Observation of the Very Rare Σ^{+}→pμ^{+}μ^{-} Decay

The first observation of the Σ^{+}→pμ^{+}μ^{-} decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 5.4  fb^{-1}, collected with the LHCb detector at a center-of-mass energy of 13 TeV. A yield of 237±16  Σ^{+}→pμ^{+}μ^{-} decays is...

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Detalles Bibliográficos
Autores: Golobardes Ribé, Elisabet, Vilasis-Cardona, Xavier, Calvo Gomez, Miriam, LHCb Collaboration - CERN
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Ramon Llull (URL)
Repositorio:DAU Arxiu Digital de la Universitat Ramon Llull
OAI Identifier:oai:dau.url.edu:20.500.14342/5827
Acceso en línea:http://hdl.handle.net/20.500.14342/5827
https://doi.org/10.1103/r3v2-kmmp
Access Level:acceso abierto
Palabra clave:Branching fraction
Flavour changing neutral currents
Leptonic, semileptonic and radiactive decays
Particle decays
Rare decays
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530.1
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Descripción
Sumario:The first observation of the Σ^{+}→pμ^{+}μ^{-} decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 5.4  fb^{-1}, collected with the LHCb detector at a center-of-mass energy of 13 TeV. A yield of 237±16  Σ^{+}→pμ^{+}μ^{-} decays is obtained, where the uncertainty is statistical only. A branching fraction of (1.08±0.17)×10^{-8} is measured, where the uncertainty includes statistical and systematic sources. No evidence of resonant structures is found in the dimuon invariant-mass distribution. All results are compatible with standard model expectations. This represents the rarest decay of a baryon ever observed.