertyaev, M. Passaseo, M. I. Adamovich, W. Beusch, A. Quareni, Aleandro Nisati, Francesco Lacava, Adamovich, M, Adinolfi, M, Alexandrov, Y, Angelini, C, Antinori, F, Bacci, C, Barberis, D, Barney, D, Batten, J, Beusch, W, Bruschini, C, Cardarelli, R, Cardini, A, Casanova, V, Ceradini, Filippo, Cianfarani, C, Ciapetti, G, Dameri, M, Darbo, G, De Santo, A, Di Ciaccio, A, Duane, A, Dufey, Jp, Farthouat, P, Flaminio, V, Forino, A, French, Br, Frenkel, A, Gemme, C, Gessaroli, R, Harrison, K, Hummadi, N, Hurst, R, Kirk, A, Lacava, F, Lassalle, Jc, Lazzeroni, C, Malferrari, L, Maljukov, S, Martellotti, G, Martinengo, P, Mazzanti, P, Mcewen, Jg, Minashvili, I, Musico, P, Nechaeva, P, Nisati, A, Orestano, Domizia, Osculati, B, Palutan, M, Passaseo, M, Penso, G, Petrolo, E, Pontecorvo, L, Quareni, A, Rotscheidt, H, Ryzhov, V, Roda, C, Rossi, L, Russakovich, N, Salvo, C, Santonico, R, Schuler, G, Semenov, A, Solovjev, A, Torelli, M, Veneziano, S, Verzocchi, M, Websdale, D, Weymann, M, Zanello, L, and Zavertyaev, M.

Subjects
Nuclear physics, Physics, body regions, Nuclear and High Energy Physics, Cross section (physics), Particle physics, media_common.quotation_subject, Beauty, Measure (physics), Production (computer science), Sample (graphics), Particle Physics - Experiment, media_common
Abstract

Using a sample of $10^8$ triggered events, produced in $\pi^-$--$\,$Cu interactions at 350~GeV$/c$, we have identified 26 beauty events. The estimated background in this sample is $0.6 \pm 0.6$ events. From these data, assuming a linear A-dependence, we measure a beauty production cross-section integrated over all $x_F$ of $5.7 {+1.3 \atop -1.1}~{\mathrm {(stat.)}} {+0.6 \atop -0.5}~{\mathrm {(syst.)}}~$nb/N.

Published
1998

46. Search for the flavour-changing neutral-current decay $D^0 \to \mu^{+}\mu^{-}$

Author

G. Martellotti, C. Gemme, A. Forino, Stefano Veneziano, V. Flaminio, Giovanni Darbo, M. Dameri, Domizia Orestano, J.G. McEwen, P. Nechaeva, Bianca Osculati, Paolo Martinengo, A. Frenkel, K. Harrison, Leonardo Paolo Rossi, Ludovico Pontecorvo, Dario Barberis, M. Cirilli, A. Duane, A. Kirk, L. Malferrari, M. Verzocchi, Corrado Angelini, D. Websdale, Gianni Penso, B. R. French, Yu. Alexandrov, C. Lazzeroni, M. I. Adamovich, A. Quareni, M. V. Zavertyaev, Filippo Ceradini, C. Cianfarani, R. Hurst, P. Mazzanti, L. Zanello, Adamovich, M, Alexandrov, Y, Angelini, C, Barberis, D, Ceradini, Filippo, Cianfarani, C, Cirilli, M, Dameri, M, Darbo, G, Duane, A, Flaminio, V, Forino, A, French, Br, Frenkel, A, Gemme, C, Harrison, K, Hurst, R, Kirk, A, Lazzeroni, C, Malferrari, L, Martellotti, G, Martinengo, P, Mazzanti, P, Mcewen, Jg, Nechaeva, P, Orestano, Domizia, Osculati, B, Penso, G, Pontecorvo, L, Quareni, A, Rossi, L, Veneziano, S, Verzocchi, M, Websdale, D, Zanello, L, and Zavertyaev, M.

