Measurements of \boldsymbolB→ Kπ and \boldsymbolB→ ππ Branching Fractions and \boldsymbolA_CP Asymmetries at Belle II

2024/05/24 by Lin, Shu-Ping
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)

paper · doi:10.48550/arxiv.2405.15352

Abstract

Analyses of B meson decays to charmless hadronic final states are an important part of the Belle II program. They are sensitive to effects from non-standard model physics and provide experimentally precise constraints on the weak interactions of quarks. We present recent Belle II results on branching fractions and direct CP-violating asymmetries of the decays B⁰ → K⁺π^-, B⁺ → K⁺π⁰, B⁺ → K⁰π⁺, and B⁰ → K⁰π⁰, and use these to test the standard model through an isospin-based sum rule. In addition, we measure the branching fraction and direct CP asymmetry of the decay B⁺ → π⁺π⁰ and the branching fraction of the decay B⁰ → π⁺π^-, which contribute towards the determination of the CKM angle ϕ₂. The data are collected with the Belle II detector from the SuperKEKB asymmetric-energy e⁺e^- collider, consisting of 387 × 10⁶ Υ(4S)→ BB events. We obtain -0.03 ± 0.13 ± 0.04 for the sum rule, in agreement with the standard model expectation of zero and with a precision comparable to the best existing determinations.

Related

• Recent measurements of branching fractions and CP asymmetries of charmless hadronic B meson decays at Belle
• Measurements of branching fractions and direct CP asymmetries in B⁰→ K⁺ π^-, B⁺ → K_{\rm S}⁰π⁺ and B⁰ → π⁺π^- using 2019 and 2020 data
• Measurement of the branching fractions and CP asymmetries of B⁺ → π⁺ π⁰ and B⁺ → K⁺ π⁰ decays in 2019-2021 Belle II data
• Measurements of branching fractions and direct \it CP-violating asymmetries in B⁺ → K⁺ π⁰~and~π⁺ π⁰ decays using 2019 and 2020 Belle II data
• Results on φ₂ from Belle