Breakthrough in Neutron Lifetime Measurement Sets New Record in Precision

Los Alamos National Laboratory-led research team has achieved a new milestone in measuring the lifetime of free neutrons with unprecedented precision. Their latest findings, published in Physical Review C, refine the neutron lifetime to 877.83 seconds, reducing the measurement uncertainty to less than 0.3 seconds. This advancement underscores the effectiveness of the UCNTau experimental setup, which employs a magneto-gravitational 'bathtub' trap to contain ultracold neutrons and determine their decay time. The UCNtau experiment's innovative design involves filling the trap with cryogenically slowed neutrons and counting their interactions with a specialized detector as they decay. Continuous improvements over five years have validated the experiment's approach, contributing to the most accurate neutron lifetime measurement to date. Looking ahead, the team is developing UCNTau+, a next-generation version of the experiment that aims to increase neutron density by up to ten times and reduce systematic uncertainties significantly. This will be achieved through enhancements such as a new neutron-loading 'elevator' and advanced scintillator detectors, with plans to commence data collec...