# What happens when matter and antimatter collide?

May 29, 2018

Particle annihilation occurs and energy is released, typically as gamma radiation.

An example is an electron-positron annihilation:

(Electron Zitterbewegung basically means a local fluctuation of the electron position.)

When these collide, each particle has mass ${m}_{e} = 9.10938356 \times {10}^{- 31} \text{kg}$. Conservation of particles, angular momentum, and energy is observed, and for the low-energy case, we write this process as:

${\text{_(-1)^(0) e + ""_(1)^(0) e -> 2}}_{0}^{0} \gamma$

The energy released is ${m}_{e} {c}^{2}$ per particle, so the total energy released is

E = 2m_ec^2 = 2 cdot 9.10938356 xx 10^(-31) "kg" cdot (2.99792458 xx 10^8 "m/s")^2

$= 1.64 \times {10}^{- 13} \text{J}$

or about $\text{1.022 MeV}$ (i.e. $\text{0.511 MeV/photon}$).