New hadron physics insights have emerged from "light-front holography", which relates the dynamics and light-front wavefunctions of hadrons in QCD(3+1) to a corresponding theory in the fifth dimension of AdS space. Remarkably, the confining potential for massless quarks takes on a unique form, and a mass gap arises if one requires the chiral QCD action to remain conformally invariant. The resulting nonperturbative relativistic light-front quantum-mechanical wave equations for mesons and baryons incorporate color confinement and other essential spectroscopic and dynamical features of hadron physics -- including a massless pion for zero quark mass and linear Regge trajectories with the same slope in the radial quantum number n and orbital angular momentum L. The application of superconformal algebra leads to new relations between meson and baryon spectroscopy and dynamics. One also finds an analytic connection between the hadron mass scale and the mass scale of the perturbative QCD running coupling. I will also discuss a number of novel predictions for hadron physics phenomenology obtained from the light-front approach.
Argonne Physics Division Seminar Schedule