Measurement of High-Q^2 Neutral Current Deep Inelastic e^+ Scattering 
Cross Sections with a Longitudinally Polarised Electron Beam at HERA

                          ZEUS Collaboration 

The cross sections for neutral current deep inelastic scattering in e+p 
collisions with a longitudinally polarised positron beam have been 
measured using the ZEUS detector at HERA. The results, based on data 
corresponding to an integrated luminosity of 140 pb^-1 at sqrt{s}=318 
GeV,are given for both positive and negative values of the longitudinal 
polarisation of the positron beam. Single differential cross sections in 
Q^2, x and y and double differential cross sections in Q^2 and x are shown 
in the kinematic region Q^2>185 GeV. The xF_3 structure function has been
measured. The measured cross sections are compared to the predictions of 
the Standard Model.