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

TL;DR

This study uses lattice QCD simulations to test predictions from AdS/QCD duals, confirming that the scales of confinement and chiral symmetry breaking can differ, depending on interaction strength.

Contribution

It provides the first lattice QCD evidence supporting the independent variation of confinement and chiral symmetry breaking scales as predicted by AdS/QCD models.

Findings

Deconfinement and chiral symmetry breaking occur at different temperatures.

The separation of these transition temperatures depends on 4-fermion interaction strength.

Results support the idea that confinement and chiral symmetry breaking are not necessarily linked.

Abstract

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 ($\chi$SB) can be varied independently from that of confinement, with the proviso that the scale of $\chi$SB 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 $\chi$SB transitions occur at different temperatures, the separation depending on the 4-fermion coupling. This confirms that the scales of confinement and $\chi$SB are, in general, different.