Measurement of Diffractive Dijet Production at the Fermilab Tevatron

Physical Review Letters 79:14 (1997) 2636-2641

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 report the observation and measurement of the rate of diffractive dijet production at the Fermilab Tevatron p¯p collider at √s=1.8TeV. In events with two jets of ET>20GeV, 1.8<|η|<3.5, and η1η2>0, we find that the diffractive to nondiffractive production ratio is RJJ=[0.75±0.05(stat)±0.09(syst)]%. By comparing this result, in combination with our measured rate for diffractive W boson production reported previously, with predictions based on a hard partonic pomeron structure, we determine the pomeron gluon fraction to be fg=0.7±0.2. © 1997 American Physical Society.

Measurement of the decay rate and the parameter αK* of the decay KL → μμγ

Zeitschrift Fur Physik C Particles and Fields 76:4 (1997) 653-657

Authors:

V Fanti, A Lai, L Musa, A Nappi, MG Setzu, RW Moore, DJ Munday, MA Parker, SF Takach, TO White, G Barr, G Bocquet, J Bremer, A Ceccucci, J Cogan, D Cundy, N Doble, G Fischer, W Funk, L Gatignon, A Gianoli, A Gonidec, P Grafstrom, W Kubischta, V Marzulli, G Kesseler, JP Matheys, A Norton, S Palestini, B Panzer-Steindel, H Taureg, M Velasco, O Vossnack, H Wahl, V Kekelidze, I Kojevnikov, I Potrebenikov, G Tatichvili, A Tkatchev, L Bertolotto, O Boyle, B Hay, NE Mc Kay, G Oakland, H Parsons, KJ Peach, C Talamonti, A Walker, P Dalpiaz, J Duclos, A Formica, PL Frabetti, M Martini, F Petrucci, M Porcu, F Rossi, M Savrie, C Simani, A Bizzeti, M Calvetti, M Lenti, A Michetti, HG Becker, T Beier, H Blümer, P Buchholz, D Coward, C Ebersberger, A Kalter, K Kleinknecht, U Koch, L Köpke, F Leber, S Luitz, B Renk, J Scheidt, J Schmidt, V Schönharting, R Wilhelm, O Zeitnitz, JC Chollet, S Crépé, L Fayard, J Ocariz, G Unal, G Anzivino, P Cenci, P Lubrano, M Pepe, P Calafiura, R Carosi, R Casali, C Cerri, F Costantini, R Fantechi, S Giudici, B Gorini, I Mannelli, G Pierazzini, M Sozzi

Abstract:

The rate of the decay of the neutral K meson into KL0 → μμγ has been measured with the NA48 detector at the CERN SPS. A total of 59 events has been observed with an estimated background of 14 events. The overall Kaon flux was determined to be 1.2 × 109. This observation corresponds to a branching ratio of (3.4 ± 0.6stat ± 0.4sys) × 10-7. Using this branching ratio the parameter αK* describing the relative strength of the two contributing amplitudes to this decay, through intermediate pseudoscalar or vector-like mesons, was measured to be αK*= -0.04-0.21+0.24. © Springer-Verlag 1997.

Measurement of the top quark pair production cross section in p¯p collisions

Physical Review Letters 79:7 (1997) 1203-1208

Authors:

S Abachi, 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, J Borders, 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 Cumings, 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, J Drinkard, 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

Abstract:

We present a measurement of the t¯t production cross section in p¯p collisions at √s=1.8TeV by the D0 experiment at the Fermilab Tevatron. The measurement is based on data from an integrated luminosity of approximately 125pb−1 accumulated during the 1992–1996 collider run. We observe 39 t¯t candidate events in the dilepton and lepton+jets decay channels with an expected background of 13.7 ± 2.2 events. For a top quark mass of 173.3 GeV/c2, we measure the t¯t production cross section to be 5.5 ± 1.8 pb. © 1997 The American Physical Society.

Properties of jets in W boson events from 1.8 TeV p̄ p collisions

Physical Review Letters 79:24 (1997) 4760-4765

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, 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, 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, S Blusk, A Bodek, W Bokhari, G Bolla, V Bolognesi, Y Bonushkin, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, J Cassada, A Castro, D Cauz, Y Cen, A Cerri, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, M Chertok, 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

Abstract:

We present a study of events with W bosons and hadronic jets produced in p̄p collisions at a center of mass energy of 1.8 TeV. The data consist of 51 400 W± → e± decay candidates from 108 pb-1 of integrated luminosity collected using the CDF detector at the Fermilab Tevatron Collider. Cross sections and jet production properties have been measured for W + ≥1 to ≥4 jet events. The data are compared to predictions of leading-order QCD matrix element calculations with added gluon radiation and simulated parton fragmentation.

Properties of six-jet events with large six-jet mass at the Fermilab proton-antiproton collider

Physical Review D - Particles, Fields, Gravitation and Cosmology 56:5 (1997) 2532-2543

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 describe the properties of six-jet events, with the six-jet mass exceeding [Formula presented] produced at the Fermilab proton-antiproton collider operating at a center-of-mass energy of 1.8 TeV. Observed distributions for a set of 20 multijet variables are compared with predictions from the HERWIG QCD parton shower Monte Carlo program, the NJETS leading order QCD matrix element Monte Carlo program, and a phase-space model in which six-jet events are distributed uniformly over the kinematically allowed region of the six-body phase space. In general the QCD predictions provide a good description of the observed six-jet distributions. © 1997 The American Physical Society.