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51. 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

52. 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

53. Hyperon production in proton-sulphur collisions at 200 GeV/c

Author

E. Andersen, M. Sené, J. L. Narjoux, Håvard Helstrup, B. De La Cruz, A. V. Singovsky, J. C. Lassalle, B. R. French, M. Morando, David H. Evans, V. Lenti, B. Ghidini, Ph. Leruste, J. Ftacnik, N. Carrer, L. Sandor, Domenico Di Bari, F. Pellegrini, F. Navach, R.A. Loconsole, R. Lietava, A.K. Holme, Alberto Andrighetto, W. Beusch, Karel Safarik, A. Jacholkowski, A. Kirk, K.L. Norman, V. A. Katchanov, M. Benayoun, J. Urban, K. Knudson, P. Ladron de Guevara, A. Abatzis, J. N. Carney, G. Løvhøiden, Davide Elia, Federico Antinori, J. Bohm, J. Kahane, M. Venables, K. Fanebust, G. Vasileiadis, J. P. Davies, P. Sennels, J.B. Kinson, M.F. Votruba, A. C. Bayes, O. Villalobos Baillie, K. Kralik, A. Volte, R. A. Ricci, R. Sené, Vito Manzari, R A. Fini, G.F. Segato, E. Quercigh, T.F. Thorsteinsen, Petr Zavada, 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 WA94

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Antiparticle, Proton, 010308 nuclear & particles physics, Hadron, Hyperon, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Sulfur, Spectral line, Nuclear physics, chemistry, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Particle, Transverse mass, 010306 general physics, Nuclear Experiment, Particle Physics - Experiment
Abstract

The WA94 experiment uses the production of strange particles and antiparticles to investigate the properties of hot hadronic matter created in heavy-ion interactions. Λ, Λ , Ξ− and Ξ + particle yields and transverse mass spectra are presented for pS interactions. These results are compared with those from SS interactions. Our results are also compared with those from pW and SW interactions of the WA85 experiment.

Published
1997
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54. 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

55. 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

56. 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

57. 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

58. A study of cascade and strange baryon production in sulphur-sulphur interactions at 200 GeV/c per nucleon

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Spectrometer, Nuclear Theory, Omega, Spectral line, Baryon, Nuclear physics, Transverse mass, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, Nucleon, Astrophysics::Galaxy Astrophysics, Particle Physics - Experiment, Nuclear Physics
Abstract

Strange and multistrange baryon and antibaryon production has been studied in sulphur sulphur interactions at 200 GeV/c per nucleon at central rapidity using the CERN Omega Spectrometer. Particle production ratios and transverse mass spectra are presented for Λ, Ξ−, Λ and Ξ−.

Published
1995

59. SEARCH FOR THE DECAY D-0-]MU(+)MU(-)

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Muon, Spectrometer, chemistry, Branching fraction, Analytical chemistry, chemistry.chemical_element, Beryllium, Tungsten, Atomic physics, Copper, Particle Physics - Experiment
Abstract

We have searched for the decay D 0 → μ + μ − among 1.25 × 10 5 μ + μ − pairs produced by 350 GeV/ c π − particles interacting in copper and tungsten targets. Using a high-resolution silicon-microstrip detector followed by a large-acceptance magnetic spectrometer and a muon filter we are able to discriminate between prompt and non-prompt muons and to measure dimuon masses. No candidate compatible with a D 0 → μ + μ − decay has been found, allowing us to set an upper limit on the branching fraction B( D 0 → μ + μ − ) of 7.6 × 10 −6 at the 90% confidence level.

Published
1995

60. Λ and Ξ− production in proton-tungsten interactions at 200 GeV/c per nucleon

Author

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

Subjects
Nuclear physics, Physics, Baryon, Particle physics, Hadron, Hyperon, Rapidity, Strangeness, Lambda baryon, Nucleon, Xi baryon
Abstract

The primary aim of the WA85 experiment is the study of strange and multistrange baryon and anti‐baryon production. Particles are detected in the kinematic window of central rapidity and pT≳1.0 GeV/c. Results on the production of Λ, Λ,Ξ− and Ξ− hyperons in proton‐tungsten interactions from the 1990 run are presented and compared with the sulphur‐tungsten data.

Published
1995
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61. Review of strange particle production from the WA85 Collaboration

Author

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

Subjects
Physics, Strange quark, Plasma formation, High Energy Physics::Phenomenology, Nuclear Theory, Hyperon, Strangeness, Nuclear physics, Baryon, Mass spectrum, Particle, High Energy Physics::Experiment, Nuclear Experiment, Nucleon
Abstract

Strange and, especially, multistrange baryon and anti‐baryon production is expected to be a useful probe in the search for Quark‐Gluon Plasma formation. A review of WA85 results on strange and multistrange particle production in SW and pW interactions at 200 GeV/c per nucleons is presented. In particular, mT distributions and relative ratios are presented for Ξ−s, Ξ−s, Λs, Λs, and K0s.

Published
1995
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62. Charged kaon spectra in SW interactions at 200 GeV/c per nucleon

Author

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

Subjects
Nuclear physics, Nuclear reaction, Physics, Particle physics, Meson, Branching fraction, Hadron, Mass spectrum, Elementary particle, Nucleon, Boson
Abstract

New results on the production of charged kaons in Sulphur‐Tungsten interactions have been obtained by the WA85 Collaboration. We present mt spectra for K+ and K− particles and the ratio

Published
1995
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63. New results on strange and multistrange baryon production and charged kaon production in sulphur sulphur interactions at 200 GeV/c per nucleon

Author

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

Subjects
Physics, Particle physics, Nuclear Theory, chemistry.chemical_element, Sulfur, Omega, Charged particle, Spectral line, Baryon, Nuclear physics, chemistry, Transverse mass, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, Nucleon
Abstract

Strange and multistrange baryon and antibaryon production has been studied in sulphur sulphur interactions at 200 GeV/c per nucleon at central rapidity. Particle production ratios and transverse mass spectra are presented for Λ, Ξ−, Ξ and Ξ−. In addition preliminary results on charged kaon production are presented, and the status of identified charged particle track reconstruction using the Omega RICH is reviewed.

