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First observation of Cherenkov ring images using hybrid photon detectors

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 411:2-3 (1998) 249-264

Authors:

E Albrecht, G Barber, JH Bibby, NH Brook, A Duane, M French, V Gibson, R Giles, AW Halley, N Harnew, M John, DG Miller, V O'Shea, R Schomaker, N Smale, D Websdale, G Wilkinson, SA Wotton

Abstract:

A ring-imaging Cherenkov detector, equipped with hybrid photon detectors, has been operated in a charged-particlc beam. Focussed ring images from various particle types were detected using silica aerogel, air and C4F10 gas radiators. The detector, a prototype for the CERN LHC-B experiment, is described and first observations are reported, © IWS Elsevier Science B.V. All rights reserved.
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A search for η′c production in photon-photon fusion at LEP

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 441:1-4 (1998) 479-490

Authors:

P Abreu, W Adam, T Adye, P Adzic, GD Alekseev, R Alemany, PP Allport, S Almehed, U Amaldi, S Amato, EG Anassontzis, P Andersson, A Andreazza, S Andringa, P Antilogus, WD Apel, Y Arnoud, B Asman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, G Barbiellini, R Barbier, DY Bardin, G Barker, A Baroncelli, M Battaglia, M Baubillier, KH Becks, M Begalli, P Beilliere, Y Belokopytov, K Belous, AC Benvenuti, C Berat, M Berggren, D Bertini, D Bertrand, M Besancon, F Bianchi, M Bigi, MS Bilenky, MA Bizouard, D Bloch, HM Blom, M Bonesini, W Bonivento, M Boonekamp, PSL Booth, AW Borgland, G Borisov, C Bosio, O Botner, B Bouquet, C Bourdarios, TJV Bowcock, I Boyko, I Bozovic, M Bozzo, P Branchini, T Brenke, RA Brenner, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, S Cabrera, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, F Carena, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, C Cerruti, V Chabaud, P Charpentier, L Chaussard, P Checchia, GA Chelkov, R Chierici, P Chochula, V Chorowicz, J Chudoba, P Collins, M Colomer, R Contri, E Cortina, G Cosme, F Cossutti, JH Cowell, HB Crawley

Abstract:

A search for the production of the η′c meson, the first radial excitation of the ground state of charmonium ηc(2980), in the photon-photon fusion reaction at LEP has been performed using the data collected by the DELPHI detector during 1992-1996. No evidence of η′c production is found in the mass region 3520-3800 MeV/c2. An upper limit for the ratio of the two-photon widths of the η′c and ηc is obtained. © 1998 Published by Elsevier Science B.V. All rights reserved.
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Two-particle angular correlations in e+e- interactions compared with QCD predictions

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 440:1-2 (1998) 203-216

Authors:

P Abreu, W Adam, T Adye, P Adzic, I Ajinenko, GD Alekseev, R Alemany, PP Allport, S Almehed, U Amaldi, S Amato, EG Anassontzis, P Andersson, A Andreazza, S Andringa, P Antilogus, WD Apel, Y Arnoud, B Asman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, G Barbiellini, R Barbier, DY Bardin, G Barker, A Baroncelli, M Battaglia, M Baubillier, KH Becks, M Begalli, P Beilliere, Y Belokopytov, K Belous, AC Benvenuti, C Berat, M Berggren, D Bertini, D Bertrand, M Besancon, F Bianchi, M Bigi, MS Bilenky, MA Bizouard, D Bloch, HM Blom, M Bonesini, W Bonivento, M Boonekamp, PSL Booth, AW Borgland, G Borisov, C Bosio, O Botner, E Boudinov, B Bouquet, C Bourdarios, TJV Bowcock, I Boyko, I Bozovic, M Bozzo, P Branchini, T Brenke, RA Brenner, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, B Buschbeck, P Buschmann, S Cabrera, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, F Carena, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, C Cerruti, V Chabaud, P Charpentier, L Chaussard, P Checchia, GA Chelkov, R Chierici, P Chliapnikov, P Chochula, V Chorowicz, J Chudoba, P Collins, M Colomer, R Contri, E Cortina

Abstract:

Two-particle angular correlations in jet cones have been measured in e+e- annihilation into hadrons at LEP energies (√s =91 and 183 GeV) and are compared with QCD predictions using the LPHD hypothesis. Two different functions have been tested. While the differentially normalized correlation function shows substantial deviations from the predictions, a globally normalized correlation function agrees well. The size of a αeffS (and other QCD parameters) and its running with the relevant angular scale, the validity of LPHD, and problems due to non-perturbative effects are discussed critically. © 1998 Elsevier Science B.V. All rights reserved.
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Measurement of

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 439:1-2 (1998) 209-224

Authors:

P Abreu, W Adam, T Adye, P Adzic, I Ajinenko, GD Alekseev, R Alemany, PP Allport, S Almehed, U Amaldi, S Amato, EG Anassontzis, P Andersson, A Andreazza, P Antilogus, WD Apel, Y Arnoud, B Åsman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, G Barbiellini, R Barbier, DY Bardin, G Barker, A Baroncelli, M Battaglia, M Baubillier, KH Becks, M Begalli, P Beilliere, Y Belokopytov, K Belous, AC Benvenuti, C Berat, M Berggren, D Bertini, D Bertrand, M Besancon, F Bianchi, M Bigi, MS Bilenky, MA Bizouard, D Bloch, M Bonesini, W Bonivento, M Boonekamp, PSL Booth, AW Borgland, G Borisov, C Bosio, O Botner, E Boudinov, B Bouquet, C Bourdarios, TJV Bowcock, I Boyko, I Bozovic, M Bozzo, P Branchini, T Brenke, RA Brenner, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, S Cabrera, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, M Canepa, F Carena, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, C Cerruti, V Chabaud, M Chapkin, P Charpentier, L Chaussard, P Checchia, GA Chelkov, M Chen, R Chierici, P Chliapnikov, P Chochula, V Chorowicz, J Chudoba, P Collins, M Colomer, R Contri, E Cortina

Abstract:

Decays of W± bosons, produced at LEP2, have been used to measure the |Vcs| element of the Cabibbo-Kobayashi-Maskawa matrix. Values for |Vcs| were extracted both from the measured hadronic branching ratio of W± decays and by tagging the flavour of hadronic jets produced in W± decays. Applying the two methods to the data collected during 1996 at energies of 161 and 172 GeV, DELPHI obtains |Vcs| = 0.091+0.15-0.14(stat) ± 0.05(syst). © 1998 Elsevier Science B.V. All rights reserved.
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Measurement of elastic Υ photoproduction at HERA

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 437:3-4 (1998) 432-444

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, N Coppola, M Corradi, S De Pasquale, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, M Pfeiffer, H Schnurbusch, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, GP Heath, HF Heath, JD McFall, D Piccioni, DG Roff, RJ Tapper, M Capua, L Iannotti, A Mastroberardino, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, J Figiel, K Klimek, MB Przybycień, L Zawiejski, L Adamczyk

Abstract:

The photoproduction reaction γp → μ+ μ-p has been studied in ep interactions using the ZEUS detector at HERA. The data sample corresponds to an integrated luminosity of 43.2pb-1. The Υ meson has been observed in photoproduction for the first time. The sum of the products of the elastic Υ(1S), Υ(2S),Υ(3S) photoproduction cross sections with their respective branching ratios is determined to be 13.3 ± 6.0(stat.)-2.3+2.7(syst.) pb at a mean photon-proton centre of mass energy of 120 GeV. The cross section is above the prediction of a perturbative QCD model. © 1998 Elsevier Science B.V. All rights reserved.
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