I Matter/antimatter collisons between "unlike" particles?

[Rob Stow]

Just about everything I have read about antimatter talks about proton/antiproton, electron/antielectron, and neutron/antineutron annihilation.

But what happens if, for example, a proton and an antineutron collide? Would a weird nucleus be created or would there be a partial annihilation with some leftover quarks and antiquarks? Other outcomes? It is easy to imagine a simple process where the antineutron in a short-lived nucleus undergoes beta decay and the resulting antiproton annihilates the proton ... but does that HAVE to happen?

 

[mfb]

This question gets asked frequently, and you should find various threads discussing it with the search function.

A proton and an antineutron would annihilate very similar to proton plus antiproton or neutron plus antineutron: They produce a few pions. Due to charge conservation, the symmetric annihilation produces as many positive as negative pions, while proton plus antineutron produces one positive pion more than negative pions.

Other combinations can lead to other results, or even no annihilation (e.g. antiprotons and electrons: they just repel each other electromagnetically, nothing else happens).

 

[Rob Stow]

This question gets asked frequently, and you should find various threads discussing it with the search function.

A proton and an antineutron would annihilate very similar to proton plus antiproton or neutron plus antineutron: They produce a few pions. Due to charge conservation, the symmetric annihilation produces as many positive as negative pions, while proton plus antineutron produces one positive pion more than negative pions.

Other combinations can lead to other results, or even no annihilation (e.g. antiprotons and electrons: they just repel each other electromagnetically, nothing else happens).

 

[Rob Stow]

Thanks for your reply. I finally have a day off to read up more on this and this time my search found those pre-existing threads on this topic ... no idea I could have bungled the search I did last week before starting this new thread. Maybe I'll get lucky and a moderator will just delete this thread?

 

[mfb]

Just let it stay as it is.