Published
1995
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64. Ω/Ξ production ratio in S-W

Author

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

Subjects
Baryon, Nuclear physics, Nuclear reaction, Chemistry, Branching fraction, Hadron, Hyperon, Rapidity, Atomic physics, Omega baryon, Xi baryon
Abstract

We have measured the (Ω−+Ω+)/(Ξ−+Ξ+) production ratio in central S‐W collisions to be 0.8±0.4 at central rapidity and pT≳1.6 GeV/c.

Published
1995
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65. First results from the 1994 lead beam run of WA97

Author

J.A. Lien, K. Fanebust, M. Dameri, M.A. Mazzoni, Federico Antinori, Erik H.M. Heijne, Leonardo Paolo Rossi, Anton Jusko, Ivan Kralik, B. R. French, Franco Meddi, P. Farthouat, T. Scognetti, Håvard Helstrup, A. Di Mauro, L. Lopez, S. Saladino, G. Vassiliadis, N. Carrer, S. Sclmane, J. Stastny, Alberto Andrighetto, S. Di Liberto, T. Virgili, A.K. Holme, M.E. Michalon-Mentzer, P. Middelkamp, H. Beker, A. Kirk, A. Volte, Jozef Urban, Paolo Martinengo, A. Pallares, S. Szafran, B. Pastirčák, Giovanni Darbo, R. Lietava, R. Sené, S. Simone, A. C. Bayes, A. Singovski, R. A. Fini, N. Armenise, C. Gemme, E. Chesi, A. Diaczek, M. T. Muciaccia, B. Sopko, V. Khodyrev, F. Pellegrini, Eugenio Cantatore, G. Romano, A. Michalon, Vito Manzari, L. Sandor, K.L. Norman, O. Villalobos Baillie, R. Blaes, Petr Zavada, B. Ghidini, R. A. Ricci, T. Reitan, G. Alexeev, J. Bán, A. Jacholkowski, E. Andersen, F. Navach, J.B. Kinson, H. Vettunen, J L. Reister, M. Morando, Ph. Leruste, I. Mácha, J. Sahagun Pareja, Dario Barberis, David H. Evans, P. Jovanovic, R. Fang, P. Sennels, B. Osculati, J. C. Lassalle, W. Geist, M. G. Catanesi, M. Sené, J. P. Davies, K. Knudson, H. Rotscheidt, T.F. Thorsteinsen, V.A. Kachanov, J. N. Carney, Gunnar Løvhøiden, F. Posa, M. Luptak, G.F. Segato, M. Vaníčková, W. Beusch, T. Kachelhoffer, Pavel Staroba, E. Quercigh, A. Inyakin, M. Benayoun, M. Pairat, Michael Campbell, D. Di Bari, J. L. Narjoux, J. Bohm, G. Grella, Michele Guida, J. Kahane, V. Lenti, T. Storaas, P. Shagin, C. Voltolini, J.M. Brom, K. Piska, J. P. Dufey, D. Elia, G. Tomasicchio, M.F. Votruba, W. Klempt, G. Rosa, Eugenio Nappi, Karel Safarik, 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), Heyd, Yvette, and Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Silicon pixel detectors, Silicon, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Nuclear Theory, chemistry.chemical_element, 01 natural sciences, law.invention, Nuclear physics, Baryon, Telescope, Lead (geology), chemistry, law, 0103 physical sciences, Quark Gluon Plasma, Nuclear Experiment, 010306 general physics, Beam (structure)
Abstract

WA97 is designed to study strange and multi-strange baryon and anti-baryon production in 160 A GeV c PbPb collisions at the SPS with a telescope of silicon microdetectors. Four planes of silicon pixel detectors were successfully employed during the 1994 Pb run. A total of 60M central PbPb events were collected. We describe the experimental setup and report on some preliminary results from the off-line analysis.

Published
1995

66. Possibility of stable spheroid molecules of ZnO

Author

B. R. French, J. R. Myers, Elizabeth C. Behrman, M. E. Zandler, and R. K. Foehrweiser

Subjects
Physics, Spheroid, Molecule, Nanotechnology, Atomic and Molecular Physics, and Optics
Published
1994

67. STUDY OF D+ AND D- FEYNMAN X DISTRIBUTIONS IN PI- -NUCLEUS INTERACTIONS AT THE SPS

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Spectrometer, Meson, Physics::Instrumentation and Detectors, Omega, Nuclear physics, symbols.namesake, symbols, Feynman diagram, High Energy Physics::Experiment, Charm (quantum number), Impact parameter, Nuclear Experiment, Beam (structure), Particle Physics - Experiment
Abstract

Experiment WA82 studied charm production by a π− beam of 340 GeV/c at the CERN Ω′ spectrometer, using a silicon microstrip vertex detector and an impact parameter trigger. Results on the xF distributions of D+ and D− mesons are presented and discussed. A clear excess of D− over D+, increasing at high xF, is observed.

Published
1993

68. Measurement of relative branching fractions for D+→K−K+K+ and Ds+→π−π+π+ decays

Author

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

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Atomic physics, Branching (polymer chemistry), Particle Physics - Experiment
Abstract

The decay modes D s + → π − π + π + and D + → K − K + K + have been studied in the hadroproduction experiment WA82. The following ratios of branching fractions have been measured: , , .

