Physicists working at the Fermilab Tevatron particle collider in Illinois have discovered a heavier relative of the neutron that they´re calling the neutral Xi-sub-b.
Smashing atoms produced the neutral Xi-sub-b, which lasted just an instant before decaying into lighter particles. Such particles are discovered by racing larger particles around a 4-mile ring at near light speed.
The Standard Model predicted the existance of neutral Xi-sub-b, but the Fermilab experiment is the first time the particle has been observed firsthand. The particle joins the three-quark baryon family which also includes protons and neutrons.