Search for CP Violation in the Decay $D^+\rightarrow K^0_S K^+$
  We search for CP violation in the decay $D^+\rightarrow K^0_S K^+$ 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 $D^+\rightarrow K^0_S K^+$ decay is measured to be $(-0.25\pm0.28\pm0.14)%$, which is the most sensitive measurement to date. After subtracting CP violation due to $K^0-\bar{K}^0$ mixing, the CP asymmetry in $D^+\rightarrow\bar{K}^0 K^+$ decay is found to be $(+0.08\pm0.28\pm0.14)%$. 
B. R. Ko, E. Won, I. Adachi, H. Aihara, K. Arinstein, D. M. Asner, T.   Aushev, A. M. Bakich, K. Belous, V. Bhardwaj, B. Bhu...
hep-ex