After sorting through some 500,000,000,000,000 fatal and extremely messy accidents between protons and anti-protons, scientists at Fermilab have picked out 25 which prove the existence of a previously undetected particle: the "neutral Xi-sub-b." And it's full of strange.
The Xi-sub-b particle is a baryon, which means that it's part of the family of "normal stuff" like protons and neutrons and atoms. Baryons are also a type of hadron, a term which you probably recognize from CERN's Large Hadron Collider. To get a bit more technical, baryons are particles that are made up of three quarks each: a proton, for example, is made of two "up" quarks and one "down" quark. Quarks themselves are a fundamental part of matter, and they come in six distinct flavors (yes, flavors is a technical term): up, down, charm, strange, top, and bottom, and by combining three of them in different ways, the Standard Model of Physics predicts the existence of a whoooooole bunch of different baryons, many of which we've never seen before.
Thanks to Fermilab, we can now the scratch the neutral Xi-sub-b off the list, with its combination of a strange quark, an up quark and a bottom quark. Spotting these little guys for the very, very brief time that they exist (before decaying into lighter particles) is important because it helps us figure out just how exactly quarks get together to form matter, which is what makes our universe all universey in that special way, and the hope is that these new particle discoveries will give us clues where to look for all those other, even more elusive hadrons.