Resonance formation in the π+ π− π0 final state in two-photon collisions

M Acciarri,D Peach,V Soulimov,D Pandoulas,A Gougas,D Duchesneau,D Ren,K Strauch,B Hartmann,A Favara,K Jenkes,G Carlino,Yu Galaktionov,S Morganti,S Costantini,F Behner,R Ostonen,J Casaus,L Romero,T Paul,M Chamizo,N Gheordanescu,M Von Der Mey,Y Zeng,S Reucroft,G Cara Romeo,N Scholz,B Fenyi,M Bourquin,D Kiss,G Castellini,C Lapoint,A Hasan,D Perret-Gallix,M Napolitano,T Moulik,J Salicio,P Duinker,S Shevchenko,W Van Rossum,T Angelescu,P Zemp,R Völkert,D Sciarrino,L Servoli,J Schwenke,H Nowak,L Tauscher,S Easo,P Levtchenko,I Korolko,D Van Dierendonck,P Lebrun,H Vogt,T Azemoon,H Hofer,S Bhattacharya,G Mirabelli,D Dibitonto,F Wittgenstein,A Degré,T Van Rhee,G Sauvage,H Suter,A Mihul,A Kasser,G Alemanni,H Tuchscherer,M Lebeau,R De Asmundis,B Borgia,A Gurtu,A Shvorob,V Koutsenko,W Krenz,I Josa-Mutuberria,Y Uchida,J Berdugo,A Buffini,N Shivarov,A Lebedev,D Boutigny,A Böhm,K Sudhakar,K Riles,D Kamrad,E Shumilov,A Engler,G Hu,G Schwering,L Fredj,R Leiste,K Freudenreich,F Muheim,A Nippe,G Passaleva,D Mcnally,R Barillère,F Denotaristefani,A Kirkby,V Commichau,E Pistolesi,U Becker,P Laurikainen,F Cotorobai,M Chemarin,M Capell,W Wallraff,F Anselmo,S Patricelli,H Anderhub,K Banicz,D Kirkby,M Tonutti,B Stoyanov,M Rattaggi,M Vivargent,C Dionisi,E Valente,G Viertel,S Pensotti,I Clare,L Baksay,E Drago,G Raven,O Rind,C Palomares,M Basile,M Sassowsky,G Rahal-Callot,G Landi,V Shoutko,P Berges,D Ruschmeier,J Busenitz,Y Zhou,P Extermann,B De La Cruz,R Faccini,M Pauluzzi,M Steuer,S Petrak,C Furetta,D Luckey,H Postema,G Ambrosi,F Ziegler,T Siedenburg,A Bay,P Le Coultre,A Chen,I Vetlitsky,J Rodin,K Lübelsmeyer,A Barczyk,F Di Lodovico,S Schmidt-Kaerst,S Banerjee,E Fiandrini,G Chiefari,M Wadhwa,P De Jong,A Vorvolakos,M Rescigno,B Monteleoni,S Braccini,V Pojidaev,P Marchesini,G Coignet,F Marzano,F Ferroni,H El Mamouni,A Pevsner,N Raja,J Gerald,D Hatzifotiadou,S Wynhoff,A Boucham,J Ulbricht,W Kittel,J Alcaraz,P Bartalini,U Uwer,V Plyaskin,A Robohm,M Schneegans,F Cesaroni,A Buijs,I Dorne,P Schmitz,Y Karyotakis,B Bertucci,A Arefiev,A Kunin,G Susinno ,V Brigljević ,B Z Yang ,P Ladrón De Guevara ,Stefan Roth ,S Gentile,A Klimentov,B N Jin ,N Cavallo,A Zalite ,M Chen,S Blyth ,M Pohl,A J.m Muijs ,C Luci,P A Razis ,S P Ahlen ,G Vesztergombi,X L Wang ,G J Bobbink ,E Sánchez ,L Cifarelli,D Piccolo,Gennaro De Pascale ,M Meschini,S Goldfarb,W Lohmann,Sachin Kumar Mangla ,P Bagnaia,J D Burger ,V Andreev ,H Rykaczewski,Ph Rosselet,P Garcı́a-Abia ,J Fay,G Forconì ,C Tully,Z Zhang,P.G Rancoita,S S Gau ,J K Kim ,Y Zalite ,C H Lin ,S J Hong ,Yong Mei ,G M Bilei ,W G ,T Aziz,Sc Yeh ,P Piroué ,F Becattini,П Спиллантини ,L Gutay ,K L Tung ,Y V Efremenko ,О Адриани ,F.C Erné,J Goldstein,L Luminari,Péter Molnár ,M Campanelli,M E Sarakinos ,J Allaby,Z P Zhang ,H R Hoorani ,H Schopper,R Clare,F J Eppling ,S N Ganguli ,D Prokofiev,J.