All Questions
3
questions
6
votes
1
answer
2k
views
What is the Noether charge associated with the the color $SU(3)$ symmetry of QCD?
A version of the Noether's theorem applies to local gauge symmetries. What is the Noether's charge associated with a non-abelian gauge symmetry such as the color $SU(3)$ and how is that derived? I ...
- 26.8k
0
votes
1
answer
120
views
If the $SU(3)$ Noether charge is not gauge-invariant how can we say Hadrons are colorless?
The Noether charge associated with global $SU(3)$ invariance is
\begin{equation}
J^{\mu}_a=-f_{abc}F_c^{\nu\mu}A_{b\mu}-i\frac{\delta \mathcal{L}_{Matter}}{\delta D_{\nu}\psi}t_a\psi
\end{equation}
...
- 2,270
12
votes
3
answers
4k
views
Why is color conserved in QCD?
According to Noether's theorem, global invariance under $SU(N)$ leads to $N^2-1$ conserved charges. But in QCD gluons are not conserved; color is. There are N colors, not $N^2-1$ colors. Am I ...
- 7,398