A measurement of the ratio of branching fractions of the decays B⁺ → K⁺μ⁺μ⁻ and B⁺ → K⁺e⁺e⁻ is presented. The proton-proton collision data used correspond to an integrated luminosity of 5.0 fb⁻¹ recorded with the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. For the dilepton mass-squared range 1.1 < q² < 6.0 GeV²=c⁴ the ratio of branching fractions is measured to be R-K = 0.846(-0.054-0.014)(+0.060+0.016), where the first uncertainty is statistical and the second systematic. This is the most precise measurement of R-K to date and is compatible with the standard model at the level of 2.5 standard deviations.
Search for Lepton-Universality Violation in B⁺ → K⁺l⁺l⁻ Decays
Lusiani, A.Membro del Collaboration Group
;Morello, M. J.Membro del Collaboration Group
;Pajero, T.Membro del Collaboration Group
;
2019
Abstract
A measurement of the ratio of branching fractions of the decays B⁺ → K⁺μ⁺μ⁻ and B⁺ → K⁺e⁺e⁻ is presented. The proton-proton collision data used correspond to an integrated luminosity of 5.0 fb⁻¹ recorded with the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. For the dilepton mass-squared range 1.1 < q² < 6.0 GeV²=c⁴ the ratio of branching fractions is measured to be R-K = 0.846(-0.054-0.014)(+0.060+0.016), where the first uncertainty is statistical and the second systematic. This is the most precise measurement of R-K to date and is compatible with the standard model at the level of 2.5 standard deviations.File | Dimensione | Formato | |
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PhysRevLett.122.191801-scoap3.pdf
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