Measurement of the Ω_c^0 Baryon Lifetime

We report a measurement of the lifetime of the Ω_c^0 baryon using proton-proton collision data at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0  fb^-1 collected by the LHCb experiment. The sample consists of about 1000  Ω_b^-→Ω_c^0μ^-ν[over ¯]_μX signal decays, where the Ω_c^0 baryon is detected in the pK^-K^-π^+ final state and X represents possible additional undetected particles in the decay. The Ω_c^0 lifetime is measured to be τ_Ω_c^0=268±24±10±2  fs, where the uncertainties are statistical, systematic, and from the uncertainty in the D^+ lifetime, respectively. This value is nearly four times larger than, and inconsistent with, the current world-average value.