  Through the embedding of superconformal quantum mechanics into AdS space, it
is possible to construct an effective supersymmetric QCD light-front
Hamiltonian for hadrons, which includes a spin-spin interaction between the
hadronic constituents. A specific breaking of conformal symmetry determines a
unique effective quark-confining potential for light hadrons, as well as
remarkable connections between the meson, baryon, and tetraquark spectra. The
pion is massless in the chiral limit and has no supersymmetric partner. The
excitation spectra of relativistic light-quark meson, baryon and tetraquark
bound states lie on linear Regge trajectories with identical slopes in the
radial and orbital quantum numbers. Although conformal symmetry is strongly
broken by the heavy quark mass, the basic underlying supersymmetric mechanism,
which transforms mesons to baryons (and baryons to tetraquarks) into each
other, still holds and gives remarkable connections across the entire spectrum
of light, heavy-light and double-heavy hadrons. Here we show that all the
observed hadrons can be related through this effective supersymmetric QCD, and
that it can be used to identify the structure of the new charmonium states.
