Precision measurements of the nucleon strange form factors at Q2 approximately 0.1 GeV2.
We report new measurements of the parity-violating asymmetry A(PV) in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with <theta(lab)> approximately 6.0 degrees . The 4He result is A(PV)=(+6.40+/-0.23(stat)+/-0.12(syst))x10(-6). The hydrogen result is A(PV)=(-1.58+/-0.12(stat)+/-0.04(syst))x10(-6). These results significantly improve constraints on the electric and magnetic strange form factors G(E)(s) and G(M)(s). We extract G(E)(s)=0.002+/-0.014+/-0.007 at <Q(2)>=0.077 GeV2, and G(E)(s)+0.09G(M)(s)=0.007+/-0.011+/-0.006 at <Q(2)>=0.109 GeV2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions.
Acha
A
A
Florida International University, Miami, Florida 33199, USA.
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Arrington
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Averett
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Bailey
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Decowski
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Holmes
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Ibrahim
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de Jager
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Kaufman
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Wilson
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Wojtsekhowski
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Yao
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Ye
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Zhan
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Zhou
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Ziskin
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