Abstract
Events containing an isolated prompt photon with high transverse energy, together with a balancing jet, have been observed for the first time in photoproduction at HERA. The data were taken with the ZEUS detector, in a γp centre of mass energy range 120-250 GeV. The fraction of the incoming photon energy participating in the production of the prompt photon and the jet, xγ, shows a strong peak near unity, consistent with LO QCD Monte Carlo predictions. In the transverse energy and pseudorapidity range 5 ≤ Eγ T < 10 GeV, -0.7 ≤ ηγ < 0.8, Ejet T ≥ 5 GeV, and -1.5 ≤ ηjet ≤ 1.8, with xOBS γ > 0.8, the measured cross section is 15.3 ± 3.8 ± 1.8 pb, in good agreement with a recent NLO calculation.
| Original language | English |
|---|---|
| Pages (from-to) | 201-216 |
| Number of pages | 16 |
| Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 413 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 1997 Nov 6 |
Bibliographical note
Funding Information:6 Supportebdy the ItalianN ationaIln stitutefo r Nuclear Physics (INFN). ’ Now at CERN. * Retired. lo Supportedb y the Particle Physics and Astronomy Research Council. ” Also at University of Torino and Alexander von Humboldt Fellow at University of Hamburg. ” Now at Dongshin University, Naju, Korea. I3 Supportedb y the Korean Ministry of Education and Korea Science and Engineering Foundation. I4 Also at DESY. I5 Alfred P. Sloan Foundation Fellow. I6 Supportedb y the US National Science Foundation. ” Supported by the Polish State Committee for Scientific Research, grant No. 115/E-343/SPUB/P03/002/97, 2P03B10612, 2PO3B14212,2 P03B10412. ‘s Supportedb y the Polish State Committee for Scientific Research, grant No. 2P03B14912.
Funding Information:
46P artially supported by the Foundation for German-Russian Collaboration DFG-RFBR (grant nos 436 RUS 113/248/3 and 436 RUS 113/248/2). 47S upportedb y the Fund for FundamentalR esearch of Russian Ministry for Science and Education and by the German Federal Ministry for Education and Science, Research and Technology (BMBF). 4* Supported by the Netherlands Foundation for Research on Matter (FOM). 49N ow at Departmento f Energy, Washington. 5oN ow at Lawrence Berkeley Laboratory, Berkeley, CA. USA. ” Now at Yale University, New Haven, CT. ‘* Supportedb y a MINERVA Fellowship. 53S upported by the German Israeli Foundation, and by the Israel Science Foundation, 54P resenta ddress:T okyo Metropolitan College of Allied Medi-caf5Sciences,T okyo 116, Japan. Supported by the Polish State Committee for Scientific Research, grant No. 2P03B09308. 56S upported by the Polish State Committee for Scientific Research, grant No. 2PO3B09208. 57S upported by the MINERVA Gesellschaft fur Forschung GmbH, the German Israeli Foundation, and the US-Israel Binational Science Foundation.
Funding Information:
Collaboration. *’ Supportedb y an EC fellowship number ERBFMBICT 950172. *’ Now at SAP A.G., Walldorf. ** Visitor from Florida State University. 23 Now at ALCATEL Mobile Communication GmbH, Stuttgart. 24 Supportedb y European Community Program PRAXIS XXI. *’ Now at DESY-Group FDET. 26 Now at DESY Computer Center. ” Visitor from Kyungpook National University, Taegu, Korea, partially supportedb y DESY. 28N ow at Fermi National Accelerator Laboratory (FNAL), Batavia. IL, USA.
Funding Information:
9 Supported by the German Federal Ministry for Education and Science, Research and Technology (BMBF), under contract numbers 057BN19P, 057FR19P. 057HH19P, 057HH29P, 057SI751. l9 Supported by the Polish State Committee for Scientific Research (grant No.
Funding Information:
3oN ow at Oxford University, supported by DAAD fellowship HSP II-AUFE III. 3’ Now at ATLAS Collaboration, Univ. of Munich. 32N ow at Clinical Operational Research Unit, University Col-le e London. 53 ’ On leave from MSU, supportedby the GIF, contract I-0444-176.07/95. 34N ow a self-employed consultant. 35S upportedb y an EC fellowship. 36P PARC Post-doctoral Fellow. 37N ow at Conduit Communications Ltd., London, U.K.. 38S upported by JSPS Postdoctoral Fellowships for Research Abroad. 39S upported by the Japanese Ministry of Education, Science and Culture (the Monbusho) and its grants for Scientific Research, 4oN ow at Wayne State University, Detroit, 4’ Partially supportedb y Comunidad Autonoma Madrid. 42S upported by the Spanish Ministry of Education and Science thf;pughf unds provided by CICYT. Supportedb y the Natural Sciences and Engineering Research Council of Canada (NSERC). 44S upportedb y the FCAR of pU6bec, Canada. 45P artially supportedb y the German Federal Ministry for Education and Science, Research and Technology (BMBF).
ASJC Scopus subject areas
- Nuclear and High Energy Physics