27 results on '"Malamant, A."'
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2. Pulsed Production of Antihydrogen in AEgIS
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Zurlo N., Auzins M., Bergmann B., Bonomi G., Brusa R.S., Burian P., Camper A., Castelli F., Ciury R., Consolati G., Doser M., Farricker A., Glöggler L., Graczykowski Ł., Grosbart M., Guatieri F., Gusakova N., Haider S., Huck S., Janik M., Kasprowicz G., Khatri G., Kłosowski Ł., Kornakov G., Krumins V., Lappo L., Linek A., Malamant J., Malbrunot C., Mariazzi S., Nowak L., Nowicka D., Oswald E., Pagano D., Penasa L., Piwiński M., Pospisil S., Povolo L., Prelz F., Rangwala S., Rienäcker B., Røhne O.M., Rotondi A., Sandaker H., Smolyanskiy P., Sowiński T., Tefelski D., Testera G., Volponi M., Welsch C.P., Wolz T., Zawada M., and Zielinski J.
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Physics ,QC1-999 - Abstract
Low-temperature antihydrogen atoms are an effective tool to probe the validity of the fundamental laws of Physics, for example the Weak Equivalence Principle (WEP) for antimatter, and -generally speaking- it is obvious that colder atoms will increase the level of precision. After the first production of cold antihydrogen in 2002 [1], experimental efforts have substantially progressed, with really competitive results already reached by adapting to cold antiatoms some well-known techniques pre- viously developed for ordinary atoms. Unfortunately, the number of antihydrogen atoms that can be produced in dedicated experiments is many orders of magnitude smaller than of hydrogen atoms, so the development of novel techniques to enhance the production of antihydrogen with well defined (and possibly controlled) conditions is essential to improve the sensitivity. We present here some experimental results achieved by the AEgIS Collaboration, based at the CERN AD (Antiproton Decelerator) on the production of antihydrogen in a pulsed mode where the production time of 90% of atoms is known with an uncertainty of ~ 250 ns [2]. The pulsed antihydrogen source is generated by the charge-exchange reaction between Rydberg positronium (Ps*) and an antiproton (p¯): p¯ + Ps* → H¯* + e−, where Ps* is produced via the implantation of a pulsed positron beam into a mesoporous silica target, and excited by two consecutive laser pulses, and antiprotons are trapped, cooled and manipulated in Penning-Malmberg traps. The pulsed production (which is a major milestone for AEgIS) makes it possible to select the antihydrogen axial temperature and opens the door for the tuning of the antihydrogen Rydberg states, their de-excitation by pulsed lasers and the manipulation through electric field gradients. In this paper, we present the results achieved by AEgIS in 2018, just before the Long Shutdown 2 (LS2), as well as some of the ongoing improvements to the system, aimed at exploiting the lower energy antiproton beam from ELENA [3].
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- 2023
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3. Search for higher twists in meson resonance production in π− N interactions atPT≥2 GeV/c
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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
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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.
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- 1995
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4. Study of the vector-vector final states centrally produced in pp interactions at 300 GeV/c
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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
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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.
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- 1994
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5. Shape distortions of meson resonances produced in hadron interactions atP T≧2 GeV/c
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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
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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.
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- 1994
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6. Study of Φ and f2(1270) meson polarization atp T ≥2 GeV/c in π- interactions at CERN SPS
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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
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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.
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- 1994
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7. Study of the centrally produced ωρ0 and ωω systems inpp interactions at 300 GeV/c
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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
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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 .
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- 1993
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8. Transverse momentum distributions for meson resonances at central rapidity andP T≧2 GeV/c
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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
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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.
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- 1993
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9. production in sulphur-tungsten interactions at 200 GeV/c per nucleon
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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
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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.
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- 1991
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10. Study of the centrally producer ?? andK $$\bar K$$ systems at 85 and 300 GeV/c
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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
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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.
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- 1991
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11. Λ and anti-Λ production in 32S + W and p + W interactions at 200 A GeV/c
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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
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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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12. Multi-strange baryon and antibaryon production in sulphur-tungsten and proton-tungsten interactions at 200 GeV/c per nucleon
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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
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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.
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- 1991
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13. 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
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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
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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.
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- 1990
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14. A search for non-q mesons in the central region
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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
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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.
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- 1990
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15. Strangeness production in sulphur-tungsten interactions at 200 GeV/c per nucleon
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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
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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.
