  We investigate $B^{\pm,0}\rightarrow \rho^0 (\omega )h^{\pm,0}$, where
$\rho^0 (\omega)$ decays to $\pi^+\pi^-$ and $h$ is any hadronic final states,
such as $\pi$ or $K$. We find large direct $CP$ asymmetries via $\rho-\omega$
interference. A possible determination of the weak phases, such as $\phi_2={\rm
arg}((V_{ud}V^*_{ub})/(V_{td}V^*_{tb}))$ and $\phi_3={\rm
arg}((V_{us}V^*_{ub})/(V_{ts}V^*_{tb}))$, is also discussed. We show the
feasibility to detect the CP asymmetries in these channels by assuming an
asymmetric $e^+e^-$ collider experiment. $10^{9}$ $B\bar B$ events are required
for the detection of this effect.

High Energy Physics - Phenomenology;High Energy Physics - Experiment