Ratios of Branching Fractions for Hadronic $b$ Meson Decays

The addition of the displaced track trigger at the second trigger level has enabled CDF in Run II to study purely hadronic $b$ hadron decays. We present ratio of branching fractions for $B^0\to D^-\pi^+(\pi^+\pi^-)$, $B_s\to D_s^-\pi^+(\pi^+\pi^-)$ and $B^0\to D_s^+ D^-$, $B_s \to D_s^+ D_s^-$. The latter provides a good handle to estimate $\Delta\Gamma/\Gamma$