Strange Quark Contribution to the Nucleon Spin from Electroweak Elastic Scattering Data

Abstract

The total contribution of strange quarks to the intrinsic spin of the nucleon can be determined from a measurement of the strange-quark contribution to the nucleon's elastic axial form factor. We have studied the strangeness contribution to the elastic vector and axial form factors of the nucleon, using all available elastic electroweak scattering data. Specifically, we combine elastic $\nu p$ and $\bar{\nu }p$ scattering cross section data from the Brookhaven E734 experiment with elastic $ep$ and quasi-elastic $ed$ and $e$-${}^4$He scattering parity-violating asymmetry data from the SAMPLE, HAPPEx, G0 and PVA4 experiments. We have not only determined these form factors at individual values of momentum-transfer ($Q^2$), as has been done recently, but also have fit the $Q^2$-dependence of these form factors using simple functional forms. We present the results of these fits using existing data, along with some expectations of how our knowledge of these form factors can be improved with data from the MicroBooNE experiment planned at Fermilab.

Proceedings for SPIN 2010 Conference, Juelich, Germany, September 27 - October 2, 2010; 7 pages, 2 figures

References in corpus (11)

• First Measurement of the Muon Neutrino Charged Current Quasielastic Double Differential Cross Section
• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering
• Strange Quark Contributions to Parity-Violating Asymmetries in the Backward Angle G0 Electron Scattering Experiment
• Measurement of Strange Quark Contributions to the Vector Form Factors of the Proton at Q**2=0.22 (GeV/c)**2
• The SAMPLE Experiment and Weak Nucleon Structure
• Electroweak nuclear response in quasi-elastic regime
• Global Analysis of Nucleon Strange Form Factors at Low $Q^2$
• Determination of the strange form factors of the nucleon from $\nu p$, $\bar{\nu }p$, and parity-violating $\vec{e}p$ elastic scattering
• Strange Quark Contribution to the Vector and Axial Form Factors of the Nucleon: Combined Analysis of G0, HAPPEx, and Brookhaven E734 Data
• Analysis of the Q^2-dependence of charged-current quasielastic processes in neutrino-nucleus interactions

Cited by in corpus (1)

• Extraction of Axial Mass and Strangeness Values from the MiniBooNE Neutral Current Elastic Cross Section Measurement