Tereza Mendes

University of São Paulo

"Crossing the Gribov horizon in lattice simulations of Yang-Mills theory"

Confinement of color charge is a puzzling property of Yang-Mills gauge theories that accounts for the fact that quarks and gluons—the basic building blocks of matter—are never found in isolation. The property may be related to how "ghost-field" correlation functions behave near the region of gauge-configuration space known as the first Gribov horizon, which (as a consequence of gauge-fixing) is approached from within as the system's volume tends to infinity. We study the issue for the lattice version of the theory by performing Monte Carlo simulations, in which representative "thermalized" gauge configurations are generated and used for evaluating the desired correlation functions. In order to gain better control over the limiting behavior of our computed correlation functions, we propose to venture away from thermalized configurations, crossing the boundaries imposed by the Gribov horizon. The main points of this presentation, i.e. the conceptual understanding of Monte Carlo sampling and finding ways to cross boundaries, are topics in which Alan has been an inspirational influence. Work in collaboration with Attilio Cucchieri.