Mixing and $CP$ violation results in $b$-hadron decays at LHCb

Measurements of mixing and $CP$ violation in $b$-hadron decays are great probes to search for physics beyond the Standard Model. A selection of recent results based upon $3.0{\mathrm{f}\mathrm{b}}^{-1}$ of LHCb data are presented. These are the first measurement of the $CP$ violating phase ${\varphi }_s$ using $B_s^0\to J\mathrm{/}\psi K^{+}{K}^{-}$ in the mass region above the $\varphi (1020)$ resonance and $B_s^0\to \psi (2S)\varphi$ decays, the determination of $B_s^0$ lifetime using $B_s^0\to D^{(\ast )-}{\mu }^{+}{\nu }_{\mu }$ decays, the updated measurements of the CKM angle $\gamma$ with $B^{\pm }\to D{K}^{\ast \pm }$ and $B_s^0\to D_s^{\mp }{K}^{\pm }$ decay modes and the CP violation searches in ${\Lambda }_b^0\to p{\pi }^{-}{\pi }^{+}{\pi }^{-}$ and $\varLambda^{0}_{b}\to pK^{-}\mu^{+}\mu^{-}$ decays.