All Questions
10
questions
4
votes
3
answers
1k
views
Is the concept of bicolored gluons mathematically precise/meaningful? Please explain
Each flavour of quark carries a colour quantum number: red, green or blue. I know what it means mathematically. But elementary textbooks (e.g, particle physics by Griffiths) also say that gluons are ...
- 11.8k
0
votes
2
answers
91
views
Quantum chromodynamics - why are there no $rrb$ or $ggr$ terms?
$$\Psi_{colour}^{qqq} = \frac{1}{\sqrt{6}}(rgb + gbr + brg -grb - rbg - bgr)$$
My lecturer stated that there cannot be any $rrb$ or $ggr$ terms in the expression above. I would like to understand what ...
- 13
3
votes
2
answers
2k
views
Confusions with gluons. How many of them are there?
Gluons are bicolored objects. They are made out of one color and one anticolor. Therefore, there seems to be nine possible states $r\bar{r},r\bar{b},r\bar{g},b\bar{r},b\bar{b},b\bar{g},g\bar{r},g\bar{...
- 11.8k
1
vote
1
answer
630
views
"Color charge" of the adjoint fermion?
What kind of "color charge" does the adjoint fermion carry?
Let us consider the SU(N) gauge theory. The gauge field is in the adjoint representation (rep).
Well-Konwn: If the fermion is in SU(N) ...
- 4,336
4
votes
1
answer
2k
views
$SU(3)$ Color Symmetry
I have following (maybe a bit general) question about the $SU(3)$-symmetry of color by quarks:
If I consider the analogy to the $SU(2)$-symmetry of isospin $I$ crucially it concers the conservation ...
- 1,395
2
votes
1
answer
688
views
What is the effect of the Gell-Mann matrices on color antiparticles?
I'm studying QCD and I can't understand how exactly are defined the color antiparticles. Indeed, we have the particle color triplet $(r,g,b)$. With the usual SU(3) algebra, we define the 8 Gell-Mann ...
- 2,296
0
votes
2
answers
1k
views
Why are 3 colors used in QCD?
The mapping of strong charge to RGB left me believing that there are only 3 conserved quantities in QCD. I recently came to the understanding that there are in fact 8 conserved quantities, as ...
- 403
5
votes
1
answer
1k
views
Permissible combinations of colour states for gluons
My lecturer has said that there are 8 types of gluons (I'm assuming that the repetition of $r\bar{b}$ is a typo that is meant to be $r\bar{g}$)
$$r\bar{b}, b\bar{r}, r\bar{g}, g\bar{r}, g\bar{b}, b\...
- 205
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
29
votes
1
answer
7k
views
Mathematically, what is color charge?
A similar question was asked here, but the answer didn't address the following, at least not in a way that I could understand.
Electric charge is simple - it's just a real scalar quantity. Ignoring ...
- 1,505