# Axion decay width

1. Jul 14, 2009

### florian101

hello
I would like to know the frequency width of a decaying axion
Lets say the axion has a mass of 10^-6 eV and it decays via the primakoff effect within a B field into one photon. Because there is only one photon in the final state I would assume that the photon frequency is quite narrow but what actually defines the width of the signal?
thanks
florian

Last edited: Jul 14, 2009
2. Jul 14, 2009

### hamster143

Spectrum of incoming axions, I think? Primakoff effect is just a fancy name for scattering, a+Z -> gamma+Z. Final frequency should be exactly computable if we know initial energy and scattering angle, simply using conservation of energy & momentum (since all particles are stable).