Measurement of τ<inf>L</inf> using the Bs0→J/ψη decay mode

Abstract

AbstractUsing a proton–proton collision data sample collected by the LHCb detector and corresponding to an integrated luminosity of $$5.7~\text {fb}^{-1}$$ 5.7

fb

- 1

, the lifetime of the light $${{B} ^0_{s}} $$

B

s 0

mass eigenstate, $$\tau _{L}$$

τ L

, is measured using the $$B^0_s \rightarrow J/\psi \eta $$

B s 0

→ J / ψ η

decay mode to be $$\begin{aligned} \tau _{\text {L}} = 1.445 \pm 0.016 \text {(stat)} \pm 0.008 \text {(syst)} \,\text {ps}. \end{aligned}$$

τ L

= 1.445 ± 0.016 (stat) ± 0.008 (syst)

ps .

A combination of this result with a previous LHCb analysis using an independent dataset corresponding to 3 fb$$^{-1}$$

- 1

of integrated luminosity gives $$\begin{aligned} \tau _{\text {L}} = 1.452 \pm 0.014 \pm 0.007 \pm 0.002 \,\text {ps}, \end{aligned}$$

τ L

= 1.452 ± 0.014 ± 0.007 ± 0.002

ps ,

where the first uncertainty is statistical, the second due to the uncorrelated part of the systematic uncertainty and the third due to the correlated part of the systematic uncertainty.