Sanjeeda Bharati Das ; Kavita Lalwani

15 September 2023

Abstract: The decay $D^{0}\longrightarrow K^{0}_{s}K^{0}_{s}$ is a singly Cabibbo-suppressed transition that involves the interference between $c\overline{u}\longrightarrow s\overline{s}$ and $c\overline{u}\longrightarrow d\overline{d}$ amplitudes, mediated by the exchange of a W boson at the tree level, that can generate CP asymmetries at the 1% level, even if the Cabibbo-Kobayashi-Maskawa phase is the only source of CP. Current experimental measurements of the CP asymmetry in $D^{0}\longrightarrow K^{0}_{s}K^{0}_{s}$ decays are still limited by the statistical precision. In this work, the signal yield and corresponding raw asymmetry (Araw) for $D^{0}\longrightarrow K^{0}_{s}K^{0}_{s}$ is measured using Belle II Monte Carlo (MC) samples at integrated luminosity of 1 ab^{−1}. The final goal of this analysis is to measure the CP asymmetry in $D^{0}\longrightarrow K^{0}_{s}K^{0}_{s}$, $D^{0}\longrightarrow K^{+}K^{-}$ using as the reference mode, with (Belle + Belle II) dataset.