1.
Phys Rev Lett
; 119(4): 042502, 2017 Jul 28.
Article
in English
| MEDLINE
| ID: mdl-29341742
ABSTRACT
We report the first result for the electron-antineutrino angular correlation (a coefficient) in free neutron ß decay from the aCORN experiment. aCORN uses a novel method in which the a coefficient is proportional to an asymmetry in proton time of flight for events where the ß electron and recoil proton are detected in delayed coincidence. Data are presented from a 15 month run at the NIST Center for Neutron Research. We obtained a=-0.1090±0.0030(stat)±0.0028(sys), the most precise measurement of the neutron a coefficient reported to date.