Improved determination of the $\beta$-${\overline{\nu }}_e$ angular correlation coefficient $a$ in free neutron decay with the $a$SPECT spectrometer

M. Beck, F. Ayala Guardia, S. Baeßler +15

We report on a precise measurement of the electron-antineutrino angular correlation ($a$ coefficient) in free neutron beta-decay from the $a$SPECT experiment. The $a$ coefficient i…