Measurement of the ${\ensuremath{\Lambda}}_{b}^{0}$ Lifetime in ${\ensuremath{\Lambda}}_{b}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{\ensuremath{\Lambda}}^{0}$ in $p\overline{p}$ Collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$

Measurement of the $Λ_{b}^{0}$ Lifetime in $Λ_{b}^{0} \to J / ψ Λ^{0}$ in $p \bar{p}$ Collisions at $\sqrt{s} = 1.96 TeV$

A. Abulencia et al. (CDF Collaboration)

Phys. Rev. Lett. 98, 122001 – Published 19 March 2007

Abstract

We report a measurement of the $Λ_{b}^{0}$ lifetime in the exclusive decay $Λ_{b}^{0} \to J / ψ Λ^{0}$ in $p \bar{p}$ collisions at $\sqrt{s} = 1.96 TeV$ using an integrated luminosity of $1.0 {fb}^{- 1}$ of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, we measure $τ (Λ_{b}^{0}) = {1.593}_{- 0.078}^{+ 0.083} (stat) \pm 0.033 (syst) ps$ . This is the single most precise measurement of $τ (Λ_{b}^{0})$ and is $3.2 σ$ higher than the current world average.