Measurement of high-Q2 deep inelastic scattering cross sections with   longitudinally polarised positron beams at HERA
  The first measurements of the cross sections for neutral and charged current deep inelastic scattering in e+p collisions with longitudinally polarised positron beams are presented. The total cross section for e+p charged current deep inelastic scattering is presented at positive and negative values of positron beam longitudinal polarisation for an integrated luminosity of 37.0 pb^-1 H1 data and 30.5 pb^-1 ZEUS data collected in 2003 and 2004 at a centre-of-mass energy of 319 GeV. In addition, the ZEUS collaboration measured the single differential cross sections for charged and neutral current deep inelastic scattering in the kinematic region Q^2>200 GeV^2. The measured cross sections are compared with the predictions of the Standard Model. The H1 collaboration extrapolate the cross section to a fully left handed positron beam and find it to be consistent with the Standard Model expectation. 
Julian Rautenberg