Piecing together the Neutrino Mass Puzzle in Search of New Particles with Precision Oscillation Experiments and Quantum Technologies

Neutrino physics has the potential to revolutionise our current understanding of the universe.

The elusive neutrino is the most abundant massive particle in nature, but one of the most tricky to measure, because of its interaction properties. One hundred trillion neutrinos from the sun are passing through your body every second, but the chance of them actually stopping is incredibly small; if you lived to be one quadrillion years old, it's possible one may stop inside during your lifetime.

Over the past five decades, neutrino experiments have overcome this challenge by developing new detector and particle beam technologies, however, in this relatively modern field, many properties and interactions of the neutrino remain shrouded in mystery.

One puzzle is the ever-increasing number of hints that there may be more neutrinos than the three we have already discovered. Does a fourth "sterile" neutrino, exist? Could it be Dark Matter? My passion is to develop novel technology which allows me to make more precise measurements than ever before of neutrinos, to answer these questions.

As a research fellow, I will use the first data from the Short Baseline Neutrino (SBN) programme: an innovative system of detectors that I spent the past seven years building, to investigate a phenomenon called neutrino oscillations. Measuring this process gives us an opportunity to probe the existence of new kinds of neutrino. Using these state-of-the-art neutrino detectors, called liquid argon Time Projection Chambers, I will measure neutrino interactions, and lead a search for sterile neutrinos with SBN.

More clues can be found in a complementary search: measuring the mass of neutrinos. In the radioactive decay of tritium, an electron and a neutrino are emitted. Using what we know about the masses of the three known neutrinos, I will use energy conservation to look for evidence of a fourth.

Directly measuring the neutrino mass is extremely challenging. Even though the neutrino is the most abundant massive particle in the universe, we can't precisely say what its mass is. My goal is to combine quantum measurement techniques with an emerging technology called Cyclotron Radiation Emission Spectroscopy, to create a detector which can measure the neutrino mass with unprecedented precision.

Current detector technologies are unable to directly measure the absolute mass of the neutrino, but this project will lay groundwork for the ultimate future experiment: solving the neutrino mass puzzle by direct measurement.