Study of the four-jet anomaly observed at LEP centre-of-mass energies of 130 and 136 GeV

P Abreu,M Trochimczuk,Yu Belokopytov,E Piotto,G Smadja,F Fontanelli,F Mandl,W De Boer,J Grahl,H Schneider,M Bigi,L Gorn,D Reid,R Moeller,A Sadovsky,P Van Dam,M Witek,D Bertini,G Myatt,K Muenich,D Vilanova,A Normand,C Caso,G Grosdidier,B Erzen,H Klein,S Haider,G Rinaudo,M Regler,P Andersson,C De Clercq,J Dolbeau,Y Sacquin,V Gracco,R Mc Kay,G Crosetti,A Sheridan,U Flagmeyer,M Mazzucato,V Chabaud,A Deghorain,Yu Gouz,E Boudinov,G Barbiellini,P.S.L Booth,S Heising,P Kubinec,E Vallazza,C Matteuzzi,M Battaglia,G Mc Pherson,P Seager,F Kapusta,A Kiiskinen,E Spiriti,V Ruhlmann-Kleider,G Polok,E Graziani,S Almehed,J Van Eldik,P Buschmann,R Mc Nulty,P Collins,H Foeth,B Loerstad,M Gaspar,S Hoorelbeke,G Cosme,F Mazzucato,M Szczekowski,K Kurvinen,A Tonazzo,A Kinvig,D Wicke,M Siebel,M Verlato,B Franek,P Roudeau,T Alderweireld,P Rebecchi,L Leinonen,L Bugge,T Burgsmueller,F Richard,R Barbier,M Pernicka,O Klapp,N Pukhaeva,D Crennell,L Di Ciaccio,Z Albrecht,A Stocchi,I Van Vulpen,G Orazi,C Parkes,P Bambade,F Tegenfeldt,P Langefeld,V Verzi,M Koratzinos,C Mulet-Marquis,C Bosio,F Naraghi,R Jacobsson,M Gandelman,P Herquet,B Golob,R Gokieli,B Muryn,B Bouquet,F Carena,A Ferrer,S Paiano,G Leder,C Walck,D Gamba,G Valenti,R Sekulin,R Strub,J Drees,E Zevgolatakos,H Saarikko,J Fayot,P Negri,T Moa,R Pain,M Berggren,F Bianchi,M Davenport,L De Paula,T Tabarelli,S Cabrera,T Buran,A Passeri,P Antilogus,G Damgaard,R Alemany,A De Min,P Delpierre,R Orava,Ph Gavillet,D Fassouliotis,H Herr,G Della Ricca,J Libby,A Pullia,G Sajot,P Sponholz,S De Brabandere,C Gaspar,Y Arnoud,A Firestone,E Falk,M Nikolenko,F Pierre,R Sosnowski,V Obraztsov,O Solovianov,G Voulgaris,B De Lotto,B Ueberschaer,J Guy,G Eigen,J Timmermans,H Rahmani,L Vitale,G Tristram,P Kokkinias,A Zalewska,K Karafasoulis,C Joram,M Pimenta,R Contri,B Åsman,L Tortora,M Baubillier,Ph Schwemling,A Van Lysebetten,A Andreazza,G Vegni,F Hahn,R Reinhardt,G Ekspong,V Kostioukhine,L Simard,W Bonivento,J Kurowska,M Szeptycka,M Moch,S Katsanevas,O Ullaland,R Lauhakangas,A Galloni,K Grzelak,F Ledroit,F Fulda-Quenzer,H Wahlen,P Branchini,N Tinti,R Janik,V Malychev,P Poropat,A Miagkov,G Lenzen,T Lesiak,K Hultqvist,F Parodi,S Squarcia,A Ruiz,E Fokitis,V Lepeltier,P Lutz,O Yushchenko,I Lippi,K Stevenson,V Nomokonov,E Cortina,U Schwickerath,T Myklebust,G Matthiae,T Podobnik,P Morettini,V Chorowicz,F Simonetto,G Borisov,L Ventura,U Mjoernmark,A Nygren,A Maio,F Terranova,A Malek,D Rakoczy,B Stugu,A Onofre,N Vassilopoulos,Z Krumstein,T Brenke,N Ghodbane,J Macnaughton,A De Angelis,M Mc Cubbin,L Chaussard,F Verbeure,N Neufeld,A Petrolini,S Tzamarias,M Feindt,M R Monge ,W D Apel ,E Migliore ,M Krammer ,A Sokolov ,Α Μάρκου ,Y Sedykh ,A Romero ,Daniel Bertrand ,P Juillot ,Erik Johansson ,A Ouraou ,R Keränen ,J M Vizan Garcia ,W Kucewicz ,Aurelio Juste Rozas ,T L Hessing ,A N Sisakian ,L G Tkatchev ,J N Jackson ,G Jarlskog ,B Maréchal ,A Tsirou ,V Lapin ,P Jałocha ,A Vodopyanov ,J P Thomas ,D Loukas ,R Brenner ,U Parzefall ,W Mitaroff ,A Tomaradze ,L Carroll ,G P Gopal ,B Jean‐Marie ,M Sannino ,J Wickens ,M E Pol ,G Gómez-Ceballos ,V Hedberg ,C Troncon ,O Passon ,E Katsoufis ,J B Hansen ,D Liko ,A Baroncelli ,D Blöch ,E Higón ,C Weiser ,T Adye ,P Renton ,L Gerdyukov ,F Barão ,N N Khovanski ,W