Recent content by Zoot

I'll think carefully about what you guys are saying. I think the best strategy for me will be to go back to basics, remove the quantum mechanics, and start by considering a classical system with angular momentum like a spinning disk or 2 masses attached by a rod, etc. spinning about the origin...

Pervect: Interesting points made. Maybe what I should be asking is: What are the 3 components of the spin angular momentum 3-vector in the boosted frame? I'm hoping this is a valid question analogous to "What are the components of the 3-momentum of a particle in a boosted frame?" I know the...

Thank you for your help Ben. It is assuring to know that I'm at least on the right track here. My hope is that the spin angular 4-momentum Sμ is similar to 4-momentum pμ in the sense that the spatial components describe the 3-momentum in all frames, not just the rest frame. It seems like...

The Pauli-Lubanski spin 4-vector for a particle in its rest frame is given by Sμ = (0, Sx, Sy, Sz). (Note this is the version from Rindler, which defines S in terms of the 4-velocity instead of 4-momentum) From the 3 spatial components, it is easy to construct a unit vector that points along...

Let me add my 2 cents worth, as this may help answer the original question in a simplistic manner (which is usually the way I think, unfortunately!). Let's say we have 3 types of fields: Scalar, Vector, and Spinor. We wish to look at these types of fields in another coordinate system (e.g. one...

I have a few basic questions about the Pauli-Lubanski spin 4-vector S. 1. I've used it in quantum mechanical calculations as an operator, that is to say each of the components of S is a matrix operator that operates on an eigenvector or eigenspinor. But my question is about the utility of S...

Thank you for replying DrDu. The Pauli-Lubansky vector is a 4-vector, which Lorentz transforms accordingly. The electron's 4-spinor transforms differently, since it is a spinor and not a vector. So what you are saying is that I should transform the DIRECTION of the electron's spin (which is...

Does a Lorentz boost change the "direction" of an electron's spin orientation? For example, if an electron is in a state "spin-up" along x, and this electron is subjected to a large boost along another direction, say z, will the electron's spin remain "spin-up" along x? What if the...

I have questions regarding the physical interpretation of Dirac 4-spinors. Using the Weyl/Chiral representation and the electron as the particle, in the rest frame of the electron, the 4-spinor reduces to two identical 2-spinors, that is to say the 4-spinor takes on the form (a b a b)...