Subjects
Physics, Nuclear and High Energy Physics, Muon, Neutral current, Spectrometer, Branching fraction, Physics::Instrumentation and Detectors, Flavour, chemistry.chemical_element, Tungsten, Copper, Momentum, chemistry, High Energy Physics::Experiment, Atomic physics, Particle Physics - Experiment
Abstract

We have searched for the decay $D^0 \rightarrow \mu^+\mu^-$ among $2.0 \times 10^5$ $\mu^+\mu^-$ pairs \hbox{produced,} in the WA92 experiment, by 350 GeV/$c$ \ $\pi^-$ particles interacting in copper and tungsten targets. \hbox{Using} a high-resolution silicon-microstrip detector followed by a large-acceptance magnetic spectrometer and a muon filter we are able to measure the momentum of the muons, to visualize the event topology near their point of origin, and thus to discriminate between prompt and non-prompt muons. No $D^0 \rightarrow \mu^+\mu^-$ candidate has been found. This result allows us to set an upper limit on the branching fraction \hbox {B$(D^0 \rightarrow \mu^+\mu^-)$} of $ 4.1 \times 10^{-6}$ at 90 \% confidence level.

Published
1997

47. A kinematical selection of glueball candidates in central production

Author

O. Villalobos Baillie, V. Lenti, A.A. Kondashov, Yu.D. Prokoshkin, Sergey S.A. Polovnikov, Irakli Minashvili, A.V. Dolgopolov, Petr P.M. Shagin, A. Jacholkowski, A. Kirk, B.C. Earl, S. Maljukov, M. Sené, D. Barberis, V. Rumyantsev, A. Semenov, Valentine Sugonyaev, K. Myklebos, Sergey Donskov, Makoto Kobayashi, G.V. Khaustov, Yuri Kulchitsky, N. Russakovich, Yoshiji Yasu, David H. Evans, R. Sené, J. N. Carney, Susumu Inaba, Freddy Binon, A.V. Singovsky, H. Rotscheidt, S. A. Sadovsky, T. Nakagawa, Andrey Lednev, V.D. Samoylenko, W. Beusch, V. Romanovsky, V.A. Polyakov, G. Tchlatchidze, J.M. Olsen, Jean-Pierre Stroot, T. Kinashi, Alexandre A.V. Inyakin, T. Jacobsen, Paolo Martinengo, Jean Pierre Peigneux, M. Stassinaki, K. M. Danielsen, M. Venables, A. Solovjev, M.F. Votruba, W. Klempt, Tsuneaki Tsuru, F.E. Close, B. R. French, G. Vassiliadis, Kunio Takamatsu, K.L. Norman, H. M. Shimizu, and J.B. Kinson

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson production, Meson, Selection (relational algebra), Glueball, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Omega, Nuclear physics, Transverse momentum, Production (computer science), High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract

A study of central meson production as a function of the difference in transverse momentum ($dP_T$) of the exchanged particles shows that undisputed $q \overline q$ mesons are suppressed at small $dP_T$ whereas the glueball candidates are enhanced.

Published
1996

48. Measurements of charmed-meson production in interactions between 350 GeV/c $\pi^-$ particles and nuclei

Author

A. Duane, Yu. Alexandrov, Paolo Martinengo, P. Nechaeva, P. Mazzanti, Dario Barberis, G. Martellotti, R. Hurst, M. V. Zavertyaev, L. Zanello, J. Batten, D. Websdale, M. I. Adamovich, A. Quareni, Bianca Maria Osculati, V. Flaminio, G. Darbo, M. Verzocchi, Filippo Ceradini, C. Cianfarani, Corrado Angelini, L. Malferrari, J.G. McEwen, Gianni Penso, M. Dameri, K. Harrison, L. Rossi, B. R. French, M. Passaseo, C. Lazzeroni, A. Frenkel, C. Gemme, A. Kirk, and A. Forino

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle decay, Pion, Meson, Hadron, Mass spectrum, Elementary particle, Atomic physics, Nucleon, Particle Physics - Experiment
Abstract

