Charge symmetry violation in the determination of strangeness form factors

Abstract

The strange quark contributions to the electromagnetic form factors of the proton are ideal quantities to study the role of hidden flavor in the properties of the proton. This has motivated intense experimental measurements of these form factors. A major remaining source of systematic uncertainty in these determinations is the assumption that charge symmetry violation (CSV) is negligible. We use recent theoretical determinations of the CSV form factors and reanalyse the available parity-violating electron scattering data, up to $Q^2$ $\sim$ 1 GeV${}^2$. Our analysis considers systematic expansions of the strangeness electric and magnetic form factors of the proton. The results provide an update to the determination of strangeness over a range of $Q^2$ where, under certain assumptions about the effective axial form factor, an emergence of non-zero strangeness is revealed in the vicinity of $Q^2$ $\sim$ 0.6 GeV${}^2$. Given the recent theoretical calculations, it is found that the current limits on CSV do not have a significant impact on the interpretation of the measurements and hence suggests an opportunity for a next generation of parity-violating measurements to more precisely map the distribution of strange quarks.

9 pages, 5 figures, 4 tables

References in corpus (14)

• Model independent extraction of the proton charge radius from electron scattering
• Precision Measurement of the Weak Charge of the Proton
• Proton and neutron electromagnetic form factors and uncertainties
• Charge Symmetry Breaking and QCD
• 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
• Testing the Standard Model by precision measurement of the weak charges of quarks
• Global Analysis of Nucleon Strange Form Factors at Low $Q^2$
• Model independent extraction of the proton magnetic radius from electron scattering
• Isospin violation in the vector form factors of the nucleon
• Strange Quark Magnetic Moment of the Nucleon at Physical Point
• Determination of the strange nucleon form factors
• Evaluation of theoretical uncertainties in parity-violating electron scattering from nucleons and nuclei
• Charge Symmetry Violation in the Electromagnetic Form Factors of the Proton