Neutrino Physics at the University of Chicago

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN.

However, the Standard Model as it currently exists leaves open many questions about the universe, including such fundamental questions as to why the Higgs mass has the value it has and why there is no antimatter in the universe. One of the primary areas to search for answers to these and other open questions about the universe, how it came to be, and why it is the way it is, is to focus on a study of the properties of neutrinos and to use what we know and can learn about neutrinos as probes of science Beyond the Standard Model (BSM).

The Standard Model predicted that there were three different kinds of neutrinos, all massless, that were distinguishable through the different interactions that they undergo whenever they interact with matter. But recent measurements have totally changed our picture of neutrinos. We now know that neutrinos do have a mass and because they do, they can actually change from one type to another.

Additionally, experimental measurements have indicated the possibility of yet an additional type of sterile neutrino. Detailed measurements of the interactions of these unusual particles are one of the most promising ways to probe for new physics beyond the Standard Model.

The Short-baseline Neutrino (SBN) Experiment at Fermilab, for which Chicago is a co-spokesperson group, will address whether the various anomalies observed in several neutrino experiments could be indications of new physics and in particular the existence of low-mass "sterile" neutrino particles. The Deep Underground Neutrino Experiment (DUNE) will make comprehensive measurements of neutrino and anti-neutrino oscillations to investigate neutrino CP violation, determine the ordering of the neutrino mass eigenstates, and perform precision tests of the neutrino Standard Model.

DUNE will take advantage of both an accelerator-based neutrino beam from Fermilab and be sensitive to extra-terrestrial neutrinos, including those from supernova explosions. Both experiments employ a transformative detector technology for neutrino physics, the liquid argon time projection chamber, which DUNE aims to realize at unprecedented scales, and for which the SBN detectors are providing invaluable experience in the construction, operation, and analysis of data.

The Chicago group plays a leading role in the design and construction of the near detector, SBND, and in preparation of both near detector and multi-detector physics analyses. On DUNE, the group has taken a leading role in development of the final design and production plan for the experiment's large wire planes, called Anode Plane Assemblies, the primary detection element of the DUNE Liquid Argon Time Projection Chambers.

The Chicago group supports and co-leads the Enrico Fermi Summer Interns program, a long-running educational program for middle school students from south-side Chicago public schools. Recognizing the importance of reaching students at an early age in the education process, the program engages the students in concepts of particle physics and gives them hands-on exposure to creative projects based on modern electronics.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.