Strangeness in the proton as measured in elastic lepton-hadron scattering

Abstract

In view of relevance of thevp-elastic scattering for the determination ofs-quark spin fraction, Δs in the proton, we reexamine the existing data. We use more refined parametrizations of both the vector and the axial vector form factors. The vector form factors are derived from the electromagnetic ones under assumptions on their strangeness content. Then we discuss the heavy quark contributions to the axial form factors and finally we perform a fit to thevp-elastic scattering data. previous conclusions about the fraction of the spin of the proton carried by thes-quark must be somewhat modified, especially if strangeness in the vector form factors is assumed.