Measurement of the axial-vector to vector coupling constant, ¦g1/f1¦, in Σ−→ne−\bar v decay

The ratio of the axial-vector to vector coupling constant, ¦g1/f1¦, in theΣ−→ne−\(\bar v\) decay was determined from the electron-neutrino angular distribution. In a sample of 454Σ−→ne−\(\bar v\) decays a search was made for subsequent neutron proton scattering in order to detect the decay neutrons. TheΣ hyperons were produced by stoppingK−-mesons in the 81 cm Saclay hydrogen bubble chamber. For the kinematical analysis 33Σ−→ne−ν events with associatednp→np interactions were accepted. The value ¦g1/f1¦=0.37 −0.19 +0.26 was obtained.