The Q2 evolution of the hadronic photon structure function Fγ2 at LEP

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

doi:10.1016/s0370-2693(98)01552-4

Abstract

New measurements at a centre-of-mass energy s ≃183 GeV of the hadronic photon structure function F γ 2( x) in the Q 2 interval, 9 GeV 2 ≤ Q 2≤30 GeV 2, are presented. The data, collected in 1997 with the L3 detector, correspond to an integrated luminosity of 51.9 pb −1. Combining with the data taken at a centre-of-mass energy of 91 GeV, the evolution of F γ 2 with Q 2 is measured in the Q 2 range from 1.2 GeV 2 to 30 GeV 2. F γ 2 shows a linear growth with ln Q 2; the value of the slope α −1d F γ 2( Q 2)/dln Q 2 is measured in two x bins from 0.01 to 0.2 and is somewhat higher than predicted.

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