Prof. Craig D. Roberts, Argonne National Laboratory, USA

Quantum Chromodynamics: the origin of mass as we know it

Gość prof. Davida Blaschkego Quantum Chromodynamics (QCD) is the strongly interacting part of the Standard Model of Particle Physics. It is supposed to describe the physics of pions, neutrons, protons; indeed, all hadrons. Hadron physics is unique at the cutting edge of modern science because Nature has provided us with just one instance of a fundamental strongly interacting theory; i.e., QCD. The community of science has never before confronted such a challenge as solving this theory. The physics of hadrons is dominated by two emergent phenomena: confinement; namely, the theory's elementary degrees-of-freedom have never been detected in isolation; and dynamical chiral symmetry breaking (DCSB), which is a remarkably effective mass generating mechanism that is responsible for the mass of more than 98% of visible matter in the Universe. These phenomena are not apparent in QCD's Lagrangian, yet they play a principal role in determining Nature's observable characteristics. I will describe how the Dyson-Schwinger equations (DSEs) of QCD explain the origin and nature of DCSB; and can be used to elucidate its far-reaching consequences. The DSEs make plain that, in solving QCD, a constructive feedback between theory and extant and forthcoming experiments will most rapidly enable progress.