# Casimir operators of QCD

Hi folks,

I was wondering if the two Casimir operators of the SU(3) color gauge group were of any physical significance, or corresponded to any familiar physical properties. For example, I know that in the Poincare group the two Casimirs correspond to mass and spin: is there a similarly natural interpretation of the Casimirs here too? (I have only done a little bit of QCD in my studies and they haven't cropped up so far, but maybe they're useful for *something*...) Any thoughts on this matter much appreciated!