In standard model, we all knew about color charges which is mediated by gluons. But why we call it as "charge" when it has nothing common with conventional electric charge? It could be considerable if the difference was limited to the forces and polarities ,but their are significant difference between the characteristics of interactions of these two charge types. Some major differences are described below:
- Charge exchange: In electromagnetic interaction, photon do not exchanges charge. after the interaction, the source charges remain same. Gluons on the other hand do indeed exchanges color charge.
- Charge of the force carriers: Beside exchanging color charge, some gluons (excluding 3 component gluons) have their own color charges. Meanwhile, photon is charge less even though it interacts with charged particles.
- Amounts of force carriers needed: It needs a lot of photons to cause electromagnetic interaction. But it needs only a few gluons to cause strong interaction (thus it called non-radiating interaction). And the reason is obvious too. The photons has much lower frequency than gluons, and that's why few gluons have energy equivalent to a lot of soft photons. Here I said soft photons because general purpose electromagnetic attraction/repulsion requires photons with frequencies below radio frequency. But what about photons with higher frequency? At higher frequency, fewer photons could interacts with charges (i.e. molecular rotation, plasma oscillation, photoelectric effect, compton scattering, electron ejection etc). But we couldn't compare these interaction with electromagnetic attraction/repulsion, because they do identical action on both positive and negative charge.
So, What do you think? Is color charge really considerable as a conventional charge?
