Measurement of an elongation of the pion source in Z decays

M Acciarri,G Schwering,H Hofer,P Le Coultre,A Buijs,B Monteleoni,T Siedenburg,H Suter,G Rahal-Callot,G Cara Romeo,R Barillère,O Grimm,A Balandras,L Tauscher,S Schmidt-Kaerst,A Seganti,G Zilizi,V Pojidaev,M Gataullin,K Lübelsmeyer,J Salicio,G Ambrosi,A Chen,P Extermann,M Pauluzzi,A Favara,D Duchesneau,S Reucroft,M Steuer,V Koutsenko,A De Salvo,H Postema,A Robohm,W Krenz,P Lebrun,G Chiefari,F Cotorobai,K Banicz,D Pandoulas,D Luckey,E Shumilov,M Basile,V Shoutko,J Rodin,H Nowak,M Lebeau,F Muheim,T Paul,A Böhm,D Kiss,Yu Galaktionov,N Shivarov,S Patricelli,F Anselmo,A Vorvolakos,R Leiste,G Passaleva,D Dufournand,P Marchesini,D Hatzifotiadou,S Cucciarelli,A Buffini,S Bhattacharya,B Cozzoni,V Plyaskin,D Perret-Gallix,J Schwenke,D Migani,P Achard,M Bourquin,D Kamrad,I Vetlitsky,M Kräber,W Kittel,D Ruschmeier,S Costantini,H El Mamouni,J Busenitz,A Bay,U Becker,A Lebedev,G Carlino,B De La Cruz,N Gheordanescu,L Lugnier,G Mirabelli,N Raja,A Degré,G Coignet,D Vicinanza,G Viertel,D Sciarrino,E Pistolesi,S Shevchenko,J Hirschfelder,T Azemoon,G Raven,K Riles,R Ostonen,R De Asmundis,A Engler,J Berdugo,E Fiandrini,M Pedace,A Gurtu,G Holzner,K Freudenreich,G Landi,P Levtchenko,G Marian,G Castellini,M Chemarin,L Servoli,S Braccini,A Arefiev,I Korolko,F Behner,G Grenier,B Stoyanov,I Clare,M Von Der Mey,F Marzano,F Di Lodovico,L Romero,A Lavorato,D Della Volpe,L Baksay,D Peach,A Barczyk,A Shvorob,C Furetta,I Vodopianov,R Faccini,M Rescigno,K Sudhakar,A Button,T Moulik,S Wynhoff,J Casaus,M Napolitano,H Anderhub,M Capell,G Alemanni,M Chamizo,R Ramelli,L Fredj,B Borgia,P Berges,H Milcent,F Ziegler,A Kunin,S Banerjee,P De Jong,B Bertucci,D Ren,E Valente,M Vivargent,F Ferroni,A Mihul,W Wallraff,S Villa,S Pensotti,C Dionisi,T Angelescu,P Bartalini,M Wadhwa,Y Uchida,J Ulbricht,P Laurikainen,R Van Gulik,H Vogt,A Hasan,P Duinker,F Denotaristefani,J Alcaraz,C Palomares,T Van Rhee,D Haas,Z Szillási ,M Diemoz,D Piccolo,K Deiters,Min Yang ,M Kaur,J Tóth,R D’alessandro ,P.G Rancoita,A Hervé,D Bourilkov,J A Van Dalen ,H S Chen ,M Maity,S Vlachos,L Gutay ,C Civinini,J A Rubio ,P A Razis ,H K Park ,Michel Fabre ,C Timmermans,D J Schotanus ,I Vorobiev,W J Metzger ,A Aloisio,L W Jones ,H G Wilkens ,H Yang ,W Lin ,Bryan Smith ,Gennaro De Pascale ,I Iashvili,A Doria,J D Swain ,G B Mohanty ,Y S Lu ,J Allaby,R Battiston,D H Kim ,B N Jin ,S Falciano,S Mele,E Leonardi,M G Alviggi ,M P Sanders ,Péter Molnár ,E Longo,B P Roe ,A