The strange electromagnetic form factors of the nucleon at low $Q^2$

The strange electric and magnetic form factors of the nucleon, $G_{E}^s$ and $G_M^s$, give the contributions of strange quarks to the charge and magnetization distributions of the nucleon, which solely arise from the sea of $s\bar s$. $G_E^s$ and $G_M^s$ can be determined by combining the well-known electromagnetic form factors of the proton and the neutron, $G_{E,M}^{\gamma,p}$ and $G_{E,M}^{\gamma,n}$, with the neutral weak form factors of the proton, $G_{E,M}^{Z,p}$, which can be measured via parity-violating (PV) elastic electron scattering. In the past 10 years, a series of definitive PV electron scattering experiments along with several theoretical studies now provide a basis for extracting precision information on these strange quark contributions. In this talk, I will briefly review the experimental technique, and give a summary of the PV elastic electron scattering measurements (at low momentum transfer in particular). A global analysis to extract $G_E^s$ and $G_M^s$ from the data and the physics implications to the ``strange sea'' will then be presented.