Direct search for charged Higgs bosons in decays of top quarks

We present a searchfor charged Higgs bosonsin decays of pair-produced top quarksin p (p) over bar collisions at roots = 1.8 TeV recorded by the D0 detector at the Fermilab Tevatroncollider. With no evidence for signal, we exclude most regions of the (MH+/-, tanbeta) parameter spacewhere the decay t --> H (+)b has a branching fraction>0.36 and B(H+/- --> taunu(tau) ) is large.