https://doi.org/10.1140/epjc/s10052-017-4984-5
Regular Article - Experimental Physics
Measurement of double-differential cross sections for top quark pair production in pp collisions at 
and impact on parton distribution functions
1
Yerevan Physics Institute, Yerevan, Armenia
2
Institut für Hochenergiephysik, Vienna, Austria
3
Institute for Nuclear Problems, Minsk, Belarus
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National Centre for Particle and High Energy Physics, Minsk, Belarus
5
Universiteit Antwerpen, Antwerpen, Belgium
6
Vrije Universiteit Brussel, Brussel, Belgium
7
Université Libre de Bruxelles, Bruxelles, Belgium
8
Ghent University, Ghent, Belgium
9
Université Catholique de Louvain, Louvain-la-Neuve, Belgium
10
Université de Mons, Mons, Belgium
11
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
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Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
13
Universidade Estadual Paulista, Universidade Federal do ABC, São Paulo, Brazil
14
Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
15
University of Sofia, Sofia, Bulgaria
16
Beihang University, Beijing, China
17
Institute of High Energy Physics, Beijing, China
18
State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China
19
Universidad de Los Andes, Bogotá, Colombia
20
Faculty of Electrical Engineering Mechanical Engineering and Naval Architecture, University of Split, Split, Croatia
21
Faculty of Science, University of Split, Split, Croatia
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Institute Rudjer Boskovic, Zagreb, Croatia
23
University of Cyprus, Nicosia, Cyprus
24
Charles University, Prague, Czech Republic
25
Universidad San Francisco de Quito, Quito, Ecuador
26
Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt
27
National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
28
Department of Physics, University of Helsinki, Helsinki, Finland
29
Helsinki Institute of Physics, Helsinki, Finland
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Lappeenranta University of Technology, Lappeenranta, Finland
31
IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
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Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France
33
Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg, CNRS-IN2P3, Strasbourg, France
34
Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France
35
Université de Lyon, Université Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
36
Georgian Technical University, Tbilisi, Georgia
37
Tbilisi State University, Tbilisi, Georgia
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RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany
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RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
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RWTH Aachen University,III. Physikalisches Institut B, Aachen, Germany
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Deutsches Elektronen-Synchrotron, Hamburg, Germany
42
University of Hamburg, Hamburg, Germany
43
Institut für Experimentelle Kernphysik, Karlsruhe, Germany
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Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece
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National and Kapodistrian University of Athens, Athens, Greece
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National Technical University of Athens, Athens, Greece
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University of Ioánnina, Ioannina, Greece
48
MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös Loránd University, Budapest, Hungary
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Wigner Research Centre for Physics, Budapest, Hungary
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Institute of Nuclear Research ATOMKI, Debrecen, Hungary
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Institute of Physics, University of Debrecen, Debrecen, Hungary
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Indian Institute of Science (IISc), Bengaluru, India
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National Institute of Science Education and Research, Bhubaneswar, India
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Panjab University, Chandigarh, India
55
University of Delhi, Delhi, India
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Saha Institute of Nuclear Physics, Kolkata, India
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Indian Institute of Technology Madras, Madras, India
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Bhabha Atomic Research Centre, Mumbai, India
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Tata Institute of Fundamental Research-A, Mumbai, India
60
Tata Institute of Fundamental Research-B, Mumbai, India
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Indian Institute of Science Education and Research (IISER), Pune, India
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Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
63
University College Dublin, Dublin, Ireland
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INFN Sezione di Bari, Università di Bari, Politecnico di Bari, Bari, Italy
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INFN Sezione di Bologna, Università di Bologna, Bologna, Italy
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INFN Sezione di Catania, Università di Catania, Catania, Italy
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INFN Sezione di Firenze, Università di Firenze, Florence, Italy
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INFN Laboratori Nazionali di Frascati, Frascati, Italy
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INFN Sezione di Genova, Università di Genova, Genova, Italy
70
INFN Sezione di Milano-Bicocca, Università di Milano-Bicocca, Milan, Italy
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INFN Sezione di Napoli, Università di Napoli ’Federico II’, Napoli, Italy, Università della Basilicata, Potenza, Italy, Università G. Marconi, Rome, Italy
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INFN Sezione di Padova, Università di Padova, Padova, Italy, Università di Trento, Trento, Italy
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INFN Sezione di Pavia, Università di Pavia, Pavia, Italy
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INFN Sezione di Perugia, Università di Perugia, Perugia, Italy
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INFN Sezione di Pisa, Università di Pisa, Scuola Normale Superiore di Pisa, Pisa, Italy
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INFN Sezione di Roma, Università di Roma, Rome, Italy
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INFN Sezione di Torino, Università di Torino, Torino, Italy, Università del Piemonte Orientale, Novara, Italy
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INFN Sezione di Trieste, Università di Trieste, Trieste, Italy
79
Kyungpook National University, Taegu, Korea
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Chonbuk National University, Jeonju, Korea
81
Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea
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Hanyang University, Seoul, Korea
83
Korea University, Seoul, Korea
