Hadron multiplicities in e+e- annihilation with heavy primary quarks

The multiple hadron production in the events induced by the heavy primary quarks in $e^+e^-$ annihilation is reconsidered with account of corrected experimental data. New value for the multiplicity in $b\bar{b}$ events is presented on the basis of pQCD estimates.Comment: 16 pages, 6 figures. Version accepted for publication in EPJ

A MEASUREMENT OF THE TAU-LIFETIME

We have reconstructed 695 three-track τ decay vertices using a high resolution drift chamber close to the interaction point. From the distribution of decay lengths we measure the lifetime to be (3.06 ±0.20±0.14)×10-13 s. Using this result we find that the ratio of charged weak coupling constant for the τ to that of the μ, G τ/G μ=0.967±0.040 consistent with the concept of lepton universality. © 1988 Springer-Verlag