Strangeness Contributions to the Static Properties of the Proton

Conference · Mon Oct 01 00:00:00 EDT 2007

OSTI ID:1967361

Paschke, Kent ^[1]

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1. University of Virginia

Precision measurements of parity violation in electron-nucleus elastic scattering at low Q2 are sensitive to the strange quark magnetic moment and the strange-charge radius of the proton, and thus provide a unique opportunity to cleanly isolate the role of the quark- antiquark sea in low-energy Quantum Chromodynamics. While recent results have placed a tight upper-bound on strange quark contributions to the electric form-factor at low Q2, significant (~10%) contributions to the proton magnetic moment are still allowed by the existing data. Results from recently completed measurements of backward-angle scattering, by the G0 and A4 collaborations, will provide an improved sensitivity to the strange magnetic form-factor GsM of the proton as well as to axial radiative corrections which are otherwise poorly constrained by existing data. An important complement to those measurements is the HAPPEX-III experiment, which will measure forward-angle scattering at Q2 ~ 0.62 GeV2 with a much greater precision than has previously been achieved in that kinematic range, with a sensitivity to the linear combination of strange-quark vector form- factors GsE + 0.48GsM. In combination with the published results from low Q2, this measurement will play a crucial role in determining the possible strange quark contribution to the magnetic moment of the proton.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1967361
• Report Number(s): JLAB-PHY-07-982; DOE/OR/23177-5940
• Resource Relation: Conference: 2007 Annual Meeting of the Division of Nuclear Physics, Newport News, Virginia, October 10–13, 2007
• Country of Publication: United States
• Language: English