- #1
JustinLevy
- 895
- 1
I'd like to focus in on some info from a previous thread that seemed too good to pass up https://www.physicsforums.com/showthread.php?p=3156965
Yes I was making that confusion, and I'd like to understand this a bit better. I have three questions to follow up if you don't mind.
Is there a technical name for these "charge e" and "charge Q", to help distinguish them? I'm realizing now looking back that I've made this mistake before, and if there are technical terms to help distinguish them it would be great.
For the electromagnetic force, is the "g" coupling the same for all particles, and that is why the "Q" quantization leads to "charge e" quantization? That makes it seems much less mysterious, but then I don't understand why people hope to find a magnetic monopole to 'help explain' charge quantization. Maybe I am missing or mixing up things again.
I never see "weak charges" listed for particles, so this is probably a naive question: Is the "weak charge" (the one equivalent to the "charge e") quantized for the weak force -- Or does the symmetry breaking ruin this?
tom.stoer said:My guess was that JustinLevy didn't see the distinction between "charge e" and "charge Q".
tom.stoer said:One must distinguish between the coupling constant e, g, ... in QED, QCD, ... which could have any value, and the charge Q, Qa, ... as qm generators of U(1), SU(n), ... The latter one is quantized in the sense of the first Casimir QaQa. But how is this related to the coupling constant? The charge operator in QCD is something like
[tex]Q^a = \int d^3x\, g\,\bar{\psi}_i (T^a)_{ik}\psi_k[/tex]
The Casimir operator has a discrete spectrum, but still g is an arbitrary multiplicative constant which is not "quantized"
Yes I was making that confusion, and I'd like to understand this a bit better. I have three questions to follow up if you don't mind.
Is there a technical name for these "charge e" and "charge Q", to help distinguish them? I'm realizing now looking back that I've made this mistake before, and if there are technical terms to help distinguish them it would be great.
For the electromagnetic force, is the "g" coupling the same for all particles, and that is why the "Q" quantization leads to "charge e" quantization? That makes it seems much less mysterious, but then I don't understand why people hope to find a magnetic monopole to 'help explain' charge quantization. Maybe I am missing or mixing up things again.
I never see "weak charges" listed for particles, so this is probably a naive question: Is the "weak charge" (the one equivalent to the "charge e") quantized for the weak force -- Or does the symmetry breaking ruin this?
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