Published
1993

69. A microstrip decay detector for beauty physics

Author

Chiara Roda, A. Menetrey, Alessandro Cardini, C. Angelini, Marco Adinolfi, D. Barney, C. Lazzeroni, Rb Hurst, Leonardo Paolo Rossi, P. Martinengo, and B. R. French

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Physics::Instrumentation and Detectors, business.industry, Track (disk drive), Detector, Microstrip, Pulse (physics), Optics, Particle, Bubble chamber, High Energy Physics::Experiment, Electronics, Detectors and Experimental Techniques, business, Instrumentation
Abstract

The Decay Detector is a compact array of 10 μm pitch silicon microstrip detectors designed to give charged track data which is sufficient, both in quantity and in precision, to allow reconstruction of beauty particle decays. It has been built for Beatrice, a fixed-target hadroproduction experiment at CERN. This “electronic bubble chamber” consists of sixteen 5 mm × 5 mm microstrip planes comprising more than 8000 detector channels packed into a volume of less than 0.8 cm 3 . The pulse heights of all channels are read by analogue front-end electronics and are then compared with individually set thresholds and pedestals. The performance of the Decay Detector has been studied in a test beam and data are presented on its spatial precision, efficiency, and other characteristics.

Published
1992

70. Results on charm hadroproduction from CERN experiment WA82

Author

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

Subjects
Physics, Particle physics, Large Hadron Collider, Spectrometer, Meson, Physics::Instrumentation and Detectors, Nuclear Theory, High Energy Physics::Phenomenology, Nuclear physics, High Energy Physics::Experiment, Charm (quantum number), Vertex detector, Impact parameter, Nuclear Experiment, Silicon microstrip detectors, Particle Physics - Experiment
Abstract

Experiment WA82 has collected data from 1987 to 1989 with the Ω’ spectrometer at the CERN SPS. The aim of WA82 was a high statistics study of charm hadroproduction, using a silicon microstrip vertex detector and an impact parameter trigger. Latest results on the nuclear dependence of charm production and on the xF distributions of D+ and D− mesons are presented and discussed.

Published
1992

71. Nuclear dependence of charm production by a 340 GeV π- beam

Author

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

Subjects
Quark, Mass number, Physics, Nuclear and High Energy Physics, Particle physics, Meson, chemistry.chemical_element, Tungsten, Omega, Charm quark, Nuclear physics, chemistry, Invariant mass, Charm (quantum number), Particle Physics - Experiment
Abstract

Charmed mesons, produced on silicon, copper and tungsten by 340 GeV π - , have been identified as peaks in invariant mass distributions. The comparison of the yields of charmed particles originating from interactions in Si, Cu and W allows the mass number dependence of the charm hadroproduction cross section to be measured. Assuming the usual parametrization σ c = σ 0 A α , we find α =0.92±0.06 for charmed mesons with 〈 x F 〉=0.24. We do not find any decrease of α with increasing x F in contrast to the case of the production of particles containing only light quarks.

Published
1992

72. WA92: A fixed target experiment to study beauty in hadronic interactions

Author

Federico Antinori, J.G. McEwen, R. Santonico, G. Martellotti, S. Gerasimov, W. Beusch, G. Penso, B. R. French, M. Dameri, C. Salvo, M. Passaseo, Filippo Ceradini, M. Torelli, A. Forino, R. Gessaroli, A. Jacholkowski, Emilio Petrolo, M. Adinolfi, Chiara Roda, M. Zaveryaev, A. Kirk, D. R. O. Morrison, L. Zanello, Giovanni Darbo, A. Frenkel, M. I. Adamovich, Polina Nechaeva, P. Mazzanti, A. Quareni, Aleandro Nisati, J. C. Lassalle, M. Weymann, G. Ciapetti, K. Harrison, L. Malferrari, M. Verzocchi, Jean-Paul Fabre, V. Flaminio, J. P. Dufey, Leonardo Paolo Rossi, Claudio Bruschini, G. Tomasini, P. Martinengo, D. Barney, V. Casanova, David Websdale, Roberto Cardarelli, B. Osculati, Alessandro Cardini, G. Schuler, C. Bacci, A. Duane, Corrado Angelini, Stefano Veneziano, A. Di Ciaccio, Domizia Orestano, Yu. Alexandrov, F. Viaggi, Francesco Lacava, Ludovico Pontecorvo, R. Hurst, S P Kharlamov, and V. Rhyzov

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Vertex (computer graphics), Particle physics, Particle decay, Meson, Detector, B meson, Impact parameter, Measure (mathematics), Atomic and Molecular Physics, and Optics, Particle detector
Abstract

The essential feature of the described experimental techniques is the use of two specially designed pieces of hardware: a high precision “decay detector” and a fast secondary vertex trigger processor. Experiment WA92 should be able to obtain a sufficient data sample to measure lifetimes of B ± and B 0 and the B hadroproduction cross section.

Published
1992

73. Short-range correlations in hadron pair production at p$_{T}$ $\geq$ 2 GeV/c

Author

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

Subjects
Physics, Particle physics, Physics and Astronomy (miscellaneous), Proton, Hadron, Elementary particle, Omega, Charged particle, Nuclear physics, Pair production, Rapidity, Nuclear Experiment, Nucleon, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

Production of oppositely charged particle pairs at largep T is studied, where both particles, are in the central rapidity region within one unit of rapidity and nearby in azimuth. The data sample, which comes fromπ − Be interactions obtained using the CERN OMEGA spectrometer, contains events with a pair of oppositely charged particles havingp T ≧2 GeV/c recoiling, against a third one withp T ≧1 GeV/c. Our data provide new information on short range correlations involving the production of the nine possible pairs made from (π +,K +,p) and $$(\pi ^ - ,K^ - ,\bar p)$$ . Comparison with Lund Monte Carlo predictions is made. Apart from proton yields, the model reproduces correctly our data. The main discrepancies observed with protons can be attributed to hard scattering of diquarks from the target nucleons.

