ATLAS

Research group

Research theme

Sub department

About

Related research groups

Search for scalar leptoquark pairs decaying to electrons and jets in p®p collisions

Physical Review Letters 79:22 (1997) 4321-4326

Authors:

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, 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 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, M Fatyga, MK Fatyga, J Featherly, S Feher, D Fein, T Ferbel, G Finocchiaro, HE Fisk, Y Fisyak, E Flattum

Abstract:

We have searched for the pair production of first generation scalar leptoquarks in the eejj channel using the full data set (123pb−1) collected with the D0 detector at the Fermilab Tevatron during 1992-1996. We observe no candidates with an expected background of approximately 0.4 events. Comparing the experimental 95% confidence level upper limit to theoretical calculations of the cross section with the assumption of a 100% branching fraction of eq, we set a lower limit on the mass of a first generation scalar leptoquark of 225 GeV/c2. The results of this analysis rule out the interpretation of the excess of high Q2 events at DESY HERA as leptoquarks which decay exclusively to eq. © 1997 The American Physical Society.
More details from the publisher

Studies of gauge boson pair production and trilinear couplings

Physical Review D - Particles, Fields, Gravitation and Cosmology 56:11 (1997) 6742-6778

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, 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 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, 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, HE Fisk

Abstract:

The gauge boson pair production processes [Formula presented], [Formula presented], [Formula presented], and [Formula presented] were studied using [Formula presented] collisions corresponding to an integrated luminosity of approximately [Formula presented] at a center-of-mass energy of [Formula presented] TeV. Analysis of [Formula presented] production with subsequent [Formula presented] boson decay to [Formula presented] [Formula presented] is reported, including a fit to the [Formula presented] spectrum of the photons which leads to limits on anomalous [Formula presented] couplings. A search for [Formula presented] production with subsequent decay to [Formula presented] [Formula presented] is presented, leading to an upper limit on the [Formula presented] production cross section and limits on anomalous [Formula presented] and [Formula presented] couplings. A search for high [Formula presented] [Formula presented] bosons in [Formula presented] and [Formula presented] production is described, where one [Formula presented] boson decays to an electron and a neutrino and the second [Formula presented] boson or the [Formula presented] boson decays to two jets. A maximum likelihood fit to the [Formula presented] spectrum of [Formula presented] bosons resulted in limits on anomalous [Formula presented] and [Formula presented] couplings. A combined fit to the three data sets which provided the tightest limits on anomalous [Formula presented] and [Formula presented] couplings is also described. Limits on anomalous [Formula presented] and [Formula presented] couplings are presented from an analysis of the photon [Formula presented] spectrum in [Formula presented] events in the decay channels [Formula presented] of the [Formula presented] boson. © 1997 The American Physical Society.
More details from the publisher

Study of the ZZγ and Zγγ Couplings in Z(νν)γ Production

Physical Review Letters 78:19 (1997) 3640-3645

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, 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 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, 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, HE Fisk

Abstract:

We have measured the ZZγ and ZZγ couplings by studying 13.1 pb−1 of pp¯→Etγ+ X data at √s = 1.8 TeV with the Dø detector at the Fermilab Tevatron Collider. This is the first study of hadronic Zγ production in the neutrino decay channel. Combining this measurement with our previous results using Z→ee and μμ yields the most stringent 95% C.L. limits to date on anomalous couplings: |h30Z|<0.4, |h40Z|<0.06 (λ=750 GeV. © 1997 The American Physical Society.
More details from the publisher

The ZEUS leading proton spectrometer and its use in the measurement of elastic ρ0 photoproduction at HERA

Zeitschrift Fur Physik C Particles and Fields 73:2 (1997) 253-268

Authors:

M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, JR Okrasiński, J Repond, R Stanek, RL Talaga, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, G Cara Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, A Contin, M Corradi, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, A Pesci, A Polini, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, J Crittenden, R Deffner, M Eckert, L Feld, A Frey, M Geerts, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, UF Katz, S Mengel, E Paul, M Pfeiffer, C Rembser, D Schramm, J Stamm, R Wedemeyer, S Campbell-Robson, A Cassidy, WN Cottingham, N Dyce, B Foster, S George, ME Hayes, GP Heath, HF Heath, D Piccioni, DG Roff, RJ Tapper, R Yoshida, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, A Caldwell, N Cartiglia, Z Jing, W Liu, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, Z Jakubowski, MB Przybycień

Abstract:

The differential cross section dσ/dt for elastic ρ0 photoproduction, γp → ρ0ρ (ρ0 → π+π-), has been measured in ep interactions at HERA. The squared four-momentum exchanged at the proton vertex, t, has been determined directly by measuring the momentum of the scattered proton using the ZEUS Leading Proton Spectrometer (LPS), a large scale system of silicon micro-strip detectors operating close to the HERA proton beam. The LPS allows the measurement of the momentum of high energy protons scattered at small angles with accuracies of 0.4% for the longitudinal momentum and 5 MeV for the transverse momentum. Photoproduction of ρ0 mesons has been investigated in the interval 0.073 < |t| < 0.40 GeV2, for photon virtualities Q2 < 1 GeV2 and photon-proton centre-of-mass energies W between 50 and 100 GeV. In the measured range, the t distribution exhibits an exponential shape with a slope parameter b = 9.8 ± 0.8 (stat.) ± 1.1 (syst.) GeV-2. The use of the LPS eliminates the contamination from events with diffractive dissociation of the proton into low mass states. © Springler-Verlag 1997.
More details from the publisher

