CP-violation in $b\to s$ Penguin Decays at BaBar

We present the new and updated $BABAR$ measurements of CP-violation studies for many $b\to s$ penguin decay modes. We report the first observation of mixing-induced CP-violation in $B^0\to {\eta }^{{}^{\mathrm{\prime }}}{K}^0$ with a significance (including systematic uncertainties) of 5.5$\sigma$. We also present the first observation of the decay $B^0\to {\rho }^0{K}^0$. Using the time-dependent Dalitz plot analysis of $B^0\to K^{+}{K}^{-}{K}^0$ decay, the CP-parameters ${\mathcal{A}}_{CP}$ and ${\beta }_{eff}$ are measured with $4.8\sigma$ significance, and we reject the solution near $\pi \mathrm{/}2-{\beta }_{eff}$ at $4.5\sigma$. We also present the updated measurements of CP-violating parameters for $B^0\to K_S^0{\pi }^0$, $K_S^0{K}_S^0{K}_S^0$ and ${\pi }^0{\pi }^0{K}_S^0$ decays. An updated measurements of the CP-violating charge asymmetries for $B^{\pm }\to {\eta }^{{}^{\mathrm{\prime }}}{K}^{\pm }$, $\eta K^{\pm}$,$\omega K^{\pm}$ decays are also presented. The measurements are based on the data sample recorded at the $\mathrm{{\rm Y}}(4S)$ resonance with $BABAR$ detector at the PEP-II $B$-meson Factory at SLAC.