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Search for new particles decaying to dijets in pp» collisions at s=1.8 TeV

Physical Review Letters 74:18 (1995) 3538-3543

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, 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, E Engels

Abstract:

We have used 19 pb-1 of data collected with the Collider Detector at Fermilab to search for new particles decaying to dijets. We exclude at 95% confidence level models containing the following new particles: axigluons with mass between 200 and 870 GeV/ c2, excited quarks with mass between 80 and 570 GeV/ c2, and color octet technirhos with mass between 320 and 480 GeV/ c2. © 1995 The American Physical Society.

Search for squarks and gluinos in pp collisions at s=1.8 TeV

Physical Review Letters 75:4 (1995) 618-623

Authors:

S Abachi, B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, J Alitti, G Lvarez, GA Alves, E Amidi, N Amos, EW Anderson, SH Aronson, R Astur, RE Avery, A Baden, V Balamurali, J Balderston, B Baldin, J Bantly, JF Bartlett, K Bazizi, J Bendich, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, A Bischoff, N Biswas, G Blazey, S Blessing, A Boehnlein, NI Bojko, F Borcherding, J Borders, C Boswell, A Brandt, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, D Casey, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, L Chevalier, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, WE Cooper, C Cretsinger, D Cullen-Vidal, M Cummings, D Cutts, OI Dahl, K De, M Demarteau, R Demina, K Denisenko, N Denisenko, D Denisov, SP Denisov, W Dharmaratna, HT Diehl, M Diesburg, G Di Loreto, R Dixon, P Draper, J Drinkard, Y Ducros, SR Dugad, S Durston-Johnson, D Edmunds, AO Efimov, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, S Fahey, T Fahland, M Fatyga, MK Fatyga

Abstract:

We present a search for events consistent with the production and decay of the squarks and gluinos of the minimal supersymmetric standard model (MSSM) in the D0 detector at the Fermilab Tevatron pp collider. We examined data for events containing large missing transverse energy and three or more jets. We observed no excess of events above the expected yield from standard model processes. For a choice of MSSM parameter values, we set a lower limit at the 95% confidence level on the mass of the gluino of 144 GeV /c2 for all squark masses and a lower limit of 212 GeV /c2 for equal squark and gluino masses. © 1995 The American Physical Society.

Second generation leptoquark search in pp̄ collisions at s=1.8 TeV

Physical Review Letters 75:20 (1995) 3618-3623

Authors:

S Abachi, B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, J Alitti, G Alvarez, GA Alves, E Amidi, N Amos, EW Anderson, SH Aronson, R Astur, RE Avery, A Baden, V Balamurali, J Balderston, B Baldin, J Bantly, JF Bartlett, K Bazizi, J Bendich, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, A Bischoff, 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, D Casey, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, L Chevalier, 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 De, M Demarteau, R Demina, K Denisenko, D Denisov, SP Denisov, W Dharmaratna, HT Diehl, M Diesburg, G Di Loreto, R Dixon, P Draper, J Drinkard, Y Ducros, SR Dugad, S Durston-Johnson, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, S Fahey, T Fahland, M Fatyga, MK Fatyga, J Featherly

Abstract:

We report on a search for second generation scalar leptoquarks with the DO detector at the Fermilab Tevatron pp̄ collider at s=1.8 TeV. This search is based on 12.7 pb-1 of data. Second generation leptoquarks are assumed to be produced in pairs and to decay into a muon and quark with branching ratio β or into a neutrino and quark with branching ratio 1-β. We obtain cross section times branching ratio limits as a function of leptoquark mass and set lower limits on the leptoquark mass at the 95% confidence level. © 1995 The American Physical Society.

51ÁÔÆæÈë¿Ú of the strong coupling constant using W+Jet processes

Physical Review Letters 75:18 (1995) 3226-3231

Authors:

S Abachi, B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, J Alitti, G Lvarez, GA Alves, E Amidi, N Amos, EW Anderson, SH Aronson, R Astur, RE Avery, A Baden, V Balamurali, J Balderston, B Baldin, J Bantly, JF Bartlett, K Bazizi, J Bendich, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, A Bischoff, 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, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, L Chevalier, 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 De, M Demarteau, R Demina, K Denisenko, N Denisenko, D Denisov, SP Denisov, W Dharmaratna, HT Diehl, M Diesburg, G Di Loreto, R Dixon, P Draper, J Drinkard, Y Ducros, SR Dugad, S Durston-Johnson, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, S Fahey, T Fahland, M Fatyga

Abstract:

The ratio of the number of W+1 jet to W+0 jet events is measured with the D0 detector using data from the 1992-93 Tevatron Collider run. For the W→eν channel with a minimum jet ET cutoff of 25 GeV, the experimental ratio is 0.065±0.003stat±0.007syst. Next-to-leading order QCD predictions for various parton distributions agree well with each other and are all over 1 standard deviation below the measurement. Varying the strong coupling constant αs in both the parton distributions and the partonic cross sections simultaneously does not remove this discrepancy. © 1995 The American Physical Society.

51ÁÔÆæÈë¿Ú of tt production in pp collisions using total transverse energy

Physical Review Letters 75:22 (1995) 3997-4002

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, C Anway-Wiese, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, P Auchincloss, 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, 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, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, D Bortoletto, J Boudreau, L Breccia, 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, D Cauz, 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, D Cronin-Hennessy, R Culbertson, 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

Abstract:

We analyze a sample of W+jet events collected with the Collider Detector at Fermilab (CDF) in pp» collisions at s=1.8 TeV to study tt» production. We employ a simple kinematical variable H, defined as the scalar sum of the transverse energies of the lepton, neutrino, and jets. For events with a W boson and four or more jets, the shape of the H distribution deviates by 3.8 standard deviations from that expected from known backgrounds to tt» production. However, this distribution agrees well with a linear combination of background and tt» events, the agreement being best for a top mass of 180 GeV/c2. © 1995 The American Physical Society.