# Physical reason for annihilation? [duplicate]

What is the fundamental reason as to why matter and antimatter annihilate?

Is it because both particles and antiparticles are excitations of quantum fields, and the annihilation process corresponds to a transition to the ground state?

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## marked as duplicate by Jim, Kyle Kanos, Ali, John Rennie, Brandon EnrightJul 16 at 15:16

is my idea about the ground state wrong? –  SuperCiocia Jul 16 at 13:08
Yup, as the most voted answer there tells you if you understand Feynman diagrams. You don't get the vacuum state (which is what I assume is your ground state) since there are photons coming out. –  ACuriousMind Jul 16 at 13:13
Always worth re-re-re-noting the existence of the Totalitarian Rule of quantum mechanics: everything which is not forbidden is mandatory. –  dmckee Jul 16 at 14:27