Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays

The differential branching fraction of the rare decay Λ 0 b  → Λμ+μ− is measured as a function of q2, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment. Eviden...

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Autores: Badalov, Alexey, Calvo Gomez, Miriam, Vilasis-Cardona, Xavier, LHCb Collaboration - CERN
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:20.500.14342/3137
Acceso en línea:http://hdl.handle.net/20.500.14342/3137
https://doi.org/10.1007/JHEP06(2015)115
Access Level:acceso abierto
Palabra clave:Gran col·lisionador d'hadrons (França i Suïssa)
Partícules (Física nuclear)
Col·lisions (Física nuclear)
Protons
539
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spelling Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decaysBadalov, AlexeyCalvo Gomez, MiriamVilasis-Cardona, XavierLHCb Collaboration - CERNGran col·lisionador d'hadrons (França i Suïssa)Partícules (Física nuclear)Col·lisions (Física nuclear)Protons539The differential branching fraction of the rare decay Λ 0 b  → Λμ+μ− is measured as a function of q2, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment. Evidence of signal is observed in the q2 region below the square of the J/ψ mass. Integrating over 15 < q2 < 20 GeV2/c4 the differential branching fraction is measured as dB(Λ0b→Λμ+μ−)/dq2=(1.18+0.09−0.08±0.03±0.27)×10−7(GeV2/c4)−1, where the uncertainties are statistical, systematic and due to the normalisation mode, Λ 0 b  → J/ψΛ, respectively. In the q2 intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (A ℓFB ) and hadron (A hFB ) systems are measured for the first time. In the range 15 < q2 < 20 GeV2/c4 they are found to be AℓFB=−0.05±0.09(stat)±0.03(syst)andAhFB=−0.29±0.07(stat)±0.03(syst).SpringerUniversitat Ramon Llull. La SalleCERN2015info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersion29 p.http://hdl.handle.net/20.500.14342/3137https://doi.org/10.1007/JHEP06(2015)115reponame:Recercat. Dipósit de la Recerca de Catalunyainstname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)InglésJournal of High Energy Physics, 2015, Vol. 2015, No.115 (Juny)Attribution 4.0 International© CERNhttp://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/openAccessoai:recercat.cat:20.500.14342/31372026-05-29T05:05:01Z
dc.title.none.fl_str_mv Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
title Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
spellingShingle Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
Badalov, Alexey
Gran col·lisionador d'hadrons (França i Suïssa)
Partícules (Física nuclear)
Col·lisions (Física nuclear)
Protons
539
title_short Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
title_full Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
title_fullStr Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
title_full_unstemmed Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
title_sort Differential branching fraction and angular analysis of Λ 0 b  → Λμ+μ− decays
dc.creator.none.fl_str_mv Badalov, Alexey
Calvo Gomez, Miriam
Vilasis-Cardona, Xavier
LHCb Collaboration - CERN
author Badalov, Alexey
author_facet Badalov, Alexey
Calvo Gomez, Miriam
Vilasis-Cardona, Xavier
LHCb Collaboration - CERN
author_role author
author2 Calvo Gomez, Miriam
Vilasis-Cardona, Xavier
LHCb Collaboration - CERN
author2_role author
author
author
dc.contributor.none.fl_str_mv Universitat Ramon Llull. La Salle
CERN
dc.subject.none.fl_str_mv Gran col·lisionador d'hadrons (França i Suïssa)
Partícules (Física nuclear)
Col·lisions (Física nuclear)
Protons
539
topic Gran col·lisionador d'hadrons (França i Suïssa)
Partícules (Física nuclear)
Col·lisions (Física nuclear)
Protons
539
description The differential branching fraction of the rare decay Λ 0 b  → Λμ+μ− is measured as a function of q2, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment. Evidence of signal is observed in the q2 region below the square of the J/ψ mass. Integrating over 15 < q2 < 20 GeV2/c4 the differential branching fraction is measured as dB(Λ0b→Λμ+μ−)/dq2=(1.18+0.09−0.08±0.03±0.27)×10−7(GeV2/c4)−1, where the uncertainties are statistical, systematic and due to the normalisation mode, Λ 0 b  → J/ψΛ, respectively. In the q2 intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (A ℓFB ) and hadron (A hFB ) systems are measured for the first time. In the range 15 < q2 < 20 GeV2/c4 they are found to be AℓFB=−0.05±0.09(stat)±0.03(syst)andAhFB=−0.29±0.07(stat)±0.03(syst).
publishDate 2015
dc.date.none.fl_str_mv 2015
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/20.500.14342/3137
https://doi.org/10.1007/JHEP06(2015)115
url http://hdl.handle.net/20.500.14342/3137
https://doi.org/10.1007/JHEP06(2015)115
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Journal of High Energy Physics, 2015, Vol. 2015, No.115 (Juny)
dc.rights.none.fl_str_mv Attribution 4.0 International
© CERN
http://creativecommons.org/licenses/by/4.0/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Attribution 4.0 International
© CERN
http://creativecommons.org/licenses/by/4.0/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 29 p.
dc.publisher.none.fl_str_mv Springer
publisher.none.fl_str_mv Springer
dc.source.none.fl_str_mv reponame:Recercat. Dipósit de la Recerca de Catalunya
instname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
instname_str Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
reponame_str Recercat. Dipósit de la Recerca de Catalunya
collection Recercat. Dipósit de la Recerca de Catalunya
repository.name.fl_str_mv
repository.mail.fl_str_mv
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