Charmed-meson production by $350$~GeV/$c$ {$\pi^-$} particles incident on copper and tungsten targets has been studied in the WA$92$ experiment, performed at the CERN $\Omega^\prime$ spectrometer. Results obtained are reported and discussed. Reconstruction of decays from the set ${\rm D}^0 \rightarrow {\rm K}^- \pi^+$, ${\rm D}^0 \rightarrow {\rm K}^- \pi^- \pi^+ \pi^+$, ${\rm D}^+ \rightarrow {\rm K}^- \pi^+ \pi^+$, ${{\rm D}_{\rm s}}^+ \rightarrow \phi \pi^+$ and charge conjugates has yielded a sample of $7280 \pm 108$ charmed mesons, produced with $\xf > 0$, $\langle \xf \rangle = 0.18$ and $\langle {\pt}^2 \rangle = 1.86~{\rm (GeV/}c{\rm )}^2$. Assuming a relationship $\sigma = \sigma_0 A^\alpha$ between the cross-section, $\sigma$, per nucleus of mass $A$ and the nucleonic cross-section, $\sigma_0$, the $\alpha$ value found for the detected charmed particles is $0.95 \pm 0.06 \pm 0.03$. Taking $\alpha = 1$, the measured cross-sections per nucleon for $\xf > 0$ production are $7.78 \pm 0.14 \pm 0.52$~$\mu$barn for ${\rm D}^0$/$\bar{\rm D}^0$, $3.28 \pm 0.08 \pm 0.29$~$\mu$barn for ${\rm D}^+$/${\rm D}^-$ and $1.29 \pm 0.16 \pm 0.33$~$\mu$barn for ${{\rm D}_{\rm s}}^+$/${{\rm D}_{\rm s}}^-$. Differential cross-sections with respect to $\xf$ and ${\pt}^2$ have been determined for the various types of charmed meson, and particle-antiparticle asymmetries have been analysed.

Published
1996

49. WA92: a fixed target experiment to trigger on and identify beauty particle decays

Author

Roberto Cardarelli, P. Musico, Irakli Minashvili, Emilio Petrolo, M. V. Zavertyaev, D. Barney, C. Bacci, B. R. French, H. Rotscheidt, David Websdale, P. Farthouat, A. Kirk, G.J. Barber, M. I. Adamovich, A. Semenov, Leonardo Paolo Rossi, B. Osculati, V. Flaminio, A. Forino, Alessandro Cardini, A. Quareni, P. Martinengo, N. Russakovich, Claudio Bruschini, Aleandro Nisati, Yu. Alexandrov, A. Di Ciaccio, G. Ciapetti, A. Solovjev, M. Weymann, M. Torelli, Ludovico Pontecorvo, V. Ryzhov, G. Martellotti, R. Hurst, A. Duane, C. Gemme, Francesco Lacava, S. Maljukov, Domizia Orestano, K. Harrison, M. Dameri, L. Zanello, Filippo Ceradini, A. Frenkel, Dario Barberis, M. Adinolfi, V. Casanova, Stefano Veneziano, N. Hummadi, Gianni Penso, F. Vernocchi, R. Gessaroli, M. Passaseo, Federico Antinori, J.G. McEwen, W. Beusch, Chiara Roda, R. Santonico, P. Mazzanti, C. Lazzeroni, L. Malferrari, C. Salvo, P. Nechaeva, Giovanni Darbo, G. Schuler, J. Batten, C. Angelini, J. P. Dufey, J. C. Lassalle, M. Verzocchi, Adamovich, M, Adinolfi, M, Alexandrov, Y, Angelini, C, Antinori, F, Bacci, C, Barber, G, Barberis, D, Barney, D, Batten, J, Beusch, W, Bruschini, C, Cardarelli, R, Cardini, A, Casanova, V, Ceradini, Filippo, Ciapetti, G, Dameri, N, Darbo, G, Diciaccio, A, Duane, A, Dufey, Jp, Farthouat, P, Flaminio, V, Forino, A, French, Br, Frenkel, A, Gemme, C, Gessaroli, R, Harrison, K, Hummadi, N, Hurst, R, Kirk, A, Lacava, F, Lassalle, Jc, Lazzeroni, C, Malferrari, L, Maljukov, S, Martellotti, G, Martinengo, P, Mazzanti, P, Mcewen, Jg, Minashvili, I, Musico, P, Nechaeva, P, Nisati, A, Orestano, Domizia, Osculati, B, Passaseo, M, Penso, G, Petrolo, E, Pontecorvo, L, Quareni, A, Rotscheidt, H, Ryzhov, V, Roda, C, Rossi, L, Russakovich, N, Salvo, C, Santonico, R, Schuler, G, Semenov, A, Solovjev, A, Torelli, M, Veneziano, S, Vernocchi, F, Verzocchi, M, Websdale, D, Weymann, M, Zanello, L, and Zavertyaev, M.

