Particle Physics

Professor Gert Aarts of the Theoretical Particle Physics Group at Swansea University is using HPC Wales’ systems to assist him in carrying out fundamental research in elementary particle physics. This research will increase our understanding of how the universe around us works, and has recently been recognised with a Royal Society Wolfson Research Merit Award which is intended to assist UK universities attract and retain scientists of outstanding achievement and potential.

The main focus of Professor Aarts’ research is Quantum Chromodynamics (QCD), the study of the strong nuclear force; one of the four fundamental forces in Nature. Professor Aarts explains:

“Everything around us is made out of atoms, which are built out of protons and neutrons, which in turn   consist of particles called quarks. Quarks are considered the most fundamental building blocks of Nature. By studying physical processes at smaller and smaller scales, we hope to understand how Nature works at its core.

The force that binds together the quarks inside protons and neutrons, the strong nuclear force, is described by a theory known as Quantum Chromodynamics (QCD). It was formulated in the early 1970s and we know how the theory works in principle.  Our research aims to probe the theory in regimes that are not easily accessible. For instance, we study what happens with quarks and the strong force at very high temperatures such as those prevalent in the early universe, or under extremely high pressure as inside neutron stars. Because the theory is so complicated, it cannot be solved with pen and paper; you have to use a computer.”

QCD is very relevant to high profile on-going and future experiments, such as those at the Large Hadron Collider (LHC), CERN and the Facility for Antiproton and Ion Research (FAIR) in Germany.  The LHC is currently investigating the properties of quarks at high temperatures by colliding lead ions accelerated almost to the speed of light. These experiments can only be carried out at a handful of very large facilities such as the LHC, with global support.  Professor Aarts and his collaborators attempt to provide theoretical insight, relevant for understanding the results. 

The complexity of the mathematics and the large-scale QCD simulations needed require access to state-of-the-art high performance computing systems. Professor Aarts says:

“In our field, access to high performance computing (HPC) facilities is essential. We are in the fortunate position to have access to HPC resources, via HPC Wales. This is of utmost importance, not only for science but also for education, since our postgraduate research students receive thorough training in HPC. In my experience, research in many different fields requires heavy computation. Researchers should not be afraid of tackling the challenge; it is possible to learn things quickly and easily, and of course if it becomes more complicated, HPC Wales has people that can help out.”

Professor Aarts is primarily motivated by a desire for a fundamental understanding of Nature. He explains:

“I was always interested in fundamental science and physics in particular. Part of doing research is learning and understanding more, so to some extent you always stay a student because you keep learning. Continually finding out new things and discovering how Nature works is really interesting.”

There are also important economic spin-offs from this type of blue-sky research. It pushes the limits of high performance computing as researchers strive for ever larger and more accurate simulations, driving enhancements in computing technology to meet these requirements.

HPC Wales is helping Professor Aarts to plan large-scale simulations related to high profile experimental resources such as the LHC, and building up a community of researchers within Wales with the skills to carry out innovative research that will contribute to the country’s future economic prosperity.