Measurement of the time-integrated $CP$ asymmetry in $D^0\to K_{\mathrm{S}}^0{K}_{\mathrm{S}}^0$ decays using opposite-side flavor tagging at Belle and Belle II

Abstract

We measure the time-integrated $CP$ asymmetry in $D^0\to K_{\mathrm{S}}^0{K}_{\mathrm{S}}^0$ decays reconstructed in $e^{+}{e}^{-}\to c\overline{c}$ 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 $D^0$ meson, we exploit the correlation between the flavor of the reconstructed decay and the electric charges of particles reconstructed in the rest of the $e^{+}{e}^{-}\to c\overline{c}$ event. This results in a sample which is independent from any other previously used at Belle or Belle II. The result, $A_{CP}(D^0\to K_{\mathrm{S}}^0{K}_{\mathrm{S}}^0)=(1.3\pm 2.0\pm 0.2)\%$, where the first uncertainty is statistical and the second systematic, is consistent with previous determinations and with $CP$ symmetry.

References in corpus (15)

• PYTHIA 6.4 Physics and Manual
• An Introduction to PYTHIA 8.2
• Observation of $CP$ violation in charm decays
• Branching ratios and direct CP asymmetries in $D\to PP$ decays
• Revisiting CP violation in $D\to PP$ and $VP$ decays
• On $SU(3{)}_F$ Breaking through Final State Interactions and CP Asymmetries in $D\to PP$ Decays
• Final-state interactions in the CP asymmetries of charm-meson two-body decays
• A $U$-Spin Anomaly in Charm CP Violation
• Measurement of the integrated luminosity of data samples collected during 2019-2022 by the Belle II experiment
• Enhanced charm CP asymmetries from final state interactions
• Two is better than one: The U-spin-CP anomaly in charm
• Measurement of $CP$ asymmetry in $D^0\to K_S^0{K}_S^0$ decays
• Novel method for the identification of the production flavor of neutral charmed mesons
• Search for $CP$ violation in D${}^0$ $\to$ K${}_{\mathrm{S}}^0$K${}_{\mathrm{S}}^0$ decays in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Measurement of the time-integrated CP asymmetry in $D^0\to K_S^0{K}_S^0$ decays using Belle and Belle II data