Observation of ExclusiveγγProduction inpp¯Collisions ats=1.96  TeV

T Aaltonen,T J Phillips,F Ptohos,S Behari,S Pagan Griso,V Papadimitriou,J Keung,A Scribano,V Saveliev,A Mitra,L Santi,G Lungu,R Culbertson,P Garosi,W Ashmanskas,M Franklin,S Klimenko,F D Snider,A Golossanov,D O Litvintsev,P E Karchin,A Elagin,S Y Noh,P F Shepard,J Boudreau,B Carls,K Ebina,B A Barnett,T Okusawa,G Volpi,D Stentz,G Pauletta,E J Jeon,D Tonelli,P Sinervo,G Busetto,P Catastini,M E Mattson,D Mietlicki,K Matera,O González,L Ortolan,T Riddick,M Hurwitz,M Gold,A Anastassov,J Vizán,C Mesropian,T Rodriguez,S Carron,K K Joo,A T Goshaw,A Pranko,D Dagenhart,S Poprocki,Y Seiya,W Ketchum,N Goldschmidt,L Nodulman,S Leo,M Tecchio,M Campbell,E Gerchtein,K Gibson,M Stancari,R Vilar,R Roser,D Chokheli,W H Chung,G Flanagan,A B Wicklund,B Auerbach,S Amerio,M Lindgren,N Ranjan,F Canelli,C Plager,K Sliwa,I Shreyber-Tecker,T Wright,G L Strycker,D Waters,C Pagliarone,R Madrak,S Lockwitz,M Hussein,P Squillacioti,A Hamaguchi,O Norniella,F Ruffini,E James,C Calancha,P Giromini,S H Kim,M Cordelli,S Rolli,M Dorigo,T Yang,F Happacher,C S Moon,J Nett,P Mazzanti,H Gerberich,S R Hahn,A Ruiz,M Vidal,G Manca,Y Funakoshi,F Wick,A Varganov,Y Kato,M Jones,D J Cox,M Datta,J D Lewis,K S Mcfarland,D Lucchesi,R Mcnulty,M J Kim,T Bae,C Bromberg,J C Yun,S Zucchelli,N Moggi,D Torretta,A Rahaman,N Ershaidat,W Badgett,H S Budd,J Yoh,R E Hughes,G B Yu,P Lukens,E Palencia,S Y Jun,J Patrick,A Boveia,V Ramakrishnan,J Naganoma,J A Appel,M Corbo,D Glenzinski,D Yamato,G Compostella,A Aurisano,T Wakisaka,C Grosso-Pilcher,J Lueck,G Introzzi,J Budagov,S Errede,P Mcintyre,K Tollefson,K Kondo,R L Wagner,C Neu,S Lami,C Vellidis,J Huston,M Heck,T Tomura,W C Wester,H Wolfe,B Álvarez González,G Velev,E Lee,M Hare,I Suslov,K Potamianos,S Torre,J Asaadi,A Artikov,Y Sakurai,M Shimojima,A Mukherjee,J Conway,A Eppig,V Khotilovich,P Schlabach,S Wolbers,M Lancaster,M J Morello,D Krop,S H Oh,P Movilla Fernandez,S Uozumi,I Oksuzian,Y Zeng,M Iori,M Feindt,J Lys,G Chlachidze,P Murat,D Goldin,A Manousakis-Katsikakis,U K Yang,T R Junk,J Thome,F Vázquez,P K Teng,D J Kong,M Kurata,A Napier,A Semenov,R Orava,Y Sudo,M Mussini,S Donati,H H Williams,N Giokaris,K Goulianos,R St Denis,Y D Oh,J Morlock,D Amidei,F Devoto,S Carrillo,T Kuhr,E Wicklund,L Pondrom,F Rimondi,M Rescigno,L Brigliadori,A Bodek,D Toback,A T Laasanen,Y Takeuchi,S Kwang,C M Ginsburg,G Piacentino,G P Yeh,P Totaro,P Wilson,T Miao,A Loginov,A Bhatti,G Giurgiu,R Forrest,V Rusu,N Hussain,K R Bland,I Bizjak,E Thomson,F Azfar,K Takemasa,D Cauz,C A Cox,W K Sakumoto,P De Barbaro,Y S Chung,G Punzi,H Miyake,A Mazzacane,Q Liu,L Demortier,I Vila,M N Mondragón ,P Bartoš ,I Redondo,D Hare,J Tang,C Clarke,S Moêd ,M E Convery,B Casal,Thomas Schwarz ,H Song,C Zhou,Y K Kim,E Halkiadakis,M Gallinaro,A Schmidt,S Jindariani,T Yoshida,M Chertok,R Lander ,K Yorita,M Kirby,J Pilot,F