"Matter annihilation" refers to the complete destruction of matter, where it is converted into energy. It implies that matter disappears, leaving behind only energy. Full definition
The absence of dark matter annihilation signals outside the Milky Way could be a crucial hint towards this richer theory of dark matter, which will be tested by future observations. (sciencedaily.com)
Possible dark matter annihilation signal in the AMS - 02 antiproton data. (sciencenews.org)
The spatial distribution of these particles might help distinguish dark matter annihilation products from more common astrophysical backgrounds. (discovermagazine.com)