Measurement of the time-integrated CP asymmetry in D⁰ → K⁰_{\rm S} K⁰_{\rm S} decays using opposite-side flavor tagging at Belle and Belle II

2025/04/22 by Belle, Collaborations, Belle II, : +378
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)

paper · doi:10.48550/arxiv.2504.15881

Abstract

We measure the time-integrated CP asymmetry in D⁰ → K⁰_{\rm S} K⁰_{\rm S} decays reconstructed in e⁺e^-→ c c events collected by the Belle and Belle II experiments. The corresponding data samples have integrated luminosities of 980 and 428 fb^-1, respectively. To infer the flavor of the D⁰ meson, we exploit the correlation between the flavor of the reconstructed decay and the electric charges of particles reconstructed in the rest of the e⁺e^-→ c c event. This results in a sample which is independent from any other previously used at Belle or Belle II. The result, A_CP(D⁰ → K⁰_{\rm S} K⁰_{\rm S}) = (1.3 ± 2.0 ± 0.2)%, where the first uncertainty is statistical and the second systematic, is consistent with previous determinations and with CP symmetry.

Related

• Measurement of the time-integrated CP asymmetry in D⁰→ K⁰_SK⁰_S decays using Belle and Belle II data
• Measurement of the time-integrated CP asymmetry in D⁰→π⁰π⁰ decays at Belle II
• Measurement of the CP asymmetry in D⁰→π⁺π^-π⁰ decays at Belle II
• Measurement of CP asymmetry in the D⁰ → K⁰_S K⁰_S decay at Belle
• CP violation in D⁰ → K_S⁰ K_S⁰ decay at Belle