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Search for leptoquark pairs decaying into vv + jets in pp̄ collisions at √s = 1.8 Tev

Physical Review Letters 88:19 (2002) 1918011-1918017

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, SN Ahmed, GD Alexeev, A Alton, GA Alves, N Amos, EW Anderson, Y Arnoud, C Avila, MM Baarmand, VV Babintsev, L Babukhadia, TC Bacon, A Baden, B Baldin, PW Balm, S Banerjee, E Barberis, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, A Bean, F Beaudette, M Begel, A Belyaev, SB Beri, G Bernardi, I Bertram, A Besson, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, G Blazey, F Blekman, S Blessing, A Boehnlein, NI Bojko, F Borcherding, K Bos, T Bose, A Brandt, R Breedon, G Briskin, R Brock, G Brooijmans, A Bross, D Buchholz, M Buehler, V Buescher, VS Burtovoi, JM Butler, F Canelli, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, KM Chan, SV Chekulaev, DK Cho, S Choi, S Chopra, JH Christenson, M Chung, D Claes, AR Clark, L Coney, B Connolly, WE Cooper, D Coppage, S Crépé-Renaudin, MAC Cummings, D Cutts, GA Davis, K Davis, K De, SJ de Jong, K Del Signore, M Demarteau, R Demina, P Demine, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, S Doulas, Y Ducros, LV Dudko

Abstract:

The results of a search for leptoquark (LQ) pairs in (85.2 ±3.7) pb-1 of pp̄ collider data collected by the DO experiments were presented. Scalar leptoquarks for the masses less than 98 GeV/c2, vector leptoquarks for masses less than 200 GeV/c2 and coupling which produced the minimum cross-section were excluded. Results showed absence of an evidence for leptoquark production and a limit was set on νν + jets as a function of the mass of leptoquark.

Search for leptoquark pairs decaying into nunu+jets in pp collisions at square root[s] = 1.8 TeV.

