https://doi.org/10.1140/epjc/s10052-013-2674-5
Regular Article - Experimental Physics
Jet and underlying event properties as a function of charged-particle multiplicity in proton–proton collisions at 
1
CERN, Geneva, Switzerland
2
Yerevan Physics Institute, Yerevan, Armenia
3
Institut für Hochenergiephysik der OeAW, Wien, Austria
4
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
12
Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
13
Universidade Estadual Paulista, São Paulo, Brazil
14
Universidade Federal do ABC, São Paulo, Brazil
15
Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
16
University of Sofia, Sofia, Bulgaria
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, Bogota, Colombia
20
Technical University of Split, Split, Croatia
21
University of Split, Split, Croatia
22
Institute Rudjer Boskovic, Zagreb, Croatia
23
University of Cyprus, Nicosia, Cyprus
24
Charles University, Prague, Czech Republic
25
Egyptian Network of High Energy Physics, Academy of Scientific Research and Technology of the Arab Republic of Egypt, Cairo, Egypt
26
National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
27
Department of Physics, University of Helsinki, Helsinki, Finland
28
Helsinki Institute of Physics, Helsinki, Finland
29
Lappeenranta University of Technology, Lappeenranta, Finland
30
DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France
31
Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France
32
Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Université de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France
33
Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France
34
CNRS-IN2P3, Institut de Physique Nucléaire de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France
35
Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia
36
I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany
37
III. Physikalisches Institut A, RWTH Aachen University, Aachen, Germany
38
III. Physikalisches Institut B, RWTH Aachen University, Aachen, Germany
39
Deutsches Elektronen-Synchrotron, Hamburg, Germany
40
University of Hamburg, Hamburg, Germany
41
Institut für Experimentelle Kernphysik, Karlsruhe, Germany
42
Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece
43
University of Athens, Athens, Greece
44
University of Ioánnina, Ioánnina, Greece
45
KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary
46
Institute of Nuclear Research ATOMKI, Debrecen, Hungary
47
University of Debrecen, Debrecen, Hungary
48
National Institute of Science Education and Research, Bhubaneswar, India
49
Panjab University, Chandigarh, India
50
University of Delhi, Delhi, India
51
Saha Institute of Nuclear Physics, Kolkata, India
52
Bhabha Atomic Research Centre, Mumbai, India
53
Tata Institute of Fundamental Research - EHEP, Mumbai, India
54
Tata Institute of Fundamental Research - HECR, Mumbai, India
55
Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
56
University College Dublin, Dublin, Ireland
57
INFN Sezione di Bari, Bari, Italy
58
Università di Bari, Bari, Italy
59
Politecnico di Bari, Bari, Italy
60
INFN Sezione di Bologna, Bologna, Italy
61
Università di Bologna, Bologna, Italy
62
INFN Sezione di Catania, Catania, Italy
63
Università di Catania, Catania, Italy
64
INFN Sezione di Firenze, Firenze, Italy
65
Università di Firenze, Firenze, Italy
66
INFN Laboratori Nazionali di Frascati, Frascati, Italy
67
INFN Sezione di Genova, Genova, Italy
68
Università di Genova, Genova, Italy
69
INFN Sezione di Milano-Bicocca, Milano, Italy
70
Università di Milano-Bicocca, Milano, Italy
71
INFN Sezione di Napoli, Napoli, Italy
72
Università di Napoli ‘Federico II’, Napoli, Italy
73
Università della Basilicata (Potenza), Napoli, Italy
74
Università G. Marconi (Roma), Napoli, Italy
75
INFN Sezione di Padova, Padova, Italy
76
Università di Padova, Padova, Italy
77
Università di Trento (Trento), Padova, Italy
78
INFN Sezione di Pavia, Pavia, Italy
79
Università di Pavia, Pavia, Italy
80
INFN Sezione di Perugia, Perugia, Italy
81
Università di Perugia, Perugia, Italy
82
INFN Sezione di Pisa, Pisa, Italy
83
Università di Pisa, Pisa, Italy
84
Scuola Normale Superiore di Pisa, Pisa, Italy
85
INFN Sezione di Roma, Roma, Italy
86
Università di Roma, Roma, Italy
87
INFN Sezione di Torino, Torino, Italy
88
Università di Torino, Torino, Italy
89
Università del Piemonte Orientale (Novara), Torino, Italy
90
INFN Sezione di Trieste, Trieste, Italy
91
Università di Trieste, Trieste, Italy
92
Kangwon National University, Chunchon, Korea
93
Kyungpook National University, Daegu, Korea
94
Institute for Universe and Elementary Particles, Chonnam National University, Kwangju, Korea
95
Korea University, Seoul, Korea
96
University of Seoul, Seoul, Korea
97
Sungkyunkwan University, Suwon, Korea
98
Vilnius University, Vilnius, Lithuania
99
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
100
Universidad Iberoamericana, Mexico City, Mexico
101
Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
102
Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
103
University of Auckland, Auckland, New Zealand
104
University of Canterbury, Christchurch, New Zealand
105
