}}</ref> инаку забранетите исто така може да се направат.) Постојат многу други можни избори, но сите се математички еквивалент, барем подеднакво комплексни, и даваат исти физички резултати.
=== Group theory details ===
Technically, QCD is a [[gauge theory]] with [[SU(3)]] gauge symmetry. Quarks are introduced as [[spinor|spinor fields]] in ''N''<sub>f</sub> [[flavour (particle physics)|flavor]]s, each in the [[fundamental representation]] (triplet, denoted '''3''') of the color gauge group, SU(3). The gluons are vector fields in the [[Adjoint representation of a Lie group|adjoint representation]] (octets, denoted '''8''') of color SU(3). For a general [[lie group|gauge group]], the number of force-carriers (like photons or gluons) is always equal to the dimension of the adjoint representation. For the simple case of SU(''N''), the dimension of this representation is {{nowrap|''N''<sup>2</sup> − 1}}.
In terms of group theory, the assertion that there are no color singlet gluons is simply the statement that [[quantum chromodynamics]] has an SU(3) rather than a [[U(N)|U(3)]] symmetry. There is no known [[A priori and a posteriori|''a priori'']] reason for one group to be preferred over the other, but as discussed above, the experimental evidence supports SU(3).<ref name="Griff"/> The U(1) group for electromagnetic field combines with a slightly more complicated group known as SU(2) – S stands for "special" – which means the corresponding matrices have determinant 1 in addition to being unitary.
