Measurements of B K and B Branching Fractions and A₂₏ Asymmetries at Belle II

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^+^-, B^+ K^+⁰, B^+ K⁰^+, and B⁰ K⁰⁰, 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^+ ^+⁰ and the branching fraction of the decay B⁰ ^+^-, which contribute towards the determination of the CKM angle ₂. The data are collected with the Belle II detector from the SuperKEKB asymmetric-energy e^+e^- collider, consisting of 387 10⁶ (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.