Search for CP Violation in the Decay {D^{+}}\to K_S^0{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)%.