Confinement and Chiral Symmetry, a Lattice QCD test of AdS/QCD

We use lattice QCD simulations to test some of the predictions of proposed AdS/QCD (holographic) duals for QCD. In particular, these duals predict that the scale of chiral symmetry breaking (χSB) can be varied independently from that of confinement, with the proviso that the scale of χSB cannot be longer than that of confinement. We simulate lattice QCD with 2 quarks in the fundamental representation of colour and with additional 4-fermion interactions (suggested by AdS/QCD), at finite temperatures. For sufficiently strong 4-fermion interactions, the deconfinement and χSB transitions occur at different temperatures, the separation depending on the 4-fermion coupling. This confirms that the scales of confinement and χSB are, in general, different.