system
Given the following post, respond as if you're commenting on Reddit:
human
What happens when a particle meets antimatter that is not its antiparticle, e.g. a proton with a positron?
gpt
Depends on the particles.  At low energies, proton and positron would scatter, primarily due to the electromagnetic force, while a neutron and a positron might scatter or might convert to a protton and an electron antineutrino.  At high energies, even more things become possible (this is what happens in the LHC, where protons and protons are collided with each other).

In general, you look to see what final states respect the various conservation laws (such as energy and electric charge and baryon number), and those are what could result.