As the archetype for all weak nuclear decays, the beta decay of the free neutron provides an important laboratory for the study of fundamental nuclear processes. In particular, the lifetime of the free neutron is a critical parameter in the theory of Big Bang Nucleosynthesis and its value is important in such issues as the universality of the weak interaction, energy production in the sun, supernova core collapse, and the efficiency of many neutrino detectors. The accurate determination of the neutron lifetime has been surprisingly challenging, and there has been a long history of significant discrepancies among "best" measurements. After a brief introduction to the theoretical issues associated with the neutron lifetime, I will discuss the methodologies for its determination, highlight the current experimental situation, and review ongoing and future prospects.

Argonne Physics Division Colloquium Schedule