https://doi.org/10.1140/epjc/s10052-014-3092-z
Regular Article - Experimental Physics
Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ
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
LAPP, Université de Savoie, CNRS/IN2P3, Annecy-Le-Vieux, France
5
Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France
6
CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France
7
LAL, Université Paris-Sud, CNRS/IN2P3, Orsay, France
8
LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris, France
9
Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany
10
Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, Germany
11
Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
12
School of Physics, University College Dublin, Dublin, Ireland
13
Sezione INFN di Bari, Bari, Italy
14
Sezione INFN di Bologna, Bologna, Italy
15
Sezione INFN di Cagliari, Cagliari, Italy
16
Sezione INFN di Ferrara, Ferrara, Italy
17
Sezione INFN di Firenze, Firenze, Italy
18
Laboratori Nazionali dell’INFN di Frascati, Frascati, Italy
19
Sezione INFN di Genova, Genoa, Italy
20
Sezione INFN di Milano Bicocca, Milan, Italy
21
Sezione INFN di Milano, Milan, Italy
22
Sezione INFN di Padova, Padua, Italy
23
Sezione INFN di Pisa, Pisa, Italy
24
Sezione INFN di Roma Tor Vergata, Rome, Italy
25
Sezione INFN di Roma La Sapienza, Rome, Italy
26
Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
27
Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Kraków, Poland
28
National Center for Nuclear Research (NCBJ), Warsaw, Poland
29
Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania
30
Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia
31
Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia
32
Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia
33
Institute for Nuclear Research of the Russian Academy of Sciences (INR RAN), Moscow, Russia
34
Budker Institute of Nuclear Physics (SB RAS) and Novosibirsk State University, Novosibirsk, Russia
35
Institute for High Energy Physics (IHEP), Protvino, Russia
36
Universitat de Barcelona, Barcelona, Spain
37
Universidad de Santiago de Compostela, Santiago de Compostela, Spain
38
European Organization for Nuclear Research (CERN), Geneva, Switzerland
39
Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
40
Physik-Institut, Universität Zürich, Zurich, Switzerland
41
Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands
42
Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, The Netherlands
43
NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine
44
Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine
45
University of Birmingham, Birmingham, UK
46
H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
47
Cavendish Laboratory, University of Cambridge, Cambridge, UK
48
Department of Physics, University of Warwick, Coventry, UK
49
STFC Rutherford Appleton Laboratory, Didcot, UK
50
School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
51
School of Physics and Astronomy, University of Glasgow, Glasgow, UK
52
Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK
53
Imperial College London, London, UK
54
School of Physics and Astronomy, University of Manchester, Manchester, UK
55
Department of Physics, University of Oxford, Oxford, UK
56
Massachusetts Institute of Technology, Cambridge, MA, USA
57
University of Cincinnati, Cincinnati, OH, USA
58
University of Maryland, College Park, MD, USA
59
Syracuse University, Syracuse, NY, USA
60
Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
61
Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China
62
Institut für Physik, Universität Rostock, Rostock, Germany
63
National Research Centre Kurchatov Institute, Moscow, Russia
64
Instituto de Fisica Corpuscular (IFIC), Universitat de Valencia-CSIC, Valencia, Spain
65
KVI-University of Groningen, Groningen, The Netherlands
66
Celal Bayar University, Manisa, Turkey
Received:
30
July
2014
Accepted:
22
September
2014
Published online:
8
October
2014
A study of χb meson production at LHCb is performed on proton–proton collision data, corresponding to 3.0 fb-1 of integrated luminosity collected at centre-of-mass energies √s = 7 and 8 TeV. The fraction of ϒ(nS) mesons originating from χb decays is measured as a function of the ϒ transverse momentum in the rapidity range 2.0 < yϒ < 4.5. The radiative transition of the χb (3P) meson to ϒ(3S) is observed for the first time. The χb1 (3P) mass is determined to be
mχb1 (3P) = 10 511.3 ± 1.7 ± 2.5 MeV/c2
where the first uncertainty is statistical and the second is systematic.
© SIF and Springer-Verlag Berlin Heidelberg, 2014
