What Happens When a Proton and an Antineutron get Together for Coffee?

What happens in a collision between "unlike" particles and antiparticles? Every time I read about antimatter the article talks about proton/antiproton, electron/positron, and neutron/antineutron annihilation ... but what happens if, for example, a proton and an antineutron get together for coffee?
- Rob Stow (age 51)
Moose Jaw, SK, Canada

They spawn all sorts of weirdo offspring.   A proton is essentially two up quarks and one down quark.   An anti-neutron is two anti-up and one anti-down quark.   The net nucleon number is zero, the net charge is plus one.  So any final state must have total charge one, and nucleon number zero.   Energy and momentum must be conserved.   For example  p +  ñ  -->  K⁺ + K⁰   or   π⁺ + π^- + π⁰  ...  or whatever as long as the conservation laws are observed.

LeeH

(published on 02/27/2017)