Published
1991

74. A study of the semileptonic decay

Author

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

Subjects
Physics, Semileptonic decay, Nuclear and High Energy Physics, Meson, Atomic physics, Omega
Abstract

The decay D+→K−π+e+νe has been studied by the hadroproduction experiment WA82. The decay is dominated by the K ∗0 (892) resonance. The ratio of branching ratios, B( D + → K ∗0 e + ν e )/B( D + → K − π + π + ) , is found to be 0.62±0.15±0.09. The K ∗0 mesons have a ratio of longitudinal to transverse polarization of 0.6±0.3+0.3−0.1.

Published
1991

75. Production of multistrange baryons and antibaryons in sulphur-tungsten interactions at 200 GeV/c per nucleon

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, chemistry.chemical_element, Tungsten, Sulfur, Omega, Baryon, Nuclear physics, chemistry, Cascade, Quark–gluon plasma, Rapidity, Nucleon, Particle Physics - Experiment
Abstract

Production of Ξ − and Ξ − has been observed for the first time in heavy ion interactions by the WA85 Experiment. Multistrange baryon and antibaryon production is expected to be a useful probe in the search for quark-gluon plasma formation. We describe the procedure used to select these cascade candidates and show that Ξ − and Ξ − decays can be identified. The ratio of Ξ Ξ production, corrected for geometrical acceptances and reconstruction efficiencies, is 0.39 ± 0.07 for sulphur-tungsten interactions in the central rapidity interval 2.3 Y lab p T >1.1 GeV/ c .

Published
1990

76. Search for narrow diquonium states in π−p interactions at 10 GeV/c

Author

S. Pensotti, B. R. French, A. S. Thompson, R. M. Turnbull, I.L. Smith, G.M. Lewis, R. Strub, L. Mandelli, Giuseppe Zito, G. Costa, E. Paul, W.A. Mitaroff, B. Ghidini, I.S. Hughes, R.A. Ronald, C. Evangelista, C. Palazzi-Cerrina, D.N. Edwards, T. Armstrong, Laura Perini, A. Palano, M. Tamborini, C. Best, M. A. Houlden, P. Mättig, and K. Müller

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Spectrometer, Atomic physics, Omega, Particle Physics - Experiment
Abstract

Narrow diquonium production in the reactions pi /sup -/p to p pi p pi /sup -/pp, p pi /sup -/p pi /sup +/ and p pi /sup 0/ is investigated in a 5.3 ev/nb experiment performed at the Omega Spectrometer. The computed upper limits are compared with the predictions of the Chan- Hogaasen model, (1977). (22 refs).

Published
1981
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77. A spin-parity analysis of the f1(1285) and f1(1420) mesons centrally produced in the reaction pp→pf(KS0K±π∓)ps at 300 GeV/c

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Meson, Parity (physics), Atomic physics
Abstract

Results are presented of an analysis of the reaction pp→p f (K S 0 K ± π ∓ )p s at 300 GeV/ c . Clear f 1 (1285) and f 1 (1420) signals are seen. A spin-parity analysis shows that both are consistent with being 1 ++ states. The f 1 (1420) is found to decay only to K ∗ K and no 0 −+ or 1 +− waves are required to describe the data. The production of the f 1 (1285) as a function of energy is not the same as that for the f 1 (1420) whose cross section is found to be constant with energy.

Published
1989
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78. Evidence for a narrow width boson of mass 2.95 GeV

Author

P. Mättig, V. Picciarelli, C. Best, A. Palano, G.M. Lewis, S. Pensotti, M. Edwards, Giuseppe Zito, C. Evangelista, E. Paul, M. A. Houlden, A. S. Thompson, J. Gordon, T. Armstrong, Laura Perini, R. Strub, W. Rühmer, K. Müller, R.A. Donald, I.S. Hughes, G. Costa, D.N. Edwards, W.A. Mitaroff, H. D. Lambacher, B. Ghidini, C. Palazzi-Cerrina, B. R. French, D. H. Miller, R. M. Turnbull, L. Mandelli, and P.L. Woodworth

Subjects
Physics, Nuclear and High Energy Physics, Large Hadron Collider, Spectrometer, Branching fraction, Resonance, Omega, Nuclear physics, Antiproton, Mass spectrum, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Boson
Abstract

In a search for resonances coupled to the p pπ − system, we have studied π − p interactions at 16 GeV/ c giving a forward antiproton, using the Omega spectrometer at CERN. In the final states involving a p , p and π − we observe a 5.6 (6.3) standard deviation enhancement in the p pπ − mass spectrum at (2.95 ± 0.01) GeV with a width consistent with the resolution ( σ = 15 MeV). The production cross section × branching ratio is estimated to be of the order 1 μb. The data are consistent with a resonance decaying partly via intermediate p p final states.

Published
1977
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79. Study of theK + K − π+ π− system centrally produced in the reactions π+ p→π+(K + K − π+ π−)p andpp→p(K + K − π+ π−)p at 85 GeV/c

Author

B. R. French, J. N. Carney, B. Ghidini, T. A. Armstrong, O. Villalobos Baillie, R. Zitoun, Giuseppe Zito, V. Lenti, I. C. Print, J.B. Kinson, A. Palano, I. J. Bloodworth, G. Vassiliadis, and M.F. Votruba

Subjects
Nuclear reaction, Physics, Crystallography, Pair production, Pion, Physics and Astronomy (miscellaneous), Meson, Branching fraction, Hadron, Vector meson, Nucleon, Engineering (miscellaneous)
Abstract

The reactions π+p→π+(K+K− π+ π−p andpp→p(K+K− π+ π−)p where the (K+K− π+ π−) system is centrally produced have been studied at 85 GeV/c. 48% of the final state proceeds through single or double vector meson resonant production i.e.,K*0(890) (37%), ϕ (4%),ρ0 (7%). Evidence is found for associatedK*0 (890)\(\bar K\)*o (890) production (6.4±1.1%) with a cross section ten times higher than that found for associated ϕ ϕ production in the same experiment.