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Seoul National University, Seoul, Korea
85
University of Seoul, Seoul, Korea
86
Sungkyunkwan University, Suwon, Korea
87
Vilnius University, Vilnius, Lithuania
88
National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia
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Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
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Universidad Iberoamericana, Mexico City, Mexico
91
Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
92
Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
93
University of Auckland, Auckland, New Zealand
94
University of Canterbury, Christchurch, New Zealand
95
National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
96
National Centre for Nuclear Research, Swierk, Poland
97
Faculty of Physics, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland
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Laboratório de Instrumentação e Física Experimental de Partículas, Lisbon, Portugal
99
Joint Institute for Nuclear Research, Dubna, Russia
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Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia
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Institute for Nuclear Research, Moscow, Russia
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Institute for Theoretical and Experimental Physics, Moscow, Russia
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Moscow Institute of Physics and Technology, Moscow, Russia
104
National Research Nuclear University ‘Moscow Engineering Physics Institute’ (MEPhI), Moscow, Russia
105
P.N. Lebedev Physical Institute, Moscow, Russia
106
Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
107
Novosibirsk State University (NSU), Novosibirsk, Russia
108
State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia
109
Faculty of Physics and Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
110
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
111
Universidad Autónoma de Madrid, Madrid, Spain
112
Universidad de Oviedo, Oviedo, Spain
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Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain
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CERN, European Organization for Nuclear Research, Geneva, Switzerland
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Paul Scherrer Institut, Villigen, Switzerland
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Institute for Particle Physics ETH Zurich, Zurich, Switzerland
117
Universität Zürich, Zurich, Switzerland
118
National Central University, Chung-Li, Taiwan
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National Taiwan University (NTU), Taipei, Taiwan
120
Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
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Physics Department Science and Art Faculty, Cukurova University, Adana, Turkey
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Physics Department, Middle East Technical University, Ankara, Turkey
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Bogazici University, Istanbul, Turkey
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Istanbul Technical University, Istanbul, Turkey
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Institute for Scintillation Materials of National Academy of Science of Ukraine, Kharkov, Ukraine
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National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine
127
University of Bristol, Bristol, UK
128
Rutherford Appleton Laboratory, Didcot, UK
129
Imperial College, London, UK
130
Brunel University, Uxbridge, UK
131
Baylor University, Waco, USA
132
Catholic University of America, Washington, DC, USA
133
The University of Alabama, Tuscaloosa, USA
134
Boston University, Boston, USA
135
Brown University, Providence, USA
136
University of California, Davis, Davis, USA
137
University of California, Los Angeles, USA
138
University of California, Riverside, Riverside, USA
139
University of California, San Diego, La Jolla, USA
140
Department of Physics, University of California, Santa Barbara, Santa Barbara, USA
141
California Institute of Technology, Pasadena, USA
142
Carnegie Mellon University, Pittsburgh, USA
143
University of Colorado Boulder, Boulder, USA
144
Cornell University, Ithaca, USA
145
Fairfield University, Fairfield, USA
146
Fermi National Accelerator Laboratory, Batavia, USA
147
University of Florida, Gainesville, USA
148
Florida International University, Miami, USA
149
Florida State University, Tallahassee, USA
150
Florida Institute of Technology, Melbourne, USA
151
University of Illinois at Chicago (UIC), Chicago, USA
152
The University of Iowa, Iowa City, USA
153
Johns Hopkins University, Baltimore, USA
154
The University of Kansas, Lawrence, USA
155
Kansas State University, Manhattan, USA
156
Lawrence Livermore National Laboratory, Livermore, USA
157
University of Maryland, College Park, USA
158
Massachusetts Institute of Technology, Cambridge, USA
159
University of Minnesota, Minneapolis, USA
160
University of Mississippi, Oxford, USA
161
University of Nebraska-Lincoln, Lincoln, USA
162
State University of New York at Buffalo, Buffalo, USA
163
Northeastern University, Boston, USA
164
Northwestern University, Evanston, USA
165
University of Notre Dame, Notre Dame, USA
166
The Ohio State University, Columbus, USA
167
Princeton University, Princeton, USA
168
University of Puerto Rico, Mayagüez, USA
169
Purdue University, West Lafayette, USA
170
Purdue University Northwest, Hammond, USA
171
Rice University, Houston, USA
172
University of Rochester, Rochester, USA
173
Rutgers, The State University of New Jersey, Piscataway, USA
174
University of Tennessee, Knoxville, USA
175
Texas A&M University, College Station, USA
176
Texas Tech University, Lubbock, USA
177
Vanderbilt University, Nashville, USA
178
University of Virginia, Charlottesville, USA
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Wayne State University, Detroit, USA
180
University of Wisconsin-Madison, Madison, WI, USA
181
CERN, 1211, Geneva 23, Switzerland
* e-mail: cms-publication-committee-chair@cern.ch
Received:
5
March
2017
Accepted:
9
June
2017
Published online:
11
July
2017
Normalized double-differential cross sections for top quark pair (
) production are measured in pp collisions at a centre-of-mass energy of 8 with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7
. The measurement is performed in the dilepton 
final state. The cross section is determined as a function of various pairs of observables characterizing the kinematics of the top quark and system. The data are compared to calculations using perturbative quantum chromodynamics at next-to-leading and approximate next-to-next-to-leading orders. They are also compared to predictions of Monte Carlo event generators that complement fixed-order computations with parton showers, hadronization, and multiple-parton interactions. Overall agreement is observed with the predictions, which is improved when the latest global sets of proton parton distribution functions are used. The inclusion of the measured cross sections in a fit of parametrized parton distribution functions is shown to have significant impact on the gluon distribution.
© CERN for the benefit of the CMS collaboration, 2017
