Eur. Phys. J. C (2016) 76: 16
https://doi.org/10.1140/epjc/s10052-015-3849-z

Regular Article - Experimental Physics

Production of exclusive dijets in diffractive deep inelastic scattering at HERA

ZEUS Collaboration

¹ INFN Bologna, Bologna, Italy
² University and INFN Bologna, Bologna, Italy
³ Physikalisches Institut der Universität Bonn, Bonn, Germany
⁴ Department of Physics, Panjab University, Chandigarh, India
⁵ Physics Department and INFN, Calabria University, Cosenza, Italy
⁶ National Centre for Particle Physics, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
⁷ The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Kraków, Poland
⁸ Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Kraków, Poland
⁹ Department of Physics, Jagellonian University, Kraków, Poland
¹⁰ Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
¹¹ Deutsches Elektronen-Synchrotron DESY, Zeuthen, Germany
¹² School of Physics and Astronomy, University of Glasgow, Glasgow, UK
¹³ Institute of Experimental Physics, Hamburg University, Hamburg, Germany
¹⁴ Institute of Particle and Nuclear Studies, KEK, Tsukuba, Japan
¹⁵ Institute of Physics and Technology of Ministry of Education and Science of Kazakhstan, Almaty, Kazakhstan
¹⁶ Institute for Nuclear Research, National Academy of Sciences, Kiev, Ukraine
¹⁷ Department of Nuclear Physics, National Taras Shevchenko University of Kyiv, Kiev, Ukraine
¹⁸ Department of Physics, McGill University, Montréal, H3A 2T8, Québec, Canada
¹⁹ Faculty of General Education, Meiji Gakuin University, Yokohama, Japan
²⁰ Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
²¹ Max-Planck-Institut für Physik, Munich, Germany
²² Department of Physics, University of Oxford, Oxford, UK
²³ INFN Padova, Padua, Italy
²⁴ Dipartimento di Fisica e Astronomia dell’ Università and INFN, Padua, Italy
²⁵ Polytechnic University, Tokyo, Japan
²⁶ Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics, Tel Aviv University, Tel Aviv, Israel
²⁷ Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
²⁸ Università di Torino and INFN, Turin, Italy
²⁹ Università del Piemonte Orientale, Novara, and INFN, Turin, Italy
³⁰ Physics and Astronomy Department, University College London, London, UK
³¹ Faculty of Physics, University of Warsaw, Warsaw, Poland
³² National Centre for Nuclear Research, Warsaw, Poland
³³ Department of Particle Physics and Astrophysics, Weizmann Institute, Rehovot, Israel
³⁴ Department of Physics, York University, Ontario, M3J 1P3, Canada

^* e-mail: mw@hep.ucl.ac.uk

Received: 28 May 2015
Accepted: 15 December 2015
Published online: 14 January 2016

Abstract

Production of exclusive dijets in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 372 pb. The measurement was performed for –p centre-of-mass energies in the range and for photon virtualities . Energy flows around the jet axis are presented. The cross section is presented as a function of and , where , x is the Bjorken variable and is the proton fractional longitudinal momentum loss. The angle is defined by the –dijet plane and the – plane in the rest frame of the diffractive final state. The cross section is measured in bins of . The results are compared to predictions from models based on different assumptions about the nature of the diffractive exchange.