The minimal content of the nucleon described by quantum chromodynamics (QCD) is merely three quarks. For many years now, deep inelastic scattering measurements have observed an abundance of quark-antiquark (q-qbar) pairs, representing a clear signature beyond the minimal three-quark picture. At more modest energies, it is largely unknown what role these quark-antiquark pairs play in the bound-state structure of the nucleon. As the lightest quark flavor outside the minimal three quarks, the strange quark provides the cleanest measure of the dynamics of q-qbar pairs in the nucleon. Here we report on the latest advances in parity-violating electron scattering measurements which have for the first time provided a direct measurement of electromagnetic currents carried by strange quarks. We also outline a recent theoretical determination based on lattice-QCD and compare this analysis with the current experimental status. We will conclude with an outlook on the future of the parity-violating experimental program.
ANL Physics Division Colloquium Schedule