Antimatter is composed of bound antiparticles similar to ordinary matter. Antiparticles have the same mass as particles of ordinary matter but with opposite charges. It is still unknown why the observable universe is composed almost entirely of ordinary matter, as opposed to a more even mixture of matter and antimatter. Many people hope that studying antimatter will uncover this mystery, however this is not as easy as studying ordinary matter. Antimatter and matter are both destroyed when they make contact with each other, releasing variable proportions of radiations like gamma rays. Antiprotons are no different. They’re among the particles produced when gold nuclei collide at nearly the speed of light.
Antiprotons, which are negatively charged particles of antimatter, have been found to have a strong nuclear force that securely binds them together in close proximity, similar to how protons are inside the nuclei of atoms. By measuring the energies, trajectories and speeds of various particles created in about 500 million gold collisions, researchers identified antiprotons and noted pairs that came into close contact. They found that an attractive strong nuclear force between antiprotons overcomes the repulsive force present due to like charges. This attractive force becomes significant when the particles are within a few millionths of a billionth of a meter of each other. Besides having indistinguishable mass and charge, this study shows that protons and antiprotons have similar behaviors as well. The study sheds more light into the structure of antimatter nuclei, further supporting other studies that claim no differences in the behavior of antimatter and ordinary matter. Any discrepancy could help scientists determine why matter, and not antimatter, dominates the universe.