Decades-Long Quest Reveals Details of the Proton’s Inner Antimatter
Twenty years ago, physicists set out to investigate a mysterious asymmetry in the proton’s interior. Their results, published today, show how antimatter helps stabilize every atom’s core.
We learn in school that a proton is a bundle of three elementary particles called quarks — two “up” quarks and a “down” quark, whose electric charges (+2/3 and −1/3, respectively) combine to give the proton its charge of +1. But that simplistic picture glosses over a far stranger, as-yet-unresolved story.
In reality, the proton’s interior swirls with a fluctuating number of six kinds of quarks, their oppositely charged antimatter counterparts (antiquarks), and “gluon” particles that bind the others together, morph into them and readily multiply. Somehow, the roiling maelstrom winds up perfectly stable and superficially simple — mimicking, in certain respects, a trio of quarks.