How to prove gluon has this quantum number assignment?

[BuckeyePhysicist]

[URGENT]How to prove gluon has this quantum number assignment?

From PDG booklet, for gluon, I^G(J^{PC}) = 0(1^-).

My questions are:

1. How to prove its P=-1?

2. Why C parity and therefore G parity are not well-defined for a gluon?
Is it because gluon have nothing to do with electromagnetic interaction so it do not have well-defined properties associated with (electric) charge conjugation transformation?

3. I=0 can be understood that gluon must be flavor singlet and have no charm, no strangeness, no bottomness and no topness. Right?

 

[Meir Achuz]

1. The gluon is a theoretical particle that is believed (in QCD) to be only virtual, so its parity can't be "measured" as can that of the photon.
In QCD, it is hypothesized as a vector gauge particle, which means spin 1 and negatve intrinsic parity. A gauge particle must have the same parity (-) as a spatial derivative.

2. Gluons have color charge which means they can't be eigenstates of C.

3. Right.