UCNA is an experiment that will probe neutron decay with unprecedented precision. Previous experiments measuring the correlation between a neutron's spin and its decay electron's momentum (the "A-correlation") have arrived at inconsistent results. The UCNA experiment will measure this correlation with a factor of four improvement in precision and will bring our understanding of the weak interaction responsible for neutron decay to a new level. The results may offer a glimpse into new phenomena beyond the Standard Model of particle physics.
The experiment is part of a broader program to develop a high intensity source of Ultra-Cold Neutrons (UCN) in the United States; a first generation source is running now at Los Alamos National Laboratory. We have been taking asymmetry data since 2008 and have recently published a precision result on the neutron's axial vector weak coupling (to read the article, click here).
This web page is a resource for the involvement of Caltech in this project.
We are also involved in another UCN experiment searching for an electric dipole moment of the neutron.
This material is based upon work supported by the National Science Foundation under grant number 1205977. Any opinions findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.