Differential branching fraction and angular analysis of Λ 0 b → Λμ+μ− decays
Fecha de publicación
2015-06-17Resumen
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).
Tipo de documento
Artículo
Versión publicada
Lengua
Inglés
Materias (CDU)
539 - Constitución física de la materia
Palabras clave
Páginas
29 p.
Publicado por
Springer
Publicado en
Journal of High Energy Physics, 2015, Vol. 2015, No.115 (Juny)
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