kiwiheretic is correct, but I wish to make a comment.
Massless particles do not have (spin) angular momentum. For massless particles we talk about "helicity." I'm not going to post a link for this as you can pretty much describe helicity in terms of angular momentum, which negates what I just said. But strictly speaking the Mathematics involved with helicity are different from that of angular momentum.
For example, a massive particle with (spin) angular momentum of 1 is in one of three possible states: spin 1, spin 0, and spin 1. A massless particle with helicity 1 is in one of two possible states: helicity 1 and helicity 1. There is no such thing as a 0 helicity state. The photon is a helicity 1 particle.
Dan
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