Update of the search for charginos nearly mass-degenerate with the lightest neutralino

Abreu, P Adam, W Adye, T Adzic, P Ajinenko, I Albrecht, Z Alderweireld, T Alekseev, GD Alemany, R Allmendinger, T Allport, PP Almehed, S Amaldi, U Amapane, N Amato, S Anassontzis, EG Andersson, P Andreazza, A Andringa, S Antilogus, P Apel, WD Arnoud, Y Asman, B Augustin, JE Augustinus, A Baillon, P Ballestrero, A Bambade, P Barao, F Barbiellini, G Barbier, R Bardin, DY Barker, G Baroncelli, A Battaglia, M Baubillier, M Becks, KH Begalli, M Behrmann, A Beilliere, P Belokopytov, Y Benekos, NC Benvenuti, AC Berat, C Berggren, M Bertrand, D Besancon, M Bigi, M Bilenky, MS Bizouard, MA Bloch, D Blom, HM Bonesini, M Boonekamp, M Booth, PSL Borgland, AW Borisov, G Bosio, C Botner, O Boudinov, E Bouquet, B Bourdarios, C Bowcock, TJV Boyko, I Bozovic, I Bozzo, M Bracko, M Branchini, P Brenner, RA Bruckman, P Brunet, JM Bugge, L Buran, T Buschbeck, B Buschmann, P Cabrera, S Caccia, M Calvi, M Camporesi, T Canale, V Carena, F Carroll, L Caso, C Gimenez, MVC Cattai, A Cavallo, FR Chabaud, V Charpentier, P Checchia, P Chelkov, GA Chierici, R Chliapnikov, P Chochula, P Chorowicz, V Chudoba, J Cieslik, K Collins, P Contri, R Cortina, E Cosme, G Cossutti, F Crawley, HB Crennell, D Crepe, S Crosetti, G Maestro, JC Czellar, S Davenport, M Da Silva, W Della Ricca, G Delpierre, P Demaria, N De Angelis, A De Boer, W De Clercq, C De Lotto, B De Min, A De Paula, L Dijkstra, H Di Ciaccio, L Dolbeau, J Doroba, K Dracos, M Drees, J Dris, M Duperrin, A Durand, JD Eigen, G Ekelof, T Ekspong, G Ellert, M Elsing, M Engel, JP Santo, ME Fanourakis, G Fassouliotis, D Fayot, J Feindt, M Ferrer, A Ferrer-Ribas, E Ferro, F Fichet, S Firestone, A Flagmeyer, U Foeth, H Fokitis, E Fontanelli, F Franek, B Frodesen, AG Fruhwirth, R Fulda-Quenzer, F Fuster, J Galloni, A Gamba, D Gamblin, S Gandelman, M Garcia, C Gaspar, C Gaspar, M Gasparini, U Gavillet, P Gazis, EN Gele, D Geralis, T Gerdyukov, L Ghodbane, N Gil, I Glege, F Gokieli, R Golob, B Gomez-Ceballos, G Goncalves, P Caballero, IG Gopal, G Gorn, L Gouz, Y Gracco, V Grahl, J Graziani, E Gris, P Grosdidier, G Grzelak, K Guy, J Haag, C Hahn, F Hahn, S Haider, S Hallgren, A Hamacher, K Hansen, J Harris, FJ Hauler, F Hedberg, V Heising, S Hernandez, JJ Herquet, P Herr, H Hessing, TL Heuser, JM Higon, E Holmgren, SO Holt, PJ Hoorelbeke, S Houlden, M Hrubec, J Huber, M Huet, K Hughes, GJ Hultqvist, K Jackson, JN Jacobsson, R Jalocha, P Janik, R Jarlskog, C Jarlskog, G Jarry, P Jean-Marie, B Jeans, D Johansson, EK Jonsson, P Joram, C Juillot, P Jungermann, L Kapusta, F Karafasoulis, K Katsanevas, S Katsoufis, EC Keranen, P Kernel, G Kersevan, BP Khokhlov, Y Khomenko, BA Khovanski, NN Kiiskinen, A King, B Kinvig, A Kjaer, NJ Klapp, O Klein, H Kluit, P Kokkinias, P Kostioukhine, V Kourkoumelis, C Kouznetsov, O Krammer, M Kriznic, E Krumstein, Z Kubinec, P Kurowska, J Kurvinen, K Lamsa, JW Lane, DW Laugier, JP Lauhakangas, R Leder, G Ledroit, F Lefebure, V Leinonen, L Leisos, A Leitner, R Lenzen, G Lepeltier, V Lesiak, T Lethuillier, M Libby, J Liebig, W Liko, D Lipniacka, A Lippi, I Loerstad, B Loken, JG Lopes, JH Lopez, JM Lopez-Fernandez, R Loukas, D Lutz, P Lyons, L MacNaughton, J Mahon, JR Maio, A Malek, A Malmgren, TGM Maltezos, S Malychev, V Mandl, F Marco, J Marco, R Marechal, B Margoni, M Marin, JC Mariotti, C Markou, A Martinez-Rivero, C Martinez-Vidal, F Garcia, SMI Masik, J Mastroyiannopoulos, N Matorras, F Matteuzzi, C Matthiae, G Mazzucato, F Mazzucato, M Mc Cubbin, M Mc Kay, R Mc Nulty, R Pherson, GM Meroni, C Meyer, WT