Measurement of the electron-antineutrino correlation in neutron beta decay: aCORN experiment

TL;DR

The aCORN experiment developed a novel asymmetry method to measure the electron-antineutrino correlation in neutron decay, achieving a total uncertainty of 3.8% in initial results and aiming for less than 2% in future measurements.

Contribution

It introduces a new asymmetry technique that bypasses the need for precision proton spectroscopy in neutron decay measurements.

Findings

Initial measurement of a = 0.1090 ± 0.0030 (stat) ± 0.0028 (sys)

Total uncertainty of 3.8% in the first run

Expected improvement to less than 2% in the next run

Abstract

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line in 2013--2014 obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), a total uncertainty of 3.8%. The second run on the new NG-C high flux beam line promises an improvement in precision to <2%.