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Spectrometer, Physics::Instrumentation and Detectors, Hadron, Tracking (particle physics), Charged particle, Nuclear physics, Particle, High Energy Physics::Experiment, Detectors and Experimental Techniques, Impact parameter, Nuclear Experiment, Instrumentation, Lepton
Abstract

We describe the detectors and trigger system used in the CERN WA92 experiment. The experiment was designed to study the production and decay of beauty particles from 350 GeV/$c\,$ $\,\pi^-$ interactions in copper and tungsten targets. Charged particle tracking is performed using the Omega spectrometer. Silicon microstrip detectors are used to provide precise tracking information in the region of the production and the decay of heavy-flavoured particles and to trigger on the resulting high impact parameter tracks. The precision of vertex reconstruction corresponds to $\pm 3.7\%$ of the mean B-decay proper lifetime. Lepton and high transverse momentum hadron signals are also used in the trigger, which accepts 29\% of B-decays and rejects 98\% of non-beauty interactions.

Published
1996

50. WA97 results on strangeness production in lead-lead collisions at 158 A GeV/c

Author

S. Simone, V. Lenti, G. Tomasicchio, J. Urban, A. Di Mauro, R. A. Loconsole, L. Šándor, F. Pellegrini, J.A. Lien, M. T. Muciaccia, Ph. Leruste, N. Carrer, J. Ftacnik, N. Armenise, M. Morando, A. Diaczek, M.F. Votruba, W. Klempt, Eugenio Nappi, Leonardo Paolo Rossi, M.E. Michalon-Mentzer, C. Salvo, J. Bán, Pavel Staroba, J. C. Lassalle, H. Rotscheidt, P. Middelkamp, Giovanni Darbo, J. L. Narjoux, K. Knudson, J. P. Davies, H. Beker, E. Chesi, B. R. French, Franco Meddi, Håvard Helstrup, E. Andersen, J. Bohm, Michele Guida, K. Piska, G. Vassiliadis, A. Kirk, P. Farthouat, P. Jovanovic, A. Volte, T. Scognetti, M. Luptak, D. Elia, G.F. Segato, Vito Manzari, M. Sené, V. Mack, R. Lietava, R. Sené, Anton Jusko, I. Mácha, T. Storås, M. Vaníčková, A. Jacholkowski, K. Fanebust, W. Geist, F. Posa, T. Kachelhoffer, C. Voltolini, K. Šafařík, M.A. Mazzoni, B. Osculati, E. Quercigh, Federico Antinori, M. Venables, V.A. Kachanov, Erik H.M. Heijne, T.F. Thorsteinsen, T. Virgili, I. Králik, K.L. Norman, Petr Zavada, Paolo Martinengo, J.B. Kinson, G. Grella, S. Szafran, P. Sennels, A. Singovski, J.C. Fontaine, G. Romano, Michael Campbell, R. A. Fini, M. Dameri, A. Michalon, G. Rosa, Gunnar Løvhøiden, Dario Barberis, D. Di Bari, Eugenio Cantatore, B. Ghidini, F. Navach, W. Beusch, D. Huss, M. Benayoun, B. Sopko, David H. Evans, J. Šťastný, M. G. Catanesi, L. Lopez, S. Saladino, A.K. Holme, Alberto Andrighetto, S. Di Liberto, B. Pastirčák, O. Villalobos Baillie, and R. A. Ricci

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, Heavy Ion Collisions, Strangeness production, Strangeness, Nuclear physics, Lead (geology), Quark Gluon Plasma, Quark–gluon plasma, Mass spectrum
Abstract

Preliminary results from WA97 measurements on Λ, Ξ and Ω production in lead-lead and proton-lead collisions are presented, along with a comparison of WA97 proton-lead data with previous WA85 proton-tungsten results. The ratio Ω gX seems to be enhanced in lead initiated reactions compared to proton initiated reactions.

Published
1996

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