https://doi.org/10.1140/epjc/s10052-018-6027-2
Regular Article - Experimental Physics
Measurement of the inclusive J/
polarization at forward rapidity in pp collisions at 
TeV
1
A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation, Yerevan, Armenia
2
Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
3
Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine, Kiev, Ukraine
4
Department of Physics and Centre for Astroparticle Physics and Space Science (CAPSS), Bose Institute, Kolkata, India
5
Budker Institute for Nuclear Physics, Novosibirsk, Russia
6
California Polytechnic State University, San Luis Obispo, CA, USA
7
Central China Normal University, Wuhan, China
8
Centre de Calcul de l’IN2P3, Villeurbanne, Lyon, France
9
Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear (CEADEN), Havana, Cuba
10
Centro de Investigación y de Estudios Avanzados (CINVESTAV), Mexico City and Mérida, Mexico
11
Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi’, Rome, Italy
12
Chicago State University, Chicago, IL, USA
13
China Institute of Atomic Energy, Beijing, China
14
Chonbuk National University, Jeonju, Republic of Korea
15
Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, Bratislava, Slovakia
16
COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan
17
Creighton University, Omaha, NE, USA
18
Department of Physics, Aligarh Muslim University, Aligarh, India
19
Department of Physics, Ohio State University, Columbus, OH, USA
20
Department of Physics, Pusan National University, Pusan, Republic of Korea
21
Department of Physics, Sejong University, Seoul, Republic of Korea
22
Department of Physics, University of California, Berkeley, CA, USA
23
Department of Physics, University of Oslo, Oslo, Norway
24
Department of Physics and Technology, University of Bergen, Bergen, Norway
25
Dipartimento di Fisica dell’Università ’La Sapienza’ and Sezione INFN, Rome, Italy
26
Dipartimento di Fisica dell’Università and Sezione INFN, Cagliari, Italy
27
Dipartimento di Fisica dell’Università and Sezione INFN, Trieste, Italy
28
Dipartimento di Fisica dell’Università and Sezione INFN, Turin, Italy
29
Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Bologna, Italy
30
Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Catania, Italy
31
Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Padova, Italy
32
Dipartimento di Fisica ‘E.R. Caianiello’ dell’Università and Gruppo Collegato INFN, Salerno, Italy
33
Dipartimento DISAT del Politecnico and Sezione INFN, Turin, Italy
34
Dipartimento di Scienze e Innovazione Tecnologica dell’Università del Piemonte Orientale and INFN Sezione di Torino, Alessandria, Italy
35
Dipartimento Interateneo di Fisica ‘M. Merlin’ and Sezione INFN, Bari, Italy
36
European Organization for Nuclear Research (CERN), Geneva, Switzerland
37
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Split, Croatia
38
Faculty of Engineering and Science, Western Norway University of Applied Sciences, Bergen, Norway
39
Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague, Czech Republic
40
Faculty of Science, P.J. Šafárik University, Košice, Slovakia
41
Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-Universität Frankfurt, Frankfurt, Germany
42
Gangneung-Wonju National University, Gangneung, Republic of Korea
43
Department of Physics, Gauhati University, Guwahati, India
44
Helmholtz-Institut für Strahlen- und Kernphysik, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
45
Helsinki Institute of Physics (HIP), Helsinki, Finland
46
Hiroshima University, Hiroshima, Japan
47
Hochschule Worms, Zentrum für Technologietransfer und Telekommunikation (ZTT), Worms, Germany
48
Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
49
Indian Institute of Technology Bombay (IIT), Mumbai, India
50
Indian Institute of Technology Indore, Indore, India
51
Indonesian Institute of Sciences, Jakarta, Indonesia
52
INFN, Laboratori Nazionali di Frascati, Frascati, Italy
53
INFN, Sezione di Bari, Bari, Italy
54
INFN, Sezione di Bologna, Bologna, Italy
55
INFN, Sezione di Cagliari, Cagliari, Italy
56
INFN, Sezione di Catania, Catania, Italy
57
INFN, Sezione di Padova, Padova, Italy
58
INFN, Sezione di Roma, Rome, Italy
59
INFN, Sezione di Torino, Turin, Italy
60
INFN, Sezione di Trieste, Trieste, Italy
61
Inha University, Incheon, Republic of Korea
62
Institut de Physique Nucléaire d’Orsay (IPNO), Institut National de Physique Nucléaire et de Physique des Particules (IN2P3/CNRS), Université de Paris-Sud, Université Paris-Saclay, Orsay, France
63
Institute for Nuclear Research, Academy of Sciences, Moscow, Russia
64
Institute for Subatomic Physics, Utrecht University/Nikhef, Utrecht, Netherlands
65
Institute for Theoretical and Experimental Physics, Moscow, Russia
66
Institute of Experimental Physics, Slovak Academy of Sciences, Košice, Slovakia
67
Institute of Physics, Bhubaneswar, India
68
Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic
69
Institute of Space Science (ISS), Bucharest, Romania
70
Institut für Kernphysik, Johann Wolfgang Goethe-Universität Frankfurt, Frankfurt, Germany
71
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, Mexico
72
Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
73
Instituto de Física, Universidad Nacional Autónoma de México, Mexico City, Mexico
74
iThemba LABS, National Research Foundation, Somerset West, South Africa
75
