https://doi.org/10.1140/epjc/s10052-019-6698-3
Regular Article - Experimental Physics
Measurement of the branching fraction and 
asymmetry 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
Université Grenoble Alpes, Université 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, Florence, Italy
19
INFN Laboratori Nazionali di Frascati, Frascati, Italy
20
INFN Sezione di Genova, Genova, 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, Rom, Italy
27
INFN Sezione di Roma La Sapienza, Rom, 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
National Research University Higher School of Economics, Moscow, Russia
40
Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia
41
Institute for High Energy Physics (IHEP), Protvino, Russia
42
ICCUB, Universitat de Barcelona, Barcelona, Spain
43
Instituto Galego de Física de Altas Enerxías (IGFAE), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
44
European Organization for Nuclear Research (CERN), Geneva, Switzerland
45
Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
46
Physik-Institut, Universität Zürich, Zürich, Switzerland
47
NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine
48
Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine
49
University of Birmingham, Birmingham, UK
50
H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
51
Cavendish Laboratory, University of Cambridge, Cambridge, UK
52
Department of Physics, University of Warwick, Coventry, UK
53
STFC Rutherford Appleton Laboratory, Didcot, UK
54
School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
55
School of Physics and Astronomy, University of Glasgow, Glasgow, UK
56
Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK
57
Imperial College London, London, UK
58
School of Physics and Astronomy, University of Manchester, Manchester, UK
59
Department of Physics, University of Oxford, Oxford, UK
60
Massachusetts Institute of Technology, Cambridge, MA, USA
61
University of Cincinnati, Cincinnati, OH, USA
62
University of Maryland, College Park, MD, USA
63
Syracuse University, Syracuse, NY, USA
64
Laboratory of Mathematical and Subatomic Physics, Constantine, Algeria
65
Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
66
University of Chinese Academy of Sciences, Beijing, China
67
South China Normal University, Guangzhou, China
68
School of Physics and Technology, Wuhan University, Wuhan, China
69
Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China
70
Departamento de Fisica, Universidad Nacional de Colombia, Bogota, Colombia
71
Institut für Physik, Universität Rostock, Rostock, Germany
72
Van Swinderen Institute, University of Groningen, Groningen, The Netherlands
73
National Research Centre Kurchatov Institute, Moscow, Russia
74
National University of Science and Technology “MISIS”, Moscow, Russia
75
National Research Tomsk Polytechnic University, Tomsk, Russia
76
Instituto de Fisica Corpuscular, Centro Mixto Universidad de Valencia-CSIC, Valencia, Spain
77
University of Michigan, Ann Arbor, USA
78
Los Alamos National Laboratory (LANL), Los Alamos, USA
80
CERN, 1211, Geneva 23, Switzerland
* e-mail: michel.de.cian@cern.ch
Received:
20
December
2018
Accepted:
15
February
2019
Published online:
24
June
2019
The branching fraction and direct asymmetry of the decay are measured using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to a total integrated luminosity of 3
. The following results are obtained: 
where the first uncertainties are statistical and the second systematic. Both measurements are the most precise to date.
© CERN for the benefit of the LHCb collaboration, 2019
