Particle Physics Seminars at BNL

An improved ultracold neutron bottle for measuring the neutron lifetime

by Dr E. Adamek

US/Eastern
Universe

Universe

Description
The neutron beta decay lifetime is an important parameter in theories of weak interaction and big bang nucleosynthesis. To this end, many experiments over the past several decades have sought to improve the precision of this value. Ultracold neutrons, or UCN, are neutrons with extremely low energies which can be contained by material walls; these have provided us with a useful tool in measuring the neutron lifetime. The most recent set of experiments have demonstrated a 6sigma discrepancy between two lifetime values, each obtained using a different method of measurement. The UCNtau experiment at Los Alamos Neutron Science Center, is a bottling experiment which is designed to hold UCN within a 600 liter magnet-lined bowl to store the neutrons through magnetogravitational trapping. The open topped nature of the storage vessel allows for detectors to be lowered into the UCN volume to take in-situ measurement of the surviving UCN after varying storage times. This talk will cover newly presented results from the most recent UCNtau experiment data.
Slides