use of nuclear emulsion. Experiment E247 at Fermilab successfully detected particles with a lifetime of the order of 10^-13 s. A follow-up experiment, WA17, which made use of the SPS accelerator at CERN confirmed the existence of the (charmed lambda baryon), with a lifetime of .

In 2011, the international team at JLab used high-resolution spectrometer measurements of the reaction H(e, e´K⁺)X at