Adam ,I Božović ,Th D Papadopoulou ,D Treille ,I A Tyapkin ,H B Crawley ,R López-Fernández ,P Zalewski ,J C Marin ,F Scuri ,P Checchia ,W Vénus ,J H Cowell ,S Němeček ,N Neumeister ,R Leitner ,T Camporesi ,S R Hahn ,V Uvarov ,J Salt ,A M Segar ,L Pape ,J Fuster ,J Lämsä ,E Križnič ,D Radojičić ,F R Cavallo ,G Hughes ,I Ajinenko ,R C Shellard ,P Jarry ,G Wilkinson ,B Tomé ,P Ferrari ,W Da Silva ,M Lethuillier ,Šárka Todorova ,J Lemonne ,E Ferrer‐Ribas ,L Peralta ,T G M Malmgren ,B S Nielsen ,K Nawrocki ,G A Chelkov ,C Green ,M S Bilenky ,M Günther ,C Bourdarios ,N Demaria ,J Marco ,K Papageorgiou ,J M Brunet ,V Pozdniakov ,D W Lane ,M L Turluer ,J J Hernández ,S Marti-Garcia ,N Mastroyiannopoulos ,M Winter ,S Amato ,M Paganoni ,T Rovelli ,A Leisos ,N Redaelli ,S Ragazzi ,C Kourkoumelis ,C Petridou ,E N Gazis ,M Houlden ,S O Holmgren ,M Ellert ,V Canale ,P Gonçalves ,H M Blom ,J Chudoba ,H T Phillips ,J Loken ,M Mulders ,P Chochula ,P Adžić ,M A E Schyns ,K Doroba ,S Fichet ,H J Grimm ,K Hamacher ,J Cuevas ,C Meroni ,M Elsing ,T Spassov ,M Boonekamp ,N I Zimin ,T Allmendinger ,C Stănescu ,G Wolf ,A G Frodesen ,H Pałka ,J P Laugier ,J P Engel ,G Tranströmer ,G W Van Apeldoorn ,C Bérat ,M Margoni ,G C Zucchelli ,B A Khomenko ,L Lyons ,D Gelé ,Ph Charpentier ,L K Resvanis ,S Navas ,M Bonesini ,I R Boyko ,F L Navarria ,O Smirnova ,H Dijkstra ,F Cossutti ,M V Castillo Gimenez ,J D Durand ,M Dris ,A Perrotta ,J M Heuser ,F Glege ,A W Borgland ,K H Becks ,J Mašík ,I González Caballero ,R Mureşan ,C F Vollmer ,G W Morton ,Rui Pedro Paiva ,E I Rosenberg ,M Dracos ,Kathy Huet ,C Jarlskog ,P Jönsson ,P P Allport ,P Brückman ,M Esṕırito Santo ,S Stanič ,R Chierici ,O Botner ,J Yi ,F Matorras ,W J Murray ,G R Smith ,U Amaldi ,D Sampsonidis ,R Nicolaidou ,J Palacios ,U Muêller ,P Kluit ,P Chliapnikov ,V Vrba ,J E Augustin ,G D Alekseev ,G J Barker ,M Begalli ,P Baillon ,M Pegoraro ,M Calvi ,T J V Bowcock ,B P Kerševan ,F Martínez-Vidal ,J Strauss ,Ph Gris ,G Fanourakis ,A Sopczak ,A Augustinus ,Xavier Moreau ,M A Bizouard ,D Zavrtanik ,R Marco ,B T King ,M Górski ,M Caccia ,A Cattai ,A L Read ,O Kouznetsov ,S Czellár ,P Privitera ,Predrag Krstić ,A C Benvenuti ,L S Vertogradov ,D Y Bardin ,A Hallgren ,L Mirabito ,E Vlasov ,E Anassontzis ,J Řídký ,A Lipniacka ,C Royon ,K Österberg ,P J Holt ,M Bozzo ,W T Meyer ,S Gamblin ,S Crépé ,P N Ratoff ,A G Olshevski ,N J Kjaer ,K Mönig ,M Besançon ,S Andringa ,P Ronchese ,A Duperrin ,R Frühwirth ,J Hrubec ,U Gasparini ,P Beillière ,V Lefébure ,T Ekelöf ,F J Harris ,P Rosinský ,J R Mahon ,I Gil ,C Garćıa ,O Røhne ,C Martínez-Rivero ,C Mariotti ,J M Lopez ,J H Lopes ,G Zumerle

doi:10.1016/s0370-2693(99)00066-0

Abstract

The four-jet events collected by DELPHI during the special LEP run at centre-of-mass energies of 130 and 136 GeV in 1997 with an integrated luminosity of 5.9 pb −1 are analysed. Their rate and the distributions of their di-jet masses, their smallest jet charges, and their di-jet charge separations all agree well with Standard Model predictions. Thus the hypothesis of pair production of a new particle with a sum of di-jet masses around 105 GeV/c 2 is not supported. The combined result of the four LEP collaborations refuting this hypothesis at over 99% confidence level is also given.

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