The Field Guide to Particle Physics : Season 2https://pasayten.org/the-field-guide-to-particle-physics©2022 The Pasayten Institute cc by-sa-4.0The definitive resource for all data in particle physics is the Particle Data Group: https://pdg.lbl.gov.The Pasayten Institute is on a mission to build and share physics knowledge, without barriers! Get in touch.The Omega BaryonIntroductionThe Omega Baryon is the strangest particle we have encountered so far. It may also be the strangest particle known to Science, literally.With a mass of 1672.4 MeV, the Omega Baryon is heavy. As well it should be. It is comprised of three, strange quarks. The three strange quarks gives the Omega an electric charge of three times minus one third, or minus one. Those strange quarks also gives it the unusually long lifetime of about 8% of a nanosecond. While short by our standards - even a bit shorter than some other strange particles - a solid fraction of a nanosecond is an enormous lifetime for a particle with such an enormous mass.The Decay of Strange QuarksAs if on brand, this strangest of the strange particles lives for so long precisely because its made from only strange quarks. The strange quarks, you might recall, struggle to decay. They wouldn’t decay- actually - if not for a mild identity crisis.The strange quarks talk to other particles both by photon, gluon and by W boson. That is, in addition to the electromagnetic force, strange quarks communicate via both the strong and weak nuclear forces. From the strong force’s perspective, strange quarks are distinct. Just like the up and down quarks. Nobody is confused, all that that subnuclear gu respects their identity as strange quarks.The weak force hedges a bit. The W-boson in particular is a little confused on who is who, and from its perspective down and strange quarks are a little mixed. Just like North and West mean slightly different things to a compass or a cartographer, down and strange quarks appear slightly different to the strong and weak forces. They’re almost aligned, but not quite.As a result, the strange quark decays by W boson as if it were a down quark. That decay is amplified by the strange quark’s heavy mass, but its still a small effect. The weak nuclear force is… well… weak.Being made of three strange quarks, the Omega baryon decays once one of its constituents does.Omega Baryon Decay ChannelsThe Omega minus decays when one of its strange quarks throws out a W boson, changing its identity to an up quark.  Typically the W-boson then decays to a pair of quarks itself, an antiup and a down quark. This all happens quickly inside the baryon itself, which subsequently explodes into a pair or triplet of particles. There there are a number of possible results.Two-thirds of the time, that anti-up quark SCORES and runs away with one of the Omega’s other strange quarks, creating one of those tricky K minus mesons that we’ve discussed previously. What’s left over? An up, a down and a strange quark, which manifests as a Lambda zero baryon.Twenty-three percent of the time, that anti-up quark isn’t so lucky. It remains stuck so the down quark that came from W boson, which together run away as a negatively charged pion.  The quarks that remain - two strange and an up - comprise the neutral cascade or Xi baryon, which of course leads to its own cascade of particle decays.Almost all the rest of the time - that’s about 8% for you bean counters out there - the Omega baryon spits out a neutral pion, decaying to a Xi minus instead.  For this to happen, that down quark has to hold on tight to that pair of strange quarks that didn’t decay.On extremely rare occasions, instead of a neutral pion, the Omega decays to Xi minus by spitting out a pi+ pi- pair. This could happen, for instance, the resulting up and antiup quarks happened to find a down-anti down pair inside the subnuclear goo.Spin and the DecupletIn addition to having three strange quarks, the Omega baryon also has three times the angular mom