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How to prove gluon has this quantum number assignment?

  1. Aug 11, 2006 #1
    [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?
  2. jcsd
  3. Aug 16, 2006 #2

    Meir Achuz

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    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.
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