Protonium

Protonium is a hypothetical form of matter proposed in theoretical physics. It is theorized to consist of exotic particles or configurations of known particles that mimic the properties of a proton but are not, in fact, protons. One speculative idea is that protonium could be a bound state of quarks arranged in a way that is not allowed by the standard model of particle physics, or it could be composed of entirely different fundamental particles that somehow possess a net charge and baryon number similar to a proton. Another concept suggests protonium could be an exotic atom where electrons are replaced by other negatively charged particles, or where the nucleus is composed of stable, non-protonic baryons.

The existence of protonium is purely theoretical and has not been experimentally verified. If it were to exist, it would likely have very different decay modes or interactions compared to ordinary protons. Such exotic matter is often invoked in discussions of dark matter or in exploring the fundamental limits of particle physics theories. Research into protonium, and other hypothetical particles like it, primarily occurs within the realm of theoretical physics and particle cosmology, aiming to understand the potential for matter beyond the Standard Model. Further experimental evidence would be required to confirm or deny its existence.