Finite Temperature Quark Propagator in Landau gauge
IDPASC Portugal - PHD Programme 2016
2016 / 2017
Theoretical Particle Physics
Universidade de Coimbra
Quantum Chromodynamics (QCD) describes the interactions between quarks and gluons. At the level of the lagrangean, the gluons are massless particles and the masses of the up and down quarks are of the order of few MeV. If the perturbative solution of QCD shows a massless gluon, the results of lattice simulations suggest that the gluon can behave as a massive boson with a mass of about 600 MeV. Similarly, the quarks can be viewed as massive particles with masses of the order of 300 MeV, a value about 30 times larger than the current quark masses that appear in the lagrangean. The generation of such high mass values is a manifestation of the dynamical breaking of chiral symmetry and of the non-perturbative dynamics of QCD. The generation of mass is a fundamental property of QCD which explains, for example, the mass of the Universe. For the quarks, the mass function can be measured from the quark propagator, which can be computed using lattice QCD simulations. This has already been done at zero temperature. A similar study taking into account the temperature is missing. The computation of the running quark mass and of the quark wave function in terms of the current quark mass, of the quark momentum and of the temperature will help in the comprehension of the chiral symmetry breaking and confinement mechanisms, two of the fundamental open questions within strong interaction physics. Furthermore, knowing these dependences is important to the understanding of modern heavy ion experimental programs and the history of the Universe. In this project we aim to compute, on the lattice, the quark propagator at finite temperature. This will allow to investigate both the chiral symmetry breaking and confinement patterns as a function of the temperature. The simulations will be performed using the supercomputer facilities at the University of Coimbra. The candidate will join a team with a large experience in lattice QCD simulations.