Measurement of the Ωc0 lifetime

We present the measurement of the lifetime of the Ωc0 we have performed using three independent data samples from two different decay modes. Using a Σ− beam of 340 GeVc we have obtained clean signals for the Ωc0 decaying i Ξ−K−π+π+ and Ω−π+π−π+, avoiding topological cuts normally used in charm analysis. The short but measurable lifetime of the Ωc0 is demonstrated by a clear enhancement of the signals at short but finite decay lengths. Using a continuous maximum likelihood method we determined the lifetime to be τωc0 = 55−11+13(stat)−23+18(syst) fs. This makes the Ωc0 the shortest living weakly decaying particle observed so far. The short value of the lifetime comfirms the predicted pattern of the charmed baryon lifetimes and demonstrates that the strong interaction plays a vital role in the lifetimes of charmed hadrons.