I know that if an electron collides with its antiparticle, the positron, they annihilate each other and energy is released. But what happens if an electron collides with other antimatter that is not its antiparticle, like an antiproton or an antineutron? Do they annihilate each other too?
No, they don’t annihilate. The electron will scatter off the other particle, though any differences in charge will of course affect the scattering. For example, an electron and a proton could become bound to make a hydrogen atom, but this couldn’t happen with an anti-proton. Any nuclear reactions (specifically electron capture) would be affected too.
In the case of free anti-neutrons, there’s a chance the anti-neutron could decay into an anti-proton and a positron. If this were to happen during the collision with an electron, the electron could potentially annihilate with the positron.
I didn’t even know that neutrons have an antiparticle. TIL
Edit: neurons -> neutrons
Lol, but, for other readers, charge isn’t the only property that has an anti-component when making up anti matter.
Positrons are just the most easily explained and are what people are probably most familiar with.
Saying “electron but with a positive charge” satisfies the curiosity of most people who are smart enough to ask the question but don’t want to write a dissertation.
Plus, PET scanners take advantage of positron/electron annihilation to do their imaging, and that happens all over the world every day.
Which is kinda weird because where else in the world but medical imaging are regular people confronted with actual modern physics. Sure, semiconductors, but they don’t actually have to confront that.
Anyway, I do prefer to say “magic” rather than explain how an MRI works for a lot of people.
