Phys. Rev. Lett. 121, 092003 (2018)

In the particle zoo, the charm baryon crew has a pretty clear pecking order when it comes to particle lifetime: theory predicts that the \({\it{\Omega }}_{\mathrm{c}}^0\) baryon, consisting of a charm and two strange quarks, has the shortest lifetime of the bunch. But predictions are made to be tested, right? And now, the LHCb Collaboration has published a new measurement of the \({\it{\Omega }}_{\mathrm{c}}^0\) lifetime, which finds a value four times larger than the current world average.

The lifetimes of charm mesons, containing a quark and another antiquark, are known with a much higher precision than those of charm baryons, and these measurements have long provided valuable information on higher-order corrections for calculations. The news that \({\it{\Omega }}_{\mathrm{c}}^0\) baryon lifetimes are not as short as we thought substantially jumbles the lifetime hierarchy — with \({\it{\Omega }}_{\mathrm{c}}^0\) overtaking both the \({\it{\Lambda}}_{\mathrm{c}}^ +\) and \({\it{\Xi}} _{\mathrm{c}}^0\) baryons. The result hints at the possibility that either smaller interference effects or additional higher-order corrections need to be considered in the theoretical predictions.