The classification table for SU(Nc) gauge theories with Nf fermions in the fundamental representation. Click on an individual theory to learn more. Key: Theories in a lighter colour lie in the conformal window; those in a darker colour have a mass gap Results in shades of grey are derived from the two loop running results with Appelquist and Terning's critical coupling for chiral symmetry breaking Lattice (and other results) are highlighted in green Theories in the conformal window are marked by their value of the anomalous dimension at the fixed point Gapped theories are marked by R - the one loop gap ratio between the scales for chiral symmetry breaking and the IR pole - a crude measure of the gap between confinement and chiral symmetry breaking Gapped theories are marked by S - the ratio of the scales at which the coupling passes half the critical coupling and that for the critical coupling using the two loop running - a crude measure of the degree of walking in the theory above the chiral symmetry breaking scale I'd also like to mark the order of the finite T phase transition at zero quark mass - not sure how at the moment!