Measurement of the $$ {\varOmega}_c^0 $$ and $$ {\Xi}_c^0 $$ baryon lifetimes using hadronic b-baryon decays

Abstract

Abstract The lifetimes of the

$$ {\varOmega}_c^0 $$

Ω c 0

and

$$ {\Xi}_c^0 $$

Ξ c 0

baryons are measured using a pp collision dataset collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb −1. The charm baryons are produced in the fully reconstructed decay chains

$$ {\varOmega}_b^{-}\to {\varOmega}_c^0\left(\to p{K}^{-}{K}^{-}{\pi}^{+}\right){\pi}^{-} $$

Ω b −

→

Ω c 0

→ p

K −

K −

π +

π −

and

$$ {\Xi}_b^{-}\to {\Xi}_c^0\left(\to p{K}^{-}{K}^{-}{\pi}^{+}\right){\pi}^{-} $$

Ξ b −

→

Ξ c 0

→ p

K −

K −

π +

π −

. The measurement uses topologically and kinematically similar B

− → D 0(→ K

−

K + π

−

π +)π

− decays for normalisation. The measured lifetimes are

$$ {\displaystyle \begin{array}{c}{\tau}_{\varOmega_c^0}=276.3\pm 19.4\left(\textrm{stat}\right)\pm 1.8\left(\textrm{syst}\right)\pm 0.7\left({\tau}_{D^0}\right)\textrm{fs},\\ {}{\tau}_{\Xi_c^0}=149.2\pm 2.5\left(\textrm{stat}\right)\pm 0.9\left(\textrm{syst}\right)\pm 0.4\ \left({\tau}_{D^0}\right)\textrm{fs},\end{array}} $$

τ

Ω c 0

= 276.3 ± 19.4

stat

± 1.8

syst

± 0.7

τ

D 0

fs ,

τ

Ξ c 0

= 149.2 ± 2.5

stat

± 0.9

syst

± 0.4

τ

D 0

fs ,

where the first uncertainty is statistical, the second systematic and the third due to the uncertainty of the D 0 lifetime. These results are consistent with previous measurements performed by the LHCb experiment.