Protons’ antimatter is even more lopsided than we thought
In the sloshing sea of particles within a proton, down antiquarks outnumber up antiquarks
Protons are messy on the inside. Made of three main quarks (illustrated with large spheres), the particles also harbor a constantly shifting collection of transient quarks and antiquarks (smaller spheres) and gluons (squiggles) that bind the quarks together.
Daniel Dominguez/CERN