SU(4) symmetry of the dynamical QCD string and genesis of hadron spectra

A large degeneracy of mesons of a given spin has recently been discovered upon reduction of the quasi-zero modes of the Dirac operator in a dynamical lattice simulation. Here it is shown that a symmetry group is consistent with the observed degeneracy. It is argued that this symmetry group is a symmetry of the dynamical QCD string. Implications of this picture for a genesis of light hadron spectra are discussed.