The Q2 dependence of dijet cross sections in γp interactions at HERA

Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 479:1-3 (2000) 37-52

Authors:

J Breitweg, S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Stanek, R Yoshida, MCK Mattingly, G Abbiendi, 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, H Hartmann, K Heinloth, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wieber, DS Bailey, O Barret, NH Brook, B Foster, GP Heath, HF Heath, JD McFall, D Piccioni, E Rodrigues, J Scott, RJ Tapper, M Capua, A Mastroberardino, M Schioppa, G Susinno

Abstract:

The dependence of the photon structure on the photon virtuality, Q2, is studied by measuring the reaction e+p → e+ + jet + jet + X at photon-proton centre-of-mass energies 134 < W < 223 GeV. Events have been selected in the Q2 ranges ≃ 0 GeV2, 0.1-0.55 GeV2, and 1.5-4.5 GeV2, having two jets with transverse energy E(T)/(jet) > 5.5 GeV in the final state. The dijet cross section has been measured as a function of the fractional momentum of the photon participating in the hard process, x(γ)/(OBS). The ratio of the dijet cross section with x(γ)/(OBS) < 0.75 to that with x(γ)/(OBS) > 0.75 decreases as Q2 increases. The data are compared with the predictions of NLO pQCD and leading-order Monte Carlo programs using various parton distribution functions of the photon. The measurements can be interpreted in terms of a resolved photon component that falls with Q2 but remains present at values of Q2 up to 4.5 GeV2. However, none of the models considered gives a good description of the data. (C) Copyright 2000 Elsevier Science B.V.

Direct Measurement of the W Boson Width in ppbar Collisions at roots = 1.8 TeV

ArXiv hep-ex/0004017 (2000)

Authors:

CDF Collaboration, T Affolder

Search for Second and Third Generation Leptoquarks Including Production via Technicolor Interactions in $p \bar{p}$ collisions at $\sqrt{s}=1.8$ TeV

ArXiv hep-ex/0004003 (2000)