Published
1987
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80. Strange-particle production in $$\bar pp$$ collisions at 5.7 GeV/ccollisions at 5.7 GeV/c

Author

H. Atherton, B. R. French, and I. Bar-Nir

Subjects
Nuclear physics, Physics, Particle physics, Strange quark, Mass spectrum, Resonance, High Energy Physics::Experiment, Production (computer science), Lambda, Bar (unit)
Abstract

\(\bar p\Lambda ^0 K^ + \),\(\bar p\Lambda ^0 K^0 \pi ^ + \) and\(\bar p\Lambda ^0 K^ + \pi ^0 \) strange-particle final states, produced in\(\bar pp\) collisions at 5.7 GeV/c, were studied in the CERN 2 metre HBC. Cross-sections for the various channels are presented. It was found that about half of the channel cross-sections are accounted for by resonance production. Several features of the resonance production are discussed. The results are compared with those obtained in pp interactions at a similar energy.

Published
1975
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81. The four-pion final state in p annihilations at 5.7 GeV/c

Author

B. R. French, M. Jires, J. Žaček, J. Böhm, V. Simak, H. Atherton, J. Sedlak, J. Skura, and J. Cvach

Subjects
Physics, Nuclear and High Energy Physics, Antiparticle, Particle physics, Annihilation, Meson, Hadron, Elementary particle, Nuclear physics, Pion, Antimatter, High Energy Physics::Experiment, Nuclear Experiment, Boson
Abstract

577 events from p p →2π + 2π − annihilations at 5.7 GeV/c are analyzed. Single-particle spectra are studied and an effective matrix element in the form Πi=14 exp(−BpTi2) is determined. The rates for production of ϱ° and f0 mesons are estimated and the influence of resonances on the angular distributions of pions and dipions is investigated. Transverse momenta correlations can be explained using peripheral phase space.

Published
1976
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82. Evidence for new states produced in the central region in the reaction pp→pf(π+π−π+π−)ps at 300 GeV/c

Author

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

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

The reaction pp→pf(π+π−π+π−)ps, where the π+π−π+π− system is centrally produced, has been studied at 300 GeV/c in an experiment designed to search for gluonic states. The π+π−π+π− mass spectrum shows evidence for the f1(1285) with a mass of 1281±1 MeV and a width of 31±5 MeV. In addition there is evidence for two new enhancements at masses of 1449±4 and 1901±13 MeV with widths of 78±18 and 312±61 MeV respectively. An analysis of the state at 1.45 GeV indicates that it is not a π+π−π+π− decay mode of the f1(1420) or ι η(1440) .

Published
1989
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83. Observation of double φ-meson production in the central region for the reactions π+p → π+(K+K+K−K−)p andpp → p(K+K+K−K−)p at 85 GeV/c

Author

A. Palano, I. J. Bloodworth, B. Ghidini, I. C. Print, J.B. Kinson, T. A. Armstrong, M.F. Votruba, R. Zitoun, Giuseppe Zito, O. Villalobos Baillie, B. R. French, J. N. Carney, G. Vassiliadis, and V. Lenti

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle decay, Crystallography, Pair production, Pion, Meson, Branching fraction, Hadron, Nucleon
Abstract

The reactions π+p → π+(K+K+K−K−)p and pp → p(K+K+K−K−)p in which the K+K+K−K− system is centrally produced have been studied at 85 GeV c . Evidence is found for φφ production. The relative rates for production of φφ, φK+K− and K+K+K−K− have been determined.

Published
1986
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84. Analysis of the reaction at 10 and 16 GeV/c

Author

M. Edwards, V. Picciarelli, R. McCluskey, G. Costa, J. Gordon, G.M. Lewis, R. M. Turnbull, W. Rühmer, C. Evangelista, R.A. Donald, B. R. French, C. Best, K. Müller, Laura Perini, S. Pensotti, M. A. Houlden, R. Strub, I.S. Hughes, W.A. Mitaroff, L. Mandelli, B. Ghidini, H. D. Lambacher, D.N. Edwards, Giuseppe Zito, T. Armstrong, E. Paul, J. Bröring, C. Palazzi-Cerrina, A. Palano, P. Mättig, and A. S. Thompson

Subjects
Nuclear physics, Momentum, Physics, Nuclear and High Energy Physics, Angular distribution, Partial wave analysis, Resonance, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Exchange model, Omega, P system
Abstract

Antiproton-proton pairs and antiproton-neutron pairs produced in the reaction π − p → p pn , were studied in the mass range from threshold to 2.6 GeV on the basis of 4 · 104 events at 10 GeV/c and 2 · 104 events at 16 GeV/c incident momentum. The cross section for peripheral production of p n pairs is significantly larger than for p p pairs. The p p production mechanism is consistent with the predictions of the one-pion exchange model, whereas the p n production cannot be sufficiently described by that model. A partial-wave analysis of the p p system, assuming pure one-pion exchange, shows that we need for a reasonable description of our data in addition to the JP = 3− resonance at 2.11 GeV and the 4+ resonance at 2.26 GeV found in an analysis of a formation experiment ( p p → π + π − ), two further resonances: a 1− state at 1.92 GeV and a 2+ state at 2.02 GeV.

