Beyond-the-Standard-Model Particle theory: Looking for the Missing Piece of the Puzzle: Sterile Neutrinos

Supervisor: Prof. Frank Deppisch

For decades, the Standard Model (SM) of particle physics has stood as the best explanation of the subatomic world, describing the properties of the basic building blocks of matter and the forces that govern them with precision unmatched in the history of science. However, we now face a set of vexing questions that force us to think what lies beyond the SM. In particular, the SM cannot explain the observed non-zero neutrino masses and mixing, dark matter, and the matter-antimatter asymmetry in the Universe. A suggestive paradigm for physics beyond the SM addressing these issues is the seesaw mechanism, originally proposed to address the neutrino mass problem. In the simplest version, it introduces sterile neutrinos -- new fermions that talk to the SM sector only through their mixing with the active neutrinos. The sterile neutrinos would be an ideal missing piece to solve the puzzles faced by the SM. In this PhD project you will explore new means to discover it and test its properties in a detailed theoretical study. After receiving training through the London intercollegiate HEP grad school and the SEPnet-NExT grad school you will start determining the constraints on sterile neutrinos under the presence of exotic interactions. This will take the form of an effective field theory analysis of the SM including sterile neutrinos with masses up to the electroweak scale. The goal is a comprehensive picture of existing constraints and the future potential of measurements such as of the neutrino mass and the cosmic neutrino background. Your research will be mainly in the context of Theoretical Particle Physics using tools from Quantum Field Theory and Group Theory, with connections to Theoretical Cosmology.

For more details please contact f.deppisch at