Bose–Einstein correlations of neutral and charged pions in hadronic Z decays

P Achard,D Mangeol,L Bellucci,P Duinker,M Diemoz,M Kaur,A Degré,C Schäfer,A Böhm,V Shoutko,H Hofer,S Bottai,A Arefiev,J Salicio,V Koutsenko,G Passaleva,M Vivargent,E Longo,M Chemarin,S Sarkar,B Echenard,F Cindolo,R Leiste,N Raja,J Pothier,N Batalova,Yu Zalite,B Borgia,G Carlino,M Weber,S Vlachos,S Pensotti,D Hatzifotiadou,Y Uchida,T Aziz,A Hervé,B Stoyanov,F Anselmo,M Meschini,P Lebrun,J Casaus,M Wang,J Kirkby,P Denes,Y Hu,L Baksay,E Pistolesi,S Reucroft,D Bourilkov,A Lebedev,P Bagnaia,C Dionisi,S Nagy,H Postema,G Organtini,S Falciano,K Deiters,J Yamamoto,M Steuer,H Vogel,R Barillère,A Krüger,S Schmidt-Kaerst,A Aloisio,T Paul,W Krenz,P.G Rancoita,F Becattini,J Hirschfelder,B Musicar,M Musy,A Doria,J Fay,J Debreczeni,G Chen,E Valente,M Pauluzzi,W Lustermann,J Alcaraz,D Schmitz,C Luci,W Fisher,J Allaby,H Suter,A Straessner,M Pedace,A Ewers,D Duchesneau,W Kittel,W Lohmann,L Romero,L Merola,B Zimmermann,M Capell,A Favara,I Vodopianov,V Pojidaev,B Bertucci,A Zichichi,S Mele,M Pohl,G Chiefari,S Sushkov,T Hebbeker,F Marzano,C Cecchi,G Alemanni,D Prokofiev,M Napolitano,M Biglietti,D Piccolo,L Xia,C Palomares,K Mazumdar,A Kunin,C Tully,H Nowak,G Grenier,N Cavallo,I Fisk,G Landi,S Wynhoff,C Rosenbleck,F Cavallari,T Siedenburg,S Shevchenko,A Shvorob,M Gataullin,F Filthaut,S Braccini,P Paolucci,S Cucciarelli,A Biland,P Raics,F Pierella,L Lista,C Furetta,S Riemann,L Taylor,M Bourquin,M Wadhwa,P Extermann,K Freudenreich,H Rykaczewski,I Clare,W Wallraff,C Sciacca,B Tellili,U Becker,G Viertel,K Lübelsmeyer,S Villa,J Mnich,P Berges,D Teyssier,R Berbeco,A Sakharov,A Barczyk,J Tóth,I Vetlitsky,D Perret-Gallix,L Cifarelli,A Buijs,B Roux,G Zilizi,S Banerjee,L Tauscher,D Haas,P Déglon,G Rahal-Callot,Yu Galaktionov,A Klimentov,G Mirabelli,P Lecomte,G Ruggiero,I Vorobiev,D Luckey,E Shumilov,M Guida,T Ferguson,A Bay,H Milcent,S Patricelli,L Luminari,S Costantini,G Schwering,J Mans,S Saremi,G Holzner,C Timmermans,J Ulbricht,E Delmeire,M Rescigno,N Shivarov,G Vesztergombi,M Felcini,P Lecoq,A Engler,D Pandoulas,M Chamizo,F Denotaristefani,J Quartieri,R Paramatti,R Battiston,A Gurtu,A Bajo,O Grimm,T Azemoon,S Gentile,D Ren,F Behner,S Likhoded,L Malgeri,M Basile,K Sudhakar,A Chen,G Coignet,V Plyaskin,A Eline,S.V Baldew,M Cerrada,J Berdugo,A Mihul,M Biasini,C Paus,H Vogt,H Anderhub,C Li,N Colino,L Servoli,H Schopper,A Rosca,R Ranieri,A Raspereza,S Giagu,E Fiandrini,R Clare,G Sultanov,G Baksay,K Riles,D Vicinanza,D Käfer,H Fesefeldt,P Wienemann,H.L Zhuang,I Josa-Mutuberrı́A,M Kräber,M Lebeau,A Nisati,P Bartalini,R Ramelli,M Dierckxsens,P Levtchenko,M Dittmar,P Piroué ,H J Lee ,M N Kienzle‐Focacci ,P A Razis ,Y H Chang ,C H Lin ,H G Wilkens ,B Z Yang ,O L Fedin ,Z M Wang ,M Aguilar-Benı́tez ,R Van Gulik ,A De Salvo ,J M Le Goff ,W J Burger ,E Sánchez ,G Forconì ,J Swain ,A Zalite ,Samuel C.c Ting ,Z Szillási ,P Le Coultre ,Virendra K Gupta ,B L Betev ,S N Ganguli ,M A Falagán ,H S Chen ,D Van Dierendonck ,О Адриани ,K L Tung ,C Maa ,L W Jones ,M T Dova ,G S Muanza ,M M Baarmand ,P H Fisher ,P De Jong ,A C König ,A J.m Muijs ,B De La Cruz ,M A Rahaman ,W Lin ,S Hou ,S Blyth ,P Tarján ,A M Cartacci ,П Спиллантини ,L Gutay ,J Z Zhao ,R De Asmundis ,H El Mamouni ,F Pauß ,Min Yang ,J A Van Dalen ,D J Schotanus ,H B Newman ,B P Roe ,V A Schegelsky ,J A Rubio ,R T Van De Walle ,V Veszprémi ,А Малинин ,J J Blaising ,J D Burger ,M G Alviggi ,F M Brochu ,Z A Liu ,G M Chen ,T Dai ,W J Metzger ,X D Cai ,T Nießen ,L Z Sun ,R R Mcneil ,P Garcı́a-Abia ,Imad Baptiste Laktineh ,G Cara Romeo ,J P Martin ,Y S Lu ,H J Yang ,J K Kim ,F Linde ,M Pioppí ,H F Chen ,Z F Gong ,V Andreev ,B A Petersen ,S M Ting ,J G Branson ,R A Ofierzynski ,W G ,S Rosier‐Lees ,Z Z Xu ,C G Yang ,M W Gruenewald ,D C Son ,M P Sanders ,R W Kraemer ,X L Wang ,D Della Volpe ,M Kopál ,P Ladrón De Guevara ,X W Tang ,G J Bobbink ,Stefan Roth ,L Boldizsár ,F Nessi‐Tedaldi ,S C Tonwar ,R Y Zhu ,G Y Zhu ,S X Wu ,D Stickland ,B N Jin ,G B Mohanty ,F J Eppling ,Z P Zhang ,A A Vorobyov ,J H Field ,S C Yeh ,Margot Zöller

