$CP$ violation in $B_s^0$ decays at LHCb

Latest LHCb measurements of $CP$ violation in the interference between mixing and decay are presented based on $pp$ collision data collected during LHC Run I, corresponding to an integrated luminosity of $3.0{\mathrm{f}\mathrm{b}}^{-1}$. Approximately $27000$ $B_s^0\to J\mathrm{/}\psi {\pi }^{+}{\pi }^{-}$ signal events are used to make what is at the moment the most precise single measurement of the $CP$-violating phase in $b\to c\bar{c}s$ transitions, ${\varphi }_s^{c\bar{c}s}=0.070\pm 0.068(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{.})\pm 0.008(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}\mathrm{.})$ rad. The most accurate measurement of the $CP$-violating phase in $b\to s\bar{s}s$ transitions, ${\varphi }_s^{s\bar{s}s}$, is found from approximately $4000$ $B_s^0\to \varphi \varphi$ signal events to be $\phi_s^{s\bar{s}s}=-0.17\pm{\rm (stat.)}0.15\pm0.03{\rm (syst.)}$ rad.