The Regge Spectrum in Phenomenology and AdS/QCD Models

The first part of the talk is devoted to the analysis of the spectrum of light non-strange mesons. According to current data, these mesons are grouped into clusters with similar masses, which can be interpreted as a manifestation of dynamical O(4) symmetry, analogous to the symmetry of the Coulomb potential in the hydrogen atom. The spectrum depends with high accuracy only on the sum of the orbital L and radial n quantum numbers and is well described by the Regge relation M² = a(L + n) + b with two parameters, a and b. The second part of the talk will demonstrate how a similar spectral structure is reproduced in holographic soft-wall models.