Measurement of the polarized parton distribution functions at HERMES

Abstract

The HERMES experiment at DESY has measured the inclusive and semi-inclusive double-spin asymmetries of polarized positrons scattering from polarized hydrogen and deuterium targets in the kinematic range of Bjorken-x 0.023 < x < 0.06 and 1 GeV2 < Q 2 < 10 GeV2. A RICH detector was installed for the deuterium running period and by providing the identification of charged pions and kaons has enabled the first measurement of charged kaon asymmetries. Based on the measured proton and deuterium asymmetries the polarized quark distributions have been extracted in leading-order pQCD.