Color coherent radiation in multijet events from p(p)over-bar collisions at √s=1.8 TeV

PHYSICS LETTERS B 414:3-4 (1997) 419-427

Authors:

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, 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 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, M Fatyga, MK Fatyga, S Feher, D Fein, T Ferbel, G Finocchiaro, HE Fisk, Y Fisyak, E Flattum, GE Forden, M Fortner, KC Frame, S Fuess, E Gallas, AN Galyaev, P Gartung, TL Geld, RJ Genik, K Genser, CE Gerber, B Gibbard, S Glenn, B Gobbi, M Goforth, A Goldschmidt, B Gomez, G Gomez, PI Goncharov, JLG Solis, H Gordon, LT Goss, K Gounder, A Goussiou, N Graf, PD Grannis, DR Green, J Green, H Greenlee, G Grim, S Grinstein, N Grossman, P Grudberg, S Grunendahl, G Guglielmo, JA Guida, JM Guida, A Gupta, SN Gurzhiev, P Gutierrez, YE Gutnikov, NJ Hadley, H Haggerty, S Hagopian, V Hagopian, KS Hahn, RE Hall, P Hanlet, S Hansen, JM Hauptman, D Hedin, AP Heinson, U Heintz, R Hernandez-Montoya, T Heuring, R Hirosky, JD Hobbs, B Hoeneisen, JS Hoftun, F Hsieh, T Hu, T Hu, T Huehn, AS Ito, E James, J Jaques, SA Jerger, R Jesik, JZY Jiang, T JOffe-Minor, K Johns, M Johnson, A Jonckheere, M Jones, H Jostlein, SY Jun, CK Jung, S Kahn, G Kalbfleisch, JS Kang, D Karmgard, R Kehoe, ML Kelly, CL Kim, SK Kim, A KLatchko, B Klima, C Klopfenstein, VI Klyukhin, VI Kochetkov, JM Kohli, D Koltick, AV Kostritskiy, J Kotcher, AV Kotwal, J Kourlas, AV Kozelov, EA Kozlovski, J Krane, MR Krishnaswamy, S Krzywdzinski, S Kunori, S Lami, H Lan, R Lander, F Landry, G Landsberg, B Lauer, A Leflat, H Li, J Li, QZ Li-Demarteau, JGR Lima, D Lincoln, SL Linn, J Linnemann, R Lipton, YC Liu, F Lobkowicz, SC Loken, S Lokos, L Lueking, AL Lyon, AKA Maciel, RJ Madaras, R Madden, L Magana-Mendoza, S Mani, HS Mao, R Markeloff, T Marshall, MI Martin, KM Mauritz, B May, AA Mayorov, R McCarthy, J McDonald, T McKibben, J McKinely, T McMahon, HL Melanson, M Merkin, KW Merritt, H Miettinen, A Mincer, CS Mishra, N Mokhov, NK Mondal, HE Montgomery, P Mooney, H da Motta, C Murphy, F Nang, M Narain, VS Narasimham, A Narayanan, HA Neal, JP Negret, P Nemethy, M Nicola, D Norman, L Oesch, V Oguri, E Oltman, N Oshima, D Owen, P Padley, M Pang, A Para, YM Park, R Partridge, N Parua, M Paterno, J Perkins, M Peters, R Piegaia, H Piekarz, Y Pischalnikov, VM Podstavkov, BG Pope, HB Prosper, S Protopopescu, J Qian, PZ Quintas, R Raja, S Rajagopalan, O Ramirez, L Rasmussen, S Reucroft, M Rijssenbeek, T Rockwell, NA Roe, P Rubinov, R Ruchti, J Rutherfoord, A Sanchez-Hernandez, A Santoro, L Sawyer, RD Schamberger, H Schellman, J Sculli, E Shabalina, C Shaffer, HC Shankar, RK Shivpuri, M Shupe, H Singh, JB Singh, V Sirotenko, W Smart, RP Smith, R Snihur, GR Snow, J Snow, S Snyder, J Solomon, PM Sood, M Sosebee, N Sotnikova, M Souza, AL Spadafora, RW Stephens, ML Stevenson, D Stewart, F Stichelbaut, DA Stoianova, D Stoker, M Strauss, K Streets, M Strovink, A Sznajder, P Tamburello, J Tarazi, M Tartaglia, TLT Thomas, J Thompson, TG Trippe, PM Tuts, N Varelas, EW Varnes, D Vititoe, AA Volkov, AP Vorobiev, HD Wahl, G Wang, J Warchol, G Watts, M Wayne, H Weerts, A White, JT White, JA Wightman, S Willis, SJ Wimpenny, JVD Wirjawan, J Womersley, E Won, DR Wood, H Xu, R Yamada, P Yamin, J Yang, T Yasuda, P Yepes, C Yoshikawa, S Youssef, J Yu, Y Yu, ZH Zhu, D Zieminska, A Zieminski, EG Zverev, A Zylberstejn
More details from the publisher