Measurement of the time-integrated CP asymmetry in $D^{0}\rightarrow K^{0}_{S}K^{0}_{S}$ decays using Belle and Belle II data

We measure the time-integrated CP asymmetry in D0→KS0KS0 decays reconstructed in e+e-→cc¯ events collected by the Belle and Belle II experiments. The corresponding data samples have integrated luminosities of 980 and 428 fb-1, respectively. The D0 decays are required to originate from the D∗+→D0π+ decay, which determines the charm flavor at production time. A control sample of D0→K+K- decays is used to correct for production and detection asymmetries. The result, (-1.4±1.3(stat)±0.1(syst))%, is consistent with previous determinations and with CP symmetry.