Measurement of Strange Quark Contributions to the Vector Form Factors of the Proton at Q**2=0.22 (GeV/c)**2

Abstract

A new measurement of the parity violating asymmetry in elastic electron scattering on hydrogen at backward angles and at a four momentum transfer of Q^2=0.22 (GeV/c)^2 is reported here. The measured asymmetry is A_LR=(-17.23 +- 0.82_stat +-0.89_syst) ppm. The Standard Model prediction assuming no strangeness is A_0=(-15.87 +- 1.22) ppm. In combination with previous results from measurements at forward angles, it it possible to disentangle for the first time the strange electric and magnetic form factors at this momentum transfer, G_E^s(0.22)=0.050 +- 0.038 +- 0.019 and G_M^s(0.22)=-0.14 +- 0.11 +- 0.11.

Submitted to Physical Review Letters

References in corpus (2)

• Parity-violating aysmmetries in elastic $\vec{e}p$ scattering in the chiral quark-soliton model: Comparison with A4, G0, HAPPEX and SAMPLE
• Strange nucleon form factors: Solitonic approach to $G_M^s$, $G_E^s$, ${\tilde{G}}_A^p$ and ${\tilde{G}}_A^n$ and comparison with world data

Cited by in corpus (18)

• Equivalence Principle Violations and Couplings of a Light Dilaton
• Precision Measurement of the Weak Charge of the Proton
• Flavor decomposition of the elastic nucleon electromagnetic form factors
• Role of diquark correlations and the pion cloud in nucleon elastic form factors
• Parity-Violating Electron Scattering and the Electric and Magnetic Strange Form Factors of the Nucleon
• Nucleon strange electromagnetic form factors
• Measurement of Parity-Violating Asymmetry in Electron-Deuteron Inelastic Scattering
• Parity-Violating Electron-Deuteron Scattering with a Twist
• Determination of the strange nucleon form factors
• Chiral Effective Theory Methods and their Application to the Structure of Hadrons from Lattice QCD
• Vertical Beam Polarization at MAMI
• Measuring the surface thickness of the weak charge density of nuclei
• Study of Two-Photon Exchange via the Beam Transverse Single Spin Asymmetry in Electron-Proton Elastic Scattering at Forward Angles over a Wide Energy Range
• Lead fluoride Cherenkov detector read out by avalanche photodiodes for measuring the intensities of pulsed antiproton beams
• Nucleon form factors and parton distributions in nonlocal chiral effective theory
• Charge Symmetry Violation in the Electromagnetic Form Factors of the Proton
• Global Fit of Electron and Neutrino Elastic Scattering Data to Determine the Strange Quark Contribution to the Vector and Axial Form Factors of the Nucleon
• Contributions to the nucleon form factors from bubble and tadpole diagrams