Migliore, E Mirabito, L Mitaroff, WA Mjoernmark, U Moa, T Moch, M Moeller, R Moenig, K Monge, MR Moraes, D Moreau, X Morettini, P Morton, G Mueller, U Muenich, K Mulders, M Mulet-Marquis, C Muresan, R Murray, WJ Muryn, B Myatt, G Myklebust, T Naraghi, F Nassiakou, M Navarria, FL Navas, S Nawrocki, K Negri, P Neufeld, N Nicolaidou, R Nielsen, BS Niezurawski, P Nikolenko, M Nomokonov, V Nygren, A Obraztsov, V Olshevski, AG Onofre, A Orava, R Orazi, G Osterberg, K Ouraou, A Paganoni, M Paiano, S Pain, R Paiva, R Palacios, J Palka, H Papadopoulou, TD Pape, L Parkes, C Parodi, F Parzefall, U Passeri, A Passon, O Pavel, T Pegoraro, M Peralta, L Pernicka, M Perrotta, A Petridou, C Petrolini, A Phillips, HT Pierre, F Pimenta, M Piotto, E Podobnik, T Pol, ME Polok, G Poropat, P Pozdniakov, V Privitera, P Pukhaeva, N Pullia, A Radojicic, D Ragazzi, S Rahmani, H Rames, J Ratoff, PN Read, AL Rebecchi, P Redaelli, NG Regler, M Rehn, J Reid, D Reinhardt, R Renton, PB Resvanis, LK Richard, F Ridky, J Rinaudo, G Ripp-Baudot, I Rohne, O Romero, A Ronchese, P Rosenberg, EI Rosinsky, P Roudeau, P Rovelli, T Royon, C Ruhlmann-Kleider, V Ruiz, A Saarikko, H Sacquin, Y Sadovsky, A Sajot, G Salt, J Sampsonidis, D Sannino, M Schwemling, P Schwering, B Schwickerath, U Scuri, F Seager, P Sedykh, Y Segar, AM Seibert, N Sekulin, R Shellard, RC Siebel, M Simard, L Simonetto, F Sisakian, AN Smadja, G Smirnov, N Smirnova, O Smith, GR Sokolov, A Sopczak, A Sosnowski, R Spassov, T Spiriti, E Squarcia, S Stanescu, C Stanic, S Stanitzki, M Stevenson, K Stocchi, A Strauss, J Strub, R Stugu, B Szczekowski, M Szeptycka, M Tabarelli, T Taffard, A Tchikilev, O Tegenfeldt, F Terranova, F Thomas, J Timmermans, J Tinti, N Tkatchev, LG Tobin, M Todorova, S Tomaradze, A Tome, B Tonazzo, A Tortora, L Tortosa, P Transtromer, G Treille, D Tristram, G Trochimczuk, M Troncon, C Turluer, ML Tyapkin, IA Tyapkin, P Tzamarias, S Ullaland, O Uvarov, V Valenti, G Vallazza, E Van Dam, P Van den Boeck, W Van Eldik, J Van Lysebetten, A van Remortal, N Van Vulpen, I Vegni, G Ventura, L Venus, W Verbeure, F Verdier, P Verlato, M Vertogradov, LS Verzi, V Vilanova, D Vitale, L Vlasov, E Vodopyanov, AS Voulgaris, G Vrba, V Wahlen, H Walck, C Washbrook, AJ Weiser, C Wicke, D Wickens, JH Wilkinson, GR Winter, M Witek, M Wolf, G Yi, J Yushchenko, O Zalewska, A Zalewski, P Zavrtanik, D Zevgolatakos, E Zimin, NI Zintchenko, A Zoller, P Zucchelli, GC Zumerle, G

P. Abreu et al., Update of the search for charginos nearly mass-degenerate with the lightest neutralino, PHYS LETT B, 485(1-3), 2000, pp. 95-106

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Physics

PHYSICS LETTERS B

0370-2693 → ACNP

485

1-3

2000

95 - 106

ISI

0370-2693(20000713)485:1-3<95:UOTSFC>2.0.ZU;2-X

The data collected by DELPHI in 1998 at the centre-of-mass energy of 189 Ge V have been used to update the search for charginos nearly mass-degenerate with the lightest supersymmetric particle, which is assumed to be the light est neutralino. Mass differences below Delta M = 3 GeV/c(2) are considered. No excess of events with respect to the Standard Model expectation has bee n observed, and exclusions in the plane of Delta M versus chargino mass are given. The new Delta M independent lower limit on the mass of the chargino is 62.4 GeV/c(2) in the higgsino scenario (which includes the gaugino mass unification scenario), if all sfermions are heavier than the lightest char gino. In the approximation of large sfermion masses the limit is 59.8 GeV/c (2), independently of the field content. (C) 2000 Published by Elsevier Sci ence B.V.