Drell-Yan asymmetries at HERA-$\vec{\rm N}$
  The production of Drell-Yan pairs in the double polarized mode of HERA-$\vec{{\rm N}}$ is studied at next-to-leading order in QCD. It is found that a measurement of this observable could yield vital information on the polarization of the light quark sea in the nucleon. 
T.Gehrmann, W.J.Stirling (Durham)