https://doi.org/10.1140/epjc/s10052-006-0206-2
Regular Article - Experimental Physics
Diffractive open charm production in deep-inelastic scattering and photoproduction at HERA
1
I. Physikalisches Institut der RWTH, Aachen, Germany
2
Vinca Institute of Nuclear Sciences, Belgrade, Serbia
3
School of Physics and Astronomy, University of Birmingham, Birmingham, UK
4
Inter-University Institute for High Energies ULB-VUB, Brussels, Belgium
5
Universiteit Antwerpen, Antwerpen, Belgium
6
Rutherford Appleton Laboratory, Chilton, Didcot, UK
7
Institute for Nuclear Physics, Cracow, Poland
8
Institut für Physik, Universität Dortmund, Dortmund, Germany
9
Joint Institute for Nuclear Research, Dubna, Russia
10
CEA, DSM/DAPNIA, CE-Saclay, Gif-sur-Yvette, France
11
DESY, Hamburg, Germany
12
Institut für Experimentalphysik, Universität Hamburg, Hamburg, Germany
13
Max-Planck-Institut für Kernphysik, Heidelberg, Germany
14
Physikalisches Institut, Universität Heidelberg, Heidelberg, Germany
15
Kirchhoff-Institut für Physik, Universität Heidelberg, Heidelberg, Germany
16
Institute of Experimental Physics, Slovak Academy of Sciences, Košice, Slovak Republic
17
Department of Physics, University of Lancaster, Lancaster, UK
18
Department of Physics, University of Liverpool, Liverpool, UK
19
Queen Mary and Westfield College, London, UK
20
Physics Department, University of Lund, Lund, Sweden
21
Physics Department, University of Manchester, Manchester, UK
22
CPPM, CNRS/IN2P3, Univ. Mediterranee, Marseille, France
23
Departamento de Fisica Aplicada, CINVESTAV, Merida, Yucatan, Mexico
24
Departamento de Fisica, CINVESTAV, Merida, Mexico
25
Institute for Theoretical and Experimental Physics, Moscow, Russia
26
Lebedev Physical Institute, Moscow, Russia
27
Max-Planck-Institut für Physik, München, Germany
28
LAL, Universite de Paris-Sud 11, IN2P3-CNRS, Orsay, France
29
LLR, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France
30
LPNHE, Universites Paris VI and VII, IN2P3-CNRS, Paris, France
31
Faculty of Science, University of Montenegro, Podgorica, Montenegro
32
Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic
33
Faculty of Mathematics and Physics, Charles University, Praha, Czech Republic
34
Dipartimento di Fisica Universita di Roma Tre and INFN Roma 3, Roma, Italy
35
Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
36
Institute of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar, Mongolia
37
Paul Scherrer Institut, Villigen, Switzerland
38
Fachbereich C, Universität Wuppertal, Wuppertal, Germany
39
Yerevan Physics Institute, Yerevan, Armenia
40
DESY, Zeuthen, Germany
41
Institut für Teilchenphysik, ETH, Zürich, Switzerland
42
Physik-Institut der Universität Zürich, Zürich, Switzerland
43
Physics Department, National Technical University, Zografou Campus, 15773, Athens, Greece
44
Rechenzentrum, Universität Wuppertal, Wuppertal, Germany
45
University of P.J. Safarik, Kosice, Slovak Republic
46
CERN, Geneva, Switzerland
47
Max-Planck-Institut für Physik, München, Germany
48
Comenius University, Bratislava, Slovak Republic
49
Helmholtz Humboldt Research Award, DESY and University Hamburg, Hamburg, Germany
* e-mail: obehnke@mail.desy.de
Received:
25
October
2006
Revised:
24
November
2006
Published online:
8
February
2007
Measurements are presented of diffractive open charm production at HERA. The event topology is given by ep→eXY where the system X contains at least one charmed hadron and is well separated by a large rapidity gap from a leading low-mass proton remnant system Y. Two analysis techniques are used for the cross section measurements. In the first, the charm quark is tagged by the reconstruction of a D*±(2010) meson. This technique is used in deep-inelastic scattering (DIS) and photoproduction (γp). In the second, a method based on the displacement of tracks from the primary vertex is used to measure the open charm contribution to the inclusive diffractive cross section in DIS. The measurements are compared with next-to-leading order QCD predictions based on diffractive parton density functions previously obtained from a QCD analysis of the inclusive diffractive cross section at H1. A good agreement is observed in the full kinematic regime, which supports the validity of QCD factorization for open charm production in diffractive DIS and γp.
© Springer-Verlag Berlin Heidelberg, 2007