New measurements of the electron-neutron spin asymmetry in neutron beta-decay

The A‐coefficient, which characterizes the angular correlation between the electron escape and the decaying neutron spin directions, is measured with an intense polarized neutron beam from the new vertical channel of the LNPI reactor. The result is A=−0,1131±0,0014 (A0=−0,1116±0,0014),implying λ=gA/gv=−1,2544±0,0036 for the ratio of the weak coupling constants.