CP asymmetries at D0

Using two independent measurements of the semileptonic CP asymmetry in the $B_s$ system, we constrain the CP violating phase of the $B_s$ system to be ${\varphi }_s=-0.70_{-0.39}^{+0.47}$. The data sample corresponds to an integrated luminosity of 1.1 fb${}^{-1}$ accumulated with D0 detector at the Fermilab Tevatron collider. We also measure the direct CP violating asymmetry in the decay $B^{+}\to J\mathrm{/}\psi K^{+}$ to be $A_{CP}(B^+ \to J/\psi K^+) = +0.0067 \pm 0.0074$(stat)$\pm0.0026$(syst). The data corresponds to an integrated luminosity of 1.6 fb${}^{-1}$.