Abstract
Photoproduction events which have two or more jets have been studied in the Wγp range 135 GeV < Wγp < 280 GeV with the ZEUS detector at HERA. A class of events is observed with little hadronic activity between the jets. The jets are separated by pseudorapidity intervals (Δη) of up to four units and have transverse energies greater than 6 GeV. A gap is defined as the absence between the jets of particles with transverse energy greater than 300 MeV. The fraction of events containing a gap is measured as a function of Δη. It decreases exponentially as expected for processes in which colour is exchanged between the jets, up to a value of Δη ∼ 3, then reaches a constant value of about 0.1. The excess above the exponential fall-off can be interpreted as evidence for hard diffractive scattering via a strongly interacting colour singlet object.
| Original language | English |
|---|---|
| Pages (from-to) | 55-68 |
| Number of pages | 14 |
| Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 369 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1996 Feb 15 |
Bibliographical note
Funding Information:’ Also at IROE Florence, Italy. * Now at Univ. of Salerno and INFN Napoli, Italy. 3 Supported by EU HCM contract ERB-CHRX-CT93-0376. 4 Supported by Worldlab, Lausanne, Switzerland. 5 Now a self-employed consultant. 6 Now at ELEKLUFT, Bonn. ’ Now also at University of Torino. * Alexander von Humboldt Fellow. g Alfred P. Sloan Foundation Fellow. lo Now at Inst. of Computer Science, Jagellonian Univ., Cracow. l1 Now at Comma-Soft, Bonn. ‘* Visitor from Florida State University. I3 Now at Univ. of Mainz. I4 Now at DESY Computer Center. I5 Supported by European Community Program PRAXIS XXI. l6 Now at Dr. Seidel Informationssysteme,F rankfurt/M. ” Now at Inst. of Accelerating Systems & Applications (IASA), Athens. l8 Now at Mercer Management Consulting, Munich. lg Now at Univ. de Strasbourg. ” Now at Andrews University, Barrien Springs, USA. *’ Now with OPAL Collaboration, Faculty of Physics at Univ. of Freiburg. ** Now at SAS-Institut GmbH, Heidelberg. u Now at GSI Darmstadt. 24A lso supported by NSERC. Z Now at Institutef or Cosmic Ray Research,U niversity of Tokyo. 26P artially supportedb y CAM. ” Partially supportedb y DESY. 28N ow at Philips Natlab, Eindhoven, NL. 2gN ow at Carleton University, Ottawa, Canada. 3oN ow at Departmento f Energy, Washington. 31N ow at HEP Div., Argonne National Lab., Argonne, IL, USA. 32N ow at Oxford Magnet Technology, Eynsham, Oxon. 33I n part supportedb y Argonne National Laboratory. 34S upported by a MINERVA Fellowship. 35N ow at Centre for SubatomicR esearch,U niv.of Alberta, Canada and TRIUMF, Vancouver, Canada. 36S upported by the Polish State Committee for Scientific Research, grant No. 2P03B09308. 37S upported by the Polish State Committee for Scientific Research, grant No. 2P03B09208. 38N ow at University of Colorado, USA. 3gN ow at High Energy Group of State University of New York,
Funding Information:
Stony Brook, NY. 4oS upported by the Natural Sciences and Engineering Research Council of Canada (NSERC) 41S upported by the FCAR of Quebec, Canada. 42S upported by the German Federal Ministry for Education and Science, Research and Technology (BMBF), under contract numbers 056BN191, 056FR19R 056HH191, 056HH291,056SI791. 43S upportedb y the MINERVA Gesellschaft fur Forschung GmbH, and by the Israel Academy of Science. 44S upported by the German Israeli Foundation, and by the Israel Academy of Science. 45S upported by the Italian National Institute for Nuclear Physics (INFN). 46S upported by the Japanese Ministry of Education, Science and Culture (the Monbusho) and its grants for Scientific Research. 47S upported by the Korean Ministry of Education and Korea Science and Engineering Foundation. 48S upportedb y the NetherlandsF oundation for Research on Matter (FOM). 4g Supported by the Polish State Committee for Scientific Research, grants No. 115/E_343/SPUB/PO3/109/95, 2PO3B 244 08~02,~ 03, pO4 and ~05, and the Foundation for Polish-German Collaboration (proj. No. 506/92). 5oS upportedb y the Polish StateC ommitteef or Scientific Research (grant No. 2 PO3B 083 OS). 5* Partially supportedb y the German Federal Ministry for Education and Science, Research and Technology (BMBF) 52S upported by the German Federal Ministry for Education and Science, Research and Technology (BMBF), and the Fund of Fun-damentalR esearch of Russian Ministry of Science and Education and by INTAS-Grant No. 93-63. 53S upported by the Spanish Ministry of Education and Science through funds provided by CICYT. 54S upported by the Particle Physics and Astronomy Research Council. 55S upported by the US Departmentof Energy. 56S upported by the US National Science Foundation.
ASJC Scopus subject areas
- Nuclear and High Energy Physics