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Results tagged with helicity
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user 38551
In particle physics, helicity is the projection of the angular momentum onto the direction of momentum. For massless spin-1⁄2 particles, helicity is equivalent to the chirality operator multiplied by $\hbar/2$, so may be used for related chirality questions as well.
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Why photon only have helicity other than spin?
But note: helicity is the component of $J$ along the momentum, $J$ is a pseudovector, the momentum is a vector, hence helicity changes sign under parity. … Therefore, in a parity-invariant theory like QED you have to include both the $+1$ and $-1$ helicity photon fields. …
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