Ukegawa,D Whiteson,M Goncharov,A Zanetti,J Guimarães Da Costa ,I Nakano,M Trovato,H Liu,A Lister,R Carosi,David Horn ,A Barbaro‐Galtieri ,K Yamamoto,J Freeman ,J Antos̆ ,R Erbacher,J Königsberg ,K Hara,B Blumenfeld,M A Ciocci,B Kilminster,G Latino,V Sorı́n ,U Husemann,F Margaroli,M Dell’Orso,J Bellinger,Y Nagai,S W Lee,D Carlsmith,A Savoy-Navarro,V Krutelyov,C Liu,P Dong,A Kasmi,S Malik,P Mastrandrea,S Shalhout ,R Wallny,R Eusebi,K J Knoepfel ,M J Frank,M Bauce,J E Garcia,S Tokár ,A Clark,M Casarsa,Th Müller ,P Lujan,C Marino,Y C Chen,A Soha,F Chlebana,R Harr ,J Nielsen,M Cavalli‐Sforza ,J R Smith,D Bortoletto,P Renton,M Herndon,F Prokoshin,S B Kim,E Rogers,K Burkett,T Dorigo,S Hou,O Stelzer-Chilton,A Safonov,A Warburton,C P Hays ,S C Seidel ,G Gómez-Ceballos ,A Höcker ,N Kimura,K Hatakeyama,M D’Errico,V Glagolev,G Bellettini,P Wagner,P Barria,M Kreps,D Benjamin,B Stelzer,J P Fernández ,A Buzatu,F Bedeschi,S Camarda,A Penzo,S Wilbur,G Gómez ,I Gorelov,A Bocci,A Mehta,Z Wu,I Yu,G Apollinari,J Russ,I K Furic ,J Dittmann ,H S Kim,T Lecompte,F Crescioli,K Sato,A Robson,J S Wilson,P Wittich,M Martı́nez ,M C Kruse ,J S Lee,P Mehtälä ,A Cerri,P Maestro,J Cuevas,A Kotwal ,S M Wang,S Lammel,B Di Ruzza ,C J Lin ,V E Barnes,J E Kim,F Scuri,R D Field ,D H Kim,M Vogel,S Leone,M Paulini,E Brücken ,А Симоненко ,D Pellett ,K Lannon,J Han ,M Albrow ,M Campanelli,M J Shochet ,S Giagu,S M Farrington ,Y J Kim,T Rodrigo,A Ivanov,A Di Canto ,J Kroll,A F Garfinkel,M S Neubauer,A Paramonov ,A Beretvas,E Schmidt ,T Kamon,B Jayatilaka,L Oakes,F Sforza,A Limosani,J Thom,S Hewamanage,J Strologas,T Shears,L Scodellaro,D W Jang ,T Liu,N D’Ascenzo,K Cho,P Bussey,A Calamba,J Nachtman,K Yi,R Moore,A Castro,A Lath,K Pitts,V Giakoumopoulou,M Deninno,R Lysák ,T Arisawa,M D’Onofrio,G A Thompson,E Pianori,K Maeshima,S S Yu,Yang Yu ,W H Hopkins ,E Lipeles,L Ristori,W-M Yao ,X Wu,B L Winer,А Суханов ,V Cavaliere,G Chiarelli,C Paus,D Bisello,L Cerrito,A Annovi,P Giannetti,J Heinrich,H S Lee,S Grinstein

doi:10.1103/physrevlett.108.081801

Abstract

We have observed exclusive γγ production in proton-antiproton collisions at √s=1.96 TeV, using data from 1.11±0.07 fb(-1) integrated luminosity taken by the Run II Collider Detector at Fermilab. We selected events with two electromagnetic showers, each with transverse energy E(T)>2.5 GeV and pseudorapidity |η|<1.0, with no other particles detected in -7.4<η<+7.4. The two showers have similar E(T) and azimuthal angle separation Δφ~π; 34 events have two charged particle tracks, consistent with the QED process pp¯→p+e(+)e(-)+p¯ by two-photon exchange, while 43 events have no charged tracks. The number of these events that are exclusive π(0)π(0) is consistent with zero and is <15 at 95% C.L. The cross section for pp¯→p+γγ+p¯ with |η(γ)|<1.0 and E(T)(γ)>2.5 GeV is 2.48(-0.35)(+0.40)(stat)(-0.51)(+0.40)(syst) pb.

Full Text