Search for the Rare Decays B → πℓ⁺ℓ⁻ and B⁰ → ηℓ⁺ℓ⁻


We present the results of a search for the rare flavor-changing neutral-current decays B → πℓ⁺ℓ⁻ (π = π^±, π⁰ and ℓ = e, μ) and B⁰ → ηℓ⁺ℓ⁻ using a sample of e⁺e⁻ → ϒ(4S) → BB̅ decays corresponding to 428 fb⁻¹ of integrated luminosity collected by the BABAR detector. No significant signal is observed, and we set an upper limit on the isospin and lepton-flavor averaged branching fraction of ℬ(Β → ηℓ⁺ℓ⁻) < 5.9 x 10⁻⁸ and a lepton-flavor averaged upper limit of ℬ(Β⁰ → ηℓ⁺ℓ⁻) < 6.4 x10⁻⁸, both at the 90% confidence level. We also report 90% confidence level branching fraction upper limits for the individual modes B⁺ → π⁺ e⁺ e⁻, B⁰ → π⁰ e⁺ e⁻, B⁺ → π⁺ μ⁺ μ⁻, B⁰ → π⁰ μ⁺ μ⁻, B⁰ → η e⁺e⁻, and B⁰ → ημ⁺ μ⁻.



Branching fractions (Nuclear physics), B mesons--Decay, Gigaelectronvolts (GeV), Leptons (Nuclear physics)


©2013 American Physical Society