Hadronic Spectra and Light-Front Wave Functions in Holographic QCD

We show how the string amplitude Φ(z) defined on the fifth dimension in AdS₅ space can be precisely mapped to the light-front wave functions of hadrons in physical space-time. We find an exact correspondence between the holographic variable z and an impact variable ζ, which represents the measure of transverse separation of the constituents within the hadrons. In addition, we derive effective four dimensional Schrödinger equations for the bound states of massless quarks and gluons which exactly reproduce the anti–de Sitter conformal field theory results and give a realistic description of the light-quark meson and baryon spectrum as well as the form factors for spacelike Q². Only one parameter which sets the mass scale, Λ_QCD, is introduced.