  After inserting the heavy quark mass dependence into QCD partonic evolution
equations, we determine the mean charged hadron multiplicity of jets produced
in high energy collisions. We thereby extend the so-called dead cone effect to
the phenomenology of multiparticle production in QCD jets and find that the
average multiplicity of heavy-quark initiated jets decreases significantly as
compared to the massless case, even taking into account the weak decay products
of the leading primary quark. We emphasize the relevance of our study as a
complementary check of $b$-tagging techniques at hadron colliders like the
Tevatron and the LHC.
