https://doi.org/10.1140/epjc/s10052-019-7181-x
Regular Article - Experimental Physics
Searches for scalar leptoquarks and differential cross-section measurements in dilepton–dijet events in proton–proton collisions at a centre-of-mass energy of 
= 13 TeV with the ATLAS experiment
1
Department of Physics, University of Adelaide, Adelaide, Australia
2
Physics Department, SUNY Albany, Albany, NY, USA
3
Department of Physics, University of Alberta, Edmonton, AB, Canada
4
Department of Physics, Ankara University, Ankara, Turkey
5
Istanbul Aydin University, Istanbul, Turkey
6
Division of Physics, TOBB University of Economics and Technology, Ankara, Turkey
7
LAPP, Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS/IN2P3, Annecy, France
8
High Energy Physics Division, Argonne National Laboratory, Argonne, IL, USA
9
Department of Physics, University of Arizona, Tucson, AZ, USA
10
Department of Physics, University of Texas at Arlington, Arlington, TX, USA
11
Physics Department, National and Kapodistrian University of Athens, Athens, Greece
12
Physics Department, National Technical University of Athens, Zografou, Greece
13
Department of Physics, University of Texas at Austin, Austin, TX, USA
14
Bahcesehir University, Faculty of Engineering and Natural Sciences, Istanbul, Turkey
15
Istanbul Bilgi University, Faculty of Engineering and Natural Sciences, Istanbul, Turkey
16
Department of Physics, Bogazici University, Istanbul, Turkey
17
Department of Physics Engineering, Gaziantep University, Gaziantep, Turkey
18
Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan
19
Institut de Física d’Altes Energies (IFAE), Barcelona Institute of Science and Technology, Barcelona, Spain
20
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
21
Physics Department, Tsinghua University, Beijing, China
22
Department of Physics, Nanjing University, Nanjing, China
23
University of Chinese Academy of Science (UCAS), Beijing, China
24
Institute of Physics, University of Belgrade, Belgrade, Serbia
25
Department for Physics and Technology, University of Bergen, Bergen, Norway
26
Physics Division, Lawrence Berkeley National Laboratory and University of California, Berkeley, CA, USA
27
Institut für Physik, Humboldt Universität zu Berlin, Berlin, Germany
28
Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland
29
School of Physics and Astronomy, University of Birmingham, Birmingham, UK
30
Centro de Investigaciónes, Universidad Antonio Nariño, Bogota, Colombia
31
Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy
32
INFN Sezione di Bologna, Bologna, Italy
33
Physikalisches Institut, Universität Bonn, Bonn, Germany
34
Department of Physics, Boston University, Boston, MA, USA
35
Department of Physics, Brandeis University, Waltham, MA, USA
36
Transilvania University of Brasov, Brasov, Romania
37
Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
38
Department of Physics, Alexandru Ioan Cuza University of Iasi, Iasi, Romania
39
National Institute for Research and Development of Isotopic and Molecular Technologies, Physics Department, Cluj-Napoca, Romania
40
University Politehnica Bucharest, Bucharest, Romania
41
West University in Timisoara, Timisoara, Romania
42
Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia
43
Department of Subnuclear Physics, Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovak Republic
44
Physics Department, Brookhaven National Laboratory, Upton, NY, USA
45
Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina
46
Cavendish Laboratory, University of Cambridge, Cambridge, UK
47
Department of Physics, University of Cape Town, Cape Town, South Africa
48
Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, South Africa
49
School of Physics, University of the Witwatersrand, Johannesburg, South Africa
50
Department of Physics, Carleton University, Ottawa, ON, Canada
51
Faculté des Sciences Ain Chock, Réseau Universitaire de Physique des Hautes Energies - Université Hassan II, Casablanca, Morocco
52
Centre National de l’Energie des Sciences Techniques Nucleaires (CNESTEN), Rabat, Morocco
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Faculté des Sciences Semlalia, Université Cadi Ayyad, LPHEA, Marrakech, Morocco
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Faculté des Sciences, Université Mohamed Premier and LPTPM, Oujda, Morocco
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Faculté des sciences, Université Mohammed V, Rabat, Morocco
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CERN, Geneva, Switzerland
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Enrico Fermi Institute, University of Chicago, Chicago, IL, USA
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LPC, Université Clermont Auvergne, CNRS/IN2P3, Clermont-Ferrand, France
59
Nevis Laboratory, Columbia University, Irvington, NY, USA
60
Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
61
Dipartimento di Fisica, Università della Calabria, Rende, Italy
