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Jet pseudorapidity distribution in direct photon events in pp collisions at vs=1.8TeV

Physical Review D Particles Fields Gravitation and Cosmology 57:3 (1998) 1359-1365

Authors:

F Abe, MG Albrow, SR Amendolia, D Amidei, J Antos, C Anway-Wiese, G Apollinari, H Areti, M Atac, P Auchincloss, F Azfar, P Azzi, N Bacchetta, W Badgett, MW Bailey, J Bao, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Bartalini, 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, S Bertolucci, A Bhatti, K Biery, M Binkley, F Bird, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, D Bortoletto, C Boswell, T Boulos, G Brandenburg, C Bromberg, 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, Y Cen, F Cervelli, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, JD Cunningham, T Daniels, F DeJongh, S Delchamps, S Dell’Agnello, M Dell’Orso, L Demortier, B Denby, M Deninno, PF Derwent, T Devlin, M Dickson, JR Dittmann, S Donati, RB Drucker, A Dunn, K Einsweiler, JE Elias, R Ely

Abstract:

We present the first measurement of the jet pseudorapidity distribution in direct photon events from a sample of (Formula presented) collisions at (Formula presented) recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily from hard quark-gluon Compton scattering, (Formula presented) with the final state quark producing the jet of hadrons. The jet pseudorapidity distribution in this model is sensitive to parton momentum fractions between 0.015 and 0.15. We find that the shape of the measured pseudorapidity distribution agrees well with next-to-leading order QCD calculations. © 1998 The American Physical Society.
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Limits on WWγ and WWZ couplings from IV boson pair production

Physical Review D 58:5 (1998) DUMMY1

Authors:

B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, GA Alves, N Amos, EW Anderson, R Astur, MM Baarmand, L Babukhadia, A Baden, V Balamurali, J Balderston, B Baldin, S Banerjee, J Bantly, E Barberis, JF Bartlett, A Belyaev, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, N Biswas, G Blazey, S Blessing, P Bloom, A Boehnlein, NI Bojko, F Borcherding, C Boswell, A Brandt, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, S Choi, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, L Coney, WE Cooper, C Cretsinger, D Cullen-Vidal, MAC Cummings, D Cutts, OI Dahl, K Davis, K De, K del Signore, M Demarteau, D Denisov, SP Denisov, HT Diehl, M Diesburg, G di Loreto, P Draper, Y Ducros, LV Dudko, SR Dugad, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, T Fahland, MK Fatyga, S Feher, D Fein, T Ferbel, G Finocchiaro, HE Fisk, Y Fisyak, E Flattum, GE Forden

Abstract:

The results of a search for W boson pair production in pp collisions at √s= 1.8 TeV with subsequent decay to eμ, ee, and μμ channels are presented. Five candidate events are observed with an expected background of 3.1 ±0.4 events for an integrated luminosity of approximately 97 pb-1. Limits on the anomalous couplings are obtained from a maximum likelihood fit of the ET spectra of the leptons in the candidate events. Assuming identical WWγ and WWZ couplings, the 95% C.L. limits are -0.62<Δκ<0.77 (X. = 0) and -0.53<λ <0.56 (Δκ=0) for a form factor scale Λ= 1.5 TeV. © 1998 The American Physical Society.
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Measurement of B hadron lifetimes using J/ψ final states at CDF

Physical Review D - Particles, Fields, Gravitation and Cosmology 57:9 (1998) 5382-5401

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, A Amadon, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, S Bagdasarov, MW Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin

Abstract:

The average bottom-hadron and individual (Formula presented), (Formula presented), and (Formula presented) meson lifetimes have been determined using decays with a (Formula presented) in the final state. The data sample consists of 110 pb(Formula presented) of (Formula presented) collisions at (Formula presented) TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992–1995. For the average lifetime of (Formula presented) hadrons decaying into (Formula presented)+X, we obtain (Formula presented) For the (Formula presented) and (Formula presented) meson lifetimes, we determine (Formula presented) (Formula presented) and (Formula presented) For the (Formula presented) meson lifetime, we find (Formula presented) ps. © 1998 The American Physical Society.
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Measurement of dijet angular distributions and search for quark compositeness

Physical Review Letters 80:4 (1998) 666-671

Authors:

B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, GA Alves, E Amidi, N Amos, EW Anderson, R Astur, MM Baarmand, A Baden, V Balamurali, J Balderston, B Baldin, S Banerjee, J Bantly, JF Bartlett, K Bazizi, A Belyaev, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, N Biswas, G Blazey, S Blessing, P Bloom, A Boehnlein, NI Bojko, F Borcherding, C Boswell, A Brandt, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, S Choi, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, WE Cooper, C Cretsinger, D Cullen-Vidal, MAC Cummings, D Cutts, OI Dahl, K Davis, K De, K Del Signore, M Demarteau, D Denisov, SP Denisov, HT Diehl, M Diesburg, G Di Loreto, P Draper, Y Ducros, LV Dudko, SR Dugad, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, T Fahland, M Fatyga, MK Fatyga, J Featherly, S Feher, D Fein, T Ferbel, G Finocchiaro, HE Fisk, Y Fisyak, E Flattum

Abstract:

We have measured the dijet angular distribution in s = 1.8 TeV pp collisions using the D0 detector. Order αs3 QCD predictions are in good agreement with the data. At 95% confidence limit the data exclude models of quark compositeness in which the contact interaction scale is below 2 TeV. © 1998 The American Physical Society.
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Measurement of jet shapes in photoproduction at HERA

European Physical Journal C 2:1 (1998) 61-75

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, M Corradi, S de Pasquale, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, F Ricci, 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, UF Katz, R Kerger, E Paul, M Pfeiffer, C Rembser, J Stamm, R Wedemeyer, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, ME Hayes, GP Heath, HF Heath, JD McFall, D Piccioni, DG Roff, RJ Tapper, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, 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

Abstract:

The shape of jets produced in quasi-real photon-proton collisions at centre-of-mass energies in the range 134-277 GeV has been measured using the hadronic energy flow. The measurement was done with the ZEUS detector at HERA. Jets are identified using a cone algorithm in the η - φ plane with a cone radius of one unit. Measured jet shapes both in inclusive jet and dijet production with transverse energies EjetT > 14 GeV are presented. The jet shape broadens as the jet pseudorapidity (ηjet) increases and narrows as EjetT increases. In dijet photoproduction, the jet shapes have been measured separately for samples dominated by resolved and by direct processes. Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct processes describe well the measured jet shapes except for the inclusive production of jets with high ηjet and low EjetT. The observed broadening of the jet shape as ηjet increases is consistent with the predicted increase in the fraction of final state gluon jets.
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