Measurement of sin 2β from B→J/ψKS0 with the CDF detector

Physical Review D American Physical Society (APS) 61:7 (2000) 072005

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, M-T Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, S Cihangir, CI Ciobanu, AG Clark, M Cobal, E Cocca, A Connolly, J Conway, J Cooper, M Cordelli, J Guimaraes da Costa, D Costanzo, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F DeJongh, S Dell’Agnello, M Dell’Orso, R Demina, L Demortier, M Deninno, PF Derwent, T Devlin, JR Dittmann, S Donati, J Done, T Dorigo, N Eddy, K Einsweiler, JE Elias, E Engels, W Erdmann, D Errede, S Errede, Q Fan, RG Feild, C Ferretti, I Fiori, B Flaugher, GW Foster, M Franklin, J Freeman, J Friedman, Y Fukui, S Gadomski, S Galeotti, M Gallinaro, T Gao, M Garcia-Sciveres, AF Garfinkel, P Gatti, C Gay, S Geer, DW Gerdes, P Giannetti, P Giromini, V Glagolev, M Gold, J Goldstein, A Gordon, AT Goshaw, Y Gotra, K Goulianos, H Grassmann, C Green, L Groer, C Grosso-Pilcher, M Guenther, G Guillian, RS Guo, C Haber, E Hafen, SR Hahn, C Hall, T Handa, R Handler, W Hao, F Happacher, K Hara, AD Hardman, RM Harris, F Hartmann, K Hatakeyama, J Hauser, J Heinrich, A Heiss, B Hinrichsen, KD Hoffman, C Holck, R Hollebeek, L Holloway, R Hughes, J Huston, J Huth, H Ikeda, M Incagli, J Incandela, G Introzzi, J Iwai, Y Iwata, E James, H Jensen, M Jones, U Joshi, H Kambara, T Kamon, T Kaneko, K Karr, H Kasha, Y Kato, TA Keaffaber, K Kelley, M Kelly, RD Kennedy, R Kephart, D Khazins, T Kikuchi, M Kirk, BJ Kim, HS Kim, SH Kim, YK Kim, L Kirsch, S Klimenko, D Knoblauch, P Koehn, A Köngeter, K Kondo, J Konigsberg, K Kordas, A Korytov, E Kovacs, J Kroll, M Kruse, SE Kuhlmann, K Kurino, T Kuwabara, AT Laasanen, N Lai, S Lami, S Lammel, JI Lamoureux, M Lancaster, G Latino, T LeCompte, AM Lee, S Leone, JD Lewis, M Lindgren, TM Liss, JB Liu, YC Liu, N Lockyer, O Long, M Loreti, D Lucchesi, P Lukens, S Lusin, J Lys, R Madrak, K Maeshima, P Maksimovic, L Malferrari, M Mangano, M Mariotti, G Martignon, A Martin, JAJ Matthews, P Mazzanti, KS McFarland, P McIntyre, E McKigney, M Menguzzato, A Menzione, E Meschi, C Mesropian, C Miao, T Miao, R Miller, JS Miller, H Minato, S Miscetti, M Mishina, N Moggi, E Moore, R Moore, Y Morita, A Mukherjee, T Muller, A Munar, P Murat, S Murgia, M Musy, J Nachtman, S Nahn, H Nakada, T Nakaya, I Nakano, C Nelson, D Neuberger, C Newman-Holmes, C-YP Ngan, P Nicolaidi, H Niu, L Nodulman, A Nomerotski, SH Oh, T Ohmoto, T Ohsugi, R Oishi, T Okusawa, J Olsen, C Pagliarone, F Palmonari, R Paoletti, V Papadimitriou, SP Pappas, A Parri, D Partos, J Patrick, G Pauletta, M Paulini, A Perazzo, L Pescara, MD Peters, TJ Phillips, G Piacentino, KT Pitts, R Plunkett, A Pompos, L Pondrom, G Pope, F Prokoshin, J Proudfoot, F Ptohos, G Punzi, K Ragan, D Reher, A Ribon, F Rimondi, L Ristori, WJ Robertson, A Robinson, T Rodrigo, S Rolli, L Rosenson, R Roser, R Rossin, WK Sakumoto, D Saltzberg, A Sansoni, L Santi, H Sato, P Savard, P Schlabach, EE Schmidt, MP Schmidt, M Schmitt, L Scodellaro, A Scott, A Scribano, S Segler, S Seidel, Y Seiya, A Semenov, F Semeria, T Shah, MD Shapiro, PF Shepard, T Shibayama, M Shimojima, M Shochet, J Siegrist, G Signorelli, A Sill, P Sinervo, P Singh, AJ Slaughter, K Sliwa, C Smith, FD Snider, A Solodsky, J Spalding, T Speer, P Sphicas, F Spinella, M Spiropulu, L Spiegel, L Stanco, J Steele, A Stefanini, J Strologas, F Strumia, D Stuart, K Sumorok, T Suzuki, R Takashima, K Takikawa, M Tanaka, T Takano, B Tannenbaum, W Taylor, M Tecchio, PK Teng, K Terashi, S Tether, D Theriot, R Thurman-Keup, P Tipton, S Tkaczyk, K Tollefson, A Tollestrup, H Toyoda, W Trischuk, JF de Troconiz, S Truitt, J Tseng, N Turini, F Ukegawa, J Valls, S Vejcik, G Velev, R Vidal, R Vilar, I Vologouev, D Vucinic, RG Wagner, RL Wagner, J Wahl, NB Wallace, AM Walsh, C Wang, CH Wang, MJ Wang, T Watanabe, T Watts, R Webb, H Wenzel, WC Wester, AB Wicklund, E Wicklund, HH Williams, P Wilson, BL Winer, D Winn, S Wolbers, D Wolinski, J Wolinski, S Worm, X Wu, J Wyss, A Yagil, W Yao, GP Yeh, P Yeh, J Yoh, C Yosef, T Yoshida, I Yu, S Yu, A Zanetti, F Zetti, S Zucchelli

Measurement of sin2β from B→J/ψKS0 with the CDF detector

Physical Review D - Particles, Fields, Gravitation and Cosmology 61:7 (2000) 1-16

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P De Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S Van Den Brink, C Bromberg, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, S Cihangir, CI Ciobanu, AG Clark, M Cobal, E Cocca, A Connolly, J Conway, J Cooper, M Cordelli, J Guimaraes Da Costa, D Costanzo, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F Dejongh

Abstract:

This paper reports an updated measurement of the standard model CP violation parameter sin 2β using the CDF Detector at Fermilab. The entire run I data sample of 110 pb-1 of proton-antiproton collisions at √s =1.8 TeV is used to identify a signal sample of ∼400 B→J/ψKS0 events, where J/ψ→μ+μ- and KS0 →π+π-. The flavor of the neutral B meson is identified at the time of production by combining information from three tagging algorithms: a same-side tag, a jet-charge tag, and a soft-lepton tag. A maximum likelihood fitting method is used to determine sin2β=0.19-0.44+0.41(stat+syst). This value of sin 2β is consistent with the standard model prediction, based upon existing measurements, of a large positive CP-violating asymmetry in this decay mode. ©2000 The American Physical Society.