doi:10.1016/s0370-2693(01)01270-9

Abstract

Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sample of 2 million hadronic Z decays collected with the L3 detector at LEP. The analysis is performed in the four-momentum difference range 300 MeV < Q < 2 GeV. The radius of the neutral pion source is found to be smaller than that of charged pions. This result is in qualitative agreement with the string fragmentation model.

Highlights

Bose-Einstein correlations (BEC), between identical bosons, have been extensively studied in hadronic final states produced in e+e−, ep, hadron-hadron and heavy-ion interactions [1,2,3]
We report a study of BEC of π0 pairs in hadronic decays of the Z boson at LEP, and compare them to BEC of pairs of identically charged pions
BEC manifest themselves as an enhanced production of pairs of identical bosons which are close to one another in phase space

Summary

Introduction

Bose-Einstein correlations (BEC), between identical bosons, have been extensively studied in hadronic final states produced in e+e−, ep, hadron-hadron and heavy-ion interactions [1,2,3]. For a mass window 120 MeV < mγγ < 150 MeV, a total of 1.3 million π0’s is selected in data. They are selected in the same kinematic range as neutral pions: | cos(θtrack)| < 0.73 and 200 MeV < Etrack < 6 GeV, where the energy is calculated from the track momentum, assuming the π± mass.

Results

Conclusion