Measurement of $B$ hadron lifetimes using $J/\psi$ final states at CDF

The average bottom-hadron and individual $B^{+}$, $B^0$, and $B_s^0$ meson lifetimes have been determined using decays with a $J/\overrightarrow{\psi }{\mu }^{+}{\mu }^{-}$ in the final state. The data sample consists of 110 pb${}^{-1}$ of $\overline{p}p$ collisions at $\sqrt{s}=1.8\mathrm{}$ TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992–1995. For the average lifetime of $B$ hadrons decaying into $J/\psi$+X, we obtain $〈{\tau }_b〉=1.533\mathrm{}\pm 0.015\left(\mathrm{stat}{)}_{\mathrm{-}0.031}^{+0.035\mathrm{}}\right(\mathrm{syst})\mathrm{}\mathrm{}\mathrm{ps}.$ For the $B^{+}$ and $B^0$ meson lifetimes, we determine $\tau {(B}^{+})=1.68\mathrm{}\pm 0.07(\mathrm{stat})\mathrm{}\pm \mathrm{}0.02(\mathrm{syst})\mathrm{}\mathrm{}\mathrm{}\mathrm{ps},$ $\tau {(B}^0)=1.58\mathrm{}\pm 0.09(\mathrm{stat})\mathrm{}\pm \mathrm{}0.02(\mathrm{syst})\mathrm{}\mathrm{}\mathrm{}\mathrm{ps},$ and $\tau {(B}^{+})/\tau {(B}^0)=1.06\mathrm{}\pm 0.07\left(\mathrm{stat}\right)\mathrm{}\pm \mathrm{}0.02\left(\mathrm{syst}\right).\mathrm{}$ For the $B_s^0$ meson lifetime, we find $\tau {(B}_s^0{)=1.34\mathrm{}}_{-0.19}^{+0.23\mathrm{}}\left(\mathrm{stat}\right)\mathrm{}\pm \mathrm{}0.05\left(\mathrm{syst}\right)$ ps.