Measurement of b hadron lifetimes in exclusive decays containing a J/psi in p-pbar collisions at sqrt(s)=1.96TeV

TL;DR

This paper reports precise measurements of b-hadron lifetimes in various decay modes using data from the CDF II detector, providing the most accurate single-experiment determinations of these quantities.

Contribution

It presents the most precise single-experiment measurements of b-hadron lifetimes and their ratios in exclusive decay modes at the Tevatron.

Findings

Measured lifetimes: τB+ = 1.639 ps, τB0 = 1.507 ps, τΛb = 1.537 ps.

Lifetime ratios: τB+/τB0 = 1.088, τΛb/τB0 = 1.020.

Abstract

We report on a measurement of $b$-hadron lifetimes in the fully reconstructed decay modes B^+ -->J/Psi K+, B^0 --> J/Psi K*, B^0 --> J/Psi Ks, and Lambda_b --> J/Psi Lambda using data corresponding to an integrated luminosity of 4.3 ${\rm fb}^{-1}$, collected by the CDF II detector at the Fermilab Tevatron. The measured lifetimes are $\tau$B^+ = $1.639 \pm 0.009 ({\rm stat}) \pm 0.009 {\rm (syst) ~ ps}$, $\tau$B^0 = $1.507 \pm 0.010 ({\rm stat}) \pm 0.008 {\rm (syst) ~ ps}$ and $\tau$Lambda_b = $1.537 \pm 0.045 ({\rm stat}) \pm 0.014 {\rm (syst) ~ ps}$. The lifetime ratios are $\tau$B^+/$\tau$B^0 = $1.088 \pm 0.009 ({\rm stat})\pm 0.004 ({\rm syst})$ and $\tau$Lambda_b/$\tau$B^0 = $1.020 \pm 0.030 ({\rm stat})\pm 0.008 ({\rm syst})$. These are the most precise determinations of these quantities from a single experiment.