Fit of the mixing angles in the six quark model and predictions on theB meson lifetime

Experimental data are used to constrain the parameters of the six quark mixing model and of a composite quark model. A combined fit of the mixing angles in the Kobayashi-Maskawa scheme gives sinθ ₁=0.228±0.011 and error contours around the best values sinθ ₂=0.12 and sinθ ₃≈0. From this, a limit of τ _B >0.35×10^?13 s for the mean lifetime of bottom-flavoured hadrons is obtained. For the composite quark model of Katsumata and Tomozawa, a value of τ _B =(0.22?0.23)10_?13 s is derived.