62
INFN Gruppo Collegato di Cosenza, Laboratori Nazionali di Frascati, Frascati, Italy
63
Physics Department, Southern Methodist University, Dallas, TX, USA
64
Physics Department, University of Texas at Dallas, Richardson, TX, USA
65
Department of Physics, Stockholm University, Stockholm, Sweden
66
Oskar Klein Centre, Stockholm, Sweden
67
Deutsches Elektronen-Synchrotron DESY, Hamburg and Zeuthen, Germany
68
Lehrstuhl für Experimentelle Physik IV, Technische Universität Dortmund, Dortmund, Germany
69
Institut für Kern- und Teilchenphysik, Technische Universität Dresden, Dresden, Germany
70
Department of Physics, Duke University, Durham, NC, USA
71
SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
72
INFN e Laboratori Nazionali di Frascati, Frascati, Italy
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Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany
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Département de Physique Nucléaire et Corpusculaire, Université de Genève, Geneva, Switzerland
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Dipartimento di Fisica, Università di Genova, Genoa, Italy
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INFN Sezione di Genova, Genoa, Italy
78
II. Physikalisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany
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SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, UK
80
LPSC, Université Grenoble Alpes, CNRS/IN2P3, Grenoble INP, Grenoble, France
81
Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge, MA, USA
82
Department of Modern Physics and State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, China
83
Institute of Frontier and Interdisciplinary Science and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Qingdao, China
84
School of Physics and Astronomy, Shanghai Jiao Tong University, KLPPAC-MoE, SKLPPC, Shanghai, China
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Tsung-Dao Lee Institute, Shanghai, China
86
Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
87
Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
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Faculty of Applied Information Science, Hiroshima Institute of Technology, Hiroshima, Japan
89
Department of Physics, Chinese University of Hong Kong, Shatin, N.T., Hong Kong
90
Department of Physics, University of Hong Kong, Hong Kong, China
91
Department of Physics and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
92
Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
93
Department of Physics, Indiana University, Bloomington, IN, USA
94
INFN Gruppo Collegato di Udine, Sezione di Trieste, Udine, Italy
95
ICTP, Trieste, Italy
96
Dipartimento di Chimica, Fisica e Ambiente, Università di Udine, Udine, Italy
97
INFN Sezione di Lecce, Lecce, Italy
98
Dipartimento di Matematica e Fisica, Università del Salento, Lecce, Italy
99
INFN Sezione di Milano, Milan, Italy
100
Dipartimento di Fisica, Università di Milano, Milan, Italy
101
INFN Sezione di Napoli, Naples, Italy
102
Dipartimento di Fisica, Università di Napoli, Naples, Italy
103
INFN Sezione di Pavia, Pavia, Italy
104
Dipartimento di Fisica, Università di Pavia, Pavia, Italy
105
INFN Sezione di Pisa, Pisa, Italy
106
Dipartimento di Fisica E. Fermi, Università di Pisa, Pisa, Italy
107
INFN Sezione di Roma, Rome, Italy
108
Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy
109
INFN Sezione di Roma Tor Vergata, Rome, Italy
110
Dipartimento di Fisica, Università di Roma Tor Vergata, Rome, Italy
111
INFN Sezione di Roma Tre, Rome, Italy
112
Dipartimento di Matematica e Fisica, Università Roma Tre, Rome, Italy
113
INFN-TIFPA, Povo, Italy
114
Università degli Studi di Trento, Trento, Italy
115
Institut für Astro- und Teilchenphysik, Leopold-Franzens-Universität, Innsbruck, Austria
116
University of Iowa, Iowa City, IA, USA
117
Department of Physics and Astronomy, Iowa State University, Ames, IA, USA
118
Joint Institute for Nuclear Research, Dubna, Russia
119
Departamento de Engenharia Elétrica, Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, Brazil
120
Universidade Federal do Rio De Janeiro COPPE/EE/IF, Rio de Janeiro, Brazil
121
Universidade Federal de São João del Rei (UFSJ), São João del Rei, Brazil
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Instituto de Física, Universidade de São Paulo, São Paulo, Brazil
123
KEK, High Energy Accelerator Research Organization, Tsukuba, Japan
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Graduate School of Science, Kobe University, Kobe, Japan
125
AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland
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Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland
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Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
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Faculty of Science, Kyoto University, Kyoto, Japan
