Three flavour QCD from the holographic principle

Building on recent research into five-dimensional holographic models of QCD, we extend this work by including the strange quark with an SU(3)L × SU(3)R gauge symmetry in the five-dimensional theory. In addition we deform the naive AdS metric with a single parameter, thereby breaking the conformal symmetry at low energies. The vector and axial vector sectors are studied in detail and both the masses and decay constants are calculated with the additional parameters. It is shown that with a single extra degree of freedom, exceptional agreement with experimental results can be obtained in the light quark sector while the kaon sector of the vector and axial vector octet is found to give around 10% agreement with lattice results. We propose some simple extensions to this work to be taken up in future research.