Phys Rev Lett 88:19 (2002) 191801

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, SN Ahmed, GD Alexeev, A Alton, GA Alves, N Amos, EW Anderson, Y Arnoud, C Avila, MM Baarmand, VV Babintsev, L Babukhadia, TC Bacon, A Baden, B Baldin, PW Balm, S Banerjee, E Barberis, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, A Bean, F Beaudette, M Begel, A Belyaev, SB Beri, G Bernardi, I Bertram, A Besson, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, G Blazey, F Blekman, S Blessing, A Boehnlein, NI Bojko, F Borcherding, K Bos, T Bose, A Brandt, R Breedon, G Briskin, R Brock, G Brooijmans, A Bross, D Buchholz, M Buehler, V Buescher, VS Burtovoi, JM Butler, F Canelli, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, KM Chan, SV Chekulaev, DK Cho, S Choi, S Chopra, JH Christenson, M Chung, D Claes, AR Clark, L Coney, B Connolly, WE Cooper, D Coppage, S Crépé-Renaudin, MAC Cummings, D Cutts, GA Davis, K Davis, K De, SJ De Jong, K Del Signore, M Demarteau, R Demina, P Demine, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, S Doulas, Y Ducros, LV Dudko, S Duensing, L Duflot, SR Dugad, A Duperrin, A Dyshkant, D Edmunds, J Ellison, JT Eltzroth, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, J Estrada, H Evans, VN Evdokimov, T Fahland, S Feher, D Fein, T Ferbel, F Filthaut, HE Fisk, Y Fisyak, E Flattum, F Fleuret, M Fortner, H Fox, KC Frame, S Fu, S Fuess, E Gallas, AN Galyaev, M Gao, V Gavrilov, RJ Genik, K Genser, CE Gerber, Y Gershtein, R Gilmartin, G Ginther, B Gómez, G Gómez, PI Goncharov, JL González Solís, H Gordon, LT Goss, K Gounder, A Goussiou, N Graf, G Graham, PD Grannis, JA Green, H Greenlee, ZD Greenwood, S Grinstein, L Groer, S Grünendahl, A Gupta, SN Gurzhiev, G Gutierrez, P Gutierrez, NJ Hadley, H Haggerty, S Hagopian, V Hagopian, RE Hall, P Hanlet, S Hansen, JM Hauptman, C Hays, C Hebert, D Hedin, JM Heinmiller, AP Heinson, U Heintz, MD Hildreth, R Hirosky, JD Hobbs, B Hoeneisen, Y Huang, I Iashvili, R Illingworth, AS Ito, M Jaffré, S Jain, R Jesik, K Johns, M Johnson, A Jonckheere, H Jöstlein, A Juste, W Kahl, S Kahn, E Kajfasz, AM Kalinin, D Karmanov, D Karmgard, R Kehoe, A Khanov, A Kharchilava, SK Kim, B Klima, B Knuteson, W Ko, JM Kohli, AV Kostritskiy, J Kotcher, B Kothari, AV Kotwal, AV Kozelov, EA Kozlovsky, J Krane, MR Krishnaswamy, P Krivkova, S Krzywdzinski, M Kubantsev, S Kuleshov, Y Kulik, S Kunori, A Kupco, VE Kuznetsov, G Landsberg, WM Lee, A Leflat, C Leggett, F Lehner, C Leonidopoulos, J Li, QZ Li, X Li, JGR Lima, D Lincoln, SL Linn, J Linnemann, R Lipton, A Lucotte, L Lueking, C Lundstedt, C Luo, AKA Maciel, RJ Madaras, VL Malyshev, V Manankov, HS Mao, T Marshall, MI Martin, KM Mauritz, AA Mayorov, R McCarthy, T McMahon, HL Melanson, M Merkin, KW Merritt, C Miao, H Miettinen, D Mihalcea, CS Mishra, N Mokhov, NK Mondal, HE Montgomery, RW Moore, M Mostafa, H Da Motta, E Nagy, F Nang, M Narain, VS Narasimham, NA Naumann, HA Neal, JP Negret, S Negroni, T Nunnemann, D O'Neil, V Oguri, B Olivier, N Oshima, P Padley, LJ Pan, K Papageorgiou, A Para, N Parashar, R Partridge, N Parua, M Paterno, A Patwa, B Pawlik, J Perkins, O Peters, P Pétroff, R Piegaia, BG Pope, E Popkov, HB Prosper, S Protopopescu, MB Przybycien, J Qian, R Raja, S Rajagopalan, E Ramberg, PA Rapidis, NW Reay, S Reucroft, M Ridel, M Rijssenbeek, F Rizatdinova, T Rockwell, M Roco, C Royon, P Rubinov, R Ruchti, J Rutherfoord, BM Sabirov, G Sajot, A Santoro, L Sawyer, RD Schamberger, H Schellman, A Schwartzman, N Sen, E Shabalina, RK Shivpuri, D Shpakov, M Shupe, RA Sidwell, V Simak, H Singh, JB Singh, V Sirotenko, P Slattery, E Smith, RP Smith, R Snihur, GR Snow, J Snow, S Snyder, J Solomon, Y Song, V Sorín, M Sosebee, N Sotnikova, K Soustruznik, M Souza, NR Stanton, G Steinbrück, RW Stephens, F Stichelbaut, D Stoker, V Stolin, A Stone, DA Stoyanova, MA Strang, M Strauss, M Strovink, L Stutte, A Sznajder, M Talby, W Taylor, S Tentindo-Repond, SM Tripathi, TG Trippe, AS Turcot, PM Tuts, V Vaniev, R Van Kooten, N Varelas, LS Vertogradov, F Villeneuve-Seguier, AA Volkov, AP Vorobiev, HD Wahl, H Wang, Z-M Wang, J Warchol, G Watts, M Wayne, H Weerts, A White, JT White, D Whiteson, DA Wijngaarden, S Willis, SJ Wimpenny, J Womersley, DR Wood, Q Xu, R Yamada, P Yamin, T Yasuda, YA Yatsunenko, K Yip, S Youssef, J Yu, Z Yu, M Zanabria, X Zhang, H Zheng, B Zhou, Z Zhou, M Zielinski, D Zieminska, A Zieminski, V Zutshi, EG Zverev, A Zylberstejn, D0 Collaboration

Abstract:

We present the results of a search for leptoquark (LQ) pairs in (85.2+/-3.7) pb(-1) of pp* collider data collected by the D0 experiment at the Fermilab Tevatron. We observe no evidence for leptoquark production and set a limit on sigma(pp*-->LQLQ-->nunu+jets) as a function of the mass of the leptoquark (m(LQ)). Assuming the decay LQ-->nuq, we exclude scalar leptoquarks for m(LQ) < 98 GeV/c(2), and vector leptoquarks for m(LQ) < 200 GeV/c(2) and coupling which produces the minimum cross section, at a 95% confidence level.
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Measurement of B-meson lifetimes using fully reconstructed B decays produced in pp̄ collisions at √s = 1.8 TeV

Physical Review D Particles Fields Gravitation and Cosmology 65:9 A (2002) 920091-920097

Authors:

D Acosta, T Affolder, H Akimoto, MG Albrow, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, E Brubaker, N Bruner, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, S Cabrera, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, JY Chung, WH Chung, YS Chung, CI Ciobanu, AG Clark, M Coca, AP Colijn, A Connolly, M Convery, J Conway, M Cordelli, J Cranshaw, R Culbertson

Abstract:

We present an improved measurement of b-meson lifetimes using fully reconstructed B-decays produced in pp̄ collisions at √s = 1.8 TeV, using 114 pb-1 of data collected at the Collider Detector at Fermilab. We obtain τ(B+) = 1.636±0.058(stat)±0.025(syst) ps, τ(B0) = 1.497±0.073(stat)±0.032(syst) ps and for the lifetime ratio τ(B+)/τ(B0) = 1.093±0.066(stat)±0.028(syst).
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Search for lepton-flavor violation in e+p collisions at DESY HERA

Physical Review D Particles Fields Gravitation and Cosmology 65:9 (2002) 920041-9200416

Authors:

S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, P Giusti, G Iacobucci, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, J Crittenden, S Goers, H Hartmann, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, O Kind, E Paul, J Rautenberg, R Renner, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wessoleck, DS Bailey, NH Brook, JE Cole, B Foster, GP Heath, HF Heath, S Robins, E Rodrigues, J Scott, RJ Tapper, M Wing, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, M Helbich, X Liu, B Mellado, S Paganis, WB Schmidke, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Olkiewicz, MB Przybycień, P Stopa, L Zawiejski, B Bednarek, I Grabowska-Bold, K Jeleń, D Kisielewska, AM Kowal, M Kowal, T Kowalski, B Mindur, E Rulikowska-Zarebska, L Suszycki, D Szuba

Abstract:

A search has been made for lepton-flavor-violating interactions of the type e+p→lX, where l denotes a μ or τ with high transverse momentum, at a center-of-mass energy √s of 300 GeV with an integrated luminosity of 47.7 pb-1 using the ZEUS detector at HERA. No evidence was found for lepton-flavor violation and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below √s, limits are set on λeq1βlq, where λeq1 is the coupling of the LQ to an electron and a first-generation quark q1 and βlq is the branching ration of the LQ to l and a quark. For LQ masses exceeding √s, limits are set on the four-fermion contact-interaction term λeqα λlqβ/M2 LQ for leptoquarks that couple to an electron and a quark qα and also to l and a quark qβ. Some of the limits are also applicable to lepton-flavor-violating processes mediated by squarks in R-parity-violating supersymmetric models. In some cases involving heavy quarks and especially for l=τ, the ZEUS limits are the most stringent published to date.
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Search for single-top-quark production in pp̄ collisions at √s=1.8 TeV

Physical Review D Particles Fields Gravitation and Cosmology 65:9 A (2002) 911021-911026

Authors:

D Acosta, T Affolder, H Akimoto, MG Albrow, P Amaral, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, E Brubaker, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, S Cabrera, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, JY Chung, YS Chung, CI Ciobanu, AG Clark, AP Colijn, A Connolly, M Convery, J Conway, M Cordelli, J Cranshaw, R Culbertson, D Dagenhart

Abstract:

We search for standard model single-top-quark production in the W-gluon fusion and W* channels using 106 pb-1 of data from pp̄ collisions at √s=1.8 TeV collected with the Collider Detector at Fermilab. We set an upper limit at 95% confidence level (C.L.) on the combined W-gluon fusion and W* single-top cross section of 14 pb, roughly six times larger than the standard model prediction. Separate 95% C.L. upper limits in the W-gluon fusion and W* channels are also determined and are found to be 13 and 18 pb, respectively.
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