Search forΘ+(1540)Pentaquark in High-Statistics Measurement ofγp→K¯0K+nat CLAS

M Battaglieri,D I Sober,V S Serov,J D Kellie,G S Mutchler,S Tkachenko,N A Baltzell,M Bellis,G E Dodge,D S Carman,C Tur,K V Dharmawardane,D G Ireland,H Avakian,N Guler,J Langheinrich,M Guidal,L Todor,M Holtrop,H Egiyan,I Nakagawa,A Teymurazyan,D Branford,R A Niyazov,G Niculescu,S Stepanyan,D Doughty,R De Vita,O Pogorelko,B B Niczyporuk,C Djalali,F X Girod,L Morand,A Tkabladze,J P Santoro,R W Gothe,W Kim,M Taiuti,Y Prok,C Butuceanu,K L Giovanetti,P Eugenio,H G Juengst,K S Egiyan,A I Ostrovidov,D P Weygand,J Goett,H S Jo,M Nozar,H Bagdasaryan,K Mikhailov,P V Degtyarenko,S A Morrow,O P Dzyubak,G Gavalian,M Khandaker,I Bedlinskiy,E Wolin,V Sapunenko,B Mckinnon,S Strauch,G Ricco,B S Ishkhanov,M Anghinolfi,I I Strakovsky,K A Griffioen,A Yegneswaran,P Ambrozewicz,J Hardie,J J Melone,P Stoler,A Gasparian,P Coltharp,E Pasyuk,U Thoma,V Gyurjyan,N Baillie,N Benmouna,J Lachniet,K Hicks,S L Careccia,G Rosner,I Niculescu,M Osipenko,A Deur,N Pivnyuk,J M Laget,M Ripani,E De Sanctis,B L Berman,R A Schumacher,D Protopopescu,S Bültmann,A V Vlassov,F W Hersman,M Ungaro,I Hleiqawi,M Kossov,Y G Sharabian,M Mirazita,P L Cole,C Paterson,V Batourine,E Clinton,S E Kuhn,S Niccolai,K Livingston,D J Tedeschi,M D Mestayer,F Sabatié,M Garçon,W J Briscoe,G Asryan,R Bradford,J R Calarco,Y Ilieva,S Pozdniakov,S Boiarinov,S Chen,J Zhang,E S Smith,V Kubarovsky,W K Brooks,J Pierce,A Stavinsky,L Zana,D Crabb,C A Meyer,B E Stokes,R Nasseripour,M H Wood,M M Ito,K Park,B Zhao,M F Vineyard,G Fedotov,S Bouchigny,R Minehart,J P Cummings,T Mibe,B A Mecking,D Dale,G P Gilfoyle,M Dugger,B A Raue,L H Kramer,C Salgado,F J Klein,G Riccardi,F Ronchetti,K S Joo ,M Gabrielyan ,V V Mochalov ,P Nadel-Turoński ,R Hakobyan ,J Ball ,S Kuleshov ,H O Funsten ,Lawrence Weinstein ,A Glamazdin ,Volker Burkert ,D Počanić ,J Li ,A Gönenç ,J Kühn ,C E Hyde‐Wright ,Barry Ritchie ,C I O Gordon ,David Jenkins ,A Biselli ,D Lawrence,P Rossi,H Crannell,C Hadjidakis,E Golovach,A V Klimenko,A Klein,L C Smith,M Williams,J W Price,L Guo,T Lee,R Miskimen,J Donnelly,J T Goetz,L Gan,V Mokeev,L Elouadrhiri

doi:10.1103/physrevlett.96.042001

Abstract

The exclusive reaction $\gamma p \to \bar K^0 K^+ n$ was studied in the photon energy range between 1.6-3.8 GeV searching for evidence of the exotic baryon $\Theta^+(1540)\to nK^+$. The decay to $nK^+$ requires the assignment of strangeness $S=+1$ to any observed resonance. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility corresponding to an integrated luminosity of 70 $pb^{-1}$. No evidence for the $\Theta^+$ pentaquark was found. Upper limits were set on the production cross section as function of center-of-mass angle and $nK^+$ mass. The 95% CL upper limit on the total cross section for a narrow resonance at 1540 MeV was found to be 0.8 nb.

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