Search for first generation scalar leptoquark pairs in pp collisions at √ s = 1.8 TeV

Physical Review Letters 80:10 (1998) 2051-2056

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, A Baden, V Balamurali, J Balderston, B Baldin, S Banerjee, J Bantly, E Barberis, 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, 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:

We have searched for first generation scalar leptoquark (LQ) pairs in the ev + jets channel using pp collider data (∫L dt ≈ 115pb-1) collected by the D0 experiment at the Fermilab Tevatron during 1992-1996. The analysis yields no candidate events. We combine the results with those from the ee + jets vv + jets channels to obtain 95% confidence level (C.L.) upper limits on the LQ pair production cross section as a function of mass and of β, the branching fraction to a charged lepton. Comparing with the next-to-leading order theory, we set 95% C.L. lower limits on the LQ mass of 225, 204, and 79 GeV/c2 for β = 1, 1/2, and 0, respectively. © 1998 The American Physical Society.

Search for flavor-changing neutral current decays of the top quark in pp collisions at √s = 1.8 TeV

Physical Review Letters 80:12 (1998) 2525-2530

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, 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, 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, RL Coxe, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F De Jongh, S Delchamps, S Dell’agnello

Abstract:

We search for the flavor-changing neutral current decays of the top quark t → λ and t → qZ (here represents the c and u quarks) in pp collisions at √s = 1.8 TeV. We use a dataset (∫ L dt˜ 110pb-1) collected during the 1992-1995 run of the Collider Detector at Fermilab. We set 95% confidence level limits on the branching fractions B(t → qλ) < 3.2% and B(t → qZ) < 33%, consistent with the standard model. © 1998 The American Physical Society.

Search for heavy pointlike dirac monopoles

Physical Review Letters 81:3 (1998) 524-529

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:

We have searched for central production of a pair of photons with high transverse energies in pp̄ collisions at √s=1.8 TeV using 70pb-1 of data collected with the D0 detector at the Fermilab Tevatron in 1994-1996. If they exist virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background and set lower 95% C.L. limits of 610 870 or 1580 GeV/c2 on the mass of a spin 0 1/2 or 1 Dirac monopole. © 1998 The American Physical Society.

Search for long-lived parents of Z° bosons inpp collisions at √s = 1.8 TeV

Physical Review D 58:5 (1998)

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, P Azzi-Bacchetta, N Bacchetta, S Bagdasarov, MW Bailey, P De Barbara, 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, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, S Bettelli, B Bevensee, A Bhatti, K Biery, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, S Blusk, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, R Brunetti, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, M Chertok, G Chiarelli, CN Chiou, F Chlebana, L Christofek, ML Chu, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, D Costanzo, C Couyoumtzelis, D Cronin-Hennessy, R Culbertson, D Dagenhart, T Daniels, F Dejongh, S Dell'Agnello, M Dell'Orso

Abstract:

We search for new long-lived particles which decay to Z0 bosons by looking for Z0→e+e- decays with displaced vertices. We find no evidence for parent particles pf the Z0 with long lifetimes in 90 pb-1 of data from the CDF experiment at Fermilab. We set a cross section limit as a function of the lifetime of the parent particle for both a generic Z0 parent and a fourth-generation, charge -1/3 quark that decays into Z0b. © 1998 The American Physical Society.

Search for the rare decay W± → Dsplusmnγ in pp̄ collisions at √s = 1.8 TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 58:9 (1998) 911011-911015

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, 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, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, S Bettelli, B Bevensee, A Bhatti, K Biery, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, S Blusk, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, R Brunetti, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, M Chertok, G Chiarelli, CN Chiou, F Chlebana, L Christofek, ML Chu, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, D Costanzo, C Couyoumtzelis, D Cronin-Hennessy, R Culbertson, D Dagenhart, T Daniels, F DeJongh, S Dell'Agnello, M Dell'Orso, R Demina, L Demortier