# Why does pair production produce an electron and positron with opposite spin?

So I was trying to understand quantum entanglement and the example that was used to describe an entangled pair of particles was of an electron and positron after it is formed from a photon in pair production . So I was wondering why is it assumed that the particles produced from a photon in pair production have opposite spin?

If anyone is looking for the video that I saw https://www.youtube.com/watch?v=tafGL02EUOA Here is the link

A correct example of entanglement is the $$π^0$$ decay into two photons, where the photons have to have opposite spins because the $$π^0$$ has spin $$0$$. Also the decay of the $$Ψ$$ resonance to a pair would be correct, it is spin 1 and decays to a pair.