Investigation of β–ν Angular Correlation in the β + Decay of 18 Ne and 14 O

The β–ν angular correlation in the β + decay of 18 Ne and 14 O has been investigated using a new experimental technique. The technique is based on the precise measurement of the energy Doppler shift of a γ-quantum following the β ± decay. The measurement with the 18 Ne isotope gives the β–ν angular correlation coefficient α = +1.06 ±0.19 which corresponds to a constraint on the scalar interaction of √{|C_S| 2 +|C'_S| 2 } ≤ 0.29| C V |. An inter-atomic interaction between the 14 O daughter atom ( 14 N) and a CO complex has been studied in a measurement with the 14 O isotope.