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Kyoto University of Education, Kyoto, Japan
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Research Center for Advanced Particle Physics and Department of Physics, Kyushu University, Fukuoka, Japan
131
Instituto de Física La Plata, Universidad Nacional de La Plata and CONICET, La Plata, Argentina
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Physics Department, Lancaster University, Lancaster, UK
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Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK
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Department of Experimental Particle Physics, Jožef Stefan Institute and Department of Physics, University of Ljubljana, Ljubljana, Slovenia
135
School of Physics and Astronomy, Queen Mary University of London, London, UK
136
Department of Physics, Royal Holloway University of London, Egham, UK
137
Department of Physics and Astronomy, University College London, London, UK
138
Louisiana Tech University, Ruston, LA, USA
139
Fysiska institutionen, Lunds universitet, Lund, Sweden
140
Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules (IN2P3), Villeurbanne, France
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Departamento de Física Teorica C-15 and CIAFF, Universidad Autónoma de Madrid, Madrid, Spain
142
Institut für Physik, Universität Mainz, Mainz, Germany
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School of Physics and Astronomy, University of Manchester, Manchester, UK
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CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France
145
Department of Physics, University of Massachusetts, Amherst, MA, USA
146
Department of Physics, McGill University, Montreal, QC, Canada
147
School of Physics, University of Melbourne, Parkville, VIC, Australia
148
Department of Physics, University of Michigan, Ann Arbor, MI, USA
149
Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA
150
B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Belarus
151
Research Institute for Nuclear Problems of Byelorussian State University, Minsk, Belarus
152
Group of Particle Physics, University of Montreal, Montreal, QC, Canada
153
P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia
154
Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia
155
National Research Nuclear University MEPhI, Moscow, Russia
156
D.V. Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow, Russia
157
Fakultät für Physik, Ludwig-Maximilians-Universität München, Munich, Germany
158
Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Munich, Germany
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Nagasaki Institute of Applied Science, Nagasaki, Japan
160
Graduate School of Science and Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Japan
161
Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
162
Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen, The Netherlands
163
Nikhef National Institute for Subatomic Physics and University of Amsterdam, Amsterdam, The Netherlands
164
Department of Physics, Northern Illinois University, DeKalb, IL, USA
165
Budker Institute of Nuclear Physics and NSU, SB RAS, Novosibirsk, Russia
166
Novosibirsk State University Novosibirsk, Novosibirsk, Russia
167
Institute for High Energy Physics of the National Research Centre Kurchatov Institute, Protvino, Russia
168
Department of Physics, New York University, New York, NY, USA
169
Ohio State University, Columbus, OH, USA
170
Faculty of Science, Okayama University, Okayama, Japan
171
Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK, USA
172
Department of Physics, Oklahoma State University, Stillwater, OK, USA
173
Joint Laboratory of Optics, Palacký University, RCPTM, Olomouc, Czech Republic
174
Center for High Energy Physics, University of Oregon, Eugene, OR, USA
175
LAL, Université Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, France
176
Graduate School of Science, Osaka University, Osaka, Japan
177
Department of Physics, University of Oslo, Oslo, Norway
178
Department of Physics, Oxford University, Oxford, UK
179
LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France
180
Department of Physics, University of Pennsylvania, Philadelphia, PA, USA
181
Konstantinov Nuclear Physics Institute of National Research Centre “Kurchatov Institute”, PNPI, St. Petersburg, Russia
182
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, USA
183
Laboratório de Instrumentação e Física Experimental de Partículas, LIP, Lisbon, Portugal
184
Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
185
Departamento de Física, Universidade de Coimbra, Coimbra, Portugal
186
Centro de Física Nuclear da Universidade de Lisboa, Lisbon, Portugal
187
Departamento de Física, Universidade do Minho, Braga, Portugal
188
Departamento de Física Teorica y del Cosmos, Universidad de Granada, Granada, Spain
189
Dep Física and CEFITEC of Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
190
Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
191
Czech Technical University in Prague, Prague, Czech Republic
192
Charles University, Faculty of Mathematics and Physics, Prague, Czech Republic
193
Particle Physics Department, Rutherford Appleton Laboratory, Didcot, UK
194
IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
195
Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA, USA
196
Departamento de Física, Pontificia Universidad Católica de Chile, Santiago, Chile
197
Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile
198
Department of Physics, University of Washington, Seattle, WA, USA
199
Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
200
Department of Physics, Shinshu University, Nagano, Japan
201
Department Physik, Universität Siegen, Siegen, Germany
202
Department of Physics, Simon Fraser University, Burnaby, BC, Canada
203
SLAC National Accelerator Laboratory, Stanford, CA, USA
204
Physics Department, Royal Institute of Technology, Stockholm, Sweden
205
Departments of Physics and Astronomy, Stony Brook University, Stony Brook, NY, USA
206
Department of Physics and Astronomy, University of Sussex, Brighton, UK
207
School of Physics, University of Sydney, Sydney, Australia
208
Institute of Physics, Academia Sinica, Taipei, Taiwan
209
E. Andronikashvili Institute of Physics, Iv. Javakhishvili Tbilisi State University, Tbilisi, Georgia
210
High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia
211
Department of Physics, Technion, Israel Institute of Technology, Haifa, Israel
212
Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
213
Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece
214
International Center for Elementary Particle Physics and Department of Physics, University of Tokyo, Tokyo, Japan
215
Graduate School of Science and Technology, Tokyo Metropolitan University, Tokyo, Japan
216
Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
217
Tomsk State University, Tomsk, Russia
218
Department of Physics, University of Toronto, Toronto, ON, Canada
219
TRIUMF, Vancouver, BC, Canada
220
Department of Physics and Astronomy, York University, Toronto, ON, Canada
221
Division of Physics and Tomonaga Center for the History of the Universe, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
222
Department of Physics and Astronomy, Tufts University, Medford, MA, USA
223
Department of Physics and Astronomy, University of California Irvine, Irvine, CA, USA
224
Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
225
Department of Physics, University of Illinois, Urbana, IL, USA
226
Instituto de Física Corpuscular (IFIC), Centro Mixto Universidad de Valencia - CSIC, Valencia, Spain
227
Department of Physics, University of British Columbia, Vancouver, BC, Canada
228
Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
229
Fakultät für Physik und Astronomie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
230
Department of Physics, University of Warwick, Coventry, UK
231
Waseda University, Tokyo, Japan
232
Department of Particle Physics, Weizmann Institute of Science, Rehovot, Israel
233
Department of Physics, University of Wisconsin, Madison, WI, USA
234
Fakultät für Mathematik und Naturwissenschaften, Fachgruppe Physik, Bergische Universität Wuppertal, Wuppertal, Germany
235
Department of Physics, Yale University, New Haven, CT, USA
236
Yerevan Physics Institute, Yerevan, Armenia
237
CERN, 1211, Geneva 23, Switzerland
* e-mail: atlas.publications@cern.ch
Received:
1
February
2019
Accepted:
31
July
2019
Published online:
3
September
2019
Searches for scalar leptoquarks pair-produced in proton–proton collisions at 
TeV at the Large Hadron Collider are performed by the ATLAS experiment. A data set corresponding to an integrated luminosity of 36.1 fb
is used. Final states containing two electrons or two muons and two or more jets are studied, as are states with one electron or muon, missing transverse momentum and two or more jets. No statistically significant excess above the Standard Model expectation is observed. The observed and expected lower limits on the leptoquark mass at 95% confidence level extend up to 1.29 TeV and 1.23 TeV for first- and second-generation leptoquarks, respectively, as postulated in the minimal Buchmüller–Rückl–Wyler model, assuming a branching ratio into a charged lepton and a quark of 50%. In addition, measurements of particle-level fiducial and differential cross sections are presented for the 
, 
and 
processes in several regions related to the search control regions. Predictions from a range of generators are compared with the measurements, and good agreement is seen for many of the observables. However, the predictions for the 
measurements in observables sensitive to jet energies disagree with the data.
© CERN for the benefit of the ATLAS collaboration, 2019
