%0 Journal Article
%T Measurement of Strange Quark Contributions to the Vector Form Factors of the Proton at Q**2=0.22 (GeV/c)**2
%A S. Baunack
%A K. Aulenbacher
%A D. Balaguer R¨ªos
%A L. Capozza
%A J. Diefenbach
%A B. Gl£¿ser
%A D. v. Harrach
%A Y. Imai
%A E. M. Kabu£¿
%A R. Kothe
%A J. H. Lee
%A H. Merkel
%A M. C. Mora Esp¨ª
%A U. M¨¹ller
%A E. Schilling
%A G. Stephan
%A C. Weinrich
%A J. Arvieux
%A M. A. El-Yakoubi
%A R. Kunne
%A F. E. Maas
%A M. Morlet
%A S. Ong
%A J. van de Wiele
%A S. Kowalski
%A Y. Prok
%A S. Taylor
%J Physics
%D 2009
%I arXiv
%R 10.1103/PhysRevLett.102.151803
%X 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) ppm. The Standard Model prediction assuming no strangeness is A_0=(-15.87 +- 1.22) ppm. In combination with previous results from measurements at forward angles, it it possible to disentangle for the first time the strange electric and magnetic form factors at this momentum transfer, G_E^s(0.22)=0.050 +- 0.038 +- 0.019 and G_M^s(0.22)=-0.14 +- 0.11 +- 0.11.
%U http://arxiv.org/abs/0903.2733v1