Angular Time-dependent Analyses of the Decays $B_d\rightarrow J/\psi K^{0*}$ and $B_s\rightarrow J/\psi\phi$ at D0

We report preliminary results on the $B_d$ untagged angular time-dependent analysis in the exclusive decay channel $B_d\rightarrow J/\psi (\rightarrow \mu^+\mu^-) K^{0*} (\rightarrow K^\pm\pi^\mp)$. We use approximately 2.8 fb$^{-1}$ of data collected at the D0 detector during 2003-2007. From our measurements we are able to measure the angular and the lifetime parameters ($|A_0|^2$, $|A_{\parallel}|^2$ $\delta_1$, $\delta_2$ and $\tau_d$) that describe this decay in the transversity basis. We performed the same analysis for the untagged decay $B_s\rightarrow J/\psi (\rightarrow \mu^+\mu^-) \phi (\rightarrow K^+K^-)$ assuming no CP violation, and measured the parameters $|A_0|^2$, $|A_{\parallel}|^2$ $\delta_2-\delta_1$, $\Delta \Gamma_s$ and $\tau_s$. Finally, we report the lifetime ratio $\tau_s/\tau_d=1.035\pm0.060\mathrm{(stat)}\pm0.004\mathrm {(syst)}$. We compare our measurements with the theoretical predictions for the factorization method and the SU(3) symmetry for these decays.