Decays of heavy quarks

The weak decay of heavy b and t quarks is discussed using the mixing angles obtained in Fritzsch's model. We find that the decay b → c dominates over b → u for 7 < or = m/sub t/ < or = 15 GeV by at least 2 to 1 and that the semileptonic branching ratio of b is approx. =14%; the b-quark lifetime is approx.1.6 x 10-13 sec for m/sub t/ approx. = 14 GeV. For t quarks of this mass we find tau/sub t/ < or approx. = 1.7 x 10-17 sec and B (t → Xμ+ν/sub μ/) < or approx. = 12%, the equality holding for the absence of nonleptonic enhancement. b-quark cascade decay is found to be an insignificant source of multimuons in ν interactions and suitably small in nu-bar interactions, consistent with the data of the CERN-Dortmund-Heidelberg-Saclay and Harvard-Pennsylvania-Wisconsin-Fermilab collaborations. Several branching ratios for exotic final states produced via b quarks in e+e- annihilation are discussed