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Search for gluinos and squarks at the Fermilab Tevatron collider

Physical Review D Particles Fields Gravitation and Cosmology 56:3 (1997) R1357-R1362

Authors:

RE Blair, KL Byrum, D Crane, SE Kuhlmann, T LeCompte, L Nodulman, J Proudfoot, RG Wagner, AB Wicklund, V Bolognesi, L Breccia, M Deninno, I Fiori, F Rimondi, S Zucchelli, S Behrends, J Bensinger, C Blocker, L Kirsch, JI Lamoureux, J Hauser, F Keyvan, M Lindgren, T Muller, D Neuberger, J Berryhill, M Contreras, R Culbertson, H Frisch, C Grosso-Pilcher, M Hohlmann, S Kopp, J Romano, D Saltzberg, M Shochet, G Sullivan, D Toback, J Wahl, J Wang, P Wilson, D Cronin-Hennessy, JR Dittmann, AT Goshaw, SA Hauger, W Kowald, SH Oh, TJ Phillips, WJ Robertson, C Wang, C Wei, M Yin, MG Albrow, M Atac, A Beretvas, JP Berge, K Biery, M Binkley, E Buckley-Geer, A Byon-Wagner, C Campagnari, S Cihangir, J Cooper, F DeJongh, S Delchamps, R Demina, PF Derwent, JE Elias, B Flaugher, GW Foster, J Freeman, S Geer, SR Hahn, RM Harris, J Hylen, J Incandela, H Jensen, U Joshi, RD Kennedy, R Kephart, H Keutelian, DH Kim, W Koska, E Kovacs, J Kroll, S Lammel, JD Lewis, P Limon, P Lukens, K Maeshima, JP Marriner, T Miao, A Mukherjee, C Nelson, C Newman-Holmes, S Park, J Patrick, KT Pitts, R Plunkett, P Schlabach, EE Schmidt

Abstract:

We report on a search for supersymmetric squark and gluino particles in a data sample of 19 [Formula presented] of [Formula presented] collisions at [Formula presented] TeV recorded by the Collider Detector at Fermilab. We searched for events containing jets plus appreciable missing transverse energy [Formula presented] This signature is indicative of pair production and subsequent decay of squarks and/or gluinos. After all cuts, there are [Formula presented] events with [Formula presented] GeV and three jets, and [Formula presented] events with [Formula presented] GeV and four jets. These numbers of events are consistent with estimates of standard model processes plus detector-induced background sources. The analysis yields lower limits on gluino and squark masses, based on the predictions from the mnimal supersymmetric extension of the standard model. At the [Formula presented] confidence level, we find gluino and squark mass limits up to 216 [Formula presented] assuming equal gluino and squark masses, and gluino mass limits up to [Formula presented] [Formula presented] independent of squark mass. © 1997 The American Physical Society.

Search for new gauge bosons decaying into dileptons in p-p collisions at s) = 1.8TeV

Physical Review Letters 79:12 (1997) 2192-2197

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, G Bolla, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F DeJongh, S Delchamps, S Dell’Agnello, M Dell’Orso, R Demina, L Demortier

Abstract:

We have searched for heavy neutral gauge bosons (Z') in dielectron and dimuon decay modes using 110pb-1 of p-p collisions at √s = 1.8TeV collected with the Collider Detector at Fermilab. We present a limit on the production cross section times branching ratio of a Z' mass. For mass MZ' > 600 GeV/c2, the upper limit is 40 fb at 95% confidence level. We set the lower mass limits of 690, 590, 620, 595, 565, 630, and 600 GeV/c2 for Z'SM, ZΨ, Zψ, Zχ, ZI, ZLR, and ZALRM, respectively. © 1997 The American Physical Society.

Search for new particles decaying into b¯b and produced in association with w bosons decaying into eν or μν at the fermilab tevatron

Physical Review Letters 79:20 (1997) 3819-3824

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P De Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, S Bettelli, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, G Bolla, V Bolognesi, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F De Jongh, S Delchamps, S Dell-Agnello, M Dell’orso, R Demina

Abstract:

We search for new particles that decay into b¯b and are produced with W bosons in p¯p collisions at √s = 1.8TeV. The search uses 109 ± 7pb-1 accumulated by the CDF experiment at Fermilab. We select events with an eν or μν, and two jets, one of them b tagged. The number of events and the two-jet mass distribution are consistent with expectations. Using W+Higgs production as a model for the acceptance, we set an upper limit on the production cross section times branching ratio for the new particle ranging from 14 to 19 pb (95% C.L.) as the particle mass varies from 70 to 120GeV/c2. © 1997 The American Physical Society.

Search for new particles decaying to dijets at CDF

Physical Review D - Particles, Fields, Gravitation and Cosmology 55:9 (1997) R5263-R5268

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, G Bolla, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F DeJongh, S Delchamps, S Dell’Agnello, M Dell’Orso, R Demina, L Demortier

Abstract:

We have used 106 pb[Formula presented] of data collected with the Collider Detector at Fermilab to search for new particles decaying to dijets. We exclude at the 95% confidence level models containing the following new particles: axigluons and flavor universal colorons with a mass between 200 and 980 GeV/[Formula presented], excited quarks with a mass between 80 and 570 GeV/[Formula presented] and between 580 and 760 GeV/[Formula presented], color octet techni-[Formula presented]’s with a mass between 260 and 480 GeV/[Formula presented], [Formula presented] bosons with a mass between 300 and 420 GeV/[Formula presented], and [Formula presented] diquarks with a mass between 290 and 420 GeV/[Formula presented]. © 1997 The American Physical Society.

The ZEUS leading proton spectrometer and its use in the measurement of elastic ρ0 photoproduction at HERA

Zeitschrift Fur Physik C Particles and Fields 73:2 (1997) 253-268

Authors:

M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, JR Okrasiński, J Repond, R Stanek, RL Talaga, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, G Cara Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, A Contin, M Corradi, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, A Pesci, A Polini, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, J Crittenden, R Deffner, M Eckert, L Feld, A Frey, M Geerts, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, UF Katz, S Mengel, E Paul, M Pfeiffer, C Rembser, D Schramm, J Stamm, R Wedemeyer, S Campbell-Robson, A Cassidy, WN Cottingham, N Dyce, B Foster, S George, ME Hayes, GP Heath, HF Heath, D Piccioni, DG Roff, RJ Tapper, R Yoshida, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, A Caldwell, N Cartiglia, Z Jing, W Liu, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, Z Jakubowski, MB Przybycień

Abstract:

The differential cross section dσ/dt for elastic ρ0 photoproduction, γp → ρ0ρ (ρ0 → π+π-), has been measured in ep interactions at HERA. The squared four-momentum exchanged at the proton vertex, t, has been determined directly by measuring the momentum of the scattered proton using the ZEUS Leading Proton Spectrometer (LPS), a large scale system of silicon micro-strip detectors operating close to the HERA proton beam. The LPS allows the measurement of the momentum of high energy protons scattered at small angles with accuracies of 0.4% for the longitudinal momentum and 5 MeV for the transverse momentum. Photoproduction of ρ0 mesons has been investigated in the interval 0.073 < |t| < 0.40 GeV2, for photon virtualities Q2 < 1 GeV2 and photon-proton centre-of-mass energies W between 50 and 100 GeV. In the measured range, the t distribution exhibits an exponential shape with a slope parameter b = 9.8 ± 0.8 (stat.) ± 1.1 (syst.) GeV-2. The use of the LPS eliminates the contamination from events with diffractive dissociation of the proton into low mass states. © Springler-Verlag 1997.