Abstract
A search for the rare decay Σ+→pμ+μ- is performed using pp collision data recorded by the LHCb experiment at center-of-mass energies s=7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. An excess of events is observed with respect to the background expectation, with a signal significance of 4.1 standard deviations. No significant structure is observed in the dimuon invariant mass distribution, in contrast with a previous result from the HyperCP experiment. The measured Σ+→pμ+μ- branching fraction is (2.2-1.3+1.8)×10-8, where statistical and systematic uncertainties are included, which is consistent with the standard model prediction.
Original language | English |
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Article number | 221803 |
Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | Physical Review Letters |
Volume | 120 |
Issue number | 22 |
Early online date | 31 May 2018 |
DOIs | |
Publication status | Published - 1 Jun 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 (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 (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 and OCEVU, and Région Auvergne-Rhône-Alpes (France), RFBR, RSF 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).
Funders | Funder number |
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Not added | ST/J004332/1, ST/N000250/1, 1681016, ST/K001604/1, ST/K003410/1, 1796908, ST/H000992/1, ST/N000463/1, ST/N000455/1, ST/L003163/1 |
AvH Foundation | |
CNRS/IN2P3 | |
EPLANET | |
FASO | |
Herchel Smith Fund | |
MinES | |
OCEVU | |
Yandex LLC | |
National Science Foundation | |
School of Energy Resources, University of Wyoming | |
H2020 Marie Skłodowska-Curie Actions | |
CERN | |
Science and Technology Facilities Council | LHCb, GRIDPP, LHCb Upgrades, ST/N000242/1 |
Leverhulme Trust | |
Royal Society | |
English-Speaking Union | |
European Commission | |
European Research Council | |
Deutsche Forschungsgemeinschaft | |
Agence Nationale de la Recherche | |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 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 | |
Generalitat Valenciana | |
Conselho Nacional de Desenvolvimento Científico e Tecnológico | |
Ministry of Science and Technology | |
Instituto Nazionale di Fisica Nucleare | |
Narodowe Centrum Nauki | |
Ministerstwo Nauki i Szkolnictwa Wyższego | |
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro | |
National Academy of Sciences of Ukraine | |
Financiadora de Estudos e Projetos | |
Russian Science Foundation | |
Région Auvergne-Rhône-Alpes | |
Institutul de Fizică Atomică |