Omega-minus particle (A138/0116) Tank Top

First observation of omega-minus particle. In this historic photograph from the 80-inch (200cm) bubble chamber at the Brookhaven National Laborat- ory. A negative kaon enters at bottom left & collides with a proton in the chamber's hydrogen to produce 3 particles, including the omega-minus, which consists of three strange quarks. The omega stravels a short distance before decaying into a negative pion, which veers to the right across the bottom part of the picture, & a neutral xi particle which leaves no track. Discovery of the omega in 1964 confirmed Murray Gell-Mann & Yuval Ne'eman's classification of subatomic particles, the "Eightfold Way".