Measurements of the branching fractions for B → K^*γ decays at Belle II

2021/10/15 by F. Abudinén, Abudinén, F., I. Adachi +664
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.2110.08219

openalex publication_date 2021/10/15 · openalex created_date 2022/07/25 · openalex updated_date 2026/08/01

Abstract

This paper reports a study of B → K^*γ decays using 62.8± 0.6 fb^-1 of data collected during 2019--2020 by the Belle II experiment at the SuperKEKB e⁺e^- asymmetric-energy collider, corresponding to (68.2 ± 0.8) × 10⁶ BB events. We find 454 ± 28, 50 ± 10, 169 ± 18, and 160 ± 17 signal events in the decay modes B⁰ → K^*0[K⁺π^-]γ, B⁰ → K^*0[K⁰_{\rm S}π⁰]γ, B⁺ → K^*+[K⁺π⁰]γ, and B⁺ → K^*+[K⁺π⁰]γ, respectively. The uncertainties quoted for the signal yield are statistical only. We report the branching fractions of these decays: B [B⁰ → K^*0[K⁺π^-]γ] = (4.5 ± 0.3 ± 0.2) × 10^-5, B [B⁰ → K^*0[K⁰_{\rm S}π⁰]γ] = (4.4 ± 0.9 ± 0.6) × 10^-5, B [B⁺ → K^*+[K⁺π⁰]γ] = (5.0 ± 0.5 ± 0.4)× 10^-5, and B [B⁺ → K^*+[K⁰_{\rm S}π⁺]γ] = (5.4 ± 0.6 ± 0.4) × 10^-5, where the first uncertainty is statistical, and the second is systematic. The results are consistent with world-average values.

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