Published
1979
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85. Baryon antibaryon production in the central region at 85 GeV/c

Author

V. Lenti, B. R. French, A. Palano, R. Childs, G. Vassiliadis, Giuseppe Zito, M.F. Votruba, I. J. Bloodworth, B. Ghidini, J.B. Kinson, R. Zitoun, T. A. Armstrong, J. N. Carney, and O. Villalobos Baillie

Subjects
Physics, Particle physics, Physics and Astronomy (miscellaneous), Nuclear Theory, High Energy Physics::Phenomenology, Elementary particle, Lambda, Central region, Nuclear physics, Baryon, Pi, Mass spectrum, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, Engineering (miscellaneous), Particle Physics - Experiment, Bar (unit)
Abstract

In a search for glueballs and exotic states decaying into baryons and antibaryons we have investigated the production of baryon antibaryon pairs produced centrally in the reactions π+/pp → π+/p(X0)p at 85 GeV/c. In particular, channels whereX0 goes to\(p\bar p,p\bar p\pi ^ + \pi ^ - ,p\bar p2\pi ^ + 2\pi ^ - \) and\(\Lambda \bar \Lambda \) have been observed. No significant new structure is observed in the mass spectra.

Published
1987
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86. An amplitude analysis of the K+K− system produced in the reaction π−p→K+K−n at 10 GeV/c

Author

B. Ghidini, E. Paul, L. Mandelli, K. Müller, S. Pensotti, G.M. Lewis, B. R. French, W.A. Mitaroff, W. Rühmer, P. Mättig, C. Evangelista, R.A. Donald, V. Picciarelli, Laura Perini, A. Palano, M. A. Houlden, I.S. Hughes, D.N. Edwards, R. M. Turnbull, and G. Costa

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Amplitude, Meson, Branching fraction, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Low Mass
Abstract

We present results on an amplitude analysis of the K+K− system produced in the reaction π−p→K+K−n from threshold up to 2.2 GeV. The branching ratios of f0 and f' to KK have been determined. In the low mass region of the KK system the observation of an S-wave enhancement at 1.3 GeV and the interference of the f0-A2-f' mesons are studied. We observe a 3− structure in the mass region of 1.7 GeV which is consistent with g0 production. With this interpretation the branching ratio g→KK has been determined. Evidence for a new structure in the Jp = 2+ wave around 1.8 GeV with a width of ∼200 MeV is presented.

Published
1980
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87. Inclusive ϕ-meson production in π-Be interactions at 85 GeV/c

Author

I.R.M. Thompson, D. Frame, P.S.L. Booth, J. C. Lassalle, D.N. Edwards, J.E.T. Lewis, B. R. French, J.J. Myerscough, M. A. Houlden, I.S. Hughes, R.A. Donald, L.J. Carroll, J.A. Richardson, D.McL. McFadzean, P.A. Kilcoyne, J.G. Lynch, A. S. Thompson, J. N. Jackson, R. M. Turnbull, and W.H. Range

Subjects
Mass number, Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, Meson, Hadron, General Physics and Astronomy, Elementary particle, Parton, Nuclear physics, Nuclear Experiment, Nucleon, Boson
Abstract

The inclusive reaction pi -Be to phi +X has been studied for 0

Published
1987
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88. Evidence for higher twist mechanisms in prompt ϱ0-meson production at PT > 2 GeV/c in 300 GeV/c Π−N interactions

Author

M. Sene, V. Lenti, M. Stassinaki, O. Villalobos Baillie, C. Neaume, J. L. Narjoux, R. Sené, J. C. Lassalle, J. Kahane, B. R. French, Z. Strachman, W. Beusch, Yves Goldschmidt-Clermont, M. Benayoun, A. Palano, M. T. Trainor, Giuseppe Zito, Gunnar Ingelman, R. Zitoun, A. Jacholkowski, I. C. Print, J.B. Kinson, K. Knudson, B. Ghidini, J. N. Carney, F. Navach, A. Malamant, M. Pimenta, Ph. Leruste, Roberto Petronzio, E. Quercigh, M.F. Votruba, A. Burns, I. J. Bloodworth, G. Vassiliadis, and H. R. Shaylor

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Scattering, Hadron, Parton, Omega, Nuclear physics, Recoil, High Energy Physics::Experiment, Twist, Nuclear Experiment
Abstract

The production of ϱ 0 mesons in hadronic interactions is investigated at high transverse momentum ( p T > 2 GeV/ c ). The data come from a sample of Π − N interactions at 300 GeV/ c obtained at the CERN OMEGA spectrometer, requiring a ϱ 0 →Π + Π − with p T (pair) > 2 GeV/ c to recoil against an opposite particle with p T (opposite) > 1 GeV/ c . The signal/(signal + background) ratio of ϱ 0 production shows an increase of 38% as x E = p T (opposite)/ p T (pair) decreases from 0.5 x E x E ⩽ 0.5. This increase is not compatible with a QCD model of parton scattering and subsequent fragmentation. It is interpreted as evidence for direct ϱ 0 production via QCD higher twist processes, in terms of which a quantitative agreement with the data is found.

Published
1987
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89. Preliminary results from the WA85 experiment on Λ and gL production in 200 a GeV/C sulphur-tungsten interactions

Author

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

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Pair production, chemistry, Branching fraction, Hadron, Analytical chemistry, Mass spectrum, chemistry.chemical_element, Tungsten, Nucleon, Lambda baryon
Published
1989
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90. Observation of centrally produced (1720) in the reaction at 300 GeV/c

Author

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

Subjects
Physics, Momentum, Nuclear and High Energy Physics, Hadron, Mass spectrum, Atomic physics, Spin (physics)
Abstract

The K + K − and K S 0 K S 0 systems centrally produced in the reaction pp→p f K K p s have been studied at 300 GeV/ c incident momentum. Both the K + K − and the K S 0 K S 0 mass spectra show large resonant production. For the first time in hadron collisions, clear evidence is found for the θ f 2 (1720) with parameters m =1713±10 MeV, Γ =181±30 MeV for the K + K − decay mode and m =1706±10 MeV, Γ =104±30 MeV for the K S 0 K S 0 decay mode. A spin analysis of the K + K − spectrum shows that for the θ f 2 (1720) J P =2 + is strongly favoured while 0 + and 1 − are excluded.