National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
106
National Centre for Nuclear Research, Swierk, Poland
107
Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
108
Laboratório de Instrumentação e Física Experimental de Partículas, Lisboa, Portugal
109
Joint Institute for Nuclear Research, Dubna, Russia
110
Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia
111
Institute for Nuclear Research, Moscow, Russia
112
Institute for Theoretical and Experimental Physics, Moscow, Russia
113
P.N. Lebedev Physical Institute, Moscow, Russia
114
Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
115
State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia
116
University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia
117
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
118
Universidad Autónoma de Madrid, Madrid, Spain
119
Universidad de Oviedo, Oviedo, Spain
120
Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain
121
European Organization for Nuclear Research, CERN, Geneva, Switzerland
122
Paul Scherrer Institut, Villigen, Switzerland
123
Institute for Particle Physics, ETH Zurich, Zurich, Switzerland
124
Universität Zürich, Zurich, Switzerland
125
National Central University, Chung-Li, Taiwan
126
National Taiwan University (NTU), Taipei, Taiwan
127
Chulalongkorn University, Bangkok, Thailand
128
Cukurova University, Adana, Turkey
129
Physics Department, Middle East Technical University, Ankara, Turkey
130
Bogazici University, Istanbul, Turkey
131
Istanbul Technical University, Istanbul, Turkey
132
Kharkov Institute of Physics and Technology, National Scientific Center, Kharkov, Ukraine
133
University of Bristol, Bristol, United Kingdom
134
Rutherford Appleton Laboratory, Didcot, United Kingdom
135
Imperial College, London, United Kingdom
136
Brunel University, Uxbridge, United Kingdom
137
Baylor University, Waco, USA
138
The University of Alabama, Tuscaloosa, USA
139
Boston University, Boston, USA
140
Brown University, Providence, USA
141
University of California, Davis, Davis, USA
142
University of California, Los Angeles, USA
143
University of California, Riverside, Riverside, USA
144
University of California, San Diego, La Jolla, USA
145
University of California, Santa Barbara, Santa Barbara, USA
146
California Institute of Technology, Pasadena, USA
147
Carnegie Mellon University, Pittsburgh, USA
148
University of Colorado at Boulder, Boulder, USA
149
Cornell University, Ithaca, USA
150
Fairfield University, Fairfield, USA
151
Fermi National Accelerator Laboratory, Batavia, USA
152
University of Florida, Gainesville, USA
153
Florida International University, Miami, USA
154
Florida State University, Tallahassee, USA
155
Florida Institute of Technology, Melbourne, USA
156
University of Illinois at Chicago (UIC), Chicago, USA
157
The University of Iowa, Iowa City, USA
158
Johns Hopkins University, Baltimore, USA
159
The University of Kansas, Lawrence, USA
160
Kansas State University, Manhattan, USA
161
Lawrence Livermore National Laboratory, Livermore, USA
162
University of Maryland, College Park, USA
163
Massachusetts Institute of Technology, Cambridge, USA
164
University of Minnesota, Minneapolis, USA
165
University of Mississippi, Oxford, USA
166
University of Nebraska-Lincoln, Lincoln, USA
167
State University of New York at Buffalo, Buffalo, USA
168
Northeastern University, Boston, USA
169
Northwestern University, Evanston, USA
170
University of Notre Dame, Notre Dame, USA
171
The Ohio State University, Columbus, USA
172
Princeton University, Princeton, USA
173
University of Puerto Rico, Mayaguez, USA
174
Purdue University, West Lafayette, USA
175
Purdue University Calumet, Hammond, USA
176
Rice University, Houston, USA
177
University of Rochester, Rochester, USA
178
The Rockefeller University, New York, USA
179
Rutgers, The State University of New Jersey, Piscataway, USA
180
University of Tennessee, Knoxville, USA
181
Texas A&M University, College Station, USA
182
Texas Tech University, Lubbock, USA
183
Vanderbilt University, Nashville, USA
184
University of Virginia, Charlottesville, USA
185
Wayne State University, Detroit, USA
186
University of Wisconsin, Madison, USA
* e-mail: cms-publication-committee-chair@cern.ch
Received:
17
October
2013
Revised:
18
November
2013
Published online:
11
December
2013
Characteristics of multi-particle production in proton-proton collisions at 
are studied as a function of the charged-particle multiplicity, N
ch. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity |η|<2.4 and transverse momentum p
T>0.25 GeV/c. Jets are reconstructed from charged-particles only and required to have p
T>5 GeV/c. The distributions of jet p
T, average p
T of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of N
ch and compared to the predictions of the pythia and herwig event generators. Predictions without multi-parton interactions fail completely to describe the N
ch-dependence observed in the data. For increasing N
ch, pythia systematically predicts higher jet rates and harder p
T spectra than seen in the data, whereas herwig shows the opposite trends. At the highest multiplicity, the data–model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