-P Ernenwein ,M Biasini,Xiaojun Yao ,Bryan Smith ,G Chen,B Zhou,S Falciano,J J Blaising ,M Cerrada,Howard A Stone ,R Moore,L Taylor,G M Chen ,A Hervé,Michel Fabre ,J M Le Goff ,C Y Chien ,A Zichichi,S Rosier‐Lees ,P Paolucci,S Hou ,R A Khan ,I H Park ,Z Z Xu ,S Sarkar,I C Brock ,Virendra K Gupta ,E Leonardi,R Y Zhu ,C Mañá ,A P Colijn ,W Lustermann,C Li,H K Park ,A A Vorobyov ,G Sultanov,M W Gruenewald ,J C Pinto ,J Xu,Herwart Opitz ,J Kirkby,C Sciacca,L Lista,H Janßen ,A M Cartacci ,W W Kinnison ,D Kim,J M You ,I Fisk,W C Van Hoek ,S Baneijee ,G Y Zhu ,D Bourilkov,C Cecchi,Yu Kamyshkov,M T Dova ,B L Betev ,J P Martin ,Y J Pei ,Samuel C.C Ting,Y G Kim ,D Stickland ,R D’alessandro ,K Deiters,A Dominguez,G Majumder,Z A Liu ,R C Ball ,M P Sanders ,P Lecoq,T Nießen ,C Leggett,N Colino,V Innocente,I Durán ,S C Kim ,C Schäfer,K F Read ,J A Rubio ,J D Swain ,M Kaur,K Lassila-Perini,R W Kraemer ,L Barone,S Müller,А Малинин ,A Nisati,A Aloisio,R Battiston,A Doria,C Paus,C Civinini,S Paoletti,J Tóth,L W Jones ,Y S Lu ,S M Ting ,O L Fedin ,P Lecomte,U K Chaturvedi ,L Boldizsár ,S C Tonwar ,E Longo,H B Newman ,D Schmitz,D H Kim ,G Massaro ,L Malgeri,F Pauß ,A Straessner,G Gratta,M Aguilar-Benı́tez ,W Lin ,J Shukla,W J Metzger ,I Vorobiev,A Baschirotto,A C König ,J C Wang ,D J Schotanus ,W J Burger ,M G Alviggi ,F Nessi‐Tedaldi ,C G Yang ,Á Csilling ,F Filthaut,A Sopczak,Z M Wang ,G Hamel De Monchenault ,T Hebbeker,H Vogel,V A Schegelsky ,J H Field ,L Z Sun ,A K Kopp ,P H Fisher ,S Dutta,D Mangeol,H F Chen ,H O Cohn ,J Kapustinsky ,S Nahn,X D Cai ,P Denes,B A Petersen ,A Biland,Y H Chang ,G Organtini,T Dai ,F.L Linde,Z F Gong ,J G Branson ,H Fesefeldt,A Weber,M Dittmar,W Lu,M Diemoz,D Son,S Mele,M Pieri,M N Kienzle‐Focacci ,M Felcini,F Cindolo,R Böck ,J Mnich,S Riemann,J B Ye ,S Chekanov ,R Mount,T Ferguson,B P Roe ,H S Chen ,A J.w Van Mil ,S X Wu ,A Maŕın ,R T Van De Walle ,N Produit,X W Tang ,M Maity,Y D Oh ,L Merola,F Cavallari,S Giagu

doi:10.1016/s0370-2693(97)01091-5

Abstract

A study of resonance formation is presented in the $\pi^+\pi^-\pi^0$ final state in two-photon collisions at LEP. The $a_2(1320)$ radiative width is measured to be $\Gamma_{\gamma\gamma}=0.98\pm0.05\pm0.09$ keV{}. The helicity 2 production is dominant. Exclusive $\pi^+\pi^-\pi^0$ production has also been studied in the mass region above the $a_2$ in the $\rho\pi$ and $f_2\pi$ channels. This region is dominated by a $\rm J^P$=$2^+$ helicity 2 wave.

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