Conservation of energy and momentum concerning pair annihilation?
Bob B asked:
Use the conservation of energy and momentum to show that pair annihilation CANNOT produce only on photon.
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Use the conservation of energy and momentum to show that pair annihilation CANNOT produce only on photon.
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Work in the center of mass frame.
Initial momentum = 0
- Final momentum = 0
But a single photon carrying all that energy can’t have zero momentum. So it won’t work.
Comment by (Ω)Mistress Bekki — December 9, 2008 @ 4:25 pm
Suppose an electron and a positron assumed to be initially at rest annihilate each other, then then if they produced one photon it would have momentum, so momentum won’t be conserved.
Theoretically another photon must be produced to conserve momentum, in this case, the two photons would have opposite directions, thus their total momentum would be zero, and momentum would be conserved.
Comment by ♘EgYpTiAn♘ ☢GuY☢ ☠☠☠☠☠ — December 11, 2008 @ 5:06 pm