Structure of flux tubes in SU(2)

The spatial distribution of the action and energy in the color fields of flux tubes is studied in lattice SU(2) field theory for static quarks at separations up to 1 fm. Special attention is paid to the structure of the color fields associated with an excited flux tube with E${}_u$ symmetry. We compare our results with hadronic string and flux-tube models. Sum rules are used to extract generalized $\beta$ functions, to describe the expected color field behavior, and to cross-check the methods used.