Phenomenological Determination of the Beauty Meson Decay Parameter $f_B$ and the CP-Violating Angle $\delta$

We fit the $\mathcal{C}\mathcal{K}\mathcal{M}$-matrix to all recent data with the following free parameters: three mixing angles, the CP-violating angle $\delta$ in the Maiani parametrisation, the top quark mass $m_t$, and the product $f_B{\cal B}{\B}^{1/2}$,where$f_B$isthe$B$-mesondecayparameterand${\cal B}{\B}$isthebagparameter\mathrm{.}Ourfitsspanacontiguousregioninthe$(f_B{\cal B}{\B}^{1/2},\ \cos\delta)$--plane,limitedby$0.117\lsim f_B{\cal B}{\B}^{1/2}/{\rm GeV}\lsim 0.231$and--0.95$\lsim$ $\cos \delta$ $\text{lsim}$ 0.70. The parameters $f_B{\mathcal{B}}_{\text{B}}^{1\mathrm{/}2}$ and $\cos \delta$ are strongly positively correlated.