Getting a flavour for New Physics with precision measurements of tree-level beauty decays

Elementary particle physics has an incredibly successful underlying theoretical framework known as the Standard Model which has produced a succession of successful predictions and subsequent discoveries in recent decades. This culminated in the discovery of the Higgs Boson in 2012, which was the last missing piece of the Standard Model. However, there are still a multitude of observed phenomena which the Standard Model cannot explain and the focus of this research is understanding the matter-antimatter asymmetry of the universe.

In the hot early universe matter and antimatter should have been created in equal amounts; this is the simple conversion of energy into matter via Einstein's famous equation, E=mc^2. Once the universe cooled the matter and antimatter would have "annihlated" to leave behind an abundance of electromagnetic radiation. This electromagnetic radiation we see today as the cosmic microwave background, the static seen on an untuned televsion. However, there is clearly an imbalance as we also see large amounts of matter, which make up the stars, galaxies and ourselves whilst no antimatter is left at all. We can understand some part of this as being due to charge-parity symmetry (that which relates matter to antimatter) being broken. In the intial stages of matter-antimatter creation charge-parity violation results in a small excess of matter, which goes on to make up the observable universe of today, after the majority annihilates with the antimatter to leave behind the electromagnetic radiation still echoing around the universe. The problem is that the amount of charge-parity violation predicted by the theoretical framework underlying our understanding of elementary particle physics is nowhere near enough (a factor several billion off) to account for the observed matter to electromagnetic radiation ratio of the universe.

This project uses data from the Large Hadron Collider to look for new fundamental physics particles which can help to explain the matter-antimatter discrepancy. By analysing millions of matter and antimatter decays produced at the LHCb experiment we can observe the subtle differences between them. The parameters we determine in this project are of particular interest because they can be measured completely independently of any input from the theoretical framework, i.e. independently of any prior knowledge. We can then use these parameters to prove the existence, and predict the behaviour, of new fundamental physics particles which explain why we live in a matter dominated universe and hence why we have atoms, molecules and life itself.