The first test of lepton flavor universality between muons and electrons using B+→K+π+π-ℓ+ℓ- (ℓ=e, μ) decays is presented. The measurement is performed with data from proton-proton collisions collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb-1. The ratio of branching fractions between B+→K+π+π-e+e- and B+→K+π+π-μ+μ- decays is measured in the dilepton invariant-mass-squared range 1.1<7.0 GeV2/c4 and is found to be RKππ-1=1.31-0.17+0.18(stat) -0.09+0.12(syst), in agreement with the standard model prediction. The first observation of the B+→K+π+π-e+e- decay is also reported.

Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2025). Test of Lepton Flavor Universality with B+ →k+π+π-ℓ+ℓ- Decays. PHYSICAL REVIEW LETTERS, 134(18) [10.1103/PhysRevLett.134.181803].

Test of Lepton Flavor Universality with B+ →k+π+π-ℓ+ℓ- Decays

Anelli A.;Borsato M.;Calvi M.;Capelli S.;Carniti P.;Fazzini D.;Garcia Pardinas J.;Kirsebom V. S.;Malentacca L.;Martinelli M.;Minotti A.;Pizzichemi M.;Salomoni M.;
2025

Abstract

The first test of lepton flavor universality between muons and electrons using B+→K+π+π-ℓ+ℓ- (ℓ=e, μ) decays is presented. The measurement is performed with data from proton-proton collisions collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb-1. The ratio of branching fractions between B+→K+π+π-e+e- and B+→K+π+π-μ+μ- decays is measured in the dilepton invariant-mass-squared range 1.1<7.0 GeV2/c4 and is found to be RKππ-1=1.31-0.17+0.18(stat) -0.09+0.12(syst), in agreement with the standard model prediction. The first observation of the B+→K+π+π-e+e- decay is also reported.
Articolo in rivista - Articolo scientifico
Branching fractions; Center-of-mass energies; Centre-of-mass energies; Dileptons; Integrated luminosity; Invariant mass; Lepton-flavor; Model prediction; Proton proton collisions; The standard model
English
9-mag-2025
2025
134
18
181803
none
Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2025). Test of Lepton Flavor Universality with B+ →k+π+π-ℓ+ℓ- Decays. PHYSICAL REVIEW LETTERS, 134(18) [10.1103/PhysRevLett.134.181803].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/578893
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