Measurement Of Strange Quark Contributions To The Vector Form Factors Of The Proton At Q(2)=0.22 (Gev/C)(2)

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))x10(-6). The standard model prediction assuming no strangeness is A(0)=(-15.87 +/- 1.22)x10(-6). In combination with previous results from measurements at forward angles, it is possible to disentangle for the first time the strange form factors at this momentum transfer, G(E)(s)=0.050 +/- 0.038 +/- 0.019 and G(M)(s)=-0.14 +/- 0.11 +/- 0.11.