First observation of forward Z→bb¯ production in pp collisions at s=8 TeV

R. Aaij, B. Adeva, Z. Ajaltouni, S. Akar, F. Alessio, M. Alexander, A. Alfonso Albero, S. Ali, G. Alkhazov, P. Alvarez Cartelle, A. A. Alves, S. Amato, S. Amerio, Y. Amhis, L. An, L. Anderlini, G. Andreassi, M. Andreotti, J. E. Andrews, R. B. ApplebyF. Archilli, P. d'Argent, J. Arnau Romeu, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, M. Baalouch, I. Babuschkin, S. Bachmann, J. J. Back, A. Badalov, C. Baesso, S. Baker, V. Balagura, W. Baldini, A. Baranov, R. J. Barlow, C. Barschel, K. Carvalho Akiba, T. Ketel, M. Merk, G. Raven, M. Schiller, N. Serra, B. Storaci, V. Syropoulos, J. van Tilburg, S. Tolk, N. Tuning, LHCb Collaboration

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

The decay Z→bb¯ is reconstructed in pp collision data, corresponding to 2 fb−1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the Z→bb¯ branching fraction is measured for candidates in the fiducial region defined by two particle-level b-quark jets with pseudorapidities in the range 2.2<η<4.2, with transverse momenta pT>20 GeV and dijet invariant mass in the range 45<mjj<165 GeV. From a signal yield of 5462±763 Z→bb¯ events, where the uncertainty is statistical, a production cross-section times branching fraction of 332±46±59 pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the Z→bb¯ production in the forward region of pp collisions.

Original languageEnglish
Pages (from-to)430-439
Number of pages10
JournalPhysics Letters. Section B : Nuclear, Elementary Particle and High-Energy Physics
Volume776
DOIs
Publication statusPublished - 10 Jan 2018

Funding

We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES , CNPq , FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF , DFG and MPG (Germany); INFN (Italy); NWO (The Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FASO (Russia); MinECo (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); NSF (USA). We acknowledge the computing resources that are provided by CERN , IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (The Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany), EPLANET , Marie Skłodowska-Curie Actions and ERC (European Union), ANR , Labex P2IO , ENIGMASS and OCEVU , and Région Auvergne-Rhône-Alpes (France), RFBR and Yandex LLC (Russia), GVA , XuntaGal and GENCAT (Spain), Herchel Smith Fund , the Royal Society , the English-Speaking Union and the Leverhulme Trust (United Kingdom). We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (The Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FASO (Russia); MinECo (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (The Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany), EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union), ANR, Labex P2IO, ENIGMASS and OCEVU, and Région Auvergne-Rhône-Alpes (France), RFBR and Yandex LLC (Russia), GVA, XuntaGal and GENCAT (Spain), Herchel Smith Fund, the Royal Society, the English-Speaking Union and the Leverhulme Trust (United Kingdom).

FundersFunder number
Not added1681016, 1796908, ST/H006737/1, ST/N000463/1, ST/N000242/1
EPLANET
Herchel Smith Fund
MinES
OCEVU
Yandex LLC
National Science Foundation
Alexander von Humboldt-Stiftung
Office of Strategic Coordination
California Department of Fish and Wildlife
Ministry of Science and Technology
Poultry Industry Council
Karlsruher Institut für Technologie
School of Energy Resources, University of Wyoming
H2020 Marie Skłodowska-Curie Actions
CERN
Science and Technology Facilities CouncilST/J004332/1, ST/N000250/1, 1641747, ST/K003410/1, LHCb, ST/N000331/1, GRIDPP, LHCb Upgrades
Leverhulme Trust
Royal Society
English-Speaking Union
European Commission
European Research Council
Deutsches Elektronen-Synchrotron
Deutsche Forschungsgemeinschaft
Agence Nationale de la Recherche
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung172637, 166208
National Natural Science Foundation of China
Russian Foundation for Basic Research
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Bundesministerium für Bildung und Forschung
Nederlandse Organisatie voor Wetenschappelijk Onderzoek
Ministerio de Economía y Competitividad
Generalitat Valenciana
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Instituto Nazionale di Fisica Nucleare
Max-Planck-Gesellschaft
Narodowe Centrum Nauki
Narodowym Centrum Nauki
Ministerstwo Nauki i Szkolnictwa Wyższego
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
Ministry of Science and Technology, Taiwan
National Academy of Sciences of Ukraine
Centre National de la Recherche Scientifique
Financiadora de Estudos e Projetos
Bundesministerium für Bildung und Frauen
Région Auvergne-Rhône-Alpes
Institut national de physique nucléaire et de physique des particules
Federal Agency for Scientific Organizations
Sociedad Española de Reumatología

    Fingerprint

    Dive into the research topics of 'First observation of forward Z→bb¯ production in pp collisions at s=8 TeV'. Together they form a unique fingerprint.

    Cite this