Search for CP Violation in the Decay $D^+\rightarrow K^0_S K^+$

We search for CP violation in the decay \({D^{+}}\to K_S^0{K^{+}}\) using a data sample with an integrated luminosity of 977 fb−1 collected with the Belle detector at the KEKB e + e − asymmetric-energy collider. No CP violation has been observed and the CP asymmetry in \({D^{+}}\to K_S^0{K^{+}}\) decay is measured to be (−0.25 ± 0.28 ± 0.14)%, which is the most sensitive measurement to date. After subtracting CP violation due to \({K^0}-{{\overline{K}}^0}\) mixing, the CP asymmetry in \({D^{+}}\to {{\overline{K}}^0}{K^{+}}\) decay is found to be (+0.08 ± 0.28 ± 0.14)%.