We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from He4 at an average scattering angle θlab=5.7° and a four-momentum transfer Q2=0.091GeV2. From these data, for the first time, the strange electric form factor of the nucleon GEs can be isolated. The measured asymmetry of APV=(6.72±0.84(stat)±0. 21(syst))×10-6 yields a value of GEs=-0.038±0.042(stat)±0. 010(syst), consistent with zero.
ASJC Scopus subject areas
- Physics and Astronomy(all)