Published
1989
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91. Angular correlations in the φφ system and evidence for hadronic ηc production

Author

W.H. Range, J.A. Richardson, D.N. Edwards, A. S. Thompson, J. C. Lassalle, I.S. Hughes, B. R. French, L.J. Carroll, J.E.T. Lewis, P.A. Kilcoyne, D.McL. McFadzean, I.R.M. Thompson, D. Frame, J.J. Myerscough, M. A. Houlden, R. M. Turnbull, P.S.L. Booth, J.G. Lynch, R.A. Ronald, and J. N. Jackson

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Spectrometer, Moment (physics), Hadron, Nucleon, Omega
Abstract

The paper describes a study of angular correlations in the φφ system produced in the reaction π − Be → φφ + X at 85 GeV/c. A sample of 33 851 candidate φφ events with φφ mass less than 3.2 GeV/c2 was obtained in an experiment using the OMEGA spectrometer at CERN with a 4-kaon trigger. Moments of the decay angular distributions are presented as a function of φφ mass over the range 2.0 to 3.2 GeV/c2. The distributions in the mass interval 2.0–2.5 GeV/c2 are best fitted by a dominance of JP = 2+. A signal in the H(222200) moment in the mass interval 2.9–3.0 GeV/c2 is interpreted as due to ηc → φφ and yields a value for (ross section) × (anching ratio) = 14.1 ± 6.3 nb/nucleon.

Published
1986
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92. Analysis of the inclusive reaction at 10 GeV/c

Author

S. Pensotti, J. Gordon, R. Strub, B. R. French, G.M. Lewis, D.N. Edwards, V. Di Gennaro, J. Bröring, B. Ghidini, V. Picciarelli, A. S. Thompson, W. Rühmer, I.S. Hughes, Giuseppe Zito, R.A. Donald, W.A. Mitaroff, A. Palano, P. Mättig, M. Steuer, E. Paul, M. Edwards, C. Best, K. Müller, M. A. Houlden, T. Armstrong, Laura Perini, C. Evangelista, R. McCluskey, G. Costa, R. M. Turnbull, C. Palazzi-Cerrina, and L. Mandelli

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Parity (physics), Polarization (waves), Finite mass
Abstract

Experimental results on the reaction π−p→K∗0 (890) X0 at 10 GeV/c are presented. By using the K∗0 polarization measurements, a detailed study of the production has been carried out as a function of the missing mass squared and of the four-momentum trasnfer squared to the K∗0. We found that: (a) K∗0 production is dominated by natural parity exchange; (b) K∗0 helicity-zero production dominates the unnatural parity exchange contribution and (c) the main features of the reaction are in agreement with the predictions of the finite mass sum rules.

Published
1980
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93. Evidence for structure in the 1.7 GeV mass region of the K+K− final state centrally produced in the reactions π+p → π+(K+K−)p and pp → p(K+K−)p at

Author

V. Lenti, M.F. Votruba, G. Vassiliadis, O. Villalobos Baillie, A. Palano, R. Zitoun, B. Ghidini, I. C. Print, I. J. Bloodworth, J.B. Kinson, Giuseppe Zito, R. Parrié, B. R. French, J. N. Carney, and T. A. Armstrong

Subjects
Physics, Nuclear and High Energy Physics, Crystallography, Meson, State (functional analysis), Atomic physics, Resonance (chemistry)
Abstract

The reactions π + p → π + (K + K − )p and pp → p(K + K − )p where the K + K − system is centrally produced have been studied at 85 GeV/ c . The K + K − spectrum contains several structures in the regions of S ∗ o , f A 2 and f′. Structure is observed in the 1.7 GeV mass region which cannot be attributed to the g meson. The most likely interpretation of the data is that we observe the θ with a mass of 1.742 GeV and a new resonance at a mass of 1.629±0.010 GeV with a width of 0.082±0.030 GeV.

Published
1986
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94. A study of K*0(890) inclusive production in the beam fragmentation region of the reaction π-p → K*0(890)X0 at 10 GeV/c

Author

V. Picciarelli, L. Mandelli, G. Costa, I.S. Hughes, L. Perini, R. M. Turnbull, G.M. Lewis, S. Pensotti, R.A. Donald, B. R. French, C. Evangelista, W.A. Mitaroff, D.N. Edwards, E. Paul, A. Palano, M. A. Houlden, B. Ghidini, and K. Müller

Subjects
Physics, Nuclear physics, Fragmentation (mass spectrometry), General Physics and Astronomy
Published
1980
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95. K∗0(890) polarization measurements in the hypercharge exchange reaction at 10 GeV/c

Author

M. Edwards, P.L. Woodworth, R.A. Donald, B. R. French, R. Strub, C. Best, C. Palazzi-Cerrina, V. Picciarelli, M. A. Houlden, K. Müller, R. M. Turnbull, R. McCluskey, W.A. Mitaroff, L. Pregernig, L. Mandelli, J. Gordon, G. Zito, W. Rühmer, J. Bröring, G.M. Lewis, S. Pensotti, C. Evangelista, P. Mättig, D.N. Edwards, G. Costa, D. H. Miller, I.S. Hughes, B. Ghidini, E. Paul, Laura Perini, A. S. Thompson, T. Armstrong, and A. Palano

Subjects
Baryon, Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Hypercharge, Meson, Quark model, Hadron, Hyperon, Elementary particle, Omega
Abstract

K∗0(890) production in the hyperchange exchange reaction π−p→K∗0(890) Λ0Σ0 at 10 GeV/c (28 448 events) is discussed. An amplitude analysis in the t′ range up to 1 GeV2 shows that the production mechanism is dominated by natural parity exchange (∼84%). Comparisons are made with predictions from a Regge model and a quark model.

