Editing Protonium (section)

==Studies==
Planned experiments will use traps as the source of low energy antiprotons. Such a beam would be allowed to impinge on atomic [[hydrogen]] targets, in the field of a laser, which is meant to excite the bound proton–antiproton pairs into an excited state of protonium with some efficiency (whose computation is an open theoretical problem). Unbound particles are rejected by bending them in a magnetic field. Since the protonium is uncharged, it will not be deflected by such a field. This undeflected protonium, if formed, would be allowed to traverse a meter of high vacuum, within which it is expected to decay via annihilation of the proton and antiproton. The decay products would give unmistakable signatures of the formation of protonium.{{Fact|date=January 2025}}

Theoretical studies of protonium have mainly used non-relativistic [[quantum mechanics]]. These give predictions for the [[binding energy]] and [[mean lifetime|lifetime]] of the states. Computed lifetimes are in the range of 0.1 to 10 [[microsecond]]s. Unlike the [[Bohr atom|hydrogen atom]], in which the dominant interactions are due to the [[Coulomb's law|Coulomb attraction]] of the electron and the proton, the constituents of protonium interact predominantly through the [[strong interaction]]. Thus multiparticle interactions involving [[meson]]s in intermediate states may be important. Hence the production and study of protonium would be of interest also for the understanding of [[internucleon force]]s.{{Fact|date=January 2025}}