# Long and winding road: understanding quantum chromodynamics

Mr Ho-Tat Lam (Croucher Scholarship 2016) is a PhD student at Princeton University with a focus in theoretical high energy physics. Prior to his work at Princeton, Lam has worked in various fields throughout physics and mathematics, including statistical physics, network science, and mathematical physics.

After completing his Bachelor's degree at the Hong Kong University of Science and Technology and gaining his master's degree at the Perimeter Institute for theoretical physics, Lam pursued a PhD degree in physics at Princeton University. He explores various research topics in theoretical high energy physics.

Theoretical high energy physics is a field that studies fundamental physics questions ranging from quantum field theories to quantum gravity. Due to the fact that these questions are difficult to study empirically, significant advances in high energy physics have been from a wholly theoretical study.

“Our approach is to build abstract models based on theory and mathematics, and explore if predictions from the model are applicable in real life.” Lam said.

The particular question Lam is interested in is strongly interacting quantum field theories. Quantum chromodynamics is a theory that predicts the existence of force-carrier particles called gluons, which transmit the strong force between particles of matter that carry strong charge. The strong force is therefore limited in its effect to the behaviour of elementary subatomic particles called quarks and of composite particles built from quarks, such as the familiar protons and neutrons that make up atomic nuclei, as well as more unstable particles called mesons.

It is known that traditional techniques of perturbation theory fail in such theory, rendering a level of difficulty in analytical calculation.

Recently, significant progress has been made towards understanding different phases of these strongly interacting theories using an alternate theoretical technique called anomaly. Lam's focus is to generalise this approach to other cases, which besides making advances in quantum chromodynamics, could also impact other fields in physics regarding the study of strongly correlated systems, such as condensed matter physics.

Besides his research, Lam enjoys the vibrant intellectual environment at Princeton.

“Princeton is a very special place for physicists. It has a university campus and the Institute of Advanced Study within 20 minutes walk,” said Lam. “There are 9-10 faculties in my field and many talented post-docs. I often attend seminars at the Institute and always enjoy the stimulating discussions with people within the Princeton community."

*Ho-Tat Lam received his undergraduate in Physics at the Hong Kong University of Science and Technology, his master’s in Physics at the Perimeter Institute of Theoretical Physics, and is currently a PhD student in Physics at Princeton University. *

To view Lam's Croucher profile, please click here.