Measurements of the antineutrino spin asymmetry in beta decay of the neutron and restrictions on the mass of a right-handed gauge boson

We report a new measurement of the neutron antineutrino spin asymmetry coefficient {ital B} in the beta decay of polarized neutrons. Combining results of measurements of the observed asymmetry {ital PB}=0.6617{plus_minus}0.0044 with measurements of the neutron beam polarization {ital P}=(66.88{plus_minus}0.22)%, we obtain the value {ital B}=0.9894{plus_minus}0.0083. This value implies that the mass of a hypothetical right-handed charged gauge boson in the left-right symmetric model of the weak interaction is greater than 281GeV/{ital c}{sup 2} (90% C. L.). This is in agreement with restrictions from muon decay and direct searches for an additional vector boson {ital W}{prime}.