https://doi.org/10.1140/epjc/s10052-018-6447-z
Regular Article - Experimental Physics
Evidence for an 
resonance in 
decays
1
Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil
2
Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
3
Center for High Energy Physics, Tsinghua University, Beijing, China
4
Institute Of High Energy Physics (IHEP), Beijing, China
5
Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IN2P3-LAPP, Annecy, France
6
Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France
7
Aix-Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France
8
LAL, Univ. Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, France
9
LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France
10
I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany
11
Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany
12
Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, Germany
13
Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
14
School of Physics, University College Dublin, Dublin, Ireland
15
INFN Sezione di Bari, Bari, Italy
16
INFN Sezione di Bologna, Bologna, Italy
17
INFN Sezione di Ferrara, Ferrara, Italy
18
INFN Sezione di Firenze, Firenze, Italy
19
INFN Laboratori Nazionali di Frascati, Frascati, Italy
20
INFN Sezione di Genova, Genoa, Italy
21
INFN Sezione di Milano-Bicocca, Milan, Italy
22
INFN Sezione di Milano, Milan, Italy
23
INFN Sezione di Cagliari, Monserrato, Italy
24
INFN Sezione di Padova, Padua, Italy
25
INFN Sezione di Pisa, Pisa, Italy
26
INFN Sezione di Roma Tor Vergata, Rome, Italy
27
INFN Sezione di Roma La Sapienza, Rome, Italy
28
Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands
29
Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, The Netherlands
30
Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
31
Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Kraków, Poland
32
National Center for Nuclear Research (NCBJ), Warsaw, Poland
33
Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania
34
Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia
35
Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia
36
Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia
37
Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), Moscow, Russia
38
Yandex School of Data Analysis, Moscow, Russia
39
Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia
40
Institute for High Energy Physics (IHEP), Protvino, Russia
41
ICCUB, Universitat de Barcelona, Barcelona, Spain
42
Instituto Galego de Física de Altas Enerxías (IGFAE), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
43
European Organization for Nuclear Research (CERN), Geneva, Switzerland
44
Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
45
Physik-Institut, Universität Zürich, Zürich, Switzerland
46
NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine
47
Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine
48
University of Birmingham, Birmingham, UK
49
H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
50
Cavendish Laboratory, University of Cambridge, Cambridge, UK
51
Department of Physics, University of Warwick, Coventry, UK
52
STFC Rutherford Appleton Laboratory, Didcot, UK
53
School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
54
School of Physics and Astronomy, University of Glasgow, Glasgow, UK
55
Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK
56
Imperial College London, London, UK
57
School of Physics and Astronomy, University of Manchester, Manchester, UK
58
Department of Physics, University of Oxford, Oxford, UK
59
Massachusetts Institute of Technology, Cambridge, MA, USA
60
University of Cincinnati, Cincinnati, OH, USA
61
University of Maryland, College Park, MD, USA
62
Syracuse University, Syracuse, NY, USA
63
Laboratory of Mathematical and Subatomic Physics, Constantine, Algeria
64
Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
65
University of Chinese Academy of Sciences, Beijing, China
66
South China Normal University, Guangzhou, China
67
School of Physics and Technology, Wuhan University, Wuhan, China
68
Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China
69
Departamento de Fisica, Universidad Nacional de Colombia, Bogotá, Colombia
70
Institut für Physik, Universität Rostock, Rostock, Germany
71
Van Swinderen Institute, University of Groningen, Groningen, Netherlands
72
National Research Centre Kurchatov Institute, Moscow, Russia
73
National University of Science and Technology “MISIS”, Moscow, Russia
74
National Research Tomsk Polytechnic University, Tomsk, Russia
75
Instituto de Fisica Corpuscular, Centro Mixto Universidad de Valencia-CSIC, Valencia, Spain
76
University of Michigan, Ann Arbor, USA
77
Los Alamos National Laboratory (LANL), Los Alamos, USA
* e-mail: giovanni.cavallero@cern.ch
Received:
21
September
2018
Accepted:
13
November
2018
Published online:
17
December
2018
A Dalitz plot analysis of 
decays is performed using data samples of pp collisions collected with the 
detector at centre-of-mass energies of 
and 
, corresponding to a total integrated luminosity of 
. A satisfactory description of the data is obtained when including a contribution representing an exotic resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 
and 
, respectively. The spin-parity assignments 
and 
are both consistent with the data. In addition, the first measurement of the branching fraction is performed and gives 
where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions.
© CERN for the benefit of the LHCb collaboration, 2018
