Eur. Phys. J. C (2007) 51: 301-315
https://doi.org/10.1140/epjc/s10052-007-0326-3

Regular Article - Experimental Physics

Diffractive photoproduction of D^*±(2010) at HERA

¹ Argonne National Laboratory, Argonne, Illinois, 60439-4815, USA
² Andrews University, Berrien Springs, Michigan, 49104-0380, USA
³ Institut für Physik, Humboldt-Universität zu Berlin, Berlin, Germany
⁴ University and INFN Bologna, Bologna, Italy
⁵ Physikalisches Institut, Universität Bonn, Bonn, Germany
⁶ H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
⁷ Physics Department, Calabria University and INFN, Cosenza, Italy
⁸ Chonnam National University, Kwangju, South Korea
⁹ Jabatan Fizik, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
¹⁰ Nevis Laboratories, Columbia University, Irvington on Hudson, New York, 10027, USA
¹¹ The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland
¹² Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Cracow, Poland
¹³ Department of Physics, Jagellonian University, Cracow, Poland
¹⁴ Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
¹⁵ Deutsches Elektronen-Synchrotron DESY, Zeuthen, Germany
¹⁶ University and INFN, Florence, Italy
¹⁷ Fakultät für Physik, Universität Freiburg i.Br., Freiburg i.Br., Germany
¹⁸ Department of Physics and Astronomy, University of Glasgow, Glasgow, UK
¹⁹ Department of Engineering in Management and Finance, Univ. of Aegean, Mytilene, Greece
²⁰ Institute of Exp. Physics, Hamburg University, Hamburg, Germany
²¹ High Energy Nuclear Physics Group, Imperial College London, London, UK
²² Institute of Particle and Nuclear Studies, KEK, Tsukuba, Japan
²³ Institute of Physics and Technology, Ministry of Education and Science of Kazakhstan, Almaty, Kazakhstan
²⁴ Center for High Energy Physics, Kyungpook National University, Daegu, South Korea
²⁵ Institut de Physique Nucléaire, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
²⁶ Departamento de Física Teórica, Universidad Autónoma de Madrid, Madrid, Spain
²⁷ Department of Physics, McGill University, Montréal, Québec, H3A 2T8, Canada
²⁸ Faculty of General Education, Meiji Gakuin University, Yokohama, Japan
²⁹ Moscow Engineering Physics Institute, Moscow, Russia
³⁰ Institute of Nuclear Physics, Moscow State University, Moscow, Russia
³¹ Max-Planck-Institut für Physik, München, Germany
³² NIKHEF and University of Amsterdam, Amsterdam, Netherlands
³³ Physics Department, Ohio State University, Columbus, Ohio, 43210, USA
³⁴ Department of Physics, University of Oxford, Oxford, UK
³⁵ Dipartimento di Fisica, Università and INFN, Padova, Italy
³⁶ Department of Physics, Pennsylvania State University, University Park, Pennsylvania, 16802, USA
³⁷ Polytechnic University, Sagamihara, Japan
³⁸ Dipartimento di Fisica, Università ’La Sapienza’ and INFN, Rome, Italy
³⁹ Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, UK
⁴⁰ Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics, Tel-Aviv University, Tel-Aviv, Israel
⁴¹ Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
⁴² Department of Physics, University of Tokyo, Tokyo, Japan
⁴³ Tokyo Metropolitan University, Department of Physics, Tokyo, Japan
⁴⁴ Università di Torino and INFN, Torino, Italy
⁴⁵ Università del Piemonte Orientale, Novara, and INFN, Torino, Italy
⁴⁶ Department of Physics, University of Toronto, Toronto, Ontario, M5S 1A7, Canada
⁴⁷ Physics and Astronomy Department, University College London, London, UK
⁴⁸ Institute of Experimental Physics, Warsaw University, Warsaw, Poland
⁴⁹ Institute for Nuclear Studies, Warsaw, Poland
⁵⁰ Department of Particle Physics, Weizmann Institute, Rehovot, Israel
⁵¹ Department of Physics, University of Wisconsin, Madison, Wisconsin, 53706, USA
⁵² Department of Physics, York University, Toronto, Ontario, Canada M3J 1P3,
⁵³ University College London, London, UK
⁵⁴ University of Hamburg, Hamburg, Germany
⁵⁵ DESY group FEB, Hamburg, Germany
⁵⁶ Stanford Linear Accelerator Center, Stanford, USA
⁵⁷ University of Liverpool, Liverpool, UK
⁵⁸ Institut of Theoretical and Experimental Physics, Moscow, Russia
⁵⁹ INP, Cracow, Poland
⁶⁰ DESY, Hamburg, Germany
⁶¹ CERN, Geneva, Switzerland
⁶² University of Tokyo, Tokyo, Japan
⁶³ Max Planck Institute, Munich, Germany
⁶⁴ KEK, Tsukuba, Japan
⁶⁵ Nagoya University, Nagoya, Japan
⁶⁶ Tokyo Metropolitan University, Department of Radiological Science, Tokyo, Japan
⁶⁷ Łódź University, Łódź, Poland
⁶⁸ Łódź University, Łódź, Poland

^* e-mail: gallo@mail.desy.de

Received: 27 March 2007
Revised: 4 May 2007
Published online: 6 June 2007

Abstract

Diffractive photoproduction of D^*±(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb^-1. The D^* mesons were reconstructed in the kinematic range: transverse momentum p_T(D^*) > 1.9 GeV and pseudorapidity |η(D^*)|<1.6, using the decay D^*+→D⁰π⁺ _s followed by D⁰→K^-π⁺(+c.c.). Diffractive events were identified by a large gap in pseudorapidity between the produced hadronic state and the outgoing proton. Cross sections are reported for photon–proton centre-of-mass energies in the range 130 < W < 300 GeV and for photon virtualities Q² < 1 GeV², in two ranges of the Pomeron fractional momentum x_IP<0.035 and x_IP<0.01. The relative contribution of diffractive events to the inclusive D^*±(2010) photoproduction cross section is about 6%. The data are in agreement with perturbative QCD calculations based on various parameterisations of diffractive parton distribution functions. The results are consistent with diffractive QCD factorisation.