All Questions
8
questions
1
vote
1
answer
186
views
Quantum Chromodynamics and Group Theory
I know nothing of QCD, but I was watching this youtube video and pondered on whether the additive structure described is a group, and if so, which is it?
As of now, I know the group must contain the ...
- 379
1
vote
1
answer
77
views
Justifying the identification of eight gluons with the ${\bf 8}$ from ${\bf 3}\otimes{\bf 3}^*$
When we combine the fundamental ${\bf 3}$ and antifundamental ${\bf 3}^*$ of color $SU(3)$ of QCD i.e. single quark of three colors and a single antiquark of 3 anticolors, nine states are obtained. ...
- 11.8k
1
vote
0
answers
70
views
Why use $SU(3)$ and not $SL(3, \mathbb{R})$ for color charge? [duplicate]
Why do we use the group $SU(3)$ and not $SL(3, \mathbb{R})$ for color charge?
As far as I can tell, the $SL(3, \mathbb{R})$ is volume and orientation preserving, by the fact that it has unit ...
- 161
3
votes
1
answer
270
views
How many glueballs are there?
As I understand there are eight types of gluons (linear combinations of color/anticolor pairs with varying amplitudes) which can combine (for very short periods) to form glueballs. If there were no ...
- 756
2
votes
1
answer
376
views
Why do we say that gluons carry color charge?
We know that gluons are Lie algebra $su(3)$-valued one-form fiels $A_{\mu}$. And because of $[A_\mu,A_\nu]$ does not vanish generally for the non-Abelian case, gluons have self-interactions. Now how ...
- 3,691
2
votes
1
answer
153
views
QCD Color Structure relation [closed]
i want to proof the following relation :
\begin{equation}
t^a t^b \otimes t^a t^b = \frac{2}{N_C} \delta^{ab} \mathbb{1} \otimes \mathbb{1} - \frac{1}{N_C} t^a \otimes t^a
\end{equation}
Right now I ...
- 379
2
votes
0
answers
56
views
Measure of interaction of two quarks and Casimir operators [closed]
Let's have two quarks, which refers to representations of $r_{1}$ and $r_{2}$ of color symmetry group. They create bounded state which refers to the representation $r$.
There is a statement that ...
user8817
5
votes
1
answer
672
views
Group theoretical reason that Gluons carry color-charge and anti-colorcharge
I was wondering how it is possible to see from the $SU(3)$ Gauge Theory alone that Gluons carry two charges colors: $g\overline{b}$ etc.
Some background:
The W-Bosons (pre-symmetry breaking) form an ...
- 10.1k