Researcher Profile: The hunt for exact results on the smallest building blocks of matter


The solution to the "confinement problem" is a kind of holy grail of particle physicists. The goal of Joseph Minahan's research project is to find accurate results in gauge theories and string theories that can lead to a better understanding of quantum theory in general. And to get a few steps closer to a solution to this elusive problem the project has just been granted 34 million SEK from the Knut and Alice Wallenberg Foundation.

Photo: Linda Koffmar

Confinement problem is perhaps the most important unsolved problem in theoretical high energy physics. There is even a special prize for whoever manages to present a solution.

In nature, the quarks and gluons, the constituents of protons and neutrons, are kept "enclosed" by the strong force in a color neutral particle. This differs from electromagnetism where oppositely charged particles may be bonded to each other, but also separated if sufficient energy is supplied.

The strong force and the electromagnetic force are both controlled quantum field theories called gauge theories. For electromagnetism, the photon is the carrier of the interaction, while the strong force is carried by gluons. The difference between these two theories is that the photon does not have an electrical charge while the gluons are charged for the strong force.

Joseph Minahan and his colleague Konstantin Zarembo believe that a possible way to solve the confinement issue may be to assume the presence of an additional symmetry, called supersymmetry, in which each particle has a superpartner with the same mass and charge. Such symmetry has never been found in nature but studies of such theories can still lead to important insights for the understanding of the gauge theories (without supersymmetry) that can be observed in nature.

- If we make sufficient progress, we can gain a better understanding of  gauge theories in general, which might also lead to evidence of gauge theories, said Joseph Minahan.

Along with Konstantin Zarembo, he published in 2003 new results concerning a particular gauge theory that led to a major breakthrough in his research field. This success led to a new global research focus in theoretical physics and established Sweden as an important nation for scientific research in that field, which now employing several hundred researchers worldwide.

Linda Koffmar