Four flavours of twisted mass fermions

Lattice QCD is a branch of theoretical physics that is concerned with the computation of processes and properties of particles governed by the strong force: quantum chromodynamics. These computations are performed on supercomputers such as the IBM Blue Gene/P in Groningen. There are a number of distinct formulations of Lattice QCD and my research has focused on only one of these formulations: twisted mass Lattice QCD. My research has been conducted in the context of a European collaboration with the name: European Twisted Mass Collaboration or ETMC. The goal of our research was to investigate whether quantum chromodynamics is the correct description of subatomic processe influenced by the strong force and at low energy. More specifically, our collaboration has looked at the effect the incorporation of the fourth quark has on computations. We were one of the first groups to study the effects of the fourth quark. Our research has shown that the influence of the fourth quark on processes and properties that we have study is barely noticeable. This was expected, but had not been shown explicitly before.