  We present a measurement of the top quark pair production cross section in
ppbar collisions at \sqrt{s}=1.96 TeV using approximately 1 fb^{-1} of data
collected with the D0 detector. We consider decay channels containing two high
pt charged leptons where one lepton is identified as an electron or a muon
while the other lepton can be an electron, a muon or a hadronically decaying
tau lepton. For a mass of the top quark of 170 GeV, the measured cross section
is 7.5 +1.0-1.0 (stat) +0.7-0.6 (syst) +0.6-0.5 (lumi) pb. Using lepton+tau
events only, we measure: \sigma_ttbar \times B(ttbar to ltau bbbar) = 0.13
+0.09-0.08 (stat) +0.06-0.06 (syst) +0.02-0.02 (lumi) pb. Comparing the
measured cross section as a function of the mass of the top quark with a
partial next-to-next-to leading order Quantum Chromodynamics theoretical
prediction, we extract a mass of the top quark of 171.5 +9.9-8.8 GeV, in
agreement with direct measurements.
