  Recent results on top quark physics with the D0 experiment in pbar-p
collisions at sqrt(s) = 1.8 TeV for an integrated luminosity of 125 pb**-1 are
reported. The direct measurement of the top quark mass uses single lepton and
dilepton events, giving the result m(top) = 172.1 +/- 7.1 GeV/c**2. The
measurement of the t-tbar production cross section includes analyses from 9 top
decay channels: dilepton (t-tbar --> e+mu, e+e, and mu+mu), electron and
neutrino (t-tbar --> e+nu), single leptons (t-tbar --> e + jets, t-tbar --> mu
+ jets) with and without b tagging, and all-jets (t-tbar --> 6 jets). We
measure the t-tbar production cross section to be 5.9 +/- 1.7 pb at m(top) =
172.1 GeV/c**2. Combining the D0 and the CDF measurements of the top quark mass
and combining their t-tbar cross sections, in both cases taking into account
error correlations, yields unofficially sigma(t-tbar) = 6.7 +/- 1.3 pb at an
averaged top quark mass of m(top) = 173.8 +/- 5.2 GeV/c**2. Preliminary results
on a search for charged Higgs production in top events, t --> Higgs + b, are
presented.
