Parity Violating Electron Scattering andStrangeness in the Nucleon

摘要

A measurement of the weak form factor of the proton allows a flavor separation of thestrangeness contribution to the electromagnetic form factors. The weak form factor is accessedexperimentally by the measurement of a parity violating (PV) asymmetry in the scattering ofpolarized electrons on unpolarized protons. An extended experimental program to measure theseparity violating asymmetries has been performed and is going on at different accelerators. After thefirst round of experiments allowing a separation of the strangeness form factors G_Es andG_Msat aQ2-value of 0.1 (GeV/c)2, new, preliminary results have been achieved at 0.23 (GeV/c)2.