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Search for scalar top and scalar bottom quarks at root s=189 GeV at LEP

Authors

Abbiendi, G Ackerstaff, K Alexander, G Allison, J Altekamp, N Anderson, KJ Anderson, S Arcelli, S Asai, S Ashby, SF Axen, D Azuelos, G Ball, AH Barberio, E Barlow, RJ Batley, JR Baumann, S Bechtluft, J Behnke, T Bell, KW Bella, G Bellerive, A Bentvelsen, S Bethke, S Betts, S Biebel, O Biguzzi, A Blobel, V Bloodworth, IJ Bock, P Bohme, J Bonacorsi, D Boutemeur, M Braibant, S Bright-Thomas, P Brigliadori, L Brown, RM Burckhart, HJ Capiluppi, P Carnegie, RK Carter, AA Carter, JR Chang, CY Charlton, DG Chrisman, D Ciocca, C Clarke, PEL Clay, E Cohen, I Conboy, JE Cooke, OC Couyoumtzelis, C Coxe, RL Cuffiani, M Dado, S Dallavalle, GM Davis, R De Jong, S de Roeck, A Dervan, P Desch, K Dienes, B Dixit, MS Dubbert, J Duchovni, E Duckeck, G Duerdoth, IP Estabrooks, PG Etzion, E Fabbri, F Fanfani, A Fanti, M Faust, AA Fiedler, F Fierro, M Fleck, I Folman, R Frey, A Furtjes, A Futyan, DI Gagnon, P Gary, JW Gascon, J Gascon-Shotkin, SM Gaycken, G Geich-Gimbel, C Giacomelli, G Giacomelli, P Gibson, V Gibson, WR Gingrich, DM Glenzinski, D Goldberg, J Gorn, W Grandi, C Graham, K Gross, E Grunhaus, J Gruwe, M Hanson, GG Hansroul, M Hapke, M Harder, K Harel, A Hargrove, CK Hauschild, M Hawkes, CM Hawkings, R Hemingway, RJ Herndon, M Herten, G Heuer, RD Hildreth, MD Hill, JC Hobson, PR Hoch, M Hocker, A Hoffman, K Homer, RJ Honma, AK Horvath, D Hossain, KR Howard, R Huntemeyer, P Igo-Kemenes, P Imrie, DC Ishii, K Jacob, FR Jawahery, A Jeremie, H Jimack, M Jones, CR Jovanovic, P Junk, TR Kanzaki, J Karlen, D Kartvelishvili, V Kawagoe, K Kawamoto, T Kayal, PI Keeler, RK Kellogg, RG Kennedy, BW Kim, DH Klier, A Kobayashi, T Kobel, M Kokott, TP Kolrep, M Komamiya, S Kowalewski, RV Kress, T Krieger, P von Krogh, J Kuhl, T Kyberd, P Lafferty, GD Landsman, H Lanske, D Lauber, J Lautenschlager, SR Lawson, I Layter, JG Lee, AM Lellouch, D Letts, J Levinson, L Liebisch, R List, B Littlewood, C Lloyd, AW Lloyd, SL Loebinger, FK Long, GD Losty, MJ Lu, J Ludwig, J Liu, D Macchiolo, A Macpherson, A Mader, W Mannelli, M Marcellini, S Markopoulos, C Martin, AJ Martin, JP Martinez, G Mashimo, T Mattig, P McDonald, WJ McKenna, J Mckigney, EA McMahon, TJ McPherson, RA Meijers, F Menke, S Merritt, FS Mes, H Meyer, J Michelini, A Mihara, S Mikenberg, G Miller, DJ Mir, R Mohr, W Montanari, A Mori, T Nagai, K Nakamura, I Neal, HA Nisius, R O'Neale, SW Oakham, FG Odorici, F Ogren, HO Oreglia, MJ Orito, S Palinkas, J Pasztor, G Pater, JR Patrick, GN Patt, J Perez-Ochoa, R Petzold, S Pfeifenschneider, P Pilcher, JE Pinfold, J Plane, DE Poffenberger, P Poli, B Polok, J Przybycien, M Rembser, C Rick, H Robertson, S Robins, SA Rodning, N Roney, JM Rosati, S Roscoe, K Rossi, AM Rozen, Y Runge, K Runolfsson, O Rust, DR Sachs, K Saeki, T Sahr, O Sang, WM Sarkisyan, EKG Sbarra, C Schaile, AD Schaile, O Scharff-Hansen, P Schieck, J Schmitt, S Schoning, A Schroder, M Schumacher, M Schwick, C Scott, WG Seuster, R Shears, TG Shen, BC Shepherd-Themistocleous, CH Sherwood, P Siroli, GP Sittler, A Skuja, A Smith, AM Snow, GA Sobie, R Soldner-Rembold, S Spagnolo, S Sproston, M Stahl, A Stephens, K Steuerer, J Stoll, K Strom, D Strohmer, R Surrow, B Talbot, SD Taras, P Tarem, S Teuscher, R Thiergen, M Thomas, J Thomson, MA Torrence, E Towers, S Trigger, I Trocsanyi, Z Tsur, E Turcot, AS Turner-Watson, MF Ueda, I Van Kooten, R Vannerem, P Verzocchi, M Voss, H Wackerle, F Wagner, A Ward, CP Ward, DR Watkins, PM Watson, AT Watson, NK Wells, PS Wermes, N White, JS Wilson, GW Wilson, JA Wyatt, TR Yamashita, S Yekutieli, G Zacek, V Zer-Zion, D

Citation

G. Abbiendi et al., Search for scalar top and scalar bottom quarks at root s=189 GeV at LEP, PHYS LETT B, 456(1), 1999, pp. 95-106

Citations number

Categorie Soggetti

Physics

Journal title

PHYSICS LETTERS B

ISSN journal

03702693 → ACNP

Volume

456

Issue

Year of publication

1999

Pages

95 - 106

Database

ISI

SICI code

0370-2693(19990603)456:1<95:SFSTAS>2.0.ZU;2-4

Abstract

Searches for a scalar top quark and a scalar bottom quack have been perform ed using a data sample of 182 pb-l at a centre-of-mass energy of root s = 1 89 GeV collected with the OPAL detector at LEP. No evidence for a signal wa s found. The 95% confidence level (C.L.) lower limit on the scalar top quar k mass is 90.3 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed st;states of the top quark is zero. In the wo rst case, when the scalar top quark decouples from the Z(0) boson, the lowe r limit is 87.2 GeV. These limits were obtained assuming that the scalar to p quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino i s larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has al so been studied. From a search for the scalar bottom quark, a mass limit of 88.6 GeV was obtained if the mass difference between the scalar bottom qua rk and the lightest neutralino is larger than 7 GeV. These limits significa ntly improve the previous OPAL limits. (C) 1999 Elsevier Science B.V. All r ights reserved.