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/M2LQ 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.

Search for single-top-quark production in pp¯ collisions at s=1.8 TeV

Physical Review D American Physical Society (APS) 65:9 (2002) 091102

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, M-T 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, S D’Auria, F DeJongh, S Dell’Agnello, M Dell’Orso, S Demers, L Demortier, M Deninno, PF Derwent, T Devlin, JR Dittmann, A Dominguez, S Donati, J Done, M D’Onofrio, T Dorigo, N Eddy, K Einsweiler, JE Elias, E Engels, R Erbacher, D Errede, S Errede, Q Fan, H-C Fang, RG Feild, JP Fernandez, C Ferretti, RD Field, I Fiori, B Flaugher, GW Foster, M Franklin, J Freeman, J Friedman, Y Fukui, I Furic, S Galeotti, A Gallas, M Gallinaro, T Gao, M Garcia-Sciveres, AF Garfinkel, P Gatti, C Gay, DW Gerdes, P Giannetti, MP Giordani, P Giromini, V Glagolev, D Glenzinski, M Gold, J Goldstein, I Gorelov, AT Goshaw, Y Gotra, K Goulianos, C Green, G Grim, P Gris, C Grosso-Pilcher, M Guenther, G Guillian, J Guimaraes da Costa, RM Haas, C Haber, SR Hahn, C Hall, T Handa, R Handler, W Hao, F Happacher, K Hara, AD Hardman, RM Harris, F Hartmann, K Hatakeyama, J Hauser, J Heinrich, A Heiss, M Herndon, C Hill, A Hocker, KD Hoffman, R Hollebeek, L Holloway, BT Huffman, R Hughes, J Huston, J Huth, H Ikeda, J Incandela, G Introzzi, A Ivanov, J Iwai, Y Iwata, E James, M Jones, U Joshi, H Kambara, T Kamon, T Kaneko, M Karagoz Unel, K Karr, S Kartal, H Kasha, Y Kato, TA Keaffaber, K Kelley, M Kelly, D Khazins, T Kikuchi, B Kilminster, BJ Kim, DH Kim, HS Kim, MJ Kim, SB Kim, SH Kim, YK Kim, M Kirby, M Kirk, L Kirsch, S Klimenko, P Koehn, K Kondo, J Konigsberg, A Korn, A Korytov, E Kovacs, J Kroll, M Kruse, SE Kuhlmann, K Kurino, T Kuwabara, AT Laasanen, N Lai, S Lami, S Lammel, J Lancaster, M Lancaster, R Lander, A Lath, G Latino, T LeCompte, K Lee, S Leone, JD Lewis, M Lindgren, TM Liss, JB Liu, YC Liu, DO Litvintsev, O Lobban, NS Lockyer, J Loken, M Loreti, D Lucchesi, P Lukens, S Lusin, L Lyons, J Lys, R Madrak, K Maeshima, P Maksimovic, L Malferrari, M Mangano, M Mariotti, G Martignon, A Martin, JAJ Matthews, P Mazzanti, KS McFarland, P McIntyre, M Menguzzato, A Menzione, P Merkel, C Mesropian, A Meyer, T Miao, R Miller, JS Miller, H Minato, S Miscetti, M Mishina, G Mitselmakher, Y Miyazaki, N Moggi, E Moore, R Moore, Y Morita, T Moulik, M Mulhearn, A Mukherjee, T Muller, A Munar, P Murat, S Murgia, J Nachtman, V Nagaslaev, S Nahn, H Nakada, I Nakano, C Nelson, T Nelson, C Neu, D Neuberger, C Newman-Holmes, C-YP Ngan, H Niu, L Nodulman, A Nomerotski, SH Oh, YD Oh, T Ohmoto, T Ohsugi, R Oishi, T Okusawa, J Olsen, W Orejudos, C Pagliarone, F Palmonari, R Paoletti, V Papadimitriou, D Partos, J Patrick, G Pauletta, M Paulini, C Paus, D Pellett, L Pescara, TJ Phillips, G Piacentino, KT Pitts, A Pompos, L Pondrom, G Pope, F Prokoshin, J Proudfoot, F Ptohos, O Pukhov, G Punzi, A Rakitine, F Ratnikov, D Reher, A Reichold, P Renton, A Ribon, W Riegler, F Rimondi, L Ristori, M Riveline, WJ Robertson, T Rodrigo, S Rolli, L Rosenson, R Roser, R Rossin, C Rott, A Roy, A Ruiz, A Safonov, R St. Denis, WK Sakumoto, D Saltzberg, C Sanchez, A Sansoni, L Santi, H Sato, P Savard, A Savoy-Navarro, P Schlabach, EE Schmidt, MP Schmidt, M Schmitt, L Scodellaro, A Scott, A Scribano, A Sedov, S Segler, S Seidel, Y Seiya, A Semenov, F Semeria, T Shah, MD Shapiro, PF Shepard, T Shibayama, M Shimojima, M Shochet, A Sidoti, J Siegrist, A Sill, P Sinervo, P Singh, AJ Slaughter, K Sliwa, C Smith, FD Snider, A Solodsky, J Spalding, T Speer, P Sphicas, F Spinella, M Spiropulu, L Spiegel, J Steele, A Stefanini, J Strologas, F Strumia, D Stuart, K Sumorok, T Suzuki, T Takano, R Takashima, K Takikawa, P Tamburello, M Tanaka, B Tannenbaum, M Tecchio, RJ Tesarek, PK Teng, K Terashi, S Tether, AS Thompson, E Thomson, R Thurman-Keup, P Tipton, S Tkaczyk, D Toback, K Tollefson, A Tollestrup, D Tonelli, H Toyoda, W Trischuk, JF de Troconiz, J Tseng, D Tsybychev, N Turini, F Ukegawa, T Vaiciulis, J Valls, S Vejcik, G Velev, G Veramendi, R Vidal, I Vila, R Vilar, I Volobouev, M von der Mey, D Vucinic, RG Wagner, RL Wagner, NB Wallace, Z Wan, C Wang, MJ Wang, SM Wang, B Ward, S Waschke, T Watanabe, D Waters, T Watts, R Webb, H Wenzel, WC Wester, AB Wicklund, E Wicklund, T Wilkes, HH Williams, P Wilson, BL Winer, D Winn, S Wolbers, D Wolinski, J Wolinski, S Wolinski, S Worm, X Wu, J Wyss, W Yao, GP Yeh, P Yeh, J Yoh, C Yosef, T Yoshida, I Yu, S Yu, Z Yu, A Zanetti, F Zetti

Search for Leptoquark Pairs Decaying into nu nu + jets in ppbar Collisions at sqrt(s) = 1.8 TeV

Physical Review Letters 88 (2002) 191801 7pp

Authors:

C Hays, P. M. Tuts, G. Landsberg, H. B. Prosper

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

Physical review letters 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.

Search for the scalar top quark in p p̄ collisions at √s = 1.8 TeV

Physical Review Letters 88:17 (2002) 1718021-1718026

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, SN Ahmed, GD Alexeev, GA Alves, N Amos, EW Anderson, Y Arnoud, 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, S Blessing, A Boehnlein, NI Bojko, F Borcherding, K Bos, 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, J Cochran, 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

Abstract:

A search for scalar top (stop) quark pair production in the inclusive electron-muon-missing transverse energy final state was presented. The search was performed within the framework of the minimal supersymmetric standard model (MSSM) assuming the sneutrino to be the lightest supersymmetric particle. No evidence for signal was found for the dominant decays of the lightest stop. The cross-section limits of the stop, chargino and sneutrino masses were also derived.