Measurement of theBc−meson lifetime in the decayBc−→J/ψπ−

The lifetime of the ${B}_{c}^{\ensuremath{-}}$ meson is measured using 272 exclusive ${B}_{c}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}(\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}){\ensuremath{\pi}}^{\ensuremath{-}}$ decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of $6.7\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the ${B}_{c}^{\ensuremath{-}}$ meson is measured to be $\ensuremath{\tau}({B}_{c}^{\ensuremath{-}})=0.452\ifmmode\pm\else\textpm\fi{}0.048(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.027(\mathrm{syst})\text{ }\text{ }\mathrm{ps}$. This is the first measurement of the ${B}_{c}^{\ensuremath{-}}$ meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.