Sum rules and 2-quark flux-tube structure

Sum rules – relating the static quark potential V® to the spatial distribution of the action and energy in the colour fields of flux-tubes – are applied in three ways: 1) To extract generalised beta-functions: 2) As a consistency check for the use of excited gluon flux-tubes and as an estimate of the quark self-energies: 3) To extract approximate sum rules using a simplified form of V®. Also the flux-tube profiles are compared with hadronic string and flux-tube models.