Zichichi,H F Chen ,E Sánchez ,H J Lee ,Z Z Xu ,R C Ball ,A Klimentov,M E Sarakinos ,P Déglon ,I Durán ,S Sarkar,G Chen,H Vogel,J H Field ,M Wang,J K Kim ,G Y Zhu ,O L Fedin ,M Felcini,W Lohmann,F.C Erné,R R Mcneil ,P Paolucci,L Luminari,Z F Gong ,G Forconì ,L Malgeri,J M You ,B L Betev ,S Gentile,S C Yeh ,D Stickland ,V Andreev ,П Спиллантини ,W G ,F Linde ,C Cecchi,J G Branson ,P Hidas,M Biasini,Z A Liu ,M N Kienzle‐Focacci ,P Denes,V A Schegelsky ,S M Ting ,D Mangeol,S N Ganguli ,P Lacenter ,S Hou ,M Cerrada,Z P Zhang ,S X Wu ,A Dominguez,J M Le Goff ,M Van Dierendonck ,D Son,T Aziz,Y H Chang ,P H Fisher ,S S Gau ,S C Kim ,J B Ye ,H B Newman ,J Mnich,S Chekanov ,Y J Pei ,L Barone,L Taylor,A M Cartacci ,M A Rahaman ,L Z Sun ,P Garcı́a-Abia ,F Becattini,A Zalite ,M Weber,R W Kraemer ,J P Martin ,P Ladrón De Guevara ,A Weber,A C König ,G Sultanov,T Hebbeker,F Pauß ,C Luci,X D Cai ,J Fay,Samuel C.C Ting,S C Tonwar ,Z M Wang ,F M Brochu ,M Dittmar,I Josa-Mutuberrı́A,U K Chaturvedi ,F Nessi‐Tedaldi ,W Lustermann,C G Yang ,C Tully,K Mazumdar,C Schäfer,Imad Baptiste Laktineh ,A J.m Muijs ,M A Falagán ,L Xia,C Sciacca,M Aguilar-Benı́tez ,A Straessner,О Адриани ,M Campanelli,D Kim,C Paus,S Blyth ,S Paoletti,F Cesaroni,Y Zalite ,G Organtini,Y D Oh ,N Produit,D Schmitz,S Giagu,P Bagnaia,P Lecoq,J D Burger ,L Boldizsár ,J Quartieri,R Clare,J J Blaising ,C H Lin ,G M Chen ,M Pohl,L Cifarelli,L Lista,I Fisk,J Pothier,D Prokofiev,P Lecomte,A K Kopp ,M Meschini,F Cindolo,H R Hoorani ,T Dai ,G S Muanza ,G Massaro ,R Y Zhu ,F J Eppling ,H Fesefeldt,N Colino,A A Vorobyov ,H Rykaczewski,Á Csilling ,S Rosier‐Lees ,K Lassila-Perini,P Wienemann,B A Petersen ,J Kirkby,T Ferguson,H Schopper,X Chéreau ,M Pieri,A Stone,A P Colijn ,W J Burger ,C Li,A Nisati,X W Tang ,А Малинин ,F Filthaut,G Vesztergombi,Virendra K Gupta ,I H Park ,N Cavallo,C Mañá ,X L Wang ,M T Dova ,S Riemann,G J Bobbink ,Howard A Stone ,R A Khan ,F Cavallari,K L Tung ,B Z Yang ,V Brigljević ,P Piroué ,L Merola,A Biland,M W Gruenewald ,T Nießen ,Margot Zöller

doi:10.1016/s0370-2693(99)00662-0

Abstract

We measure Bose-Einstein correlations between like-sign charged pion pairs in hadronic Z decays with the l3 detector at lep. The analysis is performed in three dimensions in the longitudinal center-of-mass system. The pion source is found to be elongated along the thrust axis with a ratio of transverse to longitudinal radius of 0.81±0.02 +0.03 −0.19.

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