https://doi.org/10.1140/epjc/s10052-019-6556-3
Regular Article - Experimental Physics
Search for single production of vector-like quarks decaying to a top quark and a 
boson in proton–proton collisions at 
1
Yerevan Physics Institute, Yerevan, Armenia
2
Institut für Hochenergiephysik, Wien, Austria
3
Institute for Nuclear Problems, Minsk, Belarus
4
Universiteit Antwerpen, Antwerp, Belgium
5
Vrije Universiteit Brussel, Brussels, Belgium
6
Université Libre de Bruxelles, Brussels, Belgium
7
Ghent University, Ghent, Belgium
8
Université Catholique de Louvain, Louvain-la-Neuve, Belgium
9
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
10
Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
11
Universidade Estadual Paulista, Universidade Federal do ABC, São Paulo, Brazil
12
Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria
13
University of Sofia, Sofia, Bulgaria
14
Beihang University, Beijing, China
15
Institute of High Energy Physics, Beijing, China
16
State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China
17
Tsinghua University, Beijing, China
18
Universidad de Los Andes, Bogota, Colombia
19
University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia
20
University of Split, Faculty of Science, Split, Croatia
21
Institute Rudjer Boskovic, Zagreb, Croatia
22
University of Cyprus, Nicosia, Cyprus
23
Charles University, Prague, Czech Republic
24
Escuela Politecnica Nacional, Quito, Ecuador
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
30
Lappeenranta University of Technology, Lappeenranta, Finland
31
IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
32
Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Université Paris-Saclay, Palaiseau, France
33
Université de Strasbourg, CNRS, IPHC UMR 7178, 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
38
RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany
39
RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
40
RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany
41
Deutsches Elektronen-Synchrotron, Hamburg, Germany
42
University of Hamburg, Hamburg, Germany
43
Karlsruher Institut fuer Technologie, Karlsruhe, Germany
44
Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Agia Paraskevi, Greece
45
National and Kapodistrian University of Athens, Athens, Greece
46
National Technical University of Athens, Athens, Greece
47
University of Ioánnina, Ioannina, Greece
48
MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös Loránd University, Budapest, Hungary
49
Wigner Research Centre for Physics, Budapest, Hungary
50
Institute of Nuclear Research ATOMKI, Debrecen, Hungary
51
Institute of Physics, University of Debrecen, Debrecen, Hungary
52
Indian Institute of Science (IISc), Bangalore, India
53
National Institute of Science Education and Research, HBNI, Bhubaneswar, India
54
Panjab University, Chandigarh, India
55
University of Delhi, Delhi, India
56
Saha Institute of Nuclear Physics, HBNI, Kolkata, India
57
Indian Institute of Technology Madras, Madras, India
58
Bhabha Atomic Research Centre, Mumbai, India
59
Tata Institute of Fundamental Research-A, Mumbai, India
60
Tata Institute of Fundamental Research-B, Mumbai, India
61
Indian Institute of Science Education and Research (IISER), Pune, India
62
Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
63
University College Dublin, Dublin, Ireland
64
INFN Sezione di Bari, Università di Bari, Politecnico di Bari, Bari, Italy
65
INFN Sezione di Bologna, Università di Bologna, Bologna, Italy
66
INFN Sezione di Catania, Università di Catania, Catania, Italy
67
INFN Sezione di Firenze, Università di Firenze, Florence, Italy
68
INFN Laboratori Nazionali di Frascati, Frascati, Italy
69
INFN Sezione di Genova, Università di Genova, Genoa, Italy
70
INFN Sezione di Milano-Bicocca, Università di Milano-Bicocca, Milan, Italy
71
INFN Sezione di Napoli, Università di Napoli ’Federico II’ , Napoli, Italy, Università della Basilicata, Potenza, Italy, Università G. Marconi, Rome, Italy
72
INFN Sezione di Padova, Università di Padova, Padova, Italy, Università di Trento, Trento, Italy
73
INFN Sezione di Pavia, Università di Pavia, Pavia, Italy
74
INFN Sezione di Perugia, Università di Perugia, Perugia, Italy
75
INFN Sezione di Pisa, Università di Pisa, Scuola Normale Superiore di Pisa, Pisa, Italy
76
INFN Sezione di Roma, Sapienza Università di Roma, Rome, Italy
77
INFN Sezione di Torino, Università di Torino, Torino, Italy, Università del Piemonte Orientale, Novara, Italy
78
INFN Sezione di Trieste, Università di Trieste, Trieste, Italy
79
Kyungpook National University, Daegu, Korea
80
Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea
81
Hanyang University, Seoul, Korea
82
Korea University, Seoul, Korea
83
Sejong University, Seoul, Korea
84
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
89
Universidad de Sonora (UNISON), Hermosillo, Mexico
90
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
91
Universidad Iberoamericana, Mexico City, Mexico
92
Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
93
Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
94
University of Auckland, Auckland, New Zealand
95
University of Canterbury, Christchurch, New Zealand
96
National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
97
National Centre for Nuclear Research, Swierk, Poland
98
Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
99
Laboratório de Instrumentação e Física Experimental de Partículas, Lisbon, Portugal
100
Joint Institute for Nuclear Research, Dubna, Russia
101
Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia
102
Institute for Nuclear Research, Moscow, Russia
103
