Hadronic Properties from Lattice QCD

The Standard Model of particle physics encompasses three of the four forces of nature (strong, weak and electromagnetic) and has proven to be extremely successful in describing almost all experimental tests and observations. Within the standard model, there are six flavours of quarks (u,d,s,c,b,t) which are bound together via the strong force to form protons and neutrons (jointly termed 'nucleons''), the building blocks of all matter that we see around us. This force is mediated by gluons and is described by a theory known as Quantum Chromodynamics (QCD). Unlike photons (the force carrier of the electromagnetic force), gluons are strongly self-interacting and hence it is impossible to calculate analytically the low-energy properties of QCD. Lattice gauge theory is a numerical technique to solve the equations of motion of quantum chromodynamics. This research is recognised by the international community as essential in our understanding of one of the four known fundamental forces of nature. These 'computer experiments' have the potential to make important contributions to our knowledge of the quark substructure and dynamics of hadrons. This project will perform simulations in Lattice QCD to confront some of the most important issues in theoretical particle physics. In particular, I will calculate the probability of the transistion s->u, which is a chief ingredient in further constraining the validity of the Standard Model, at an accuracy that has never before been possible. This is important for experiments searching physics beyond the SM in the flavour sector, such as LHCb. The other major topic that will be examined is the internal structure of the nucleons, including the internal distribution of electric and magnetic charge, and how the momentum of the nucleon is shared amongst its constituents. Information on these and other various aspects of nucleon structure can be gained through the determination of a special type of function known as ``Generalised Parton Distributions''. An investigation of the generalised parton distributions of the nucleon are a primary objective of the research programme of Jefferson Laboratory, which has recently been approved for an energy upgrade. A full mapping of the parameter space spanned by the generalised parton distributions is an extremely extensive task which needs support from non-perturbative techniques like lattice simulations. This highlights the importance of a lattice study that is alligned with the experimental efforts at Jefferson Lab.