- #1

nrqed

Science Advisor

Homework Helper

Gold Member

- 3,764

- 293

So one possible multiplet contains j=-1/2 and j=0. That corresponds to a left-handed spinor and a complex scalar so that's the chiral multiplet.

Another possibility is j=-1 and j=-1/2 which corresponds to a vector particle and a left-handed spinor (so a gauge multiplet).

I am confused by the fact that the helicity of a massless vector particle is -1. A photon, say, has two physical degrees of freedom. I know that helicity is not the same issue as teh issue of degrees of freedom since the left-handed spinor has two dof even if the helicity is -1/2. However, my confusion stems from the fact that a photon may be observed with right or left-handed polarization so it seemed to me that it has two possible helicity states. In which case it woul dnot make sense to assign only one helicity value to a gauge particle in a SUSY multiplet.

Clearly I am not understanding correctly the concept of helicity in the case of gauge particles. Can someone clear this up?

Thanks