Published
1980
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96. Observation of double φ-meson production in the central region for the reaction pp→pf(K+K−K+K−)ps at 300 GeV/c

Author

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

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Meson production, Atomic physics, Central region, Particle Physics - Experiment
Abstract

The reaction pp→p f (K + K − K + K − )p s in which the K + K − K + K − system is centrally produced has been studied at 300 GeV/ c . φφ production has been observed and the ratio σ (φK + K − )/ σ ( φφ ) is 1.0±0.3. The cross section for central production of φφ is found to be the same at 300 GeV/ c and 85 GeV/ c . An angular analysis of the φφ system favours J P =2 + over 0 − .

Published
1989
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97. Direct ϱ0 production at large pT

Author

H. R. Shaylor, J. Kahane, A. Jacholkowski, B. Ghidini, A. Kirk, I. J. Bloodworth, M. T. Trainor, M. Stassinaki, A. Volte, G. Vassiliadis, R. Childs, R. Sené, M.F. Votruba, B. R. French, Z. Strachman, A. Belogianni, O. Villalobos Baillie, Michele Arturo Caponero, A. Malamant, W. Beusch, M. Benayoun, F. Navach, I. C. Print, J.B. Kinson, Gunnar Ingelman, Ph. Leruste, Roberto Petronzio, E. Quercigh, R. Fini, G. Zito, J. P. Dufey, A. Palano, J. L. Narjoux, Yves Goldschmidt-Clermont, M. Sené, V. Lenti, K. Knudson, J. N. Carney, R. Zitoun, and J. C. Lasalle

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Meson, Scattering, Hadron, Parton, Omega, Atomic and Molecular Physics, and Optics, Nuclear physics, Recoil, High Energy Physics::Experiment, Nuclear Experiment
Abstract

The production of ϱ 0 mesons in hadronic interactions is investigated at high transverse momentum (p T > 2 GeV/c). The data come from a sample of π-N interactions at 300 GeV/c obtained at the CERN Omega Spectrometer, requiring at ϱ 0 → π + π − with p T (pair) > 2 GeV/c to recoil against an opposite particle with p T (opposite) > 1 GeV/c. The signal/(signal + background) ratio of ϱ 0 production shows an increase of 38% as ξ E = p T (opposite)/p T (pair) decreases from 0.5 ξ E ξ E ⩽ 0.5. This increase is not compatible with a QCD model of parton scattering and subsequent fragmentation, and gives a strong indication that direct ϱ 0 production has been observed. Data has now been taken at 150 GeV/c and additional signatures to be used to identify direct ϱ 0 production are discussed.

Published
1989
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98. Search for baryonium production in p and K−p interactions at 12 GeV

Author

P.T. Campbell, T. A. Armstrong, J. Pinfold, B. R. French, A.D.J. Banks, B. Baccari, W.H. Range, D.N. Edwards, M. A. Houlden, J. N. Jackson, S.H.P. Geer, R.A. Donald, J.E.T. Lewis, J.A. Richardson, P.S.L. Booth, L.J. Carroll, and G. Rudolph

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Production (computer science), P system
Abstract

A search has been made for narrow structures in p p, p pπ− and Λ0 p systems. No significant structures are seen. The upper limit at the 99.5% confidence level for production of narrow states in the p p system in the mass range 2.0–2.2 GeV is 40 nb.

Published
1981
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99. Inclusive production in π−p interactions at 16 GeV/c

Author

S. Pensotti, Giuseppe Zito, A. S. Thompson, P. Mättig, D.N. Edwards, B. Ghidini, C. Evangelista, R.A. Donald, W.A. Mitaroff, I.S. Hughes, M. Edwards, K. Müller, G.M. Lewis, V. Picciarelli, C. Best, M. A. Houlden, B. R. French, A. Palano, T. Armstrong, W. Rühmer, David Miller, P.L. Woodworth, E. Paul, L. Pregernig, L. Mandelli, G. Costa, R. M. Turnbull, C. Palazzi-Cerrina, J. Gordon, and R. Strub

Subjects
Scattering cross-section, Nuclear physics, Physics, Nuclear and High Energy Physics, Cross section (physics), Production (computer science), Omega
Abstract

Inclusive K ∗0 production is studied in π − p interactions at 16 GeV/ c with x ϝ > 0.2. The K ∗0 is found to be pre-dominantly centrally produced with cross section σ( K ∗0 ) = (72 ± 12) μb for x ϝ > 0.2 and compares closely to data on K ∗0 production in π + p interactions at the same energy.

Published
1977
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100. Backward elastic scattering and ϱ− production in π−p collisions at 10 GeV/c

Author

G. Costa, B. Ghidini, V. Lenti, R. M. Turnbull, I.S. Hughes, Laura Perini, E. Paul, A. Palano, L. Mandelli, W.A. Mitaroff, R.A. Donald, and B. R. French

Subjects
Baryon, Physics, Elastic scattering, Nuclear and High Energy Physics, Matrix (mathematics), Proton, Production (computer science), Spin density, Atomic physics, Helicity
Abstract

The reactions π − p → p π − and π − p → p ϱ − ( ϱ − → π − π 0 ) at 10 GeV/ c with the proton in the forward direction in the c.m.s. are discussed on the basis of 953 elastic scattering events and 2240 events of the reaction π − p → p π − π 0 . The total backward cross sections are 0.52±0.10 and 1.52±0.28 μ b, respectively. In both cases the production mechanism is compatible with the dominance of the baryonic Δ δ Regge trajectory exchange. The ϱ − decay angular distributions are studied in the u -channel helicity frame and the spin density matrix elements are presented as functions of u .

Published
1982
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