Reconstruction of B → ρℓ ν_ℓ decays identified using hadronic decays of the recoil B meson in 2019 -- 2021 Belle II data

2022/11/28 by F. Abudinén, Belle II Collaboration, Abudinén, F. +670
Medicine · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Medical Imaging Techniques and Applications #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.2211.15270

openalex publication_date 2022/11/28 · openalex created_date 2022/12/10 · openalex updated_date 2026/07/28

Abstract

We present results on the semileptonic decays B⁰ → ρ^- ℓ⁺ ν_ℓ and B⁺ → ρ⁰ ℓ⁺ ν_ℓ in a sample corresponding to 189.9/fb of Belle II data at the SuperKEKB e^- e⁺ collider. Signal decays are identified using full reconstruction of the recoil B meson in hadronic final states. We determine the total branching fractions via fits to the distributions of the square of the "missing" mass in the event and the dipion mass in the signal candidate and find B(B⁰→ρ^-ℓ⁺ ν_ℓ) = (4.12 ± 0.64(stat) ± 1.16(syst)) × 10^-4 and B(B⁺→ρ⁰ℓ⁺ν_ℓ) = (1.77 ± 0.23 (stat) ± 0.36 (syst)) × 10^-4 where the dominant systematic uncertainty comes from modeling the nonresonant B→ (ππ)ℓ⁺ν_ℓ contribution.

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