Regarding electron-positron annihilation

  • Level: High School 
  • Thread starter Rev. Cheeseman
  • Start date
  • Tags Tags
    annihilation
5 replies · 2K views · last reply
Rev. Cheeseman
Messages
360
Reaction score
21
When an electron meets an anti-electron which is also known as positron and collide, the particles will become photons. But where did the photons go after the electron-positron annihilation happened?
 
Vanadium 50 said:
Outward.
I mean do they ended up absorbed by something or simply gone?
 
They simply propagate out away from the point of annihilation at the speed of light. Whether they get absorbed depends on what they encounter along the way. It's similar to what happens to the photons that leave your flashlight.
 
If the photons have high enough energy, they can in turn produce new electron-positron pairs. This bubble-chamber picture shows a positron (orange) entering from the lower left and annihilating with an electron in the bubble-chamber fluid. One of the photons (purple-dot path) produces an electron-positron pair (green) at upper right. The other photon (invisible) leaves the field of view.

Annotated bubble-chamber photograph of particle tracks in curved magnetic field, with labels 'electron-positron pair production' at upper right and 'electron-positron annihilation' at center, and colored path overlays marking the positron track and photon paths.


(Source at CERN)
 
wonderingchicken said:
I mean do they ended up absorbed by something or simply gone?
Depends on what they hit. Just like photons from a light bulb or a star.