8.3 Holographic Hadron Basis Functions 113 value. Similarly the pion stack can be used to reproduce the towers of states associated with each pseudo-Goldstone of the chiral symmetry breaking (i.e. the pions, kaons and eta meson). The relative weighting is parameterised by R , a measure of g 2 $_{YM}$N , which we fit. Our holographic model of the hadron spectrum is based on the Constable- Myers geometry discussed in chapter 4. We then compactify it to five di- mensions, in exactly the same way we did in chapter 6 when trying to regulate the infrared of holographic descriptions of QCD. We remind the reader that this model spontaneously forms a chiral condensate, and has a complete orthogonal set of functions for both the vector meson sector and pionic-like sector. Henceforth we denote these two sets as g$_{n}$ ( r ) and f$_{n}$ ( r ) respectively, matching the notation used in chapters 4 and 6. The mass of the lowest lying ρ meson can be dialled by choosing the conformal symmetry breaking scale in the model, and the mass of the lowest lying pion can be dialled by choosing the asymptotic quark mass. The excited states in both stacks are then predicted: m$_{ρ}$ ∗ = 1737 MeV, m$_{π}$ ∗ = 1701 MeV (c.f. experimental values of 1459 and 1300 MeV respectively). So whilst they don’t precisely reproduce the experimental values the pattern is at least roughly right. As stated above, we assume that the g$_{n}$ functions associated with each hadron stack are not that different from the ρ -stack functions, and simply rescale the r coordinate such that the mass of the lowest member of each stack is correct. We class the pions, kaons and η (548) mesons as pionic, and use the f$_{n}$