Measurement of theΛc+lifetime

We observe 97 decays of the charmed baryon, the ..lambda../sub c//sup +/, into a pK/sup -/..pi../sup +/ final state in a Fermilab photoproduction experiment. The mass is measured to be 2286.2 +- 1.7 +- 0.7 MeV/c/sup 2/. The positions of the production and decay vertices are reconstructed with the use of silicon microstrip vertex detector. From these measurements, we determine the lifetime of the ..lambda../sub c/ to be (0.22 +- 0.03 +- 0.02) x 10/sup -12/ s.