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- 1990
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16. Λ and production in sulphur-tungsten interactions at 200 GeV/c per nucleon
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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
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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.
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- 1990
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17. A study of the centrally produced ?+???0 system formed in the reactionpp?p f (?+???0)p s at 300 GeV/c
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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
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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).
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- 1990
- Full Text
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18. Short-range correlations in hadron pair production at p$_{T}$ $\geq$ 2 GeV/c
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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
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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
19. Production of multistrange baryons and antibaryons in sulphur-tungsten interactions at 200 GeV/c per nucleon
- Author
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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
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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
20. Evidence for new states produced in the central region in the reaction pp→pf(π+π−π+π−)ps at 300 GeV/c
- Author
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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
- Full Text
- View/download PDF
21. Evidence for higher twist mechanisms in prompt ϱ0-meson production at PT > 2 GeV/c in 300 GeV/c Π−N interactions
- Author
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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
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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
- Full Text
- View/download PDF
22. Preliminary results from the WA85 experiment on Λ and gL production in 200 a GeV/C sulphur-tungsten interactions
- Author
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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
- Full Text
- View/download PDF
23. Observation of centrally produced (1720) in the reaction at 300 GeV/c
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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
- Full Text
- View/download PDF
24. 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
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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
- Full Text
- View/download PDF
25. Direct ϱ0 production at large pT
- Author
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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
- Full Text
- View/download PDF
26. A search for glueballs in the central region in the reaction pp → pf(X0)ps at 300 GeV/c using the CERN Ω spectrometer
- Author
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E. Quercigh, Giuseppe Zito, V. Lenti, M. Stassinaki, M. T. Trainor, I. J. Bloodworth, J. L. Narjoux, A. Kirk, A. Malamant, Ph. Leruste, Presented by Andrew Kirk, Yves Goldschmidt-Clermont, A. Jacholkowski, B. R. French, G. Vassiliadis, N. Redaelli, T. A. Armstrong, Leonardo Paolo Rossi, M. Sene, J.B. Kinson, R. Childs, H. R. Shaylor, A. Palano, K. Knudson, R. Zithoun, J. N. Carney, M.F. Votruba, O. Villalobos Baillie, Michele Arturo Caponero, R. Sené, B. Ghidini, F. Navach, W. Beusch, M. Benayoun, and J. Kahane
- Subjects
Nuclear physics ,Momentum ,Physics ,Particle physics ,Large Hadron Collider ,Meson ,Spectrometer ,Antiproton ,Transverse momentum ,Mass spectrum ,Central region ,Particle Physics - Experiment - Abstract
The aim of this experiment is to search for gluonic mesons in the reaction pp → pf(X0)ps at 300 GeV/c incident momentum, where the X0 system is a centrally produced meson. Preliminary results are presented on the two‐body (π+π−, K+K−, K0SK0S, pp), three body (K0SK±π±) and four‐body (2π+2π−) decays of the X0 system.
- Published
- 1989
- Full Text
- View/download PDF
27. Use of silicon microstrip detectors for precise measurement of high momenta
- Author
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A. Jacholkowski, I. J. Bloodworth, Yves Goldschmidt-Clermont, B. Ghidini, E. Quercigh, A. Malamant, R. Zitoun, M. T. Trainor, O. Villalobos Baillie, J. L. Narjoux, A. Kirk, W. Beusch, R. Sené, T. A. Armstrong, N. G. Redaelli, R. Childs, H. R. Shaylor, M. Benayoun, Giuseppe Zito, M. Sené, M.F. Votruba, F. Navach, B. R. French, Michele Arturo Caponero, J.B. Kinson, G. Vassiliadis, Leonardo Paolo Rossi, Ph. Leruste, J. N. Carney, A. Palano, J. Kahane, V. Lenti, M. Stassinaki, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and WA76
- Subjects
Physics ,Nuclear and High Energy Physics ,Large Hadron Collider ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,business.industry ,01 natural sciences ,7. Clean energy ,law.invention ,Nuclear physics ,Momentum ,Telescope ,Optics ,law ,0103 physical sciences ,Calibration ,High Energy Physics::Experiment ,Detectors and Experimental Techniques ,010306 general physics ,business ,Instrumentation ,Silicon microstrip detectors - Abstract
The WA76 experiment performed at the Ω facility at CERN required a high precision measurement of the forward produced particle whose momentum was close to 300 GeV/c. A telescope made of 12 silicon microstrip detectors has been built and operated for such a purpose.
- Published
- 1989
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