Measurement of isolated photon production in deep inelastic ep scattering

S Chekanov,M Zolko,W Hain,Ie Korol,I Abt,Iu Sorokin,M Turcato,A Nigro,P Kulinski,R Brugnera,D Notz,A Bruni,O Behnke,A.S Proskuryakov,A Kotański,J Szuba,S Fazio,W Słomiński,K Oliver,R Hamatsu,J Malka,R Ingbir,B Pawlik,G Grigorescu,A Keramidas,H Kowalski,V Viazlo,F Karstens,C Uribe-Estrada,M.C.K Mattingly,D Szuba,A Salii,J Ciborowski,A Parenti,M Adamus,L Suszycki,E Ron,J Tomaszewska,E Hilger,A Longhin,F Mohamad Idris,F Januschek,D.S Zotkin,B Musgrave,M Kuze,O Volynets,O Bachynska,B Foster,B.O Zhautykov,R Walczak,E Brownson,H Wolfe,G Grzelak,L Bellagamba,J Whyte,G Bari,V Monaco,E Lohrmann,N Okazaki,M Wlasenko,U Noor,D Boscherini,V Drugakov,J De Favereau,S De Pasquale,D Gladkov,U Holm,H Hartmann,R Hori,J Grebenyuk,S Fourletov,D Hochman,O Ota,Y.D Ri,P Roloff,J Del Peso,D Nicholass,U Samson,M Basile,A Bertolin,J Sztuk,A Garfagnini,A Raval,I Gialas,S Magill,K Papageorgiu,L Zawiejski,G Sartorelli,K Horton,V Aushev,B Brzozowska,T Namsoo,C Youngman,T Theedt,S Bhadra,A Galas,T Tsurugai,A Bamberger,B.Y Oh,G Marini,P Stopa,U Karshon,S Dusini,S Limentani,M Borodin,A Polini,K Wrona,B Kamaluddin,A Stifutkin,T Kanno,T Tymieniecka,R Yoshida,T Matsumoto,I Rubinsky,P Kaur,S Schlenstedt,B Kahle,R.C.E Devenish,S Antonelli,A Eskreys,Y Iga,K Olkiewicz,U Schneekloth,M Derrick,S Kananov,Y Eisenberg,B Reisert,C Blohm,F Dal Corso,K Borras,J Repond,O Zenaiev,H Stadie,K Tokushuku,C Glasman,M Ishitsuka,H.‐P Jakob ,A T Doyle ,Z A Ibrahim ,L Adamczyk,M Bindi,J Ferrando,V A Kuzmin ,І Каденко ,А Спиридонов ,A Margotti,D Kisielewska,D C Son ,M Arneodo,N Coppola,R Nania,L.M Shcheglova,M Wing,O Kuprash,A Tapper ,S Kitamura,А Антонов ,P Schleper,B Bylsma,R Mankel,Z Ren,A F Żarnecki ,A Mastroberardino,S Boutle ,J Y Kim ,H Perrey,R Klanner,M Kaur,A N Barakbaev ,N Bruemmer ,A Contin,I.-A Melzer-Pellmann,N Vlasov ,T Bołd,J C Hart ,D H Saxon ,L Cifarelli,M Forrest,R J Nowak ,G Iacobucci,A I Robertson ,I Makarenko,I Brock,R Ciesielski,W Perlański ,F Barreiro,F Sciulli,E.G Boos,Ning Ye ,V Schoenberg ,Wolfram Dietrich Zeuner ,P Goettlicher ,Y Yamazaki,W B Schmidke ,P G Pelfer ,Olga Lukina ,M Jiménez ,P Ermolov ,L A Khein ,C Gwenlan,J Whitmore ,E Tassi,G Wolf,W H Smith ,A Verbytskyi,L K Gladilin ,I Katkov ,A Pellegrino,P Bussey ,J M Butterworth ,L S Durkin ,Y Onishchuk ,E Gallo,W Lohmann,H Tiecke,G Susinno,I O Skillicorn ,K Nagano,D Bartsch,R Shehzadi,Wan Ahmad Tajuddin Wan Abdullah ,A E Nuncio-Quiroz ,A Huettmann ,I M Gregor ,J Behr,B Loehr ,J Terrón,M Ruspa,S Miglioranzi,P Łużniak,M Schioppa,A Lee,A G Yaguees-Molina ,T Haas,D Dobur,R K Dementiev ,C Grab ,V Sosnovtsev,A Caldwell,G Hartner,U Behrens,G Bruni,L Stančo ,Yu A Golubkov ,J J Chwastowski ,E Lobodzinska,C D Catterall ,J Łukasik,M Capua,S Yamada,G Barbagli,P Kooijman,U Klein,T W Jones ,A Savin ,J Figiel,M Vázquez,B A Dolgoshein ,M Lisovyi,F Corriveau,R Sacchi,M Juengst ,J H Loizides ,S Suchkov,I A Korzhavina ,V Libov,J Schwartz,M Przybycień,G D’agostini ,R Carlin,A M Cooper-Sarkar ,P Antonioli,M Corradi,B B Levchenko ,T Schöerner-Sadenius ,A Geiser,P Pluciński ,T Y Ling ,D Reeder ,J Maeda,A Zichichi,D Kollár ,K Piotrzkowski,U Koetz ,D Lontkovskyi,N S Pokrovskiy ,K Long ,M Costa,A Montanari,A Stern,F Cindolo,Inderpal Singh ,V Sola,T P Stewart ,A Solano,J M Pawlak ,M I Ferrero ,H Abramowicz

doi:10.1016/j.physletb.2010.02.045

Abstract

Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320 pb−1. Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges 4<ETγ<15 GeV and −0.7<ηγ<0.9 for exchanged photon virtualities, Q2, in the range 10<Q2<350 GeV2 and for invariant masses of the hadronic system WX>5 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q2, x, ETγ and ηγ. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range.

Highlights

In the study of high-energy collisions involving hadrons, events in which an isolated highenergy photon is observed provide a direct probe of the underlying partonic process, since the emission of these photons is unaffected by parton hadronisation.Isolated high-energy photon production has been studied in a number of fixed-target and hadron-collider experiments [1]
Results are presented from a new inclusive measurement of isolated photon production in neutral current deep inelastic scattering (DIS)
Leading-logarithm parton-shower Monte Carlo (MC) and perturbative QCD predictions are compared to the measurements

Summary

Introduction

In the study of high-energy collisions involving hadrons, events in which an isolated highenergy photon is observed provide a direct probe of the underlying partonic process, since the emission of these photons is unaffected by parton hadronisation.Isolated high-energy photon production has been studied in a number of fixed-target and hadron-collider experiments [1].

Results

Conclusion