LHCb $\bigtriangleup A_{CP}$ of $D$ meson and R-Parity Violation
  LHCb collaboration has recently announced a measurement of the difference of time-integrated CP asymmetries between $D\rightarrow K^+K^-$ and $D \rightarrow \pi^+\pi^-$. This result provides the evidence of large direct CP violation in $D$ meson and reveals some important implications on underlying new physics. It is shown that the direct CP violation in $D$ meson can be enhanced by R-parity violating supersymmetry, while CP violations in $K$ and $B$ mesons are suppressed by this new physics, which is in consistence with previous experiments. Constraints on the model parameters and some consequences are also discussed. 
Xue Chang, Ming-Kai Du, Chun Liu, Jia-Shu Lu, Shuo Yang
hep-ph