A neutron-antineutron oscillation experiment at the European Spallation Source

Neutral particle oscillations have proven to be extremely valuable probes of fundamental physics. For instance, kaon oscillations provided us with our first insight into CP-violation, B oscillations form the most fertile ground for the continued study of CP-violation, and neutrino oscillations suggest the existence of a new, important energy scale well below the GUT scale. Neutrons oscillating into antineutrons could offer a unique probe of baryon number violation. The construction of the European Spallation Source in Lund, with first beam expected in 2019, together with modern neutron optical techniques, offers an opportunity to conduct an experiment with 2 orders of magnitude improvement in sensitivity to the neutron oscillation probability. Here, a general overview of the European Spallation Source will be given and the physics case for a neutron oscillation experiment will be discussed, together with the main experimental challenges and possible solutions.