The existence of our Universe depends critically on the following empirical facts: the proton is massive, i.e. the mass-scale for strong interactions is vastly different to that of electromagnetism; and it is absolutely stable, despite being a composite object constituted from three valence quarks; but, on the other hand, the pion is unnaturally light, possessing a lepton-like mass, even though it is constituted from the same degrees-of-freedom that produce the proton. These qualities are fundamental emergent phenomena, having their foundation in confinement and dynamical chiral symmetry breaking, the understanding of which is crucial if science is to reveal our origins, and could potentially be central to learning how to complete the picture of Nature by moving beyond the Standard Model. Confinement and dynamical chiral symmetry breaking will only be fully understood when we have a solution to QCD. In the meantime, their manifold observable implications are being signalled in a variety of theoretical studies. This presentation will explain their connection with the existence of a unique running charge in QCD, running masses for the gluons and quarks, and the empirical expression of these features in hadron observables, with predictions that can be validated at contemporary and anticipated facilities.
Argonne Physics Division Seminar Schedule