positronia

Positronia is a hypothetical type of exotic atom where an electron orbits a positron, instead of a nucleus. A positron is the antiparticle of the electron, possessing the same mass but a positive electric charge. In positronia, the electron and positron are bound together by their electrostatic attraction. This structure is analogous to a regular atom, where a negatively charged electron orbits a positively charged nucleus, or to positronium, where an electron orbits an antimeason.

The formation of positronia would require the presence of a sufficient density of positrons, which are typically produced in high-energy particle physics experiments or through certain radioactive decays. The properties of positronia, such as its size and energy levels, would be similar to those of hydrogen, but with the electron and positron in place of the proton and electron. However, positronia is predicted to be highly unstable. Due to matter-antimatter annihilation, the electron and positron would very rapidly annihilate each other, producing gamma rays. The lifetime of positronia would therefore be extremely short, on the order of picoseconds, making its direct observation challenging. While theoretical studies have explored its potential existence and properties, positronia has not been experimentally confirmed. Its study remains within the realm of theoretical physics and high-energy particle research.