First, I need to be able to do equations in my post but it has been a long time since I posted here. Someone please point me to a resource that gives the how-to.(adsbygoogle = window.adsbygoogle || []).push({});

If you make a infinitesimal rotation of the free-field Lagrangian for the Dirac equation, you get an extra term because the Dirac gamma matrices and the rotation generator do not commute. I'll show you when I can. So what do we make of this?

There is more to the question, and I know it has something to do with thePauli-Lubanski pseudovectoroperator. Anything you can tell me about the Pauli-Lubanski pseudovector would also be appreciated.

Todd

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# Dirac Lagrangian not invariant under rotations?

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