positron

Electron-positron pair creation from ultra high energy gamma rays has been a known thing for a long time.

Both + decay and electron capture have an analogous process for positrons.

The additional data will help the determination of dark matter vs. pulsars as the positron source.

You can even make a hydrogen atom out of an antiproton and a positron, called antihydrogen.

In it, Dr. Watchstop builds a machine capable of disproving this theory by utterly destroying an electron without creating a positron.

And clearly, there is considerable debate whether the positron excess is from dark matter particle annihilation or from nearby pulsars.

The neutron will decay into a proton by emitting and electron, while the anti-neutron will decay into an anti-proton while emitting a positron.

For instance, the electron can shoot of a virtual photon, which creates an electron/positron pair, which annhilate and create a new photon, which is then absorbed by the original electron.

Not to "actually" here, but actually... while positron/electron annihilation results in just photons most of the time the situation with anti-proton/proton annihilation is much more complex.

When an anti-hydrogen atom collides with any normal atom an electron will annihilate with the anti-hydrogen's positron leaving behind a negatively charged anti-proton which will fairly rapidly collide with a positively charged proton in a nucleus.

X' + nubar + e- -> X'' + 2 e- But it is only possible if the anti-neutrino is actually a normal neutrino, since otherwise the second reaction would need to create a positron, which would mean that the initial and final nucleus are identical, which means that there is no mass difference to create the electron positron pair.