Johann-Wolfgang-Goethe Universität Frankfurt Institut für Informatik, Fachbereich Informatik und Mathematik, Frankfurt, Germany
76
Joint Institute for Nuclear Research (JINR), Dubna, Russia
77
Korea Institute of Science and Technology Information, Daejeon, Republic of Korea
78
KTO Karatay University, Konya, Turkey
79
Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes, CNRS-IN2P3, Grenoble, France
80
Lawrence Berkeley National Laboratory, Berkeley, CA, USA
81
Lund University Department of Physics, Division of Particle Physics, Lund, Sweden
82
Nagasaki Institute of Applied Science, Nagasaki, Japan
83
Nara Women’s University (NWU), Nara, Japan
84
School of Science, Department of Physics, National and Kapodistrian University of Athens, Athens, Greece
85
National Centre for Nuclear Research, Warsaw, Poland
86
National Institute of Science Education and Research, HBNI, Jatni, India
87
National Nuclear Research Center, Baku, Azerbaijan
88
National Research Centre Kurchatov Institute, Moscow, Russia
89
Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
90
Nikhef, National institute for subatomic physics, Amsterdam, Netherlands
91
NRC Kurchatov Institute IHEP, Protvino, Russia
92
NRNU Moscow Engineering Physics Institute, Moscow, Russia
93
Nuclear Physics Group, STFC Daresbury Laboratory, Daresbury, UK
94
Nuclear Physics Institute of the Czech Academy of Sciences, Řež u Prahy, Czech Republic
95
Oak Ridge National Laboratory, Oak Ridge, TN, USA
96
Petersburg Nuclear Physics Institute, Gatchina, Russia
97
Physics Department, Faculty of science, University of Zagreb, Zagreb, Croatia
98
Physics Department, Panjab University, Chandigarh, India
99
Physics Department, University of Jammu, Jammu, India
100
Physics Department, University of Rajasthan, Jaipur, India
101
Physikalisches Institut, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
102
Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
103
Physik Department, Technische Universität München, Munich, Germany
104
Research Division and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
105
Rudjer Bošković Institute, Zagreb, Croatia
106
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
107
Saha Institute of Nuclear Physics, Kolkata, India
108
School of Physics and Astronomy, University of Birmingham, Birmingham, UK
109
Sección Física, Departamento de Ciencias, Pontificia Universidad Católica del Perú, Lima, Peru
110
Shanghai Institute of Applied Physics, Shanghai, China
111
Stefan Meyer Institut für Subatomare Physik (SMI), Vienna, Austria
112
SUBATECH, IMT Atlantique, Université de Nantes, CNRS-IN2P3, Nantes, France
113
Suranaree University of Technology, Nakhon Ratchasima, Thailand
114
Technical University of Košice, Košice, Slovakia
115
Technische Universität München, Excellence Cluster ’Universe’, Munich, Germany
116
The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland
117
The University of Texas at Austin, Austin, TX, USA
118
Universidad Autónoma de Sinaloa, Culiacán, Mexico
119
Universidade de São Paulo (USP), São Paulo, Brazil
120
Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
121
Universidade Federal do ABC, Santo Andre, Brazil
122
University College of Southeast Norway, Tonsberg, Norway
123
University of Cape Town, Cape Town, South Africa
124
University of Houston, Houston, TX, USA
125
University of Jyväskylä, Jyväskylä, Finland
126
University of Liverpool, Department of Physics Oliver Lodge Laboratory, Liverpool, UK
127
University of Tennessee, Knoxville, TN, USA
128
University of the Witwatersrand, Johannesburg, South Africa
129
University of Tokyo, Tokyo, Japan
130
University of Tsukuba, Tsukuba, Japan
131
Université Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, France
132
Université de Lyon, Université Lyon 1, CNRS/IN2P3, IPN-Lyon, Villeurbanne, Lyon, France
133
Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000, Strasbourg, France
134
IRFU, Department de Physique Nucléaire (DPhN), Université Paris-Saclay Centre dÉtudes de Saclay (CEA), Saclay, France
135
Università degli Studi di Pavia, Pavia, Italy
136
Università di Brescia, Brescia, Italy
137
V. Fock Institute for Physics, St. Petersburg State University, St. Petersburg, Russia
138
Variable Energy Cyclotron Centre, Kolkata, India
139
Warsaw University of Technology, Warsaw, Poland
140
Wayne State University, Detroit, MI, USA
141
Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, Münster, Germany
142
Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest, Hungary
143
Yale University, New Haven, CT, USA
144
Yonsei University, Seoul, Republic of Korea
145
CERN, 1211, Geneva 23, Switzerland
* e-mail: alice-publications@cern.ch
Received:
23
May
2018
Accepted:
22
June
2018
Published online:
9
July
2018
We report on the measurement of the inclusive J/ polarization parameters in pp collisions at a center of mass energy 
TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.23 pb
. J/ resonances are reconstructed in their di-muon decay channel in the rapidity interval 
and over the transverse-momentum interval 
. The three polarization parameters (
, 
, 
) are measured as a function of 
both in the helicity and Collins-Soper reference frames. The measured J/ polarization parameters are found to be compatible with zero within uncertainties, contrary to expectations from all available predictions. The results are compared with the measurement in pp collisions at 
TeV.
© CERN for the benefit of the ALICE collaboration, 2018
