Eur. Phys. J. C (2015) 75: 580
https://doi.org/10.1140/epjc/s10052-015-3710-4

Regular Article - Experimental Physics

Combination of measurements of inclusive deep inelastic scattering cross sections and QCD analysis of HERA data

H1 and ZEUS Collaborations

¹ I. Physikalisches Institut der RWTH, Aachen, Germany
² Institute of Physics and Technology of Ministry of Education and Science of Kazakhstan, Almaty, Kazakhstan
³ Inter-University Institute for High Energies ULB-VUB, Brussels and Universiteit Antwerpen, Antwerpen, Belgium
⁴ Univerzitet u Banjoj Luci, Arhitektonsko-gra d̄ ko-geodetski fakultet, Banja Luka, Bosnia-Herzegovina
⁵ Universität Bielefeld, Bielefeld, Germany
⁶ School of Physics and Astronomy, University of Birmingham, Birmingham, UK
⁷ INFN Bologna, Bologna, Italy
⁸ University and INFN Bologna, Bologna, Italy
⁹ Physikalisches Institut der Universität Bonn, Bonn, Germany
¹⁰ National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest, Romania
¹¹ Department of Physics, Panjab University, Chandigarh, India
¹² Physics Department and INFN, Calabria University, Cosenza, Italy
¹³ STFC, Rutherford Appleton Laboratory, Didcot, Oxfordshire, UK
¹⁴ Institut für Physik, TU Dortmund, Dortmund, Germany
¹⁵ Joint Institute for Nuclear Research, Dubna, Russia
¹⁶ CERN, Geneva, Switzerland
¹⁷ CEA, DSM/Irfu, CE-Saclay, Gif-sur-Yvette, France
¹⁸ School of Physics and Astronomy, University of Glasgow, Glasgow, UK
¹⁹ II. Physikalisches Institut, Universität Göttingen, Göttingen, Germany
²⁰ Institut für Experimentalphysik, Universität Hamburg, Hamburg, Germany
²¹ Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
²² Physikalisches Institut, Universität Heidelberg, Heidelberg, Germany
²³ Institute of Experimental Physics, Slovak Academy of Sciences, Košice, Slovak Republic
²⁴ The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Kraków, Poland
²⁵ Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Kraków, Poland
²⁶ Department of Physics, Jagellonian University, Kraków, Poland
²⁷ National Centre for Particle Physics, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
²⁸ Institute for Nuclear Research, National Academy of Sciences, Kyiv, Ukraine
²⁹ Department of Nuclear Physics, National Taras Shevchenko University of Kyiv, Kyiv, Ukraine
³⁰ Department of Physics, University of Lancaster, Lancaster, UK
³¹ Department of Physics, University of Liverpool, Liverpool, UK
³² School of Physics and Astronomy, Queen Mary, University of London, London, UK
³³ Physics and Astronomy Department, University College London, London, UK
³⁴ Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, 13288, France
³⁵ Departamento de Fisica Aplicada, CINVESTAV, Mérida, Yucatán, Mexico
³⁶ Institute for Theoretical and Experimental Physics, Moscow, Russia
³⁷ Lebedev Physical Institute, Moscow, Russia
³⁸ Institute for Information Transmission Problems RAS, Moscow, Russia
³⁹ Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
⁴⁰ Max-Planck-Institut für Physik, Munich, Germany
⁴¹ Department of Physics, York University, Ontario, M3J 1P3, Canada
⁴² LAL, Université Paris-Sud, CNRS/IN2P3, Orsay, France
⁴³ Department of Physics, University of Oxford, Oxford, UK
⁴⁴ INFN Padova, Padova, Italy
⁴⁵ Dipartimento di Fisica e Astronomia dell’ Università and INFN, Padua, Italy
⁴⁶ LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France
⁴⁷ Faculty of Science, University of Montenegro, Podgorica, Montenegro
⁴⁸ Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic
⁴⁹ Faculty of Mathematics and Physics, Charles University, Praha, Czech Republic
⁵⁰ Department of Physics, McGill University, Montreal, QC, H3A 2T8, Canada
⁵¹ Department of Particle Physics and Astrophysics, Weizmann Institute, Rehovot, Israel
⁵² Dipartimento di Fisica, Università di Roma Tre and INFN Roma 3, Rome, Italy
⁵³ Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
⁵⁴ Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics, Tel Aviv University, Tel Aviv, Israel
⁵⁵ Polytechnic University, Tokyo, Japan
⁵⁶ Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
⁵⁷ Università di Torino and INFN, Turin, Italy
⁵⁸ Università del Piemonte Orientale, Novara, and INFN, Turin, Italy
⁵⁹ Institute of Particle and Nuclear Studies, KEK, Tsukuba, Japan
⁶⁰ Institute of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar, Mongolia
⁶¹ IPNL, Université Claude Bernard Lyon 1, CNRS/IN2P3, Villeurbanne, France
⁶² Paul Scherrer Institut, Villigen, Switzerland
⁶³ Faculty of Physics, University of Warsaw, Warsaw, Poland
⁶⁴ National Centre for Nuclear Research, Warsaw, Poland
⁶⁵ Fachbereich C, Universität Wuppertal, Wuppertal, Germany
⁶⁶ Yerevan Physics Institute, Yerevan, Armenia
⁶⁷ Faculty of General Education, Meiji Gakuin University, Yokohama, Japan
⁶⁸ Deutsches Elektronen-Synchrotron DESY, Zeuthen, Germany
⁶⁹ Institut für Teilchenphysik, ETH, Zurich, Switzerland
⁷⁰ Physik-Institut der Universität Zürich, Zurich, Switzerland

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

Received: 22 June 2015
Accepted: 29 September 2015
Published online: 8 December 2015

Abstract

A combination is presented of all inclusive deep inelastic cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current scattering for zero beam polarisation. The data were taken at proton beam energies of 920, 820, 575 and 460 GeV and an electron beam energy of 27.5 GeV. The data correspond to an integrated luminosity of about 1 fb and span six orders of magnitude in negative four-momentum-transfer squared, , and Bjorken x. The correlations of the systematic uncertainties were evaluated and taken into account for the combination. The combined cross sections were input to QCD analyses at leading order, next-to-leading order and at next-to-next-to-leading order, providing a new set of parton distribution functions, called HERAPDF2.0. In addition to the experimental uncertainties, model and parameterisation uncertainties were assessed for these parton distribution functions. Variants of HERAPDF2.0 with an alternative gluon parameterisation, HERAPDF2.0AG, and using fixed-flavour-number schemes, HERAPDF2.0FF, are presented. The analysis was extended by including HERA data on charm and jet production, resulting in the variant HERAPDF2.0Jets. The inclusion of jet-production cross sections made a simultaneous determination of these parton distributions and the strong coupling constant possible, resulting in . An extraction of and results on electroweak unification and scaling violations are also presented.