HAPPEX: Strange Quarks in the Proton and He4
HAPPEX results from our 2005 run for the parity-violating asymmetry A{sub PV} in elastic scattering of 3 GeV electrons off hydrogen and {sup 4}He targets at ({theta}{sub lab}) {approx} 6.0{sup o} are presented. The {sup 4}He result is A{sub PV} = (+6.40 {+-} 0.23 (stat) {+-} 0.12 (syst)) x 10{sup -6}. The hydrogen result is A{sub PV} = (-1.58 {+-} 0.12 (stat) {+-} 0.04 (syst)) x 10{sup -6}. The asymmetry for hydrogen is a linear combination of G{sub E}{sup s} and G{sub M}{sup s}, the strange quark contributions to the electric and magnetic form factors of the nucleon, respectively, and that for {sup 4}He is a function of G{sub E}{sup s} alone. The measurements imply G{sub E}{sup s} + 0.09 G{sub M}{sup s} = 0.007 {+-} 0.011 {+-} 0.006 at <Q{sup 2}> = 0.109 GeV{sup 2} and G{sub E}{sup s} = 0.002 {+-} 0.014 {+-} 0.007 at <Q{sup 2}> = 0.077GeV{sup 2}.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE - Office of Energy Research (ER)
- DOE Contract Number:
- AC05-84ER40150
- OSTI ID:
- 897294
- Report Number(s):
- JLAB-PHY-06-584; DOE/ER/40150-4195; TRN: US200704%%765
- Resource Relation:
- Conference: 17th International Spin Physics Symposium (SPIN06), 2-7 Oct 2006, Kyoto, Japan
- Country of Publication:
- United States
- Language:
- English
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