Spectrum of the QCD flux tube in 3d SU(2) lattice gauge theory

Evidence from the lattice suggests that formation of a flux tube between a q (q) over bar pair in the QCD vacuum leads to quark confinement. For large separations between the quarks, it is conjectured that the flux tube has a behavior similar to an oscillating bosonic string, supported by lattice data for the groundstate q (q) over bar potential. We measure the excited states of the flux tube in 3d SU(2) gauge theory with three different couplings inside the scaling region. We compare our results to predictions of effective string theories. (C) 2009 Elsevier B.V. All rights reserved.