This award will support the study of spatial and temporal symmetries in the interactions of low energy neutrons. It seeks to answer the following questions: a) Why is our universe made up of matter but not anti-matter? b) What is the interplay between forces that bind the nucleus? The first question will be addressed by measuring the separation of electric charge in the neutron, a quantity that would change if time ran backwards. It involves the same violation of symmetry necessary to convert antimatter into matter or vice versa. Our contribution is to efficiently guide polarized neutrons thirty meters from the source into the experimental apparatus. The second question explores the forces involved in the capture of neutrons on protons to form deuterium. Even though the strong force dominates by seven orders of magnitude, the weak force would be responsible for an asymmetric distribution in the production of gamma rays, which we seek to measure. This asymmetry distinguishes our universe from a mirror reflection, one with directions in space reversed. These experiments will help unravel our understanding the interactions and structure of protons and neutrons.
These projects will have significant effect on undergraduate and graduate students at the University of Kentucky, especially women, minorities, and students from the Appalachian region. These students have the opportunity of participating in cutting-edge research at Los Alamos National Laboratory (LANL) and Oak Ridge National Laboratory (ORNL). The PI is incorporating portions of this work into a course on modern physics, and is developing an introduction to scientific programming for students involved in the analysis of these experiments. General purpose software libraries developed for this research will be made publicly available. The work on neutron guides will benefit subsequent experiments at the Spallation Neutron Source at ORNL.
