Implications of NonspectatorB-Meson Decays andB-Lifetime Measurements

The nonspectator contributions to the $B$-meson decays are calculated with use of the measured ratio $\frac{{\tau }_{D^{+}}}{{\tau }_{D^0}}$ and the assumption $\frac{f_B^2}{f_D^2}=\frac{m_D}{m_B}$. We find $\frac{{\tau }_{B^{+}}}{{\tau }_{B^0}}=1.4\mathrm{} \mathrm{to} 1.8$. From the measured values of $B$-meson lifetime, the semileptonic branching ratio, the ratio $\frac{\Gamma (b\to \mathrm{ue}\nu )}{\Gamma (b\to \mathrm{ce}\nu )}$, and the $\epsilon$ parameter, the constraints on Kobayashi-Maskawa angles are evaluated and their implications for $m_t$, $\left|\frac{{\epsilon }^{\prime }}{\epsilon }\right|$, $B^0-{\bar{B}}^0$ mixing, and $K\to \pi \nu \bar{\nu }$ are presented.