Institute for Theoretical and Experimental Physics, Moscow, Russia
104
Moscow Institute of Physics and Technology, Moscow, Russia
105
National Research Nuclear University ’Moscow Engineering Physics Institute’ (MEPhI), Moscow, Russia
106
P.N. Lebedev Physical Institute, Moscow, Russia
107
Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
108
Novosibirsk State University (NSU), Novosibirsk, Russia
109
Institute for High Energy Physics of National Research Centre ’Kurchatov Institute’, Protvino, Russia
110
National Research Tomsk Polytechnic University, Tomsk, Russia
111
University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia
112
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
113
Universidad Autónoma de Madrid, Madrid, Spain
114
Universidad de Oviedo, Oviedo, Spain
115
Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain
116
Department of Physics, University of Ruhuna, Matara, Sri Lanka
117
CERN, European Organization for Nuclear Research, Geneva, Switzerland
118
Paul Scherrer Institut, Villigen, Switzerland
119
ETH Zurich, Institute for Particle Physics and Astrophysics (IPA), Zurich, Switzerland
120
Universität Zürich, Zurich, Switzerland
121
National Central University, Chung-Li, Taiwan
122
National Taiwan University (NTU), Taipei, Taiwan
123
Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok, Thailand
124
Çukurova University, Physics Department, Science and Art Faculty, Adana, Turkey
125
Middle East Technical University, Physics Department, Ankara, Turkey
126
Bogazici University, Istanbul, Turkey
127
Istanbul Technical University, Istanbul, Turkey
128
Institute for Scintillation Materials of National Academy of Science of Ukraine, Kharkov, Ukraine
129
National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine
130
University of Bristol, Bristol, UK
131
Rutherford Appleton Laboratory, Didcot, UK
132
Imperial College, London, UK
133
Brunel University, Uxbridge, UK
134
Baylor University, Waco, USA
135
Catholic University of America, Washington, DC, USA
136
The University of Alabama, Tuscaloosa, USA
137
Boston University, Boston, USA
138
Brown University, Providence, USA
139
University of California, Davis, Davis, USA
140
University of California, Los Angeles, USA
141
University of California, Riverside, Riverside, USA
142
University of California, San Diego, La Jolla, USA
143
Department of Physics, University of California, Santa Barbara, Santa Barbara, USA
144
California Institute of Technology, Pasadena, USA
145
Carnegie Mellon University, Pittsburgh, USA
146
University of Colorado Boulder, Boulder, USA
147
Cornell University, Ithaca, USA
148
Fermi National Accelerator Laboratory, Batavia, USA
149
University of Florida, Gainesville, USA
150
Florida International University, Miami, USA
151
Florida State University, Tallahassee, USA
152
Florida Institute of Technology, Melbourne, USA
153
University of Illinois at Chicago (UIC), Chicago, USA
154
The University of Iowa, Iowa City, USA
155
Johns Hopkins University, Baltimore, USA
156
The University of Kansas, Lawrence, USA
157
Kansas State University, Manhattan, USA
158
Lawrence Livermore National Laboratory, Livermore, USA
159
University of Maryland, College Park, USA
160
Massachusetts Institute of Technology, Cambridge, USA
161
University of Minnesota, Minneapolis, USA
162
University of Mississippi, Oxford, USA
163
University of Nebraska-Lincoln, Lincoln, USA
164
State University of New York at Buffalo, Buffalo, USA
165
Northeastern University, Boston, USA
166
Northwestern University, Evanston, USA
167
University of Notre Dame, Notre Dame, USA
168
The Ohio State University, Columbus, USA
169
Princeton University, Princeton, USA
170
University of Puerto Rico, Mayaguez, USA
171
Purdue University, West Lafayette, USA
172
Purdue University Northwest, Hammond, USA
173
Rice University, Houston, USA
174
University of Rochester, Rochester, USA
175
Rutgers, The State University of New Jersey, Piscataway, USA
176
University of Tennessee, Knoxville, USA
177
Texas A&M University, College Station, USA
178
Texas Tech University, Lubbock, USA
179
Vanderbilt University, Nashville, USA
180
University of Virginia, Charlottesville, USA
181
Wayne State University, Detroit, USA
182
University of Wisconsin, Madison, Madison, WI, USA
183
CERN, 1211, Geneva 23, Switzerland
* e-mail: cms-publication-committee-chair@cern.ch
Received:
23
September
2018
Accepted:
27
December
2018
Published online:
30
January
2019
A search is presented for the single production of vector-like quarks in proton–proton collisions at 
. The data, corresponding to an integrated luminosity of 35.9
, were recorded with the CMS experiment at the LHC. The analysis focuses on the vector-like quark decay into a top quark and a boson, with one muon or electron in the final state. The mass of the vector-like quark candidate is reconstructed from hadronic jets, the lepton, and the missing transverse momentum. Methods for the identification of 
quarks and of highly Lorentz boosted hadronically decaying top quarks and bosons are exploited in this search. No significant deviation from the standard model background expectation is observed. Exclusion limits at 95% confidence level are set on the product of the production cross section and branching fraction as a function of the vector-like quark mass, which range from 0.3 to 0.03
for vector-like quark masses of 700 to 2000
. Mass exclusion limits up to 1660 are obtained, depending on the vector-like quark type, coupling, and decay width. These represent the most stringent exclusion limits for the single production of vector-like quarks in this channel.
© CERN for the benefit of the CMS collaboration, 2019
