Measurement of theΛc+lifetime

Abstract

We observe 97 decays of the charmed baryon, the ${\Lambda }_c^{+}$, into a ${\mathrm{pK}}^{\mathrm{-}}$ ${\pi }^{+}$ final state in a Fermilab photoproduction experiment. The mass is measured to be 2286.2±1.7±0.7 MeV/$c^2$. 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 ${\Lambda }_c$ to be (0.22±0.03 ±0.02)×${10}^{\mathrm{-}12}$ s.