Eur. Phys. J. C (2007) 50: 299-314
https://doi.org/10.1140/epjc/s10052-007-0257-z

Regular Article - Experimental Physics

Measurement of open beauty production at HERA in the D^*μ final state

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 and INFN, Calabria University, 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 Experimental 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 Department of Physics, Tokyo Metropolitan University, 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, M3J 1P3, Canada

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

Received: 26 September 2006
Revised: 31 January 2007
Published online: 15 March 2007

Abstract

The production of beauty quarks with a and a muon in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb^-1. Low transverse-momentum thresholds for the muon and D^* meson allow for a measurement of beauty production closer to the production threshold than previous measurements. The beauty signal was extracted using the charge correlations and angular distributions of the muon with respect to the D^* meson. Cross sections for photoproduction and deep inelastic scattering are somewhat higher than, but compatible with, next-to-leading-order QCD predictions, and compatible with other measurements.