Thursday, November 23, 2017
It’s been 100 years since scientists first split open the atom and realized it was not the smallest thing to exist. It’s been more than 50 years since they started to suspect that the atom’s components— protons, neutrons, and electrons—weren’t either. Protons and neutrons have components of their own, called quarks, which are particles so tiny they’re almost impossible to study.
Electrons and positrons are not made up of quarks. They are in a separate "family" of particles known as leptons. Leptons and quarks are "fundamental" (indivisible) particles. Leptons do not experience the "strong" or "hadronic" force that protons and neutrons do.
A combination of three quarks creates a hadron, which, when stable, we know as a proton or neutron. But a combination of four quarks is something scientists have never been able to prove exists. That would be the tetraquark, which scientists have been chasing without success since the 1960s.
Now, researchers are about to publish what they say is proof that the tetraquark exists, that it’s stable, and that they can generate it in the Large Hadron Collider at the CERN particle physics lab in Switzerland.
Story via live science https://www.livescience.com/60900-tetraquark-particle-exists.html