Search for squarks and gluinos in single-photon events with jets and large missing transverse energy in p¯p collisions at √ s = 1.8 TeV

Physical Review Letters 82:1 (1999) 29-34

Authors:

B Abbott, M Abolins, V Abramov, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, GA Alves, N Amos, EW Anderson, R Astur, MM Baarmand, VV Babintsev, L Babukhadia, A Baden, V Balamurali, B Baldin, S Banerjee, J Bantly, E Barberis, P Baringer, 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 Breedon, 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, A Dyshkant, 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

Abstract:

We search for new physics using events with one high transverse energy photon, two or more jets, and an apparent imbalance in transverse energy, in pp¯ collisions at the Fermilab Tevatron at √ s=1.8TeV. Such events are predicted for production of supersymmetric particles in some models. No excess is observed beyond expected background. For the parameter space of the minimal supersymmetric standard model with branching fraction B(∼ Χ02→ = γ ∼ Χ01) = 1 and mΧ02- mΧ01> 20 GeV, we obtain a 95% confidence level lower mass limit of 310 GeV for equal mass squarks and gluinos. The results are also interpreted in models with low energy gauge mediated supersymmetry breaking. © 1999 The American Physical Society.

Search for squarks and gluinos in events containing jets and a large imbalance in transverse energy

Physical Review Letters 83:24 (1999) 4937-4942

Authors:

B Abbott, M Abolins, V Abramov, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, GA Alves, N Amos, EW Anderson, MM Baarmand, VV Babintsev, L Babukhadia, A Baden, B Baldin, S Banerjee, J Bantly, E Barberis, P Baringer, 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 Breedon, G Briskin, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, SV Chekulaev, W Chen, S Choi, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, L Coney, WE Cooper, D Coppage, 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, A Dyshkant, 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, HE Fisk, Y Fisyak, E Flattum, GE Forden

Abstract:

Using data corresponding to an integrated luminosity of 79pb−1, D0 has searched for events containing multiple jets and large missing transverse energy in pp¯ collisions at √s = 1.8TeV at the Fermilab Tevatron collider. Observing no significant excess beyond what is expected from the standard model, we set limits on the masses of squarks and gluinos and on the model parameters m0 and m1/2, in the framework of the minimal low-energy supergravity models of supersymmetry. For tanβ=2 and A0 = 0, with μ < 0, we exclude all models with m˜q<250 GeV/c2. For models with equal squark and gluino masses, we exclude m < 260 GeV/c2. © 1999 The American Physical Society.

Small angle J/ψ production in pp¯ collisions at √s=1.8TeV

Physical Review Letters 82:1 (1999) 35-40

Authors:

B Abbott, M Abolins, V Abramov, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, GA Alves, N Amos, EW Anderson, R Astur, MM Baarmand, VV Babintsev, L Babukhadia, A Baden, V Balamurali, B Baldin, S Banerjee, J Bantly, E Barberis, P Baringer, 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 Breedon, 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, A Dyshkant, 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

Abstract:

This paper presents the first measurement of inclusive J/ψ production cross section in the forward pseudorapidity region 2.5≤|ηJ/ψ|≤3.7 in pp¯ collisions at √S=1.8 TeV. The results are based on 9.8 pb−1 of data collected using the D0 detector at the Fermilab Tevatron Collider. The inclusive J/ψ cross section for transverse momenta between 1 and 16 GeV/c is compared with theoretical models of charmonium production. © 1998 The American Physical Society.

Studies of WW and WZ production and limits on anomalous WWγ and WWZ couplings

Physical Review D - Particles, Fields, Gravitation and Cosmology 60:7 (1999)

Authors:

B Abbott, M Abolins, V Abramov, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, V Akimov, GA Alves, N Amos, EW Anderson, MM Baarmand, VV Babintsev, L Babukhadia, A Baden, B Baldin, S Banerjee, J Bantly, E Barberis, P Baringer, 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 Breedon, G Briskin, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, SV Chekulaev, W Chen, S Choi, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, L Coney, WE Cooper, D Coppage, 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, A Dyshkant, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, H Evans, VN Evdokimov, T Fahland, MK Fatyga, S Feher, D Fein, T Ferbel, HE Fisk, Y Fisyak

Abstract:

Evidence of anomalous (Formula presented) and (Formula presented) production was sought in (Formula presented) collisions at a center-of-mass energy of (Formula presented) The final states (Formula presented) jet (Formula presented) (Formula presented) and (Formula presented) were studied using a data sample corresponding to an integrated luminosity of approximately (Formula presented) No evidence of anomalous diboson production was found. Limits were set on anomalous (Formula presented) and (Formula presented) couplings and were combined with our previous results. The combined 95% confidence level anomalous coupling limits for (Formula presented) are (Formula presented) (Formula presented) and (Formula presented) (Formula presented) assuming the (Formula presented) couplings are equal to the (Formula presented) couplings. © 1999 The American Physical Society.

The measurement of sin(2β)

Proceedings of Science 3 (1999)

Abstract:

Since the first observation in 1964, CP violation remains one of the most elusive aspects of the standard model. The CDF collaboration has reported the first evidence of CP violation in the B system using the world's largest sample of B → J/ψKS0 decays. The direct measurement of sin(2β)=0.79+0.41−0.44(combined statistical and systematic error) agrees with the standard model predictions. New data collected from the B-factories and from the upgraded experiments at the Tevatron should allow a more precise measurement of sin 2β in the near future.