Antimatter of Fact: Collider Generates Most Massive Antinucleus Yet
Thursday, March 24, 2011 - 07:00
in Physics & Chemistry
Most people know two things about helium. One is that it makes your voice comically high-pitched when you inhale it; the other is that it is extremely light, which is why balloons filled with the stuff float upward through the heavier air. But in particle physics terms--and especially when it comes to the nuclear physics of antimatter--helium is no lightweight. With two protons and two neutrons, ordinary helium is four times as massive as hydrogen, the lightest element. (Both hydrogen and helium have other stable isotopes--atomic varieties with differing masses--but they are rare in nature.) [More]