Low energy particle physics
Low-energy particle physics is an area of particle physics covering most things not done at the highest energies. It encompasses what goes under the names of flavour-, precision- and hadronic physics and has strong connections to some areas of nuclear physics. Within the Lund theory group, Johan Bijnens, together with students and post docs, works on projects within all these aspects.
In the history of particle physics this area has and continues to play a major role. Symmetries, like time-reversal, charge-conjugation, parity and various flavour symmetries are a cornerstone in the theory approaches.
Flavour physics studies, not surprisingly, the physics of flavour. This is the area where all aspects of the fact that there are six different quarks are studied. The main objcets of study here are mesons and baryons containing heavier quarks in states with lighter quarks. The relevant theory involves both Quantum Chromodynamics (QCD) and a large amount of modelling using methods of effective field theory.
Precision physics studies low-energy quantities to very high precision, examples are the magnetic moments of the muon and the electron. Theory needs to obtain a similar precision as the experiment and requires the interplay of many different techniques. A large part of a possible particle physics program at the European Spallation Source (ESS) falls in this category.
Hadronic physics is the study of the strong interaction at low-energies. Perturbative QCD is not directly applicable here and hence modelling and effective field theory, especially.
The group is active in many of the areas mentioned above, directly in phenomenology but also in developing methods. The general principles also show up in many studies of beyond the standard model physics.