ETD

• screening masses
• theta-dependence
• topological freezing
• Yang-Mills theory

In this thesis we have computed the theta dependence of screening masses, at finite temperature, in the Yang-Mills SU(3) theory. To achieve numerical results the theory has been simulated on the lattice, using Monte Carlo methods. The exponential suppression of the correlators between spatially averaged Polyakov loops, is used to extract the value of the screening mass. To perform the simulations, an analytical continuation in theta has been implemented, and variational methods have been used to extract the most optimal operator used in the screening masses extraction. An interesting use for the second order coefficient of the Taylor expansion of the value of the screening mass, is its ability to quantify the systematc error that arises when simulations fail to properly sample the entire